Studies of alternative RNA splicing (ARS) have the potential to provide an abundance of novel targets for development of new biomarkers and therapeutics in oncology, which will be necessary to improve outcomes for patients with cancer and mitigate cancer disparities. ARS, a key step in gene expression enabling individual genes to encode multiple proteins, is emerging as a major driver of abnormal phenotypic heterogeneity. Recent studies have begun to identify RNA splicing-related genetic and genomic variation in tumors, oncogenes dysregulated by ARS, RNA splice variants driving race-related cancer aggressiveness and drug response, spliceosome-dependent transformation, and RNA splicing-related immunogenic epitopes in cancer. In addition, recent studies have begun to identify and test, preclinically and clinically, approaches to modulate and exploit ARS for therapeutic application, including splice-switching oligonucleotides, small molecules targeting RNA splicing or RNA splice variants, and combination regimens with immunotherapies. Although ARS data hold such promise for precision oncology, inclusion of studies of ARS in translational and clinical cancer research remains limited. Technologic developments in sequencing and bioinformatics are being routinely incorporated into clinical oncology that permit investigation of clinically relevant ARS events, yet ARS remains largely overlooked either because of a lack of awareness within the clinical oncology community or perceived barriers to the technical complexity of analyzing ARS. This perspective aims to increase such awareness, propose immediate opportunities to improve identification and analysis of ARS, and call for bioinformaticians and cancer researchers to work together to address the urgent need to incorporate ARS into cancer biology and precision oncology.

Authors

Robinson, TJ; Freedman, JA; Al Abo, M; Deveaux, AE; LaCroix, B; Patierno, BM; George, DJ; Patierno, SR

MLA Citation

Robinson, Timothy J., et al. “Alternative RNA Splicing as a Potential Major Source of Untapped Molecular Targets in Precision Oncology and Cancer Disparities..” Clin Cancer Res, vol. 25, no. 10, May 2019, pp. 2963–68. Pubmed, doi:10.1158/1078-0432.CCR-18-2445.

PMID

30755441

Source

pubmed

Published In

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research

Volume

25

Issue

10

Publish Date

2019

Start Page

2963

End Page

2968

DOI

10.1158/1078-0432.CCR-18-2445

Authors

Ware, KE; Gupta, S; Eng, J; Foo, W-C; Crawford, L; Austin, G; Puviindran, B; Freedman, J; Patierno, SR; Zhang, T; Corcoran, D; Pierobon, M; Petricoin, E; Somarelli, JA; Armstong, AJ

MLA Citation

Ware, Kathryn E., et al. “Abstract B038: Convergent hormone therapy resistance mediated by stress/dormancy-like pathways in prostate cancer.” Poster Presentations  Proffered Abstracts, American Association for Cancer Research, 2018. Crossref, doi:10.1158/1538-7445.prca2017-b038.

Source

crossref

Published In

Poster Presentations Proffered Abstracts

Publish Date

2018

DOI

10.1158/1538-7445.prca2017-b038

Authors

Al Abo, M; Patierno, SR; Freedman, JA

MLA Citation

Al Abo, Muthana, et al. “Alternative RNA splicing and prostate cancer aggressiveness..” Cancer Research, vol. 78, no. 16, AMER ASSOC CANCER RESEARCH, 2018, pp. 111–12.

Source

wos

Published In

Cancer Research

Volume

78

Issue

16

Publish Date

2018

Start Page

111

End Page

112

Prostate cancer (PCa) is a clinically and molecularly heterogeneous disease, with variation in outcomes only partially predicted by grade and stage. Additional tools to distinguish indolent from aggressive disease are needed. Phenotypic characteristics of stemness correlate with poor cancer prognosis. Given this correlation, we identified single-nucleotide polymorphisms (SNPs) of stemness-related genes and examined their associations with PCa survival. SNPs within stemness-related genes were analyzed for association with overall survival of PCa in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Significant SNPs predicted to be functional were selected for linkage disequilibrium analysis and combined and stratified analyses. Identified SNPs were evaluated for association with gene expression. SNPs of CD44 (rs9666607), ABCC1 (rs35605 and rs212091) and GDF15 (rs1058587) were associated with PCa survival and predicted to be functional. A role for rs9666607 of CD44 and rs35605 of ABCC1 in RNA splicing regulation, rs212091 of ABCC1 in miRNA binding site activity and rs1058587 of GDF15 in causing an amino acid change was predicted. These SNPs represent potential novel prognostic markers for overall survival of PCa and support a contribution of the stemness pathway to PCa patient outcome.

Authors

Freedman, JA; Wang, Y; Li, X; Liu, H; Moorman, PG; George, DJ; Lee, NH; Hyslop, T; Wei, Q; Patierno, SR

MLA Citation

Freedman, Jennifer A., et al. “Single-nucleotide polymorphisms of stemness genes predicted to regulate RNA splicing, microRNA and oncogenic signaling are associated with prostate cancer survival..” Carcinogenesis, vol. 39, no. 7, July 2018, pp. 879–88. Pubmed, doi:10.1093/carcin/bgy062.

Website

https://hdl.handle.net/10161/18503

PMID

29726910

Source

pubmed

Published In

Carcinogenesis

Volume

39

Issue

7

Publish Date

2018

Start Page

879

End Page

888

DOI

10.1093/carcin/bgy062

Authors

LaCroix, BL; Patierno, BM; Sullenger, BA; George, DJ; Patierno, SR; Freedman, JA

MLA Citation

LaCroix, Bonnie L., et al. “Development of a novel therapeutic splice-switching oligonucleotide targeting race-related androgen receptor signaling and aggressive prostate cancer..” Cancer Epidemiology Biomarkers & Prevention, vol. 27, no. 7, AMER ASSOC CANCER RESEARCH, 2018, pp. 46–46.

Source

wos

Published In

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology

Volume

27

Issue

7

Publish Date

2018

Start Page

46

End Page

46

Authors

LaCroix, BL; Patierno, BM; Sullenger, BA; George, DJ; Patierno, SR; Freedman, JA

MLA Citation

LaCroix, Bonnie L., et al. “Nutritional profiling reveals glutamine-utilizing transaminases as a metabolic vulnerability of TAZ/YAP-driven breast cancer cells.” Cancer Epidemiology Biomarkers & Prevention, vol. 27, no. 7, AMER ASSOC CANCER RESEARCH, 2018, pp. 148–148.

Source

wos

Published In

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology

Volume

27

Issue

7

Publish Date

2018

Start Page

148

End Page

148

Authors

Patierno, B; Glover, W; Ribar, T; Kittles, R; Foo, W-C; McCall, S; Huang, J; George, D; Freedman, J; Patierno, S; Wood, K; Hsu, D

MLA Citation

Patierno, Brendon, et al. “Establishment of African American prostate cancer patient-derived primary cell lines and xenografts..” Cancer Epidemiology Biomarkers & Prevention, vol. 27, no. 7, AMER ASSOC CANCER RESEARCH, 2018, pp. 96–96.

Source

wos

Published In

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology

Volume

27

Issue

7

Publish Date

2018

Start Page

96

End Page

96

Authors

Deveaux, A; Wang, B-D; Lacroix, B; Patierno, B; Zhang, D; Owzar, K; Lee, N; George, D; Freedman, J; Patierno, S

MLA Citation

Deveaux, April, et al. “Race-related differential splicing of the insulin receptor: A novel target underlying prostate cancer disparities.” Cancer Epidemiology Biomarkers & Prevention, vol. 27, no. 7, AMER ASSOC CANCER RESEARCH, 2018, pp. 138–39.

Source

wos

Published In

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology

Volume

27

Issue

7

Publish Date

2018

Start Page

138

End Page

139

Authors

LeBlanc, TW; Herring, K; Chilcott, J; Bletcher, K; Osaki, M; Manassei, H; Pendergraft, T; Corbett, C; Zafar, Y; Higgins, A; Patierno, SR

MLA Citation

LeBlanc, Thomas William, et al. “Development of a digital patient navigation application: Results from subject interviews..” Journal of Clinical Oncology, vol. 36, no. 15_suppl, American Society of Clinical Oncology (ASCO), 2018, pp. e22146–e22146. Crossref, doi:10.1200/jco.2018.36.15_suppl.e22146.

Source

crossref

Published In

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology

Volume

36

Issue

15_suppl

Publish Date

2018

Start Page

e22146

End Page

e22146

DOI

10.1200/jco.2018.36.15_suppl.e22146

Authors

LeBlanc, TW; Herring, K; Chilcott, J; Bletcher, K; Osaka, M; Manassei, H; Pendergraft, T; Corbett, C; Zafar, Y; Higgins, A; Patierno, SR

MLA Citation

LeBlanc, Thomas William, et al. “Development of a digital patient navigation application: Preliminary results from patient interviews..” Journal of Clinical Oncology, vol. 36, no. 7_suppl, American Society of Clinical Oncology (ASCO), 2018, pp. 161–161. Crossref, doi:10.1200/jco.2018.36.7_suppl.161.

Source

crossref

Published In

Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology

Volume

36

Issue

7_suppl

Publish Date

2018

Start Page

161

End Page

161

DOI

10.1200/jco.2018.36.7_suppl.161

Authors

Patierno, S; Sitkin, SB

MLA Citation

Patierno, S., and S. B. Sitkin. “Editors’ note.” Behavioral Science and Policy, vol. 4, no. 1, Jan. 2018, pp. ii–iii.

Source

scopus

Published In

Behavioral Science and Policy

Volume

4

Issue

1

Publish Date

2018

Start Page

ii

End Page

iii

This corrects the article DOI: 10.1038/ncomms15921.

Authors

Wang, B-D; Ceniccola, K; Hwang, S; Andrawis, R; Horvath, A; Freedman, JA; Olender, J; Knapp, S; Ching, T; Garmire, L; Patel, V; Garcia-Blanco, MA; Patierno, SR; Lee, NH

MLA Citation

Wang, Bi-Dar, et al. “Corrigendum: Alternative splicing promotes tumour aggressiveness and drug resistance in African American prostate cancer..” Nat Commun, vol. 8, Sept. 2017. Pubmed, doi:10.1038/ncomms16161.

PMID

28952599

Source

pubmed

Published In

Nature Communications

Volume

8

Publish Date

2017

Start Page

16161

DOI

10.1038/ncomms16161

Evidence suggests that cells with a stemness phenotype play a pivotal role in oncogenesis, and prostate cells exhibiting this phenotype have been identified. We used two genome-wide association study (GWAS) datasets of African descendants, from the Multiethnic/Minority Cohort Study of Diet and Cancer (MEC) and the Ghana Prostate Study, and two GWAS datasets of non-Hispanic whites, from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial and the Breast and Prostate Cancer Cohort Consortium (BPC3), to analyze the associations between genetic variants of stemness-related genes and racial disparities in susceptibility to prostate cancer. We evaluated associations of single-nucleotide polymorphisms (SNPs) in 25 stemness-related genes with prostate cancer risk in 1,609 cases and 2,550 controls of non-Hispanic whites (4,934 SNPs) and 1,144 cases and 1,116 controls of African descendants (5,448 SNPs) with correction by false discovery rate ≤0.2. We identified 32 SNPs in five genes (TP63, ALDH1A1, WNT1, MET and EGFR) that were significantly associated with prostate cancer risk, of which six SNPs in three genes (TP63, ALDH1A1 and WNT1) and eight EGFR SNPs showed heterogeneity in susceptibility between these two racial groups. In addition, 13 SNPs in MET and one in ALDH1A1 were found only in African descendants. The in silico bioinformatics analyses revealed that EGFR rs2072454 and SNPs in linkage with the identified SNPs in MET and ALDH1A1 (r2  > 0.6) were predicted to regulate RNA splicing. These variants may serve as novel biomarkers for racial disparities in prostate cancer risk.

Authors

Wang, Y; Freedman, JA; Liu, H; Moorman, PG; Hyslop, T; George, DJ; Lee, NH; Patierno, SR; Wei, Q

MLA Citation

Wang, Yanru, et al. “Associations between RNA splicing regulatory variants of stemness-related genes and racial disparities in susceptibility to prostate cancer..” Int J Cancer, vol. 141, no. 4, Aug. 2017, pp. 731–43. Pubmed, doi:10.1002/ijc.30787.

PMID

28510291

Source

pubmed

Published In

Int J Cancer

Volume

141

Issue

4

Publish Date

2017

Start Page

731

End Page

743

DOI

10.1002/ijc.30787

Clinical challenges exist in reducing prostate cancer (PCa) disparities. The RNA splicing landscape of PCa across racial populations has not been fully explored as a potential molecular mechanism contributing to race-related tumour aggressiveness. Here, we identify novel genome-wide, race-specific RNA splicing events as critical drivers of PCa aggressiveness and therapeutic resistance in African American (AA) men. AA-enriched splice variants of PIK3CD, FGFR3, TSC2 and RASGRP2 contribute to greater oncogenic potential compared with corresponding European American (EA)-expressing variants. Ectopic overexpression of the newly cloned AA-enriched variant, PIK3CD-S, in EA PCa cell lines enhances AKT/mTOR signalling and increases proliferative and invasive capacity in vitro and confers resistance to selective PI3Kδ inhibitor, CAL-101 (idelalisib), in mouse xenograft models. High PIK3CD-S expression in PCa specimens associates with poor survival. These results highlight the potential of RNA splice variants to serve as novel biomarkers and molecular targets for developmental therapeutics in aggressive PCa.

Authors

Wang, B-D; Ceniccola, K; Hwang, S; Andrawis, R; Horvath, A; Freedman, JA; Olender, J; Knapp, S; Ching, T; Garmire, L; Patel, V; Garcia-Blanco, MA; Patierno, SR; Lee, NH

MLA Citation

Wang, Bi-Dar, et al. “Alternative splicing promotes tumour aggressiveness and drug resistance in African American prostate cancer..” Nat Commun, vol. 8, June 2017. Pubmed, doi:10.1038/ncomms15921.

PMID

28665395

Source

pubmed

Published In

Nature Communications

Volume

8

Publish Date

2017

Start Page

15921

DOI

10.1038/ncomms15921

Emerging evidence from epidemiological studies suggests a link between environmental chemical exposure and progression of aggressive breast cancer subtypes. Of all clinically distinct types of breast cancers, the most lethal phenotypic variant is inflammatory breast cancer (IBC). Overexpression of epidermal growth factor receptors (EGFR/HER2) along with estrogen receptor (ER) negativity is common in IBC tumor cells, which instead of a solid mass present as rapidly proliferating diffuse tumor cell clusters. Our previous studies have demonstrated a role of an adaptive response of increased antioxidants in acquired resistance to EGFR-targeting drugs in IBC. Environmental chemicals are known to induce oxidative stress resulting in perturbations in signal transduction pathways. It is therefore of interest to identify chemicals that can potentiate EGFR mitogenic effects in IBC. Herein, we assessed in ER-negative IBC cells a subset of chemicals from the EPA ToxCast set for their effect on EGFR activation and in multiple cancer phenotypic assays. We demonstrated that endocrine-disrupting chemicals such as bisphenol A (BPA) and 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane can increase EGFR/ERK signaling. BPA also caused a corresponding increase in expression of SOD1 and anti-apoptotic Bcl-2, key markers of antioxidant and anti-apoptotic processes. BPA potentiated clonogenic growth and tumor spheroid formation in vitro, reflecting IBC-specific pathological characteristics. Furthermore, we identified that BPA was able to attenuate the inhibitory effect of an EGFR targeted drug in a longer-term anchorage-independent growth assay. These findings provide a potential mechanistic basis for environmental chemicals such as BPA in potentiating a hyperproliferative and death-resistant phenotype in cancer cells by activating mitogenic pathways to which the tumor cells are addicted for survival.

Authors

Sauer, SJ; Tarpley, M; Shah, I; Save, AV; Lyerly, HK; Patierno, SR; Williams, KP; Devi, GR

MLA Citation

Sauer, Scott J., et al. “Bisphenol A activates EGFR and ERK promoting proliferation, tumor spheroid formation and resistance to EGFR pathway inhibition in estrogen receptor-negative inflammatory breast cancer cells..” Carcinogenesis, vol. 38, no. 3, Mar. 2017, pp. 252–60. Pubmed, doi:10.1093/carcin/bgx003.

PMID

28426875

Source

pubmed

Published In

Carcinogenesis

Volume

38

Issue

3

Publish Date

2017

Start Page

252

End Page

260

DOI

10.1093/carcin/bgx003

Authors

Freedman, J; Wang, Y; Liu, H; Moorman, P; Hyslop, T; George, D; Lee, N; Wei, Q; Patierno, S

MLA Citation

Freedman, Jennifer, et al. “Abstract B58: Single-nucleotide polymorphisms of race-related alternatively spliced genes associate with prostate cancer risk, aggressiveness and/or survival.” Epidemiology, Lifestyle, and Genetics, American Association for Cancer Research, 2017. Crossref, doi:10.1158/1538-7755.disp16-b58.

Source

crossref

Published In

Epidemiology, Lifestyle, and Genetics

Publish Date

2017

DOI

10.1158/1538-7755.disp16-b58

BACKGROUND: Whether patient navigation improves outcomes for patients with comorbidities is unknown. The aims of this study were to determine the effect of comorbidities on the time to diagnostic resolution after an abnormal cancer screening test and to examine whether patient navigation improves the timeliness and likelihood of diagnostic resolution for patients with comorbidities in comparison with no navigation. METHODS: A secondary analysis of comorbidity data collected by Patient Navigation Research Program sites using the Charlson Comorbidity Index (CCI) was conducted. The participants were 6,349 patients with abnormal breast, cervical, colon, or prostate cancer screening tests between 2007 and 2011. The intervention was patient navigation or usual care. The CCI data were highly skewed across projects and cancer sites, and the CCI scores were categorized as 0 (CCI score of 0 or no comorbidities identified; 76% of cases); 1 (CCI score of 1; 16% of cases), or 2 (CCI score ≥ 2; 8% of cases). Separate adjusted hazard ratios for each site and cancer type were obtained, and then they were pooled with a meta-analysis random effects methodology. RESULTS: Patients with a CCI score ≥ 2 had delayed diagnostic resolution after an abnormal cancer screening test in comparison with those with no comorbidities. Patient navigation reduced delays in diagnostic resolution, with the greatest benefits seen for those with a CCI score ≥ 2. CONCLUSIONS: Persons with a CCI score ≥ 2 experienced significant delays in timely diagnostic care in comparison with patients without comorbidities. Patient navigation was effective in reducing delays in diagnostic resolution among those with CCI scores > 1. Cancer 2017;123:312-318. © 2016 American Cancer Society.

Authors

Whitley, EM; Raich, PC; Dudley, DJ; Freund, KM; Paskett, ED; Patierno, SR; Simon, M; Warren-Mears, V; Snyder, FR; Patient Navigation Research Program Investigators,

MLA Citation

Whitley, Elizabeth M., et al. “Relation of comorbidities and patient navigation with the time to diagnostic resolution after abnormal cancer screening..” Cancer, vol. 123, no. 2, Jan. 2017, pp. 312–18. Pubmed, doi:10.1002/cncr.30316.

PMID

27648520

Source

pubmed

Published In

Cancer

Volume

123

Issue

2

Publish Date

2017

Start Page

312

End Page

318

DOI

10.1002/cncr.30316

Authors

Barrett, NJ; Vann, T; Wilder, J; ingraham, K; Worthy, V; Boyce, X; Reyes, R; Chirinios, M; Wigfall, P; Robinson, W; Patierno, S

MLA Citation

Barrett, N. J., et al. “Implementing a Health Equity Agenda at the Duke Cancer Institute.” Oncology Issues, vol. September-October 2016, Sept. 2016, pp. 48–57.

Website

http://hdl.handle.net/10161/12945

Source

manual

Published In

Oncology Issues

Volume

September -October 2016

Publish Date

2016

Start Page

48

End Page

57

Treatment with androgen-targeted therapies can induce upregulation of epithelial plasticity pathways. Epithelial plasticity is known to be important for metastatic dissemination and therapeutic resistance. The goal of this study is to elucidate the functional consequence of induced epithelial plasticity on AR regulation during disease progression to identify factors important for treatment-resistant and metastatic prostate cancer. We pinpoint the epithelial plasticity transcription factor, Snail, at the nexus of enzalutamide resistance and prostate cancer metastasis both in preclinical models of prostate cancer and in patients. In patients, Snail expression is associated with Gleason 9-10 high-risk disease and is strongly overexpressed in metastases as compared to localized prostate cancer. Snail expression is also elevated in enzalutamide-resistant prostate cancer cells compared to enzalutamide-sensitive cells, and downregulation of Snail re-sensitizes enzalutamide-resistant cells to enzalutamide. While activation of Snail increases migration and invasion, it is also capable of promoting enzalutamide resistance in enzalutamide-sensitive cells. This Snail-mediated enzalutamide resistance is a consequence of increased full-length AR and AR-V7 expression and nuclear localization. Downregulation of either full-length AR or AR-V7 re-sensitizes cells to enzalutamide in the presence of Snail, thus connecting Snail-induced enzalutamide resistance directly to AR biology. Finally, we demonstrate that Snail is capable of mediating-resistance through AR even in the absence of AR-V7. These findings imply that increased Snail expression during progression to metastatic disease may prime cells for resistance to AR-targeted therapies by promoting AR activity in prostate cancer.

Authors

Ware, KE; Somarelli, JA; Schaeffer, D; Li, J; Zhang, T; Park, S; Patierno, SR; Freedman, J; Foo, W-C; Garcia-Blanco, MA; Armstrong, AJ

MLA Citation

Ware, Kathryn E., et al. “Snail promotes resistance to enzalutamide through regulation of androgen receptor activity in prostate cancer..” Oncotarget, vol. 7, no. 31, Aug. 2016, pp. 50507–21. Pubmed, doi:10.18632/oncotarget.10476.

Website

http://hdl.handle.net/10161/15123

PMID

27409172

Source

pubmed

Published In

Oncotarget

Volume

7

Issue

31

Publish Date

2016

Start Page

50507

End Page

50521

DOI

10.18632/oncotarget.10476

Authors

Freedman, JA; Robinson, TJ; LaCroix, B; Patierno, BM; George, DJ; Sullenger, BA; Patierno, SR

MLA Citation

Freedman, Jennifer A., et al. “Abstract B18: Development of novel therapeutic splice-switching oligonucleotides against aggressive prostate cancer in men of African descent.” Cell, Molecular, and Tumor Biology, American Association for Cancer Research, 2016. Crossref, doi:10.1158/1538-7755.disp15-b18.

Source

crossref

Published In

Cell, Molecular, and Tumor Biology

Publish Date

2016

DOI

10.1158/1538-7755.disp15-b18

OBJECTIVE: As part of the Patient Navigation Research Program, we examined the effect of patient navigation versus usual care on timely diagnostic follow-up, defined as clinical management for women with cervical abnormalities within accepted time frames. METHODS: Participants from four Patient Navigation Research Program centers were divided into low- and high-risk abnormality groups and analyzed separately. Low-risk participants (n = 2088) were those who enrolled with an initial Pap test finding of atypical squamous cells of undetermined significance (ASCUS) with a positive high-risk human papillomavirus (HPV) serotype, atypical glandular cells, or low-grade squamous intraepithelial lesion (LGSIL). High-risk participants were those with an initial finding of high-grade squamous intraepithelial lesion (HGSIL) (n = 229). A dichotomous outcome of timely diagnostic follow-up within 180 days was used for the low-risk abnormality group and timely diagnostic follow-up within 60 days for the high-risk group, consistent with treatment guidelines. A logistic mixed-effects regression model was used to evaluate the intervention effect using a random effect for study arm within an institution. A backward selection process was used for multivariable model building, considering the impact of each predictor on the intervention effect. RESULTS: Low-risk women in the patient navigation arm showed an improvement in the odds of timely diagnostic follow-up across all racial groups, but statistically significant effects were only observed in non-English-speaking Hispanics (OR 5.88, 95% CI 2.81-12.29). No effect was observed among high-risk women. CONCLUSION: These results suggest that patient navigation can improve timely diagnostic follow-up among women with low-risk cervical abnormalities, particularly in non-English-speaking Hispanic women.

Authors

Paskett, ED; Dudley, D; Young, GS; Bernardo, BM; Wells, KJ; Calhoun, EA; Fiscella, K; Patierno, SR; Warren-Mears, V; Battaglia, TA; PNRP Investigators,

MLA Citation

Paskett, Electra D., et al. “Impact of Patient Navigation Interventions on Timely Diagnostic Follow Up for Abnormal Cervical Screening..” J Womens Health (Larchmt), vol. 25, no. 1, Jan. 2016, pp. 15–21. Pubmed, doi:10.1089/jwh.2014.5094.

PMID

26625131

Source

pubmed

Published In

J Womens Health (Larchmt)

Volume

25

Issue

1

Publish Date

2016

Start Page

15

End Page

21

DOI

10.1089/jwh.2014.5094

BACKGROUND: Patient navigation may reduce cancer disparities associated with socioeconomic status (SES) and household factors. This study examined whether these factors were associated with delays in diagnostic resolution among patients with cancer screening abnormalities and whether patient navigation ameliorated these delays. METHODS: This study analyzed data from 5 of 10 centers of the National Cancer Institute's Patient Navigation Research Program, which collected SES and household data on employment, income, education, housing, marital status, and household composition. The primary outcome was the time to diagnostic resolution after a cancer screening abnormality. Separate adjusted Cox proportional hazard models were fit for each SES and household factor, and an interaction between that factor and the intervention status was included. RESULTS: Among the 3777 participants (1968 in the control arm and 1809 in the navigation intervention arm), 91% were women, and the mean age was 44 years; 43% were Hispanic, 28% were white, and 27% were African American. Within the control arm, the unemployed experienced a longer time to resolution than those employed full-time (hazard ratio [HR], 0.85; P = .02). Renters (HR, 0.81; P = .02) and those with other (ie, unstable) housing (HR, 0.60; P < .001) had delays in comparison with homeowners. Never married (HR, 0.70; P < .001) and previously married participants (HR, 0.85; P = .03) had a longer time to care than married participants. There were no differences in the time to diagnostic resolution with any of these variables within the navigation intervention arm. CONCLUSIONS: Delays in diagnostic resolution exist by employment, housing type, and marital status. Patient navigation eliminated these disparities in the study sample. These findings demonstrate the value of providing patient navigation to patients at high risk for delays in cancer care.

Authors

Rodday, AM; Parsons, SK; Snyder, F; Simon, MA; Llanos, AAM; Warren-Mears, V; Dudley, D; Lee, J-H; Patierno, SR; Markossian, TW; Sanders, M; Whitley, EM; Freund, KM

MLA Citation

Rodday, Angie Mae, et al. “Impact of patient navigation in eliminating economic disparities in cancer care..” Cancer, vol. 121, no. 22, Nov. 2015, pp. 4025–34. Pubmed, doi:10.1002/cncr.29612.

PMID

26348120

Source

pubmed

Published In

Cancer

Volume

121

Issue

22

Publish Date

2015

Start Page

4025

End Page

4034

DOI

10.1002/cncr.29612

BACKGROUND: There is limited understanding of the association between barriers to care and clinical outcomes within patient navigation programs. METHODS: Secondary analyses of data from the intervention arms of the Patient Navigation Research Program were performed, which included navigated participants with abnormal breast and cervical cancer screening tests from 2007 to 2010. Independent variables were: 1) the number of unique barriers to care (0, 1, 2, or ≥3) documented during patient navigation encounters; and 2) the presence of socio-legal barriers originating from social policy (yes/no). The median time to diagnostic resolution of index screening abnormalities was estimated using Kaplan-Meier cumulative incidence curves. Multivariable Cox proportional hazards regression examined the impact of barriers on time to resolution, controlling for sociodemographics and stratifying by study center. RESULTS: Among 2600 breast screening participants, approximately 75% had barriers to care documented (25% had 1 barrier, 16% had 2 barriers, and 34% had ≥3 barriers). Among 1387 cervical screening participants, greater than one-half had barriers documented (31% had 1 barrier, 11% had 2 barriers, and 13% had ≥3 barriers). Among breast screening participants, the presence of barriers was associated with less timely resolution for any number of barriers compared with no barriers. Among cervical screening participants, only the presence of ≥2 barriers was found to be associated with less timely resolution. Both types of barriers, socio-legal and other barriers, were found to be associated with delay among breast and cervical screening participants. CONCLUSIONS: Navigated women with barriers resolved cancer screening abnormalities at a slower rate compared with navigated women with no barriers. Further innovations in navigation care are necessary to maximize the impact of patient navigation programs nationwide.

Authors

Ramachandran, A; Snyder, FR; Katz, ML; Darnell, JS; Dudley, DJ; Patierno, SR; Sanders, MR; Valverde, PA; Simon, MA; Warren-Mears, V; Battaglia, TA; Patient Navigation Research Program Investigators,

MLA Citation

Ramachandran, Ambili, et al. “Barriers to health care contribute to delays in follow-up among women with abnormal cancer screening: Data from the Patient Navigation Research Program..” Cancer, vol. 121, no. 22, Nov. 2015, pp. 4016–24. Pubmed, doi:10.1002/cncr.29607.

PMID

26385420

Source

pubmed

Published In

Cancer

Volume

121

Issue

22

Publish Date

2015

Start Page

4016

End Page

4024

DOI

10.1002/cncr.29607

PURPOSE: African Americans (AA) exhibit higher rates of prostate cancer incidence and mortality compared with European American (EA) men. In addition to socioeconomic influences, biologic factors are believed to play a critical role in prostate cancer disparities. We investigated whether population-specific and -enriched miRNA-mRNA interactions might contribute to prostate cancer disparities. EXPERIMENTAL DESIGN: Integrative genomics was used, combining miRNA and mRNA profiling, miRNA target prediction, pathway analysis, and functional validation, to map miRNA-mRNA interactions associated with prostate cancer disparities. RESULTS: We identified 22 AA-specific and 18 EA-specific miRNAs in prostate cancer versus patient-matched normal prostate, and 10 "AA-enriched/-depleted" miRNAs in AA prostate cancer versus EA prostate cancer comparisons. Many of these population-specific/-enriched miRNAs could be paired with target mRNAs that exhibited an inverse pattern of differential expression. Pathway analysis revealed EGFR (or ERBB) signaling as a critical pathway significantly regulated by AA-specific/-enriched mRNAs and miRNA-mRNA pairings. Novel miRNA-mRNA pairings were validated by qRT-PCR, Western blot, and/or IHC analyses in prostate cancer specimens. Loss/gain of function assays performed in population-specific prostate cancer cell lines confirmed miR-133a/MCL1, miR-513c/STAT1, miR-96/FOXO3A, miR-145/ITPR2, and miR-34a/PPP2R2A as critical miRNA-mRNA pairings driving oncogenesis. Manipulating the balance of these pairings resulted in decreased proliferation and invasion, and enhanced sensitization to docetaxel-induced cytotoxicity in AA prostate cancer cells. CONCLUSIONS: Our data suggest that AA-specific/-enriched miRNA-mRNA pairings may play a critical role in the activation of oncogenic pathways in AA prostate cancer. Our findings also suggest that miR-133a/MCL1, miR-513c/STAT1, and miR-96/FOXO3A may have clinical significance in the development of novel strategies for treating aggressive prostate cancer.

Authors

Wang, B-D; Ceniccola, K; Yang, Q; Andrawis, R; Patel, V; Ji, Y; Rhim, J; Olender, J; Popratiloff, A; Latham, P; Lai, Y; Patierno, SR; Lee, NH

MLA Citation

Wang, Bi-Dar, et al. “Identification and Functional Validation of Reciprocal microRNA-mRNA Pairings in African American Prostate Cancer Disparities..” Clin Cancer Res, vol. 21, no. 21, Nov. 2015, pp. 4970–84. Pubmed, doi:10.1158/1078-0432.CCR-14-1566.

PMID

26089375

Source

pubmed

Published In

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research

Volume

21

Issue

21

Publish Date

2015

Start Page

4970

End Page

4984

DOI

10.1158/1078-0432.CCR-14-1566

OBJECTIVE: Circulating tumor cells (CTCs) have known prognostic implications in metastatic castration-resistant prostate cancer, but little is known regarding its utility in biochemical recurrence (BR) of prostate cancer. The primary objectives were to determine whether CTCs are measurable in patients with BR and whether it can reliably predict prostate-specific antigen (PSA) increase and PSA doubling times (PSADTs). METHODS: BR was identified in patients after prostatectomy or radiation or both, with a PSA increase of ≥ 0.2 for prior prostatectomy or > 2 mg/dL increase for post-nadir in prior radiotherapy. CTCs were enumerated at baseline at the time of study entry using the CellSearch (Janssen Diagnostics, Raritan, NJ) test. RESULTS: The median age for all 36 patients accrued was 69.5 years (range, 51-91) with a median PSA of 1.65 ng/mL (range, 0.2-65.8). Gleason scores ranged from 5 to 9 (median, 7). The majority had prostatectomy (n = 25), external beam radiotherapy (n = 9), CyberKnife (Accuray, Sunnyvale, CA) (n = 1), and combined radiohormonal therapy (n = 1). PSADT ranged from 0.35 to 55 months, with a median of 7.43 months. The incidence of positive CTCs was 8.3% (3 patients), of whom 2 had biopsy-proven bony lesions on presenting with equivocal scans and PSADTs of 2.27 and 3.08 months, respectively. The third CTC-positive patient had a PSADT of 4.99 months. CONCLUSIONS: Obtaining CTCs in unselected patients presenting with BR has a relatively low yield. However, obtaining a positive CTC raises the suspicion of the presence of metastatic disease and may have utility for longitudinal follow-ups of patients with BR.

Authors

Aragon-Ching, JB; Siegel, RS; Frazier, H; Andrawis, R; Hendricks, F; Phillips, M; Jarrett, T; Guebre-Xabiher, H; Patierno, S; Simmens, SJ

MLA Citation

Aragon-Ching, Jeanny B., et al. “Circulating Tumor Cells in Biochemical Recurrence of Prostate Cancer..” Clin Genitourin Cancer, vol. 13, no. 5, Oct. 2015, pp. e341–45. Pubmed, doi:10.1016/j.clgc.2015.04.003.

PMID

25956468

Source

pubmed

Published In

Clin Genitourin Cancer

Volume

13

Issue

5

Publish Date

2015

Start Page

e341

End Page

e345

DOI

10.1016/j.clgc.2015.04.003

Authors

Patierno, S; Freedman, J; Wang, B; Lee, N; George, D

MLA Citation

Patierno, S., et al. “322 Novel alternative splice variants as potential biomarkers and therapeutic targets in aggressive prostate cancer in men of African descent.” European Journal of Cancer, vol. 50, Elsevier BV, 2014, pp. 105–105. Crossref, doi:10.1016/s0959-8049(14)70448-4.

Source

crossref

Published In

European Journal of Cancer

Volume

50

Publish Date

2014

Start Page

105

End Page

105

DOI

10.1016/s0959-8049(14)70448-4

Authors

Barrett, NJ; Worthy, V; Boyce-Manon, X; Reyes, R; Banks, L; Patierno, S; Chu, C

MLA Citation

Barrett, Nadine Josann, et al. “Abstract A30: Using the principles of community-based participatory research to build an office of health equity within a nationally designated cancer institute.” Behavioral and Social Science, American Association for Cancer Research, Nov. 2014. Crossref, doi:10.1158/1538-7755.disp13-a30.

Website

http://hdl.handle.net/10161/12947

Source

crossref

Published In

Behavioral and Social Science

Publish Date

2014

DOI

10.1158/1538-7755.disp13-a30

PURPOSE: Poor and underserved women face barriers in receiving timely and appropriate breast cancer care. Patient navigators help individuals overcome these barriers, but little is known about whether patient navigation improves quality of care. The purpose of this study is to examine whether navigated women with breast cancer are more likely to receive recommended standard breast cancer care. PATIENTS AND METHODS: Women with breast cancer who participated in the national Patient Navigation Research Program were examined to determine whether the care they received included the following: initiation of antiestrogen therapy in patients with hormone receptor-positive breast cancer; initiation of postlumpectomy radiation therapy; and initiation of chemotherapy in women younger than age 70 years with triple-negative tumors more than 1 cm. This is a secondary analysis of a multicenter quasi-experimental study funded by the National Cancer Institute to evaluate patient navigation. Multiple logistic regression was performed to compare differences in receipt of care between navigated and non-navigated participants. RESULTS: Among participants eligible for antiestrogen therapy, navigated participants (n = 380) had a statistically significant higher likelihood of receiving antiestrogen therapy compared with non-navigated controls (n = 381; odds ratio [OR], 1.73; P = .004) in a multivariable analysis. Among the participants eligible for radiation therapy after lumpectomy, navigated participants (n = 255) were no more likely to receive radiation (OR, 1.42; P = .22) than control participants (n = 297). CONCLUSION: We demonstrate that navigated participants were more likely than non-navigated participants to receive antiestrogen therapy. Future studies are required to determine the full impact patient navigation may have on ensuring that vulnerable populations receive quality care.

Authors

Ko, NY; Darnell, JS; Calhoun, E; Freund, KM; Wells, KJ; Shapiro, CL; Dudley, DJ; Patierno, SR; Fiscella, K; Raich, P; Battaglia, TA

MLA Citation

Ko, Naomi Y., et al. “Can patient navigation improve receipt of recommended breast cancer care? Evidence from the National Patient Navigation Research Program..” J Clin Oncol, vol. 32, no. 25, Sept. 2014, pp. 2758–64. Pubmed, doi:10.1200/JCO.2013.53.6037.

PMID

25071111

Source

pubmed

Published In

Journal of Clinical Oncology

Volume

32

Issue

25

Publish Date

2014

Start Page

2758

End Page

2764

DOI

10.1200/JCO.2013.53.6037

BACKGROUND: We developed and validated a Patient Satisfaction with Cancer-Related Care (PSCC) measure using classical test theory methods. The present study applied item response theory (IRT) analysis to determine item-level psychometric properties, facilitate development of short forms, and inform future applications for the PSCC. METHODS: We applied unidimensional IRT models to PSCC data from 1,296 participants (73% female; 18 to 86 years). An unconstrained graded response model (GRM) and a Rasch Model were fitted to estimate indices for model comparison using likelihood ratio (LR) test and information criteria. We computed item and latent trait parameter estimates, category and operating characteristic curves, and tested information curves for the better fitting model. RESULTS: The GRM fitted the data better than the Rasch Model (LR = 828, df = 17, p < 0.001). The log-likelihood (-17,390.38 vs. -17,804.26) was larger, and the AIC and BIC were smaller for the GRM compared to the Rash Model (AIC = 34,960.77 vs. 35,754.73; BIC = 35,425.80 vs. 36,131.92). Item parameter estimates (IPEs) showed substantial variation in items' discriminating power (0.94 to 2.18). Standard errors of the IPEs were small (threshold parameters mostly around 0.1; discrimination parameters 0.1 to 0.2), confirming the precision of the IPEs. CONCLUSION: The GRM provides precise IPEs that will enable comparable scores from different subsets of items, and facilitate optimal selections of items to estimate patients' latent satisfaction level. Given the large calibration sample, the IPEs can be used in settings with limited resources (e.g., smaller samples) to estimate patients' satisfaction.

Authors

Jean-Pierre, P; Cheng, Y; Paskett, E; Shao, C; Fiscella, K; Winters, P; Patient Navigation Research Program,

MLA Citation

Jean-Pierre, Pascal, et al. “Item response theory analysis of the patient satisfaction with cancer-related care measure: a psychometric investigation in a multicultural sample of 1,296 participants..” Support Care Cancer, vol. 22, no. 8, Aug. 2014, pp. 2229–40. Pubmed, doi:10.1007/s00520-014-2202-7.

PMID

24664356

Source

pubmed

Published In

Support Care Cancer

Volume

22

Issue

8

Publish Date

2014

Start Page

2229

End Page

2240

DOI

10.1007/s00520-014-2202-7

BACKGROUND: Patient navigation is a promising intervention to address cancer disparities but requires a multisite controlled trial to assess its effectiveness. METHODS: The Patient Navigation Research Program compared patient navigation with usual care on time to diagnosis or treatment for participants with breast, cervical, colorectal, or prostate screening abnormalities and/or cancers between 2007 and 2010. Patient navigators developed individualized strategies to address barriers to care, with the focus on preventing delays in care. To assess timeliness of diagnostic resolution, we conducted a meta-analysis of center- and cancer-specific adjusted hazard ratios (aHRs) comparing patient navigation vs usual care. To assess initiation of cancer therapy, we calculated a single aHR, pooling data across all centers and cancer types. We conducted a metaregression to evaluate variability across centers. All statistical tests were two-sided. RESULTS: The 10521 participants with abnormal screening tests and 2105 with a cancer or precancer diagnosis were predominantly from racial/ethnic minority groups (73%) and publically insured (40%) or uninsured (31%). There was no benefit during the first 90 days of care, but a benefit of navigation was seen from 91 to 365 days for both diagnostic resolution (aHR = 1.51; 95% confidence interval [CI] = 1.23 to 1.84; P < .001)) and treatment initiation (aHR = 1.43; 95% CI = 1.10 to 1.86; P < .007). Metaregression revealed that navigation had its greatest benefits within centers with the greatest delays in follow-up under usual care. CONCLUSIONS: Patient navigation demonstrated a moderate benefit in improving timely cancer care. These results support adoption of patient navigation in settings that serve populations at risk of being lost to follow-up.

Authors

Freund, KM; Battaglia, TA; Calhoun, E; Darnell, JS; Dudley, DJ; Fiscella, K; Hare, ML; LaVerda, N; Lee, J-H; Levine, P; Murray, DM; Patierno, SR; Raich, PC; Roetzheim, RG; Simon, M; Snyder, FR; Warren-Mears, V; Whitley, EM; Winters, P; Young, GS; Paskett, ED; Writing Group of the Patient Navigation Research Program,

MLA Citation

Freund, Karen M., et al. “Impact of patient navigation on timely cancer care: the Patient Navigation Research Program..” J Natl Cancer Inst, vol. 106, no. 6, June 2014. Pubmed, doi:10.1093/jnci/dju115.

PMID

24938303

Source

pubmed

Published In

J Natl Cancer Inst

Volume

106

Issue

6

Publish Date

2014

Start Page

dju115

DOI

10.1093/jnci/dju115

BACKGROUND: Patient navigation--the provision of logistical, educational, and emotional support needed to help patients "navigate around" barriers to high-quality cancer treatment offers promise. No patient-reported outcome measures currently exist that assess patient navigation from the patient's perspective. We use a partial independence item response theory model to report on the psychometric properties of the Patient Satisfaction with Navigation, Logistical measure developed for this purpose. METHODS: We used data from an ethnically diverse sample (n = 1873) from the National Cancer Institute Patient Navigation Research Program. We included individuals with the presence of an abnormal breast, cervical, colorectal, or prostate cancer finding. RESULTS: The partial independence item response theory model fit well. Results indicated that scores derived from responses provide extremely precise and reliable measurement between -2.5 SD below and 2 SD above the mean and acceptably precise and reliable measurement across nearly the entire range. CONCLUSIONS: Our findings provide evidence in support of the Patient Satisfaction with Navigation, Logistical. Scale users should utilize 1 of the 2 described methods to create scores.

Authors

Carle, AC; Jean-Pierre, P; Winters, P; Valverde, P; Wells, K; Simon, M; Raich, P; Patierno, S; Katz, M; Freund, KM; Dudley, D; Fiscella, K

MLA Citation

Carle, Adam C., et al. “Psychometric evaluation of the patient satisfaction with logistical aspects of navigation (PSN-L) scale using item response theory..” Med Care, vol. 52, no. 4, Apr. 2014, pp. 354–61. Pubmed, doi:10.1097/MLR.0000000000000089.

PMID

24848207

Source

pubmed

Published In

Med Care

Volume

52

Issue

4

Publish Date

2014

Start Page

354

End Page

361

DOI

10.1097/MLR.0000000000000089

BACKGROUND: Navigators can facilitate timely access to cancer services, but to the authors' knowledge there are little data available regarding their economic impact. METHODS: The authors conducted a cost-consequence analysis of navigation versus usual care among 10,521 individuals with abnormal breast, cervical, colorectal, or prostate cancer screening results who enrolled in the Patient Navigation Research Program study from January 1, 2006 to March 31, 2010. Navigation costs included diagnostic evaluation, patient and staff time, materials, and overhead. Consequences or outcomes were time to diagnostic resolution and probability of resolution. Differences in costs and outcomes were evaluated using multilevel, mixed-effects regression modeling adjusting for age, race/ethnicity, language, marital status, insurance status, cancer, and site clustering. RESULTS: The majority of individuals were members of a minority (70.7%) and uninsured or publically insured (72.7%). Diagnostic resolution was higher for navigation versus usual care at 180 days (56.2% vs 53.8%; P = .008) and 270 days (70.0% vs 68.2%; P < .001). Although there were no differences in the average number of days to resolution between the 2 groups (110 days vs 109 days; P = .63), the probability of ever having diagnostic resolution was higher for the navigation group versus the usual-care group (84.5% vs 79.6%; P < .001). The added cost of navigation versus usual care was $275 per patient (95% confidence interval, $260-$290; P < .001). There was no significant difference in stage distribution among the 12.4% of patients in the navigation group vs 11% of the usual-care patients diagnosed with cancer. CONCLUSIONS: Navigation adds costs and modestly increases the probability of diagnostic resolution among patients with abnormal screening test results. Navigation is only likely to be cost-effective if improved resolution translates into an earlier cancer stage at the time of diagnosis.

Authors

Bensink, ME; Ramsey, SD; Battaglia, T; Fiscella, K; Hurd, TC; McKoy, JM; Patierno, SR; Raich, PC; Seiber, EE; Warren-Mears, V; Whitley, E; Paskett, ED; Mandelblatt, S; Patient Navigation Research Program,

MLA Citation

Bensink, Mark E., et al. “Costs and outcomes evaluation of patient navigation after abnormal cancer screening: evidence from the Patient Navigation Research Program..” Cancer, vol. 120, no. 4, Feb. 2014, pp. 570–78. Pubmed, doi:10.1002/cncr.28438.

PMID

24166217

Source

pubmed

Published In

Cancer

Volume

120

Issue

4

Publish Date

2014

Start Page

570

End Page

578

DOI

10.1002/cncr.28438

BACKGROUND: Patient navigation (PN) is a system-level strategy to decrease cancer mortality rates by reducing barriers to cancer care. Barriers to resolution among participants in the PN intervention arm with a breast or cervical abnormality in the Patient Navigation Research Program and navigators' actions to address those barriers were examined. METHODS: Data from seven institutions (2005-2010) included 1,995 breast and 1,194 cervical patients. A stratified Cox proportional hazards regression model was used to examine the effects of barriers on time to resolution of an abnormal screening test or clinical finding. FINDINGS: The range of unique barriers was 0 to 12 and 0 to 7 among participants with breast and cervical abnormalities, respectively. About two thirds of breast and one half of cervical participants had at least one barrier resulting in longer time to diagnostic resolution among breast (adjusted hazard ratio [HR], 0.744; p < .001) and cervical (adjusted HR, 0.792; p < .001) participants. Patient- and system-level barriers were most common. Frequent navigator actions were making arrangements, scheduling appointments, referrals, and education. CONCLUSIONS: Having a barrier resulted in a delay in diagnostic resolution of an abnormal screening test or clinical finding. Health care systems can use these findings to improve existing PN programs or when developing new programs.

Authors

Katz, ML; Young, GS; Reiter, PL; Battaglia, TA; Wells, KJ; Sanders, M; Simon, M; Dudley, DJ; Patierno, SR; Paskett, ED

MLA Citation

Katz, Mira L., et al. “Barriers reported among patients with breast and cervical abnormalities in the patient navigation research program: impact on timely care..” Womens Health Issues, vol. 24, no. 1, Jan. 2014, pp. e155–62. Pubmed, doi:10.1016/j.whi.2013.10.010.

PMID

24439942

Source

pubmed

Published In

Womens Health Issues

Volume

24

Issue

1

Publish Date

2014

Start Page

e155

End Page

e162

DOI

10.1016/j.whi.2013.10.010

Apoptosis-resistance and metabolic imbalances are prominent features of cancer cells. We have recently reported on populations of human fibroblasts that exhibit resistance to mitochondrial-mediated apoptosis, acquired as a result of a single genotoxic exposure. The objective of the present study was to investigate the intrinsic bioenergetic profile of the death-resistant cells, as compared to the clonogenic control cells. Therefore, we analyzed the basic bioenergetic parameters including oxygen consumption and extracellular acidification rates, coupling efficiency, and spare respiratory capacity. Our data demonstrate a strong correlation between enhanced spare respiratory capacity and death-resistance, which we postulate to be indicative of the earliest stages of carcinogenesis.

Authors

Nickens, KP; Wikstrom, JD; Shirihai, OS; Patierno, SR; Ceryak, S

MLA Citation

Nickens, Kristen P., et al. “A bioenergetic profile of non-transformed fibroblasts uncovers a link between death-resistance and enhanced spare respiratory capacity..” Mitochondrion, vol. 13, no. 6, Nov. 2013, pp. 662–67. Pubmed, doi:10.1016/j.mito.2013.09.005.

PMID

24075934

Source

pubmed

Published In

Mitochondrion

Volume

13

Issue

6

Publish Date

2013

Start Page

662

End Page

667

DOI

10.1016/j.mito.2013.09.005

Authors

Wang, B-D; Andrawis, R; Rice, D; Ahmed, F; Frazier, H; Jarrett, T; Patierno, S; Lee, N

MLA Citation

Wang, Bi-Dar, et al. “977 GENOMIC STUDY OF PROSTATE CANCER DISPARITIES BETWEEN AFRICAN AMERICAN AND CAUCASIAN AMERICAN POPULATIONS.” Journal of Urology, vol. 189, no. 4S, Ovid Technologies (Wolters Kluwer Health), 2013. Crossref, doi:10.1016/j.juro.2013.02.559.

Source

crossref

Published In

The Journal of Urology

Volume

189

Issue

4S

Publish Date

2013

DOI

10.1016/j.juro.2013.02.559

Authors

Bensink, ME; Ramsey, SD; Battaglia, T; Fiscella, K; Hurd, TC; Mckoy, JM; Patierno, SR; Raich, PC; Seiber, EE; Warren-Mears, V; Whitley, E; Paskett, ED; Mandelblatt, S

MLA Citation

Bensink, M. E., et al. “Costs and outcomes evaluation of patient navigation after abnormal cancer screening: Evidence From the Patient Navigation Research Program.” Cancer, 2013.

Source

scopus

Published In

Cancer

Publish Date

2013

Authors

Simon, MA; Patterson, AK; Risendal, BC; Patierno, S

MLA Citation

Simon, M. A., et al. “Erratum: Survivorship navigation outcome measures: A report from the ACS Patient Navigation Working Group on Survivorship Navigation (Cancer (2011) 117 (3575-84)).” Cancer, vol. 118, no. 21, Nov. 2012. Scopus, doi:10.1002/cncr.27546.

Source

scopus

Published In

Cancer

Volume

118

Issue

21

Publish Date

2012

Start Page

5450

DOI

10.1002/cncr.27546

BACKGROUND: Patient Navigation (PN) originated in Harlem as an intervention to help poor women overcome access barriers to timely breast cancer treatment. Despite rapid, nationally widespread adoption of PN, empirical evidence on its effectiveness is lacking. In 2005, National Cancer Institute initiated a multicenter PN Research Program (PNRP) to measure PN effectiveness for several cancers. The George Washington Cancer Institute, a project participant, established District of Columbia (DC)-PNRP to determine PN's ability to reduce breast cancer diagnostic time (number of days from abnormal screening to definitive diagnosis). METHODS: A total of 2,601 women (1,047 navigated; 1,554 concurrent records-based nonnavigated) were examined for breast cancer from 2006 to 2010 at 9 hospitals/clinics in DC. Analyses included only women who reached complete diagnostic resolution. Differences in diagnostic time between navigation groups were tested with ANOVA models including categorical demographic and treatment variables. Log transformations normalized diagnostic time. Geometric means were estimated and compared using Tukey-Kramer P value adjustments. RESULTS: Average-geometric mean [95% confidence interval (CI)]-diagnostic time (days) was significantly shorter for navigated, 25.1 (21.7, 29.0), than nonnavigated women, 42.1 (35.8, 49.6). Subanalyses revealed significantly shorter average diagnostic time for biopsied navigated women, 26.6 (21.8, 32.5) than biopsied nonnavigated women, 57.5 (46.3, 71.5). Among nonbiopsied women, diagnostic time was shorter for navigated, 27.2 (22.8, 32.4), than nonnavigated women, 34.9 (29.2, 41.7), but not statistically significant. CONCLUSIONS: Navigated women, especially those requiring biopsy, reached their diagnostic resolution significantly faster than nonnavigated women. IMPACT: Results support previous findings of PN's positive influence on health care. PN should be a reimbursable expense to assure continuation of PN programs.

Authors

Hoffman, HJ; LaVerda, NL; Young, HA; Levine, PH; Alexander, LM; Brem, R; Caicedo, L; Eng-Wong, J; Frederick, W; Funderburk, W; Huerta, E; Swain, S; Patierno, SR

MLA Citation

Hoffman, Heather J., et al. “Patient navigation significantly reduces delays in breast cancer diagnosis in the District of Columbia..” Cancer Epidemiol Biomarkers Prev, vol. 21, no. 10, Oct. 2012, pp. 1655–63. Pubmed, doi:10.1158/1055-9965.EPI-12-0479.

PMID

23045540

Source

pubmed

Published In

Cancer Epidemiol Biomarkers Prev

Volume

21

Issue

10

Publish Date

2012

Start Page

1655

End Page

1663

DOI

10.1158/1055-9965.EPI-12-0479

BACKGROUND: Patient satisfaction (PS), a key measure of quality of cancer care, is a core study outcome of the multi-site National Cancer Institute-funded Patient Navigation Research Program. Despite large numbers of underserved monolingual Spanish speakers (MSS) residing in USA, there is no validated Spanish measure of PS that spans the whole spectrum of cancer-related care. The present study reports on the validation of the Patient Satisfaction with Cancer Care (PSCC) measure for Spanish (PSCC-Sp) speakers receiving diagnostic and therapeutic cancer-related care. METHODS: Original PSCC items were professionally translated and back translated to ensure cultural appropriateness, meaningfulness, and equivalence. Then, the resulting 18-item PSCC-Sp measure was administered to 285 MSS. We evaluated latent structure and internal consistency of the PSCC-Sp using principal components analysis (PCA) and Cronbach coefficient alpha (α). We used correlation analyses to demonstrate divergence and convergence of the PSCC-Sp with a Spanish version of the Patient Satisfaction with Interpersonal Relationship with Navigator (PSN-I-Sp) measure and patients' demographics. RESULTS: The PCA revealed a coherent set of items that explicates 47% of the variance in PS. Reliability assessment demonstrated that the PSCC-Sp had high internal consistency (α = 0.92). The PSCC-Sp demonstrated good face validity and convergent and divergent validities as indicated by moderate correlations with the PSN-I-Sp (p = 0.003) and nonsignificant correlations with marital status and household income (all p(s) > 0.05). CONCLUSION: The PSCC-Sp is a valid and reliable measure of PS and should be tested in other MSS populations.

Authors

Jean-Pierre, P; Fiscella, K; Winters, PC; Paskett, E; Wells, K; Battaglia, T; Patient Navigation Research Program Group,

MLA Citation

Jean-Pierre, Pascal, et al. “Psychometric validation and reliability analysis of a Spanish version of the patient satisfaction with cancer-related care measure: a patient navigation research program study..” Support Care Cancer, vol. 20, no. 9, Sept. 2012, pp. 1949–56. Pubmed, doi:10.1007/s00520-011-1297-3.

PMID

22038482

Source

pubmed

Published In

Support Care Cancer

Volume

20

Issue

9

Publish Date

2012

Start Page

1949

End Page

1956

DOI

10.1007/s00520-011-1297-3

Inappropriate survival signaling after DNA damage may facilitate clonal expansion of genetically compromised cells, and it is known that protein tyrosine phosphatase (PTP) inhibitors activate key survival pathways. In this study we employed the genotoxicant, hexavalent chromium [Cr(VI)], which is a well-documented carcinogen of occupational and environmental concern. Cr(VI) induces a complex array of DNA damage, including DNA double strand breaks (DSBs). We recently reported that PTP inhibition bypassed cell cycle arrest and abrogated Cr(VI)-induced clonogenic lethality. Notably, PTP inhibition resulted in an increase in forward mutations at the HPRT locus, supporting the hypothesis that PTP inhibition in the presence of DNA damage may lead to genomic instability (GIN), via cell cycle checkpoint bypass. The aim of the present study was to determine the effect of PTP inhibition on DNA DSB formation and chromosomal integrity after Cr(VI) exposure. Diploid human lung fibroblasts were treated with Cr(VI) in the presence or absence of the PTP inhibitor, sodium orthovanadate, for up to 24h, and cells were analyzed for DNA DSBs and chromosomal damage. Cr(VI) treatment induced a rapid increase in DNA DSBs, and a significant increase in total chromosomal damage (chromatid breaks and gaps) after 24h. In sharp contrast, PTP inhibition abrogated both DNA DSBs and chromosomal damage after Cr(VI) treatment. In summary, PTP inhibition in the face of Cr(VI) genotoxic stress decreases chromosomal instability (CIN) but increases mutagenesis, which we postulate to be a result of error-prone DNA repair.

Authors

Kost, GC; Patierno, SR; Wise, SS; Holmes, AL; Wise, JP; Ceryak, S

MLA Citation

Kost, Gina Chun, et al. “Protein tyrosine phosphatase (PTP) inhibition enhances chromosomal stability after genotoxic stress: decreased chromosomal instability (CIN) at the expense of enhanced genomic instability (GIN)?.” Mutat Res, vol. 735, no. 1–2, July 2012, pp. 51–55. Pubmed, doi:10.1016/j.mrfmmm.2012.05.001.

PMID

22583656

Source

pubmed

Published In

Mutation Research

Volume

735

Issue

1-2

Publish Date

2012

Start Page

51

End Page

55

DOI

10.1016/j.mrfmmm.2012.05.001

BACKGROUND: The Patient Navigation Research Program (PNRP) is a cooperative effort of nine research projects, with similar clinical criteria but with different study designs. To evaluate projects such as PNRP, it is desirable to perform a pooled analysis to increase power relative to the individual projects. There is no agreed-upon prospective methodology, however, for analyzing combined data arising from different study designs. Expert opinions were thus solicited from the members of the PNRP Design and Analysis Committee. PURPOSE: To review possible methodologies for analyzing combined data arising from heterogeneous study designs. METHODS: The Design and Analysis Committee critically reviewed the pros and cons of five potential methods for analyzing combined PNRP project data. The conclusions were based on simple consensus. The five approaches reviewed included the following: (1) analyzing and reporting each project separately, (2) combining data from all projects and performing an individual-level analysis, (3) pooling data from projects having similar study designs, (4) analyzing pooled data using a prospective meta-analytic technique, and (5) analyzing pooled data utilizing a novel simulated group-randomized design. RESULTS: Methodologies varied in their ability to incorporate data from all PNRP projects, to appropriately account for differing study designs, and to accommodate differing project sample sizes. LIMITATIONS: The conclusions reached were based on expert opinion and not derived from actual analyses performed. CONCLUSIONS: The ability to analyze pooled data arising from differing study designs may provide pertinent information to inform programmatic, budgetary, and policy perspectives. Multisite community-based research may not lend itself well to the more stringent explanatory and pragmatic standards of a randomized controlled trial design. Given our growing interest in community-based population research, the challenges inherent in the analysis of heterogeneous study design are likely to become more salient. Discussion of the analytic issues faced by the PNRP and the methodological approaches we considered may be of value to other prospective community-based research programs.

Authors

Roetzheim, RG; Freund, KM; Corle, DK; Murray, DM; Snyder, FR; Kronman, AC; Jean-Pierre, P; Raich, PC; Holden, AE; Darnell, JS; Warren-Mears, V; Patierno, S; PNRP Design and Analysis Committee for the Patient Navigation Research Program Investigators,

MLA Citation

Roetzheim, Richard G., et al. “Analysis of combined data from heterogeneous study designs: an applied example from the patient navigation research program..” Clin Trials, vol. 9, no. 2, Apr. 2012, pp. 176–87. Pubmed, doi:10.1177/1740774511433284.

PMID

22273587

Source

pubmed

Published In

Clin Trials

Volume

9

Issue

2

Publish Date

2012

Start Page

176

End Page

187

DOI

10.1177/1740774511433284

Airborne hexavalent chromate, Cr(VI), has been identified by the Environmental Protection Agency as a possible health threat in urban areas, due to the carcinogenic potential of some of its forms. Particulate chromates are produced in many different industrial settings, with high levels of aerosolized forms historically documented. Along with an increased risk of lung cancer, a high incidence of allergic asthma has been reported in workers exposed to certain inhaled particulate Cr(VI) compounds. However, a direct causal association between Cr(VI) and allergic asthma has not been established. We recently showed that inhaled particulate Cr(VI) induces an innate neutrophilic inflammatory response in BALB/c mice. In the current studies we investigated how the inflammation induced by inhaled particulate Cr(VI) might alter the pathology of an allergic asthmatic response. We used a well-established mouse model of allergic asthma. Groups of ovalbumin protein (OVA)-primed mice were challenged either with OVA alone, or with a combination of OVA and particulate zinc chromate, and various parameters associated with asthmatic responses were measured. Co-exposure to particulate Cr(VI) and OVA mediated a mixed form of asthma in which both eosinophils and neutrophils are present in airways, tissue pathology is markedly exacerbated, and airway hyperresponsiveness is significantly increased. Taken together these findings suggest that inhalation of particulate forms of Cr(VI) may augment the severity of ongoing allergic asthma, as well as alter its phenotype. Such findings may have implications for asthmatics in settings in which airborne particulate Cr(VI) compounds are present at high levels.

Authors

Schneider, BC; Constant, SL; Patierno, SR; Jurjus, RA; Ceryak, SM

MLA Citation

Schneider, Brent C., et al. “Exposure to particulate hexavalent chromium exacerbates allergic asthma pathology..” Toxicol Appl Pharmacol, vol. 259, no. 1, Feb. 2012, pp. 38–44. Pubmed, doi:10.1016/j.taap.2011.12.001.

PMID

22178736

Source

pubmed

Published In

Toxicol Appl Pharmacol

Volume

259

Issue

1

Publish Date

2012

Start Page

38

End Page

44

DOI

10.1016/j.taap.2011.12.001

Authors

Norris, L; Bretsch, J; LaMonte, S; Pratt-Chapman, M; Cowens-Alvarado, R; Sharpe, K; Patierno, S

MLA Citation

Norris, L., et al. “Addressing Gaps in the US Healthcare System to Improve Cancer Survivor Quality of Life.” Psycho Oncology, vol. 21, Feb. 2012, pp. 1–2.

Source

wos-lite

Published In

Psycho Oncology

Volume

21

Publish Date

2012

Start Page

1

End Page

2

Authors

Cannady, RS; Willis, A; Wiatrek, D; Stein, K; Cowens-Alvarado, R; Pratt-Chapman, M; Patierno, S; Sharpe, K

MLA Citation

Cannady, R. S., et al. “Understanding Cancer Survivors' Needs to Improve Quality of Life.” Psycho Oncology, vol. 21, Feb. 2012, pp. 1–1.

Source

wos-lite

Published In

Psycho Oncology

Volume

21

Publish Date

2012

Start Page

1

End Page

1

Authors

Pratt-Chapman, M; Roberts, S; Leonard, J; Cowens-Alvarado, R; Sharpe, K; Patierno, S

MLA Citation

Pratt-Chapman, M., et al. “Directing National Policy Changes to Improve Cancer Survivor Quality of Life.” Psycho Oncology, vol. 21, Feb. 2012, pp. 2–2.

Source

wos-lite

Published In

Psycho Oncology

Volume

21

Publish Date

2012

Start Page

2

End Page

2

Acquisition of death-resistance is critical in the evolution of neoplasia. Our aim was to model the early stages of carcinogenesis by examining intracellular alterations in cells that have acquired apoptosis-resistance after exposure to a complex genotoxin. We previously generated sub-populations of BJ-hTERT human diploid fibroblasts, which have acquired death-resistance following exposure to hexavalent chromium [Cr(VI)], a broad-spectrum genotoxicant. Long-term exposure to certain forms of Cr(VI) is associated with respiratory carcinogenesis. Here, we report on the death-sensitivity of subclonal populations derived from clonogenic survivors of BJ-hTERT cells treated with 5 μM Cr(VI) (DR1, DR2), or selected by dilution-based cloning without treatment (CC1). Following Cr(VI) treatment, CC1 cells downregulated expression of the anti-apoptotic protein Bcl-2 and exhibited extensive expression of cleaved caspase 3. In contrast, the DR cells exhibited no cleaved caspase 3 expression and maintained expression of Bcl-2 following recovery from 24 h Cr(VI) exposure. The DR cells also exhibited attenuated mitochondrial-membrane depolarization and mitochondrial retention of cytochrome c and SMAC/DIABLO following Cr(VI) exposure. The DR cells exhibited less basal mtDNA damage, as compared to CC1 cells, which correlates with intrinsic (non-induced) death-resistance. Notably, there was no difference in p53 protein expression before or after treatment among all cell lines. Taken together, our data suggest the presence of more resilient mitochondria in death-resistant cells, and that death-resistance can be acquired in normal human cells early after genotoxin exposure. We postulate that resistance to mitochondrial-mediated cell death and mitochondrial dysregulation may be an initial phenotypic alteration observed in early stage carcinogenesis.

Authors

Nickens, KP; Han, Y; Shandilya, H; Larrimore, A; Gerard, GF; Kaldjian, E; Patierno, SR; Ceryak, S

MLA Citation

Nickens, Kristen P., et al. “Acquisition of mitochondrial dysregulation and resistance to mitochondrial-mediated apoptosis after genotoxic insult in normal human fibroblasts: a possible model for early stage carcinogenesis..” Biochim Biophys Acta, vol. 1823, no. 2, Feb. 2012, pp. 264–72. Pubmed, doi:10.1016/j.bbamcr.2011.10.005.

PMID

22057391

Source

pubmed

Published In

Biochimica Et Biophysica Acta

Volume

1823

Issue

2

Publish Date

2012

Start Page

264

End Page

272

DOI

10.1016/j.bbamcr.2011.10.005

BACKGROUND: Delays in follow-up after breast cancer screening contribute to disparities in breast cancer outcomes. The objective of this research was to determine the impact of race/ethnicity and health insurance on diagnostic time, defined as number of days from suspicious finding to diagnostic resolution. METHODS: This retrospective cohort study of 1538 women examined for breast abnormalities between 1998-2010 at 6 hospitals/clinics in the District of Columbia measured mean diagnostic times between non-Hispanic whites (NHWs), non-Hispanic blacks (NHBs), and Hispanics with private, government, or no health insurance by using a full-factorial ANOVA model. RESULTS: Respective average--geometric mean (95% CI)--diagnostic times (in days) for NHWs, NHBs, and Hispanics were 16 (12, 21), 27 (23, 33), and 51 (35, 76) among privately insured; 12 (7, 19), 39 (32, 48), and 71 (48, 105) among government insured; 45 (17, 120), 60 (39, 92), and 67 (56, 79) among uninsured. Government insured NHWs had significantly shorter diagnostic times than government insured NHBs (P = .0003) and Hispanics (P < .0001). Privately insured NHWs had significantly shorter diagnostic times than privately insured NHBs (P = .03) and Hispanics (P < .0001). Privately insured NHBs had significantly shorter diagnostic times than uninsured NHBs (P = .03). CONCLUSIONS: Insured minorities waited >2 times longer to reach their diagnostic resolution than insured NHWs. Having private health insurance increased the speed of diagnostic resolution in NHBs; however, their diagnostic time remained significantly longer than for privately insured NHWs. These results suggest diagnostic delays in minorities are more likely caused by other barriers associated with race/ethnicity than by insurance status.

Authors

Hoffman, HJ; LaVerda, NL; Levine, PH; Young, HA; Alexander, LM; Patierno, SR; District of Columbia Citywide Patient Navigator Research Program Research Group,

MLA Citation

Hoffman, Heather J., et al. “Having health insurance does not eliminate race/ethnicity-associated delays in breast cancer diagnosis in the District of Columbia..” Cancer, vol. 117, no. 16, Aug. 2011, pp. 3824–32. Pubmed, doi:10.1002/cncr.25970.

PMID

21815134

Source

pubmed

Published In

Cancer

Volume

117

Issue

16

Publish Date

2011

Start Page

3824

End Page

3832

DOI

10.1002/cncr.25970

Survivorship navigation is a relatively new concept in the field of patient navigation but an important one. This article highlights the essential functions of the survivorship navigator and defines core outcomes and measures for navigation in the survivorship period. Barriers to access to care experienced by patients during active cancer treatment can continue into the post-treatment period, affecting quality follow-up care for survivors. These barriers to care can be particularly acute for non-English speakers, immigrants, the uninsured, the underinsured, and other vulnerable populations. The survivorship navigator can help reduce barriers and facilitate access to survivorship care and services through communication and information exchange for patients. Survivorship navigation may improve appropriate health care utilization through education and care coordination, potentially improving health outcomes and quality of life of survivors while reducing cost to the health care system. Survivorship navigators can also educate survivors on how to improve their overall wellness, thereby directly impacting the health of a growing population of cancer survivors.

Authors

Pratt-Chapman, M; Simon, MA; Patterson, AK; Risendal, BC; Patierno, S

MLA Citation

Pratt-Chapman, Mandi, et al. “Survivorship navigation outcome measures: a report from the ACS patient navigation working group on survivorship navigation..” Cancer, vol. 117, no. 15 Suppl, Aug. 2011, pp. 3575–84. Pubmed, doi:10.1002/cncr.26261.

PMID

21780092

Source

pubmed

Published In

Cancer

Volume

117

Issue

15 Suppl

Publish Date

2011

Start Page

3575

End Page

3584

DOI

10.1002/cncr.26261

BACKGROUND: Patient satisfaction is an important outcome measure of quality of cancer care and 1 of the 4 core study outcomes of the National Cancer Institute (NCI)-sponsored Patient Navigation Research Program to reduce race/ethnicity-based disparities in cancer care. There is no existing patient satisfaction measure that spans the spectrum of cancer-related care. The objective of this study was to develop a Patient Satisfaction With Cancer Care measure that is relevant to patients receiving diagnostic/therapeutic cancer-related care. METHODS: The authors developed a conceptual framework, an operational definition of Patient Satisfaction With Cancer Care, and an item pool based on literature review, expert feedback, group discussion, and consensus. The 35-item Patient Satisfaction With Cancer Care measure was administered to 891 participants from the multisite NCI-sponsored Patient Navigation Research Program. Principal components analysis (PCA) was conducted for latent structure analysis. Internal consistency was assessed using Cronbach coefficient alpha (α). Divergent analysis was performed using correlation analyses between the Patient Satisfaction With Cancer Care, the Communication and Attitudinal Self-Efficacy-Cancer, and demographic variables. RESULTS: The PCA revealed a 1-dimensional measure with items forming a coherent set explaining 62% of the variance in patient satisfaction. Reliability assessment revealed high internal consistency (α ranging from 0.95 to 0.96). The Patient Satisfaction With Cancer Care demonstrated good face validity, convergent validity, and divergent validity, as indicated by moderate correlations with subscales of the Communication and Attitudinal Self-Efficacy-Cancer (all P < .01) and nonsignificant correlations with age, primary language, marital status, and scores on the Rapid Estimate of Adult Literacy in Medicine Long Form (all P > .05). CONCLUSIONS: The Patient Satisfaction With Cancer Care is a valid tool for assessing satisfaction with cancer-related care for this sample.

Authors

Jean-Pierre, P; Fiscella, K; Freund, KM; Clark, J; Darnell, J; Holden, A; Post, D; Patierno, SR; Winters, PC; Patient Navigation Research Program Group,

MLA Citation

Jean-Pierre, Pascal, et al. “Structural and reliability analysis of a patient satisfaction with cancer-related care measure: a multisite patient navigation research program study..” Cancer, vol. 117, no. 4, Feb. 2011, pp. 854–61. Pubmed, doi:10.1002/cncr.25501.

PMID

20922802

Source

pubmed

Published In

Cancer

Volume

117

Issue

4

Publish Date

2011

Start Page

854

End Page

861

DOI

10.1002/cncr.25501

Certain forms of hexavalent chromium [Cr(VI)] are known respiratory carcinogens that induce a broad spectrum of DNA damage. Cr(VI)-carcinogenesis may be initiated or promoted through several mechanistic processes including, the intracellular metabolic reduction of Cr(VI) producing chromium species capable of interacting with DNA to yield genotoxic and mutagenic effects, Cr(VI)-induced inflammatory/immunological responses, and alteration of survival signaling pathways. Cr(VI) enters the cell through non-specific anion channels, and is metabolically reduced by agents including ascorbate, glutathione, and cysteine to Cr(V), Cr(IV), and Cr(III). Cr(III) has a weak membrane permeability capacity and is unable to cross the cell membrane, thereby trapping it within the cell where it can bind to DNA and produce genetic damage leading to genomic instability. Structural genetic lesions produced by the intracellular reduction of Cr(VI) include DNA adducts, DNA-strand breaks, DNA-protein crosslinks, oxidized bases, abasic sites, and DNA inter- and intrastrand crosslinks. The damage induced by Cr(VI) can lead to dysfunctional DNA replication and transcription, aberrant cell cycle checkpoints, dysregulated DNA repair mechanisms, microsatelite instability, inflammatory responses, and the disruption of key regulatory gene networks responsible for the balance of cell survival and cell death, which may all play an important role in Cr(VI) carcinogenesis. Several lines of evidence have indicated that neoplastic progression is a result of consecutive genetic/epigenetic changes that provide cellular survival advantages, and ultimately lead to the conversion of normal human cells to malignant cancer cells. This review is based on studies that provide a glimpse into Cr(VI) carcinogenicity via mechanisms including Cr(VI)-induced death-resistance, the involvement of DNA repair mechanisms in survival after chromium exposure, and the activation of survival signaling cascades in response to Cr(VI) genotoxicity.

Authors

Nickens, KP; Patierno, SR; Ceryak, S

MLA Citation

Nickens, Kristen P., et al. “Chromium genotoxicity: A double-edged sword..” Chem Biol Interact, vol. 188, no. 2, Nov. 2010, pp. 276–88. Pubmed, doi:10.1016/j.cbi.2010.04.018.

PMID

20430016

Source

pubmed

Published In

Chem Biol Interact

Volume

188

Issue

2

Publish Date

2010

Start Page

276

End Page

288

DOI

10.1016/j.cbi.2010.04.018

PURPOSE: Aberrant DNA methylation changes are common somatic alterations in prostate carcinogenesis. We examined the methylation status of six genes in prostate tissue specimens from African American (AA) and Caucasian (Cau) males. EXPERIMENTAL DESIGN: We used pyrosequencing to quantitatively measure the methylation status of GSTP1, AR, RARbeta2, SPARC, TIMP3, and NKX2-5. Real-time PCR was used to determine gene expression, and gene reactivation was analyzed by 5-aza-2'-deoxycytidine and/or trichostatin A treatment. RESULTS: Statistical analysis showed significantly higher methylation in the prostate cancer tissue samples in comparison with matched normal samples for GSTP1 (P = 0.0001 for AA; P = 0.0008 for Cau), RARbeta2 (P < 0.001 for AA and Cau), SPARC (P < 0.0001 for AA and Cau), TIMP3 (P < 0.0001 for AA and Cau), and NKX2-5 (P < 0.0001 for AA; P = 0.003 for Cau). Overall, we observed significant differences (P < 0.05) in the methylation level for all genes, except GSTP1, in the AA samples in comparison with the Cau samples. Furthermore, regression analysis revealed significantly higher methylation for NKX2-5 (P = 0.008) and TIMP3 (P = 0.039) in normal prostate tissue samples from AA in comparison with Cau, and a statistically significant association of methylation with age for NKX2-5 (P = 0.03) after adjusting for race. CONCLUSION: Our findings show higher methylation of several genes in prostate tissue samples from AA in comparison with Cau and may potentially contribute to the racial differences that are observed in prostate cancer pathogenesis.

Authors

Kwabi-Addo, B; Wang, S; Chung, W; Jelinek, J; Patierno, SR; Wang, B-D; Andrawis, R; Lee, NH; Apprey, V; Issa, J-P; Ittmann, M

MLA Citation

Kwabi-Addo, Bernard, et al. “Identification of differentially methylated genes in normal prostate tissues from African American and Caucasian men..” Clin Cancer Res, vol. 16, no. 14, July 2010, pp. 3539–47. Pubmed, doi:10.1158/1078-0432.CCR-09-3342.

PMID

20606036

Source

pubmed

Published In

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research

Volume

16

Issue

14

Publish Date

2010

Start Page

3539

End Page

3547

DOI

10.1158/1078-0432.CCR-09-3342

Polo-like kinase 1 (Plk1) is a key regulator of mitosis. Aberrant Plk1 activity is found in tumors, but little is known regarding its role in the DNA damage response of normal cells and its potential contribution to the early stages of carcinogenesis. Inappropriate survival signaling after DNA damage may facilitate clonal expansion of genetically compromised cells, and it is known that protein tyrosine phosphatase (PTP) inhibitors activate key survival pathways. In this study, we employed hexavalent chromium [Cr(VI)], a well-documented genotoxicant, to investigate the mechanism by which survival pathway activation could lead to loss of checkpoint control via a mechanism involving Plk1. We recently reported that PTP inhibition enhances clonogenic survival and mutagenesis after Cr(VI) exposure by overriding Cr-induced growth arrest. Here, we report that checkpoint bypass, facilitated by PTP inhibition, was associated with decreased Cdk1 Tyr15 phosphorylation, as well as increased Plk1 activity and nuclear localization. Plk1 was necessary for increased survival after PTP inhibition and Cr(VI) exposure in normal human fibroblasts via enhanced mitotic progression. In addition, pharmacological inhibition of Plk1 abolished the PTP inhibitor-induced bypass of the G(2)/M checkpoint. Notably, Plk1 overexpression increased survival and mutagenesis after Cr(VI) exposure in wild-type Saccharomyces cerevisiae. Taken together, our data indicate that Plk1 activation and nuclear localization are necessary for PTP-regulated mitotic progression after DNA damage. Our studies highlight a role for Plk1 in the loss of checkpoint control, increased survival and mutagenesis after genotoxic exposure in normal cells, which in turn may lead to genomic instability and carcinogenesis.

Authors

Chun, G; Bae, D; Nickens, K; O'Brien, TJ; Patierno, SR; Ceryak, S

MLA Citation

Chun, Gina, et al. “Polo-like kinase 1 enhances survival and mutagenesis after genotoxic stress in normal cells through cell cycle checkpoint bypass..” Carcinogenesis, vol. 31, no. 5, May 2010, pp. 785–93. Pubmed, doi:10.1093/carcin/bgq014.

PMID

20089605

Source

pubmed

Published In

Carcinogenesis

Volume

31

Issue

5

Publish Date

2010

Start Page

785

End Page

793

DOI

10.1093/carcin/bgq014

BACKGROUND: Diminished expression or activity of prostate apoptosis response protein 4 (Par-4) has been demonstrated in a number of cancers, although reports on Par-4 expression during colon cancer progression are lacking. An understanding of the molecular events in conjunction with the genetic networks affected by Par-4 is warranted. RESULTS: Colon cancer specimens derived from patients have significantly diminished expression of Par-4 mRNA relative to paired normal colon. Hence, the functional consequences of reintroducing Par-4 into HT29 colon cancer cells were assessed. Overexpression augmented the interaction of Par-4 with NF kappaB in the cytosol but not nucleus, and facilitated apoptosis in the presence of 5-fluorouracil (5-FU). Analogous findings were obtained when AKT1 pro-survival signaling was inhibited. Transcriptome profiling identified approximately 700 genes differentially regulated by Par-4 overexpression in HT29 cells. Nearly all Par-4-regulated genes were shown by promoter analysis to contain cis-binding sequences for NF kappaB, and meta-analysis of patient expression data revealed that one-third of these genes exist as a recurrent co-regulated network in colon cancer specimens. Sets of genes involved in programmed cell death, cell cycle regulation and interestingly the microRNA pathway were found overrepresented in the network. Noteworthy, Par-4 overexpression decreased NF kappaB occupancy at the promoter of one particular network gene DROSHA, encoding a microRNA processing enzyme. The resulting down-regulation of DROSHA was associated with expression changes in a cohort of microRNAs. Many of these microRNAs are predicted to target mRNAs encoding proteins with apoptosis-related functions. Western and functional analyses were employed to validate several predictions. For instance, miR-34a up-regulation corresponded with a down-regulation of BCL2 protein. Treating Par-4-overexpressing HT29 cells with a miR-34a antagomir functionally reversed both BCL2 down-regulation and apoptosis by 5-FU. Conversely, bypassing Par-4 overexpression by direct knockdown of DROSHA expression in native HT29 cells increased miR-34a expression and 5-FU sensitivity. CONCLUSION: Our findings suggest that the initiation of apoptotic sensitivity in colon cancer cells can be mediated by Par-4 binding to NF kappaB in the cytoplasm with consequential changes in the expression of microRNA pathway components.

Authors

Wang, B-D; Kline, CLB; Pastor, DM; Olson, TL; Frank, B; Luu, T; Sharma, AK; Robertson, G; Weirauch, MT; Patierno, SR; Stuart, JM; Irby, RB; Lee, NH

MLA Citation

Wang, Bi-Dar, et al. “Prostate apoptosis response protein 4 sensitizes human colon cancer cells to chemotherapeutic 5-FU through mediation of an NF kappaB and microRNA network..” Mol Cancer, vol. 9, Apr. 2010. Pubmed, doi:10.1186/1476-4598-9-98.

PMID

20433755

Source

pubmed

Published In

Molecular Cancer

Volume

9

Publish Date

2010

Start Page

98

DOI

10.1186/1476-4598-9-98

BACKGROUND: Chronic inflammation is implicated in the development of several human cancers, including lung cancer. Certain particulate hexavalent chromium [Cr(VI)] compounds are well-documented human respiratory carcinogens that release genotoxic soluble chromate and are associated with fibrosis, fibrosarcomas, adenocarcinomas, and squamous cell carcinomas of the lung. Despite this, little is known about the pathologic injury and immune responses after repetitive exposure to particulate chromates. OBJECTIVES: In this study we investigated the lung injury, inflammation, proliferation, and survival signaling responses after repetitive exposure to particulate chromate. METHODS: BALB/c mice were repetitively treated with particulate basic zinc chromate or saline using an intranasal exposure regimen. We assessed lungs for Cr(VI)-induced changes by bronchoalveolar lavage, histologic examination, and immunohistochemistry. RESULTS: Single exposure to Cr(VI) resulted in inflammation of lung tissue that persists for up to 21 days. Repetitive Cr(VI) exposure induced a neutrophilic inflammatory airway response 24 hr after each treatment. Neutrophils were subsequently replaced by increasing numbers of macrophages by 5 days after treatment. Repetitive Cr(VI) exposure induced chronic peribronchial inflammation with alveolar and interstitial pneumonitis dominated by lymphocytes and macrophages. Moreover, chronic toxic mucosal injury was observed and accompanied by increased airway pro-matrix metalloprotease-9. Injury and inflammation correlated with airways becoming immunoreactive for phosphorylation of the survival signaling protein Akt and the proliferation marker Ki-67. We observed a reactive proliferative response in epithelial cells lining airways of chromate-exposed animals. CONCLUSIONS: These data illustrate that repetitive exposure to particulate chromate induces chronic injury and an inflammatory microenvironment that may promote Cr(VI) carcinogenesis.

Authors

Beaver, LM; Stemmy, EJ; Schwartz, AM; Damsker, JM; Constant, SL; Ceryak, SM; Patierno, SR

MLA Citation

Beaver, Laura M., et al. “Lung inflammation, injury, and proliferative response after repetitive particulate hexavalent chromium exposure..” Environ Health Perspect, vol. 117, no. 12, Dec. 2009, pp. 1896–902. Pubmed, doi:10.1289/ehp.0900715.

PMID

20049209

Source

pubmed

Published In

Environ Health Perspect

Volume

117

Issue

12

Publish Date

2009

Start Page

1896

End Page

1902

DOI

10.1289/ehp.0900715

OBJECTIVES: The Sexual Health Inventory for Men (SHIM) is a widely used scale for the screening and diagnosis of erectile dysfunction (ED). Our objective was to incorporate the SHIM into our prostate cancer screening program to estimate the prevalence of ED among men screened for prostate cancer. METHODS: During September 2006, men younger than 75 years of age living in the Washington, DC area were invited to participate in the George Washington University Prostate Cancer Screening Program. The SHIM questionnaire was administered to all participants. Information regarding primary care physician use, phosphodiesterase-5 inhibitor use, serum prostate-specific antigen levels, and digital rectal examination findings was also obtained. Those who registered SHIM scores of 17 or less or who were taking a phosphodiesterase-5 inhibitor were considered to have ED. RESULTS: Overall, 333 men attended the program. Of the 328 men, 123 (37.5%) met our definition of ED; 30 (9%) were using a phosphodiesterase-5 inhibitor and 93 (28%) had an SHIM score of 17 or less. Univariate analysis suggested a significant difference in the prevalence of ED between African-American men and non-African-American men, with 25% and 41%, respectively, found to have a SHIM score of 17 or less (P < .01); however, this difference was not significant once we controlled for age (P > .05). Among our participants, 33% lacked a primary care physician. Of these, 22% had a SHIM score of 17 or less. CONCLUSIONS: The results of our study have shown that ED increases in a nonlinear fashion with age, consistent with the findings of previous reports. Of greater concern, however, given the strong association between ED and cardiovascular disease, was the number of those with ED who lacked a primary care physician.

Authors

Bianco, FJ; McHone, BR; Wagner, K; King, A; Burgess, J; Patierno, S; Jarrett, TW

MLA Citation

Bianco, Fernando J., et al. “Prevalence of erectile dysfunction in men screened for prostate cancer..” Urology, vol. 74, no. 1, July 2009, pp. 89–93. Pubmed, doi:10.1016/j.urology.2008.03.036.

PMID

19428072

Source

pubmed

Published In

Urology

Volume

74

Issue

1

Publish Date

2009

Start Page

89

End Page

93

DOI

10.1016/j.urology.2008.03.036

Certain forms of hexavalent chromium [Cr(VI)] are human carcinogens. Our recent work has shown that a broad range protein tyrosine phosphatase (PTP) inhibitor, sodium orthovanadate (SOV), abrogated both Cr(VI)-induced growth arrest and clonogenic lethality. Notably, SOV enhanced Cr(VI) mutation frequency, ostensibly through forced survival of genetically damaged cells. In the present study, co-treatment with this PTP inhibitor bypassed the Cr(VI)-induced G(1)/S checkpoint arrest in diploid human lung fibroblasts (HLF). Moreover, the PTP inhibitor abrogated the Cr(VI)-induced decrease in the expression of key effectors of the G(1)/S checkpoint [Cyclin D1, phospho Ser 807/811 Rb (pRB), p27]. Cr(VI)-induced G(1) arrest was associated with the cytoplasmic appearance of pRb and the nuclear localization of p27, both of which were reversed by the PTP inhibitor. The PTP inhibitor's reversal of G(1)/S checkpoint effector localization after Cr exposure was found to be Akt1-dependent, as this was abrogated by transfection with either akt1 siRNA or an Akt1-kinase dead plasmid. Furthermore, Akt1 activation alone was sufficient to induce G(1)/S checkpoint bypass and to prevent Cr(VI)-induced changes in pRb and p27 localization. In conclusion, this work establishes Akt1 activation to be both sufficient to bypass the Cr(VI)-induced G(1)/S checkpoint, as well as necessary for the observed PTP inhibitor effects on key mediators of the G(1)/S transition. The potential for Akt to bypass G(1)/S checkpoint arrest in the face of genotoxic damage could increase genomic instability, which is a hallmark of neoplastic progression.

Authors

Lal, MA; Bae, D; Camilli, TC; Patierno, SR; Ceryak, S

MLA Citation

Lal, Madhu A., et al. “AKT1 mediates bypass of the G1/S checkpoint after genotoxic stress in normal human cells..” Cell Cycle, vol. 8, no. 10, May 2009, pp. 1589–602. Pubmed, doi:10.4161/cc.8.10.8547.

PMID

19377290

Source

pubmed

Published In

Cell Cycle

Volume

8

Issue

10

Publish Date

2009

Start Page

1589

End Page

1602

DOI

10.4161/cc.8.10.8547

Translesion synthesis (TLS) is a unique DNA damage tolerance mechanism involved in the replicative bypass of genetic lesions in favor of uninterrupted DNA replication. TLS is critical for the generation of mutations by many different chemical and physical agents, however, there is no information available regarding the role of TLS in carcinogenic metal-induced mutagenesis. Hexavalent chromium (Cr(VI))-containing compounds are highly complex genotoxins possessing both mutagenic and clastogenic activities. The focus of this work was to determine the impact that TLS has on Cr(VI)-induced mutagenesis in Saccharomyces cerevisiae. Wild-type yeast and strains deficient in TLS polymerases (i.e. Polzeta (rev3), Poleta (rad30)) were exposed to Cr(VI) and monitored for cell survival and forward mutagenesis at the CAN1 locus. In general, TLS deficiency had little impact on Cr(VI)-induced clonogenic lethality or cell growth. rad30 yeast exhibited higher levels of basal and induced mutagenesis compared to Wt and rev3 yeast. In contrast, rev3 yeast displayed attenuated Cr(VI)-induced mutagenesis. Moreover, deletion of REV3 in rad30 yeast (rad30 rev3) resulted in a significant decrease in basal and Cr(VI) mutagenesis relative to Wt and rad30 single mutants indicating that mutagenesis primarily depended upon Polzeta. Interestingly, rev3 yeast were similar to Wt yeast in susceptibility to Cr(VI)-induced frameshift mutations. Mutational analysis of the CAN1 gene revealed that Cr(VI)-induced base substitution mutations accounted for 83.9% and 100.0% of the total mutations in Wt and rev3 yeast, respectively. Insertions and deletions comprised 16.1% of the total mutations in Cr(VI) treated Wt yeast but were not observed rev3 yeast. This work provides novel information regarding the molecular mechanisms of Cr(VI)-induced mutagenesis and is the first report demonstrating a role for TLS in the fixation of mutations induced by a carcinogenic metal.

Authors

O'Brien, TJ; Witcher, P; Brooks, B; Patierno, SR

MLA Citation

O’Brien, Travis J., et al. “DNA polymerase zeta is essential for hexavalent chromium-induced mutagenesis..” Mutat Res, vol. 663, no. 1–2, Apr. 2009, pp. 77–83. Pubmed, doi:10.1016/j.mrfmmm.2009.01.012.

PMID

19428373

Source

pubmed

Published In

Mutation Research

Volume

663

Issue

1-2

Publish Date

2009

Start Page

77

End Page

83

DOI

10.1016/j.mrfmmm.2009.01.012

Certain particulate hexavalent chromium [Cr(VI)] compounds are human respiratory carcinogens that release genotoxic soluble chromate, and are associated with fibrosis, fibrosarcomas, adenocarcinomas and squamous cell carcinomas of the lung. We postulate that inflammatory processes and mediators may contribute to the etiology of Cr(VI) carcinogenesis, however the immediate (0-24 h) pathologic injury and immune responses after exposure to particulate chromates have not been adequately investigated. Our aim was to determine the nature of the lung injury, inflammatory response, and survival signaling responses following intranasal exposure of BALB/c mice to particulate basic zinc chromate. Factors associated with lung injury, inflammation and survival signaling were measured in airway lavage fluid and in lung tissue. A single chromate exposure induced an acute immune response in the lung, characterized by a rapid and significant increase in IL-6 and GRO-alpha levels, an influx of neutrophils, and a decline in macrophages in lung airways. Histological examination of lung tissue in animals challenged with a single chromate exposure revealed an increase in bronchiolar cell apoptosis and mucosal injury. Furthermore, chromate exposure induced injury and inflammation that progressed to alveolar and interstitial pneumonitis. Finally, a single Cr(VI) challenge resulted in a rapid and persistent increase in the number of airways immunoreactive for phosphorylation of the survival signaling protein Akt, on serine 473. These data illustrate that chromate induces both survival signaling and an inflammatory response in the lung, which we postulate may contribute to early oncogenesis.

Authors

Beaver, LM; Stemmy, EJ; Constant, SL; Schwartz, A; Little, LG; Gigley, JP; Chun, G; Sugden, KD; Ceryak, SM; Patierno, SR

MLA Citation

Beaver, Laura M., et al. “Lung injury, inflammation and Akt signaling following inhalation of particulate hexavalent chromium..” Toxicol Appl Pharmacol, vol. 235, no. 1, Feb. 2009, pp. 47–56. Pubmed, doi:10.1016/j.taap.2008.11.018.

PMID

19109987

Source

pubmed

Published In

Toxicol Appl Pharmacol

Volume

235

Issue

1

Publish Date

2009

Start Page

47

End Page

56

DOI

10.1016/j.taap.2008.11.018

Although the consequences of genotoxic injury include cell cycle arrest and apoptosis, cell survival responses after genotoxic injury can produce intrinsic death-resistance and contribute to the development of a transformed phenotype. Protein tyrosine phosphatases (PTPs) are integral components of key survival pathways, and are responsible for their inactivation, while PTP inhibition is often associated with enhanced cell proliferation. Our aim was to elucidate signaling events that modulate cell survival after genotoxin exposure. Diploid human lung fibroblasts (HLF) were treated with Cr(VI) (as Na(2)CrO(4)), the soluble oxyanionic dissolution product of certain particulate chromates, which are well-documented human respiratory carcinogens. In vitro soluble Cr(VI) induces a wide spectrum of DNA damage, in both the presence and absence of a broad-range PTP inhibitor, sodium orthovanadate (SOV). Notably, SOV abrogated Cr(VI)-induced clonogenic lethality. The enhanced survival of Cr(VI)-exposed cells after SOV treatment was predominantly due to a bypass of cell cycle arrest, as there was no effect of the PTP inhibitor on Cr-induced apoptosis. Moreover, the SOV effect was not due to decreased Cr uptake as evidenced by unchanged Cr-DNA adduct burden. Additionally, the bypass of Cr-induced growth arrest by SOV was accompanied by a decrease in Cr(VI)-induced expression of cell cycle inhibiting genes, and an increase in Cr(VI)-induced expression of cell cycle promoting genes. Importantly, SOV resulted in an increase in forward mutations at the HPRT locus, supporting the hypothesis that PTP inhibition in the presence of certain types of DNA damage may lead to increased genomic instability, via bypass of cell cycle checkpoints.

Authors

Bae, D; Camilli, TC; Chun, G; Lal, M; Wright, K; O'Brien, TJ; Patierno, SR; Ceryak, S

MLA Citation

Bae, Dongsoon, et al. “Bypass of hexavalent chromium-induced growth arrest by a protein tyrosine phosphatase inhibitor: enhanced survival and mutagenesis..” Mutat Res, vol. 660, no. 1–2, Jan. 2009, pp. 40–46. Pubmed, doi:10.1016/j.mrfmmm.2008.10.006.

PMID

19013184

Source

pubmed

Published In

Mutation Research

Volume

660

Issue

1-2

Publish Date

2009

Start Page

40

End Page

46

DOI

10.1016/j.mrfmmm.2008.10.006

BACKGROUND: Patient, provider, and systems barriers contribute to delays in cancer care, a lower quality of care, and poorer outcomes in vulnerable populations, including low-income, underinsured, and racial/ethnic minority populations. Patient navigation is emerging as an intervention to address this problem, but navigation requires a clear definition and a rigorous testing of its effectiveness. Pilot programs have provided some evidence of benefit, but have been limited by evaluation of single-site interventions and varying definitions of navigation. To overcome these limitations, a 9-site National Cancer Institute Patient Navigation Research Program (PNRP) was initiated. METHODS: The PNRP is charged with designing, implementing, and evaluating a generalizable patient navigation program targeting vulnerable populations. Through a formal committee structure, the PNRP has developed a definition of patient navigation and metrics to assess the process and outcomes of patient navigation in diverse settings, compared with concurrent continuous control groups. RESULTS: The PNRP defines patient navigation as support and guidance offered to vulnerable persons with abnormal cancer screening or a cancer diagnosis, with the goal of overcoming barriers to timely, quality care. Primary outcomes of the PNRP are 1) time to diagnostic resolution; 2) time to initiation of cancer treatment; 3) patient satisfaction with care; and 4) cost effectiveness, for breast, cervical, colon/rectum, and/or prostate cancer. CONCLUSIONS: The metrics to assess the processes and outcomes of patient navigation have been developed for the NCI-sponsored PNRP. If the metrics are found to be valid and reliable, they may prove useful to other investigators.

Authors

Freund, KM; Battaglia, TA; Calhoun, E; Dudley, DJ; Fiscella, K; Paskett, E; Raich, PC; Roetzheim, RG; Patient Navigation Research Program Group,

MLA Citation

Freund, Karen M., et al. “National Cancer Institute Patient Navigation Research Program: methods, protocol, and measures..” Cancer, vol. 113, no. 12, Dec. 2008, pp. 3391–99. Pubmed, doi:10.1002/cncr.23960.

PMID

18951521

Source

pubmed

Published In

Cancer

Volume

113

Issue

12

Publish Date

2008

Start Page

3391

End Page

3399

DOI

10.1002/cncr.23960

Certain hexavalent chromium [Cr(VI)] compounds are human lung carcinogens. Although much is known about Cr-induced DNA damage, very little is known about mechanisms of Cr(VI) mutagenesis and the role that DNA repair plays in this process. Our goal was to investigate the role of excision repair (ER) pathways in Cr(VI)-mediated mutagenesis in mammalian cells. Repair-proficient Chinese hamster ovary cells (AA8), nucleotide excision repair (NER)-deficient (UV-5) and base excision repair (BER)-inhibited cells were treated with Cr(VI) and monitored for forward mutation frequency at the hypoxanthine-guanine phosphoribosyltransferase (HPRT) locus. BER was inhibited using methoxyamine hydrochloride (Mx), which binds to apurinic/apyrimidinic sites generated during BER. Notably, we found that both NER-deficient (UV-5 and UV-41) and BER-inhibited (AA8 + Mx) cells displayed attenuated Cr(VI) mutagenesis. To determine whether this was unique to Cr(VI), we included the alkylating agent, methylmethane sulfonate (MMS) and ultraviolet (UV) radiation (260 nm) in our studies. Similar to Cr(VI), UV-5 cells exhibited a marked attenuation of MMS mutagenesis, but were hypermutagenic following UV exposure. Moreover, UV-5 cells expressing human xeroderma pigmentosum complementation group D displayed similar sensitivity to Cr(VI) and MMS-induced mutagenesis as AA8 controls, indicating that the genetic loss of NER was responsible for attenuated mutagenesis. Interestingly, Cr(VI)-induced clastogenesis was also attenuated in NER-deficient and BER-inhibited cells. Taken together, our results suggest that NER and BER are required for Cr(VI) and MMS-induced genomic instability. We postulate that, in the absence of ER, DNA damage is channeled into an error-free system of DNA repair or damage tolerance.

Authors

Brooks, B; O'Brien, TJ; Ceryak, S; Wise, JP; Wise, SS; Defabo, E; Patierno, SR

MLA Citation

Brooks, Bradford, et al. “Excision repair is required for genotoxin-induced mutagenesis in mammalian cells..” Carcinogenesis, vol. 29, no. 5, May 2008, pp. 1064–69. Pubmed, doi:10.1093/carcin/bgn058.

PMID

18332048

Source

pubmed

Published In

Carcinogenesis

Volume

29

Issue

5

Publish Date

2008

Start Page

1064

End Page

1069

DOI

10.1093/carcin/bgn058

Fanconi anemia (FA) is a rare autosomal recessive disorder characterized by congenital abnormalities, progressive bone marrow failure, and cancer susceptibility. FA cells are hypersensitive to DNA crosslinking agents. FA is a genetically heterogeneous disease with at least 11 complementation groups. The eight cloned FA proteins interact in a common pathway with established DNA-damage-response proteins, including BRCA1 and ATM. Six FA proteins (A, C, E, F, G, and L) regulate the monoubiquitination of FANCD2 after DNA damage by crosslinking agents, which targets FANCD2 to BRCA1 nuclear foci containing BRCA2 (FANCD1) and RAD51. Some forms of hexavalent chromium [Cr(VI)] are implicated as respiratory carcinogens and induce several types of DNA lesions, including DNA interstrand crosslinks. We have shown that FA-A fibroblasts are hypersensitive to both Cr(VI)-induced apoptosis and clonogenic lethality. Here we show that Cr(VI) treatment induced monoubiquitination of FANCD2 in normal human fibroblasts, providing the first molecular evidence of Cr(VI)-induced activation of the FA pathway. FA-A fibroblasts demonstrated no FANCD2 monoubiquitination, in keeping with the requirement of FA-A for this modification. We also found that Cr(VI) treatment induced significantly more S-phase-dependent DNA double strand breaks (DSBs), as measured by gamma-H2AX expression, in FA-A fibroblasts compared to normal cells. However, and notably, DSBs were repaired equally in both normal and FA-A fibroblasts during recovery from Cr(VI) treatment. While previous research on FA has defined the genetic causes of this disease, it is critical in terms of individual risk assessment to address how cells from FA patients respond to genotoxic insult.

Authors

Vilcheck, SK; Ceryak, S; O'Brien, TJ; Patierno, SR

MLA Citation

Vilcheck, Susan K., et al. “FANCD2 monoubiquitination and activation by hexavalent chromium [Cr(VI)] exposure: activation is not required for repair of Cr(VI)-induced DSBs..” Mutat Res, vol. 610, no. 1–2, Nov. 2006, pp. 21–30. Pubmed, doi:10.1016/j.mrgentox.2006.06.009.

PMID

16893675

Source

pubmed

Published In

Mutation Research

Volume

610

Issue

1-2

Publish Date

2006

Start Page

21

End Page

30

DOI

10.1016/j.mrgentox.2006.06.009

Some hexavalent chromium [Cr(VI)]-containing compounds are lung carcinogens. Once within cells, Cr(VI) is reduced to trivalent chromium [Cr(III)] which displays an affinity for both DNA bases and the phosphate backbone. A diverse array of genetic lesions is produced by Cr including Cr-DNA monoadducts, DNA interstrand crosslinks (ICLs), DNA-Cr-protein crosslinks (DPCs), abasic sites, DNA strand breaks and oxidized bases. Despite the large amount of information available on the genotoxicity of Cr, little is known regarding the molecular mechanisms involved in the removal of these lesions from damaged DNA. Recent work indicates that nucleotide excision repair (NER) is involved in the processing of Cr-DNA adducts in human and rodent cells. In order to better understand this process at the molecular level and begin to identify the Cr-DNA adducts processed by NER, the incision of CrCl(3) [Cr(III)]-damaged plasmid DNA was studied using a thermal-resistant UvrABC NER endonuclease from Bacillus caldotenax (Bca). Treatment of plasmid DNA with Cr(III) (as CrCl(3)) increased DNA binding as a function of dose. For example, at a Cr(III) concentration of 1 microM we observed approximately 2 Cr(III)-DNA adducts per plasmid. At this same concentration of Cr(III) we found that approximately 17% of the plasmid DNA contained ICLs ( approximately 0.2 ICLs/plasmid). When plasmid DNA treated with Cr(III) (1 microM) was incubated with Bca UvrABC we observed approximately 0.8 incisions/plasmid. The formation of endonuclease IV-sensitive abasic lesions or Fpg-sensitive oxidized DNA bases was not detected suggesting that the incision of Cr(III)-damaged plasmid DNA by UvrABC was not related to the generation of oxidized DNA damage. Taken together, our data suggest that a sub-fraction of Cr(III)-DNA adducts is recognized and processed by the prokaryotic NER machinery and that ICLs are not necessarily the sole lesions generated by Cr(III) that are substrates for NER.

Authors

O'Brien, TJ; Jiang, G; Chun, G; Mandel, HG; Westphal, CS; Kahen, K; Montaser, A; States, JC; Patierno, SR

MLA Citation

O’Brien, Travis J., et al. “Incision of trivalent chromium [Cr(III)]-induced DNA damage by Bacillus caldotenax UvrABC endonuclease..” Mutat Res, vol. 610, no. 1–2, Nov. 2006, pp. 85–92. Pubmed, doi:10.1016/j.mrgentox.2006.06.015.

PMID

16890479

Source

pubmed

Published In

Mutation Research

Volume

610

Issue

1-2

Publish Date

2006

Start Page

85

End Page

92

DOI

10.1016/j.mrgentox.2006.06.015

The metabolic reduction of hexavalent chromium [Cr(VI)] in the presence of DNA generates several lesions which impede DNA replication and gene transcription. However, the relative contribution of molecular oxygen to Cr-induced genetic damage is unclear. To elucidate the role of dioxygen in Cr genotoxicity, we studied the formation of Cr-induced lesions in DNA treated with either Cr(VI) and the physiological reductant, ascorbic acid (Asc), or Cr(III), under ambient and hypoxic (<1% oxygen) conditions. We found that hypoxia did not impede the reduction of Cr(VI) by Asc throughout a 2 h treatment. In contrast, Cr-DNA binding under these conditions was reduced up to 70% by hypoxia, and a 50-90% decrease in the frequency of Cr-induced Taq polymerase-arresting DNA adducts was also observed. In the presence of Cr(VI)/Asc, formation of Cr-DNA interstrand crosslinks (ICLs) under hypoxia was 50% or less of that under ambient conditions. Kinetic studies found that hypoxia reduced the rate at which Cr interacted with DNA, but not the ultimate steady state level of Cr-DNA binding. The inhibitory effect of hypoxia on Cr(VI)/Asc genotoxicity could not be explained solely by alterations in the reactivity of intermediate Cr(V) species because Cr(III)-DNA binding and Cr(III)-induced ICL formation were also impaired by hypoxia. Moreover, Cr(V) was generated to similar levels in ambient and hypoxic reactions. Hypoxia did not affect ICL formation by the inorganic chemotherapeutic agent cisplatin, suggesting that these effects were specific for Cr(III). Taken together, these results support a role for dioxygen in facilitating the formation of Cr-DNA coordination complexes.

Authors

O'Brien, TJ; Mandel, HG; Sugden, KD; Komarov, AM; Patierno, SR

MLA Citation

O’Brien, Travis J., et al. “Hypoxia impedes the formation of chromium DNA-adducts in a cell-free system..” Biochem Pharmacol, vol. 70, no. 12, Dec. 2005, pp. 1814–22. Pubmed, doi:10.1016/j.bcp.2005.09.016.

PMID

16242673

Source

pubmed

Published In

Biochemical Pharmacology

Volume

70

Issue

12

Publish Date

2005

Start Page

1814

End Page

1822

DOI

10.1016/j.bcp.2005.09.016

The reactive species produced by the reduction of Cr(VI), particularly Cr(III), can form both ionic and coordinate covalent complexes with DNA. These Cr(III)-DNA interactions consist of Cr-DNA monoadducts, Cr-DNA ternary adducts, and Cr-DNA interstrand cross-links (Cr-ICLs), the latter of which are DNA polymerase arresting lesions (PALs). We sought to determine the impact of Cr-DNA interactions on the formation of replication blocking lesions in S. cerevisiae using a PCR-based method. We found that target sequence (TS) amplification using DNA isolated from Cr(VI)-treated yeast actually increased as a function of Cr(VI) concentration. Moreover, the enhanced TS amplification was reproduced in vitro using Cr(III)-treated DNA. In contrast, PCR amplification of TS from DNA isolated from yeast exposed to equitoxic doses of the inorganic DNA cross-linking agent cisplatin (CDDP), was decreased in a concentration-dependent manner. This paradox suggested that a specific Cr-DNA interaction, such as an ionic Cr-DNA complex, was responsible for the enhanced TS amplification, thereby masking the replication-blocking effect of certain ternary Cr-DNA adducts (i.e. interstrand cross-links). To test this possibility, we removed ionically associated Cr from the DNA using salt extraction prior to PCR analysis. This procedure obviated the increased amplification and revealed a dose-dependent decrease in TS amplification and an increase in Cr-PALs. These data from DNA analyzed ex vivo after treatment of intact cells indicate that ionic interactions of Cr with DNA result in increased DNA amplification whereas coordinate-covalent Cr-DNA complexes lead to formation of Cr-PALs. Thus, these results suggest that treatment of living cells with Cr(VI) leads to two modes of Cr-binding, which may have conflicting effects on DNA replication.

Authors

Fornsaglio, JL; O'Brien, TJ; Patierno, SR

MLA Citation

Fornsaglio, Jamie L., et al. “Differential impact of ionic and coordinate covalent chromium (Cr)-DNA binding on DNA replication..” Mol Cell Biochem, vol. 279, no. 1–2, Nov. 2005, pp. 149–55. Pubmed, doi:10.1007/s11010-005-8287-z.

PMID

16283524

Source

pubmed

Published In

Molecular and Cellular Biochemistry

Volume

279

Issue

1-2

Publish Date

2005

Start Page

149

End Page

155

DOI

10.1007/s11010-005-8287-z

Some hexavalent chromium (Cr(VI))-containing compounds are human lung carcinogens. While ample information is available on the genetic lesions produced by Cr, surprisingly little is known regarding the cellular mechanisms involved in the removal of Cr-DNA adducts. Nucleotide excision repair (NER) is a highly versatile pathway that is responsive to a variety of DNA helix-distorting lesions. Binary Cr-DNA monoadducts do not produce a significant degree of helical distortion. However, these lesions are unstable due to the propensity of Cr(III) to form DNA adducts (DNA interstrand crosslinks, DNA-protein/amino acid ternary adducts) which may serve as substrates for NER. Therefore, the focus of this study was to determine the role of NER in the processing of Cr-DNA damage using normal (CHO-AA8) and NER-deficient [UV-5 (XP-D); UV-41 (ERCC4/XP-F)] hamster cells. We found that both UV-5 and UV-41 cells exhibited an increased sensitivity towards Cr(VI)-induced clonogenic lethality relative to AA8 cells and were completely deficient in the removal of Cr-DNA adducts. In contrast, repair-complemented UV-5 (expressing hamster XPD) and UV-41 (expressing human ERCC4) cells exhibited similar clonogenic survival and removed Cr-DNA adducts to a similar extent as AA8 cells. In order to extend these findings to the molecular level, we examined the ability of Cr(III)-damaged DNA to induce DNA repair synthesis in cell extracts. Repair synthesis was observed in reactions using extracts derived from AA8, or repair-complemented, but not NER-deficient cells. Cr(III)-induced repair resynthesis was sensitive to inhibition by the DNA polymerase delta/epsilon inhibitor, aphidicolin, but not 2',3'-dideoxythymidine triphosphate (ddTTP), a polymerase beta inhibitor. These results collectively suggest that NER functions in the protection of cells from Cr(VI) lethality and is essential for the removal of Cr(III)-DNA adducts. Consequently, NER may represent an important mechanism for preventing Cr(VI)-induced mutagenesis and neoplastic transformation.

Authors

O'Brien, TJ; Brooks, BR; Patierno, SR

MLA Citation

O’Brien, Travis J., et al. “Nucleotide excision repair functions in the removal of chromium-induced DNA damage in mammalian cells..” Mol Cell Biochem, vol. 279, no. 1–2, Nov. 2005, pp. 85–95. Pubmed, doi:10.1007/s11010-005-8225-0.

PMID

16283517

Source

pubmed

Published In

Molecular and Cellular Biochemistry

Volume

279

Issue

1-2

Publish Date

2005

Start Page

85

End Page

95

DOI

10.1007/s11010-005-8225-0

Certain hexavalent chromium [Cr(VI)] compounds are known genotoxic respiratory carcinogens, which induce apoptosis as a predominant mode of cell death. Selection of cells that are resistant to apoptosis may be a factor in tumour progression. We developed sub-populations of telomerase-transfected human fibroblasts (BJ-hTERT) that survived a 99% clonogenically lethal exposure to Cr(VI) (B-5Cr). B-5Cr cells were markedly resistant to apoptosis induced by several agents and exhibited increased clonogenic survival, especially at apoptogenic doses. B-5Cr cells did not exhibit altered cellular uptake of Cr(VI) and retained a normal p53 response to Cr(VI) exposure. We conducted large-scale gene expression analysis at different time-points after a secondary genotoxic Cr(VI) insult in B-5Cr and BJ-hTERT cells using Affymetrix Genechip human genome arrays. Cr(VI) exposure led to differential regulation of many genes, which affect a diverse set of cellular activities such as transcription, signal transduction, stress response, cell adhesion, DNA repair, apoptosis and cell cycle modulation. We compared Cr(VI)-induced altered gene expression in the B-5Cr cells to that in the parental cells and identified 223, 147 and 204 genes with at least a two-fold difference in expression at 4, 8 and 18 h after exposure, respectively. Cluster analysis by gene function revealed altered expression of genes involved in apoptosis, cell cycle regulation and DNA repair. Our data suggest an alteration in gene expression that may favor cell survival and/or incomplete DNA repair after genotoxic exposure. Selection of cells with altered expression of these genes may constitute the early stages of tumour progression.

Authors

Pritchard, DE; Ceryak, S; Ramsey, KE; O'Brien, TJ; Ha, L; Fornsaglio, JL; Stephan, DA; Patierno, SR

MLA Citation

Pritchard, Daryl E., et al. “Resistance to apoptosis, increased growth potential, and altered gene expression in cells that survived genotoxic hexavalent chromium [Cr(VI)] exposure..” Mol Cell Biochem, vol. 279, no. 1–2, Nov. 2005, pp. 169–81. Pubmed, doi:10.1007/s11010-005-8292-2.

PMID

16283527

Source

pubmed

Published In

Molecular and Cellular Biochemistry

Volume

279

Issue

1-2

Publish Date

2005

Start Page

169

End Page

181

DOI

10.1007/s11010-005-8292-2

OBJECTIVES: To report several samples of invasive human prostate cancer showing angiotropism, and to use human prostate cancer cells stably expressing green fluorescence protein (GFP) in in vitro and in vivo models to assess the dissemination pathway of prostate cancer cells. MATERIALS AND METHODS: Malignant melanoma and prostate carcinoma cells can migrate along anatomical structures such as nerves; previous studies showed that melanoma cells can be perivascular, on the outside of the endothelium, i.e. they are angiotropic, which suggests the hypothesis that melanoma cells also may migrate along vascular channels, termed 'extravascular migratory metastasis' (EVMM). Thus we examined histologically 10 human prostatic carcinoma specimens for the presence of angiotropism. In vitro, the PC-3 prostate cancer cells were co-cultures with capillary-like structures. In vivo, PC-3 cells were implanted on the chick chorio-allantoic membrane (CAM). RESULTS: Histologically, in all 10 cases, angiotropism was detected at least focally within the tumour or at the advancing front of the tumour. In vitro, the PC-3 cells spread along the external surface of the vascular tubules; in vivo, PC-3 cells formed a cuff around some vessels a few millimetres beyond the tumour, showing angiotropism. Histopathology of the CAM confirmed the perivascular location of tumour cells and the absence of tumour cells within the vessel lumina. CONCLUSION: The presence of angiotropic tumour cells in human invasive prostate cancers, associated with the angiotropism of GFP prostate cancer cells cultivated in vitro and in vivo in angiogenic models, raises the possibility that some prostate tumour cells may migrate along the external surface of vessels as a mechanism of spread, i.e. EVMM.

Authors

Lugassy, C; Vernon, SE; Warner, JW; Le, CQ; Manyak, M; Patierno, SR; Barnhill, RL

MLA Citation

Lugassy, Claire, et al. “Angiotropism of human prostate cancer cells: implications for extravascular migratory metastasis..” Bju Int, vol. 95, no. 7, May 2005, pp. 1099–103. Pubmed, doi:10.1111/j.1464-410X.2005.05474.x.

PMID

15839940

Source

pubmed

Published In

Bju International

Volume

95

Issue

7

Publish Date

2005

Start Page

1099

End Page

1103

DOI

10.1111/j.1464-410X.2005.05474.x

Authors

Patierno, S; Zellalem, W; Ho, A; Parsons, C; Tonini, M; Stemini, C

MLA Citation

Patierno, S., et al. “Peripheral N-methyl-D-aspartate receptors (NMDA-R) mediate endogenous opioid release induced by abdominal surgery in enteric neurons..” Gastroenterology, vol. 128, no. 4, 2005, pp. A362–A362.

Source

wos-lite

Published In

Gastroenterology

Volume

128

Issue

4

Publish Date

2005

Start Page

A362

End Page

A362

© 2005 by Taylor & Francis Group, LLC. All tissues have a rate at which cells naturally die, while other cells divide to take their place. The skin, for example, consists of large numbers of cells that are dying or dead and are constantly sloughed off, while new layers of skin regenerate by cell division beneath the cell surface. Maintaining the homeostatic balance of cell loss and cell gain is crucial to the health and survival of the tissue and organism, and so the balance is tightly regulated in all tissues throughout the body. Disturbing this balance of cell loss and cell proliferation can lead to disease. Tumor formation occurs when cell division exceeds cell death. This happens in one of two ways: either cell proliferation is increased so that it occurs faster than cell death or cell death is prevented or slowed so that it no longer keeps up with cell division. The progression of cellular changes leading to this excess growth and formation of a malignant tumor is the process known as multistage carcinogenesis. Most, if not all, of the morphological and biochemical characteristics of malignant cells have as their source either genetical or epigenetical alterations in gene expression. Therefore, the controls that usually tightly regulate the cell growth and death processes on a molecular level must be examined and manipulated in order to fully understand multistage carcinogenesis. Many factors can contribute to carcinogenesis, including viruses, chemicals, radiation, diet, hormones, and genetical predisposition.

Authors

Carlisle, DL; Patierno, SR

MLA Citation

Carlisle, D. L., and S. R. Patierno. “Carcinogenesis and molecular genetics.” Cancer Risk Assessment, 2005, pp. 1–15.

Source

scopus

Publish Date

2005

Start Page

1

End Page

15

Certain hexavalent chromium [Cr(VI)] compounds are implicated as occupational respiratory carcinogens. Cr(VI) induces a broad spectrum of DNA damage, but Cr(VI)-induced DNA double-strand breaks (DSBs) have not been reported. Previously we found that Cr(VI) activates the ataxia telangiectasia mutated (ATM) kinase. ATM is activated specifically in response to DSBs. Therefore, the objective of this study was to investigate DSB induction by Cr(VI) exposure with the overarching hypothesis that S phase-dependent DSBs are produced by Cr(VI) exposure. To test this hypothesis, normal human fibroblasts were treated with either Cr(VI) or neocarzinostatin (NCS). DSBs were analyzed by both comet assay under neutral conditions, which detects primarily DNA DSBs, and phosphorylation of histone H2AX (gamma-H2AX) and the resultant formation of nuclear foci, which are considered to be indicative of DSBs. Induction of DSBs was observed after Cr(VI) exposure, however, the Cr(VI)-induced DSBs were abrogated by G(1) synchronization. Furthermore, our data showed that Cr(VI)-induced DSBs were only observed in the S phase population, whereas no significant DSBs were observed in Cr(VI)-treated G(1) synchronized cells. In contrast, NCS-induced DSBs were equally distributed in all cell cycle phases in both asynchronous and G(1) synchronized cells. Moreover, Cr(VI)-induced gamma-H2AX foci formation was restricted to PCNA-positive cells, whereas NCS-induced gamma-H2AX foci formed in both PCNA-positive and PCNA-negative cells. These results indicate that Cr(VI)-induced DSBs are S phase-dependent. Finally, our data showed that Cr(VI)-induced gamma-H2AX production was significantly decreased in ATM(-/-) cells compared with ATM(+/+) cells. Taken together, these results suggest that Cr(VI)-induced activation of ATM involves the formation of S phase-dependent DSBs. Examining the mechanism of Cr(VI)-induced DSBs will aid in understanding the interrelated mechanisms of Cr(VI) toxicity and carcinogenesis.

Authors

Ha, L; Ceryak, S; Patierno, SR

MLA Citation

Ha, Linan, et al. “Generation of S phase-dependent DNA double-strand breaks by Cr(VI) exposure: involvement of ATM in Cr(VI) induction of gamma-H2AX..” Carcinogenesis, vol. 25, no. 11, Nov. 2004, pp. 2265–74. Pubmed, doi:10.1093/carcin/bgh242.

PMID

15284180

Source

pubmed

Published In

Carcinogenesis

Volume

25

Issue

11

Publish Date

2004

Start Page

2265

End Page

2274

DOI

10.1093/carcin/bgh242

Authors

Henson, DE; Patierno, SR

MLA Citation

Henson, Donald E., and Steven R. Patierno. “Breast cancer aggressiveness and racial disparity..” Breast Cancer Res Treat, vol. 87, no. 3, Oct. 2004, pp. 291–96. Pubmed, doi:10.1007/s10549-004-8687-x.

PMID

15528972

Source

pubmed

Published In

Breast Cancer Research and Treatment

Volume

87

Issue

3

Publish Date

2004

Start Page

291

End Page

296

DOI

10.1007/s10549-004-8687-x

Previous studies have demonstrated that some tumor cells occupy a pericyte-like location in melanoma, forming angio-tumoral complexes. We hypothesized that these tumor cells are migrating along the abluminal surface of the endothelium, a mechanism termed "extravascular migratory metastasis." In the present study, we have used human and murine melanoma cells that stably express enhanced green fluorescence protein (GFP) to examine, in an ex vivo co-culture model, melanoma cell interactions with vessels that have sprouted from rat aortic rings. We also used in vivo tumor growth on the chick chorioallantoic membrane (CAM) to observe the dissemination pathway of melanoma cells. In the ex vivo rat aorta system, we observed a pericyte-like location of tumor cells that were spreading along the vascular channels. For examination of the CAM in vivo, we have used the Lugassy preparation, allowing one to obtain striking images of the relationship between fluorescent GFP cells and microvessels. Melanoma cells were found cuffing the outside of vessels around the tumor. Tumor cells were observed along the vessels several centimeters from the tumor. Confocal microscopy and histopathology confirmed the pericyte-like location of tumor cells, without any observable intravasation. The results indicate that melanoma cells can migrate along the abluminal surface of vessels. This study also demonstrates that these models can provide quantitation analysis that may prove useful in elucidating the molecular interactions involved in extravascular migratory metastasis.

Authors

Lugassy, C; Kleinman, HK; Engbring, JA; Welch, DR; Harms, JF; Rufner, R; Ghanem, G; Patierno, SR; Barnhill, RL

MLA Citation

Lugassy, Claire, et al. “Pericyte-like location of GFP-tagged melanoma cells: ex vivo and in vivo studies of extravascular migratory metastasis..” Am J Pathol, vol. 164, no. 4, Apr. 2004, pp. 1191–98. Pubmed, doi:10.1016/S0002-9440(10)63207-5.

PMID

15039208

Source

pubmed

Published In

The American Journal of Pathology

Volume

164

Issue

4

Publish Date

2004

Start Page

1191

End Page

1198

DOI

10.1016/S0002-9440(10)63207-5

The hypercoagulability exhibited by most cancer patients leads to serious complications such as venous thromboembolism and contributes to the pathogenesis of tumor growth and metastasis by promoting angiogenesis. The key player in this vicious cycle is tissue factor (TF), the initiator of blood coagulation. Although TF normally safeguards vascular integrity by inducing hemostasis upon injury, abnormal expression of TF in different tumors and related vascular endothelial cells contributes to unnecessary clot formation in cancer patients. Clotting-dependent induction of tumor angiogenesis is primarily mediated by TF-induced generation of thrombin and subsequent deposition of cross-linked fibrin. A cross-linked fibrin network provides a provisional proangiogenic matrix that facilitates blood vessel infiltration. Clotting-independent mechanisms of TF-induced tumor angiogenesis have also been described, mediated primarily by the cytoplasmic tail of the TF receptor. TF activation could contribute to the venous thromboembolism that has been reported as a complication of the use of novel antiangiogenic agents in combination with chemotherapy. Anticoagulants, such as low-molecular-weight heparin, may act to prevent these complications both by interfering with TF-mediated activation of clotting and by directly down-regulating angiogenesis. Thus, TF may prove to be a novel target for cancer therapy.

Authors

Fernandez, PM; Patierno, SR; Rickles, FR

MLA Citation

Fernandez, Patricia M., et al. “Tissue factor and fibrin in tumor angiogenesis..” Semin Thromb Hemost, vol. 30, no. 1, Feb. 2004, pp. 31–44. Pubmed, doi:10.1055/s-2004-822969.

PMID

15034796

Source

pubmed

Published In

Seminars in Thrombosis and Hemostasis

Volume

30

Issue

1

Publish Date

2004

Start Page

31

End Page

44

DOI

10.1055/s-2004-822969

Cell proliferation and apoptosis are controlled by tightly orchestrated signaling pathways that culminate in transcriptional activation/repression of multiple proteins. Dysregulation of cell cycle and/or apoptosis control may lead to genomic instability, neoplastic transformation and tumor progression. Under certain conditions, some hexavalent chromium [Cr(VI)] compounds are toxic and carcinogenic in the human respiratory tract, and we have shown that they induce apoptosis and/or cell cycle arrest in a p53-dependent fashion. There is increasing evidence linking extracellular signal-regulated kinase (ERK) activation with the DNA damage response, by both p53-dependent and -independent mechanisms. Here, the aim was to study the effect of Cr(VI) transcriptional regulation of key cell cycle inhibitors and pro- and anti-apoptotic proteins, as well as the role of ERK activation in the Cr(VI) genotoxic response. Diploid human lung fibroblasts were incubated with 3-9 uM Na2CrO4, and RNA was isolated at 4, 8, and 24 h, as well as 24 h after Cr(VI) exposure was terminated (recovery). mRNA expression was quantitated by RNase protection assay with a 32P-labeled multi-transcript probe containing gene sequences for the cdk inhibitors, p21waf1/cip1, p27kip1, p16INK4a, p15INK4b; the pro-apoptotic proteins bcl-XS and bax; the anti-apoptotic proteins bcl-W, bcl-XL, and bcl2, GADD45, and cyclin A. In general, bcl-W and bcl-XL expression were both downregulated after Cr exposure, to around 50% at 24 h, which was more pronounced after the recovery period. At Cr(VI) concentrations < or = 6 uM, bcl2 expression was upregulated. Of particular interest is that bax expression was reduced, in a dose and time-dependent fashion, however that of bcl-XS was elevated by nearly 3-fold after 8 h, and declined to control levels at the end of the recovery period. Expression of GADD45 and p21 were both upregulated by 2-fold at 8 h, but declined to control levels during recovery. Neither the expression of p27 nor that of p16 were apparently affected by Cr(VI) exposure, however the expression of p15 was markedly increased after exposure to all concentrations of Cr(VI). Finally, the expression of cyclin A was decreased after 24 h Cr(VI) exposure. Cr(VI) induced a transient burst of ERK activity (2-6-fold over control) around 0.5-3 h after exposure. However, inhibition of ERK activation with PD98059 had no effect on the Cr-induced alterations in gene expression. Moreover, Cr(VI)-induced clonogenic lethality, as assessed after 24 h exposure to 1 and 2 uM Cr(VI), was also not affected by ERK inhibition. These data suggest that both p53-dependent and -independent apoptotic and growth-inhibitory pathways are markedly affected by Cr(VI) exposure. However, the ability of Cr(VI) to affect key apoptotic and growth arresting genes, and thus clonogenic lethality, appears to be independent of ERK. Continued investigation into the cellular and molecular mechanisms of Cr(VI)-induced cell cycle and apoptosis control should further the understanding of Cr(VI)-associated carcinogenesis.

Authors

Ceryak, S; Zingariello, C; O'Brien, T; Patierno, SR

MLA Citation

Ceryak, Susan, et al. “Induction of pro-apoptotic and cell cycle-inhibiting genes in chromium (VI)-treated human lung fibroblasts: lack of effect of ERK..” Mol Cell Biochem, vol. 255, no. 1–2, Jan. 2004, pp. 139–49.

PMID

14971655

Source

pubmed

Published In

Molecular and Cellular Biochemistry

Volume

255

Issue

1-2

Publish Date

2004

Start Page

139

End Page

149

Chromium(VI) (Cr(VI)) can suppress both DNA replication and transcription as a result of chromium (Cr)-induced DNA damage. While progress has been made in the characterization of Cr-induced DNA polymerase arresting lesions, very little information is available on the inhibition of transcription by this metal. The aim of the present study was to identify the molecular mechanisms involved in the reduction of RNA synthesis by Cr. Following treatment with a moderately cytotoxic dose (approximately LC50) of Cr(VI) (150 microM for 2 h), total RNA synthesis was initially suppressed in CHO cells and recovered to control levels within 72 h post-treatment. In vitro nuclear run-on transcription assays of nuclei isolated from Cr(VI)-treated cells showed a similar amount of RNA synthesis suppression as observed in intact cells. Qualitative analysis of nascent transcripts revealed a general, concentration-dependent reduction in size suggesting that transcriptional elongation was inhibited following Cr-treatment. Transcriptional initiation in these nuclei was also reduced. To better determine whether transcriptional suppression was related to Cr-induced DNA damage we examined the transcriptional activity of T7 RNA polymerase on Cr(III)-treated plasmid DNA. Treatment of pGEM3Z-TS DNA with Cr(III) resulted in transcriptional arrest which occurred primarily at GC-rich and palindromic regions. However, in contrast to the cellular data, transcriptional initiation was unaffected in the in vitro transcription arrest assays. Taken together, these results suggest that the suppression of RNA synthesis by Cr is related to chromium-induced template DNA damage which prevents elongation leading to premature RNA polymerase arrest.

Authors

Xu, J; Manning, FCR; O'Brien, TJ; Ceryak, S; Patierno, SR

MLA Citation

Xu, Jian, et al. “Mechanisms of chromium-induced suppression of RNA synthesis in cellular and cell-free systems: relationship to RNA polymerase arrest..” Mol Cell Biochem, vol. 255, no. 1–2, Jan. 2004, pp. 151–60.

PMID

14971656

Source

pubmed

Published In

Molecular and Cellular Biochemistry

Volume

255

Issue

1-2

Publish Date

2004

Start Page

151

End Page

160

Certain hexavalent chromium (Cr(VI))-containing compounds are recognized occupational human lung carcinogens and may pose an environmental health risk. The carcinogenicity of Cr(VI) is targeted to particulate forms of moderate to low solubility. Soluble Cr(VI) oxyanions in the immediate cellular microenvironment traverse the cell membrane by non-specific anionic transporters. Cr(VI) is reductively metabolized within cells by agents including ascorbic acid (Asc), glutathione (GSH) and cysteine (Cys). During Cr(VI) reduction, a diverse range of genetic lesions are generated including Cr-DNA binary (mono) adducts, Cr-DNA ternary adducts, DNA protein crosslinks (DPCs), bi-functional (DNA interstrand crosslinks (ICLs)) adducts, single-strand breaks (SSBs) and oxidized bases. Some forms of Cr damage, such as ICLs, present physical barriers to DNA replication/transcription and, thus, likely promote a terminal cell fate such as apoptosis or terminal growth arrest. Other lesions, such as ternary DNA adducts, are potentially pre-mutagenic. Cr(VI) exposure elicits a classical DNA damage response within cells including activation of the p53 signaling pathway and cell cycle arrest or apoptosis. Moreover, Cr(VI) also induces the ATM-dependent DNA damage response pathway which is paradoxically required for both apoptosis and survival after Cr(VI) insult. In yeast, moderately cytotoxic concentrations of Cr(VI) result in an initial G1 arrest and delayed S phase progression, whereas less toxic levels of Cr(VI) induce G2 arrest, which requires homologous recombination for exit and survival. The past several years has witnessed many important advances in our understanding of the genetic/cellular damage produced by exposure to Cr(VI). Further information is needed regarding the potential involvement of oxygen radicals in Cr genotoxicity, the specific DNA repair pathways activated by Cr and the complex signaling mechanisms involved in the cellular response to Cr(VI). These pertinent issues must be considered in relation to the potential role that each plays in the induction of human respiratory tract cancer by particulate Cr(VI) compounds.

Authors

O'Brien, TJ; Ceryak, S; Patierno, SR

MLA Citation

O’Brien, Travis J., et al. “Complexities of chromium carcinogenesis: role of cellular response, repair and recovery mechanisms..” Mutat Res, vol. 533, no. 1–2, Dec. 2003, pp. 3–36. Pubmed, doi:10.1016/j.mrfmmm.2003.09.006.

PMID

14643411

Source

pubmed

Published In

Mutation Research

Volume

533

Issue

1-2

Publish Date

2003

Start Page

3

End Page

36

DOI

10.1016/j.mrfmmm.2003.09.006

In addition to its primary role in hemostasis and blood coagulation, thrombin is a potent mitogen capable of inducing cellular functions. Therefore, it should come as no surprise that thrombin has proved to be of importance in the behavior of cancer. In this review, we focus on the ability of tissue factor (TF) and thrombin to influence tumor angiogenesis. Both exert their influence on angiogenesis through clotting-dependent and clotting-independent mechanisms: (1). directly affecting signaling pathways that mediate cell functions, and (2). mediating clot formation, thereby providing a growth media for tumor cells. Therefore, anticoagulant drugs may prove efficacious in cancer treatment due to their ability to reduce the characteristic hypercoagulability of cancer and alter the fundamental biology of cancer.

Authors

Rickles, FR; Patierno, S; Fernandez, PM

MLA Citation

Rickles, Frederick R., et al. “Tissue factor, thrombin, and cancer..” Chest, vol. 124, no. 3 Suppl, Sept. 2003, pp. 58S-68S. Pubmed, doi:10.1378/chest.124.3_suppl.58s.

PMID

12970125

Source

pubmed

Published In

Chest

Volume

124

Issue

3 Suppl

Publish Date

2003

Start Page

58S

End Page

68S

DOI

10.1378/chest.124.3_suppl.58s

The ataxia telangiectasia mutated (ATM) protein plays a central role in early stages of DNA double strand break (DSB) detection and controls cellular responses to this damage. Although hypersensitive to ionizing radiation-induced clonogenic lethality, ataxia telangiectasia cells are paradoxically deficient in their ability to undergo ionizing radiation-induced apoptosis. This contradiction illustrates the complexity of the central role of ATM in DNA damage response and the need for further understanding. Certain hexavalent chromium (Cr(VI)) compounds are implicated as occupational respiratory carcinogens at doses that are both genotoxic and cytotoxic. Cr(VI) induces a broad spectrum of DNA damage, but Cr(VI)-induced DSBs have not been reported. Here, we examined the role of ATM in the cellular response to Cr(VI) and found that Cr(VI) activates ATM. We also show that physiological targets of ATM, p53 Ser-15 and Chk2 Thr-68, were phosphorylated by Cr(VI) exposure in an ATM-dependent fashion. We found that ATM-/- cells were markedly resistant to Cr(VI)-induced apoptosis but considerably more sensitive to Cr(VI)-induced clonogenic lethality than wild type cells, indicating that resistance to Cr(VI)-induced apoptosis did not confer a selective survival advantage. However, analysis of long term growth arrest revealed a striking difference: ATM-/- cells were markedly less able to recover from Cr(VI)-induced growth arrest. This indicates that terminal growth arrest is the fate of these apoptosis-resistant cells. In summary, ATM is involved in cellular response to a complex genotoxin that may not directly induce DSBs. Our data suggest that ATM is a major signal initiator for genotoxin-induced apoptosis but, paradoxically, also contributes to maintenance of cell survival by facilitating recovery/escape from terminal growth arrest. The results also strongly suggest that terminal growth arrest is not merely an extended or even irreversible form of checkpoint arrest, but instead an independent and unique cell fate pathway.

Authors

Ha, L; Ceryak, S; Patierno, SR

MLA Citation

Ha, Linan, et al. “Chromium (VI) activates ataxia telangiectasia mutated (ATM) protein. Requirement of ATM for both apoptosis and recovery from terminal growth arrest..” J Biol Chem, vol. 278, no. 20, May 2003, pp. 17885–94. Pubmed, doi:10.1074/jbc.M210560200.

PMID

12637545

Source

pubmed

Published In

The Journal of Biological Chemistry

Volume

278

Issue

20

Publish Date

2003

Start Page

17885

End Page

17894

DOI

10.1074/jbc.M210560200

Authors

Rickles, FR; Patierno, SR; Fernandez, PM

MLA Citation

Rickles, Frederick R., et al. “Targeting the endothelium in cancer--the importance of the interaction of hemostatic mechanisms and the vascular wall for tumor growth and angiogenesis..” Pathophysiol Haemost Thromb, vol. 33 Suppl 1, 2003, pp. 1–4. Pubmed, doi:10.1159/000073276.

PMID

12954987

Source

pubmed

Published In

Pathophysiology of Haemostasis and Thrombosis

Volume

33 Suppl 1

Publish Date

2003

Start Page

1

End Page

4

DOI

10.1159/000073276

We have identified in malignant melanoma an angiotumoral complex in which tumor cells occupy a pericytic location along the endothelium of microvessels without evidence of intravasation. We have suggested that this pericytic-like angiotropism could be a marker of an extravascular migration of tumor cells along the abluminal surface of vessels. The extravascular migratory metastasis proposed for melanoma has close analogies with glioma migration. To compare our hypothesis of extravascular migration by melanoma with the migration of glioma cells, we have used the B16 murine melanoma cell line and the GL26 murine glioma cell line in an in vivo murine brain tumor model and in vitro using endothelial cells that have formed capillary-like structures and have been cocultivated with tumor cells. In the brain tumors, a clear progression of glioma and melanoma cells was observed along the abluminal surface of vessels, where they occupied a pericytic location along the periendothelial laminin. In vitro, time-lapse videomicroscopy recorded the migration of tumor cells toward endothelial tubules. After 24 hours, both the melanoma cells and the glioma cells were localized along the external surfaces of the vascular tubules, occupying a pericytic-like location. These similarities between glioma and melanoma support the hypothesis of an extravascular migration of melanoma cells, particularly along the abluminal surface of vessels.

Authors

Lugassy, C; Haroun, RI; Brem, H; Tyler, BM; Jones, RV; Fernandez, PM; Patierno, SR; Kleinman, HK; Barnhill, RL

MLA Citation

Lugassy, Claire, et al. “Pericytic-like angiotropism of glioma and melanoma cells..” Am J Dermatopathol, vol. 24, no. 6, Dec. 2002, pp. 473–78.

PMID

12454598

Source

pubmed

Published In

The American Journal of Dermatopathology

Volume

24

Issue

6

Publish Date

2002

Start Page

473

End Page

478

The genotoxicity associated with the metabolic reduction of hexavalent chromium [Cr(VI)] is complex and can impede DNA polymerase-mediated replication in vitro. The exact biochemical nature of Cr-induced polymerase arresting lesions (PALs) is not understood, but is believed to involve the formation of Cr-DNA interstrand cross-links (ICLs). The aim of this investigation was to determine the dependence of direct Cr-DNA interactions on the development of PALs in DNA treated with trivalent Cr [Cr(III)] or with Cr(VI) in the presence of ascorbic acid (Asc), a major intracellular reductant, using an in vitro, acellular system. The formation of Cr-DNA adducts, ICLs, and PALs was maximal at Asc:Cr(VI) molar ratios of 0.5-2, but gradually decreased at higher ratios. EDTA, a Cr(III) chelator, significantly decreased Cr-DNA binding and ICL and PAL formation. Co-treatment of DNA with Cr(VI)/Asc and mannitol, a Cr(V) chelator, selectively inhibited the formation of mono/bifunctional DNA adducts and PALs produced by Cr(VI) reduction, but had no effect on Cr(III)-DNA binding or Cr(III)-induced polymerase arrest. Blocking Cr-DNA phosphate interaction by preincubation of DNA with MgCl(2) abrogated DNA binding and ICL and PAL production. DNA strand breaks and abasic sites may lead to the in vitro arrest of DNA polymerases; however, we failed to detect significant increases in the frequency of these lesions following Cr(VI)/Asc treatment. These data indicate that the bifunctional adduction of Cr to DNA phosphates (ICLs) constitutes a major PAL. Furthermore, the generation of DNA strand breaks and abasic sites by Cr(VI) reduction is insufficient to explain PALs observed in vitro.

Authors

O'Brien, T; Mandel, HG; Pritchard, DE; Patierno, SR

MLA Citation

O’Brien, Travis, et al. “Critical role of chromium (Cr)-DNA interactions in the formation of Cr-induced polymerase arresting lesions..” Biochemistry, vol. 41, no. 41, Oct. 2002, pp. 12529–37. Pubmed, doi:10.1021/bi020452j.

PMID

12369844

Source

pubmed

Published In

Biochemistry

Volume

41

Issue

41

Publish Date

2002

Start Page

12529

End Page

12537

DOI

10.1021/bi020452j

Fanconi anemia (FA) is an autosomal recessive disorder characterized by diverse developmental abnormalities, progressive bone marrow failure, and a markedly increased incidence of malignancy. FA cells are hypersensitive to DNA cross-linking agents, suggesting a general defect in the repair of DNA cross-links. Some forms of hexavalent chromium [Cr(VI)] are implicated as respiratory carcinogens and induce several types of DNA lesions, including ternary DNA-Cr-DNA interstrand cross-links (Cr-DDC). We hypothesized that human FA complementation group A (FA-A) cells would be hypersensitive to Cr(VI) and Cr(VI)-induced apoptosis. Using phosphatidylserine translocation and caspase-3 activation, human FA-A fibroblasts were found to be markedly hypersensitive to chromium-induced apoptosis compared with CRL-1634 cells, which are normal human foreskin fibroblasts (CRL). The clonogenicity of FA-A cells was also significantly decreased compared with CRL cells after Cr(VI) treatment. There was no significant difference in either Cr(VI) uptake or Cr-DNA adduct formation between FA-A and CRL cells. These results show that FA-A cells are hypersensitive to Cr(VI) and Cr-induced apoptosis and that this hypersensitivity is not due to increased Cr(VI) uptake or increased Cr-DNA adduct formation. The results also suggest that Cr-DDC may be proapoptotic lesions. These results are the first to show that FA cells are hypersensitive to an environmentally relevant DNA cross-linking agent.

Authors

Vilcheck, SK; O'Brien, TJ; Pritchard, DE; Ha, L; Ceryak, S; Fornsaglio, JL; Patierno, SR

MLA Citation

Vilcheck, Susan K., et al. “Fanconi anemia complementation group A cells are hypersensitive to chromium(VI)-induced toxicity..” Environ Health Perspect, vol. 110 Suppl 5, Oct. 2002, pp. 773–77. Pubmed, doi:10.1289/ehp.02110s5773.

PMID

12426130

Source

pubmed

Published In

Environmental Health Perspectives

Volume

110 Suppl 5

Publish Date

2002

Start Page

773

End Page

777

DOI

10.1289/ehp.02110s5773

Authors

Lugassy, C; Kleinman, HK; Fernandez, PM; Patierno, SR; Webber, MM; Ghanem, G; Spatz, A; Barnhill, RL

MLA Citation

Lugassy, Claire, et al. “Human melanoma cell migration along capillary-like structures in vitro: a new dynamic model for studying extravascular migratory metastasis..” J Invest Dermatol, vol. 119, no. 3, Sept. 2002, pp. 703–04. Pubmed, doi:10.1046/j.1523-1747.2002.01857.x.

PMID

12230517

Source

pubmed

Published In

Journal of Investigative Dermatology

Volume

119

Issue

3

Publish Date

2002

Start Page

703

End Page

704

DOI

10.1046/j.1523-1747.2002.01857.x

Currently, there are very few diagnostic or therapeutic strategies targeted at controlling tumor growth and progression towards metastasis. Uteroglobin (UG) is a naturally occurring, small, stable, secretory protein that is normally expressed by most cells of epithelial origin but is known to be lost during the progression of prostate, lung, and uterine cancers to invasive malignancy. Uteroglobin -/- knockout mice appear to be extremely cancer prone. Both pharmacological and transgenic reconstitution of recombinant human UG (rhUG) to prostate, lung, and endometrial tumor cell lines markedly inhibits their invasiveness and antagonizes the neoplastic phenotype. In preliminary studies, rhUG inhibited angiogenesis in the ex vivo rat aorta model and showed antitumor activity against human prostate tumor cells (PC-3) in the chick chorioallantoic membrane assay, reducing both tumor volume and vascularity. A recent in vivo pilot study showed that twice daily dosing with rhUG resulted in a statistically significant increase in survival without evidence of toxicity in severe combined immunodeficient mice challenged with a PC-3 cell metastasizing tumor. Thus, rhUG may slow the progression of cancer by inhibiting both tumor cell invasiveness and tumor angiogenesis. It therefore holds the potential to serve as a new weapon in the arsenal of cytostatic, antimetastatic, adjuvant treatment for cancer. In this paper, we will briefly discuss the therapeutic potential of uteroglobin-based strategies for managing prostate cancer.

Authors

Patierno, SR; Manyak, MJ; Fernandez, PM; Baker, A; Weeraratna, AT; Chou, DS; Szlyk, G; Geib, KS; Walsh, C; Patteras, J

MLA Citation

Patierno, Steven R., et al. “Uteroglobin: a potential novel tumor suppressor and molecular therapeutic for prostate cancer..” Clin Prostate Cancer, vol. 1, no. 2, Sept. 2002, pp. 118–24.

PMID

15046703

Source

pubmed

Published In

Clinical Prostate Cancer

Volume

1

Issue

2

Publish Date

2002

Start Page

118

End Page

124

A broad spectrum of genetic damage results from exposure to hexavalent chromium. These lesions can result in DNA and RNA polymerase arrest, chromosomal aberrations, point mutations and deletions. Because of the complexity of Cr genotoxicity, the repair of Cr(VI)-induced DNA damage is poorly understood. Therefore, our aim was to investigate the sensitivities of DNA repair-deficient Saccharomyces cerevisiae strains to Cr(VI)-induced growth inhibition and lethality. Wild-type, translesion synthesis (rev3) and excision repair (apn1, ntg1, ntg2, rad1) mutants exhibited similar survival following Cr(VI) treatment (0-50mM) and underwent at least one population doubling within 2-4h post-treatment. The simultaneous loss of several excision repair genes (apn1 rad1 ntg1 ntg2) led to slower growth after Cr(VI) exposure (10mM) manifested as an initial delay in S phase progression. Higher concentrations of Cr(VI) (25mM) resulted in a prolonged transit through S phase in every strain tested. A G(2)/M arrest was evident within 1-2h after Cr(VI) treatment (10mM) in all strains and cells subsequently divided after this transient delay. In contrast to all other strains, only recombination-deficient (rad52, rad52 rev3) yeast were markedly hypersensitive towards Cr(VI) lethality. RAD52 mutant strains (rad52, rad52 rev3) also exhibited a significant delay (>6h) in the resumption of replication after Cr(VI) exposure which was related to the immediate and apparently terminal arrest of these yeast in G(2)/M after Cr(VI) treatment. These results, taken together with the recombinogenic effects of Cr(VI) in yeast containing a functional RAD52 gene, suggest that RAD52-mediated recombination is critical for the normal processing of lethal Cr-induced genetic lesions and exit from G(2) arrest. Furthermore, only the combined inactivation of multiple excision repair genes affects cell growth after Cr(VI) treatment.

Authors

O'Brien, TJ; Fornsaglio, JL; Ceryak, S; Patierno, SR

MLA Citation

O’Brien, Travis J., et al. “Effects of hexavalent chromium on the survival and cell cycle distribution of DNA repair-deficient S. cerevisiae..” Dna Repair (Amst), vol. 1, no. 8, Aug. 2002, pp. 617–27.

PMID

12509285

Source

pubmed

Published In

Dna Repair

Volume

1

Issue

8

Publish Date

2002

Start Page

617

End Page

627

The cellular responses to carcinogen exposure influence cellular fate, which in turn modulates the neoplastic response. Certain hexavalent chromium [Cr(VI)] compounds are implicated as occupational respiratory carcinogens at doses that are both genotoxic and cytotoxic. We examined the mechanism of Cr(VI)-induced apoptosis in normal human fibroblasts (BJ) immortalized by human telomerase gene transfection (BJ-hTERT), and we assessed the spectrum of cumulative cellular fates [(a) regaining of replicative potential; (b) terminal growth arrest; or (c) apoptosis] for a narrow range of increasingly genotoxic doses of Cr(VI). Exposure of BJ-hTERT cells to Cr(VI) resulted in a dose-dependent increase in apoptosis that involved mitochondrial disruption as evidenced by mitochondrial membrane depolarization and cytochrome c release. The initial response to Cr(VI) exposure was inhibition of cell cycle progression. At the lowest dose tested (1 microM; 32% clonogenic survival), the cell cycle inhibition led to terminal growth arrest but no apoptosis. The fraction of terminally growth arrested cells increased as the dose was increased to 3 microM but then decreased at 4, 5, and 6 microM as apoptosis became the predominant cell fate. Our results suggest that cell populations exposed to Cr(VI) have a different spectrum of responses, depending on the extent of DNA damage, and that the regaining of replicative potential after relatively higher genotoxic exposures may be attributable to either escape from, or resistance to, terminal growth arrest or apoptosis.

Authors

Pritchard, DE; Ceryak, S; Ha, L; Fornsaglio, JL; Hartman, SK; O'Brien, TJ; Patierno, SR

MLA Citation

Pritchard, D. E., et al. “Mechanism of apoptosis and determination of cellular fate in chromium(VI)-exposed populations of telomerase-immortalized human fibroblasts..” Cell Growth Differ, vol. 12, no. 10, Oct. 2001, pp. 487–96.

PMID

11682460

Source

pubmed

Published In

Cell Growth & Differentiation : the Molecular Biology Journal of the American Association for Cancer Research

Volume

12

Issue

10

Publish Date

2001

Start Page

487

End Page

496

Physiological stress conditions associated with the tumor microenvironment play a role in resistance to anticancer therapy. In this study, treatment of EMT6 mouse mammary tumor cells with hypoxia or the chemical stress agents brefeldin A (BFA) or okadaic acid (OA) causes the development of resistance to the topoisomerase II inhibitor etoposide. The mechanism of physiological stress-induced drug resistance may involve the activation of stress-responsive proteins and transcription factors. Our previous work shows that treatment with BFA or OA causes activation of the nuclear transcription factor NF-kappa B. Pretreatment with the proteasome inhibitor carbobenzyoxyl-leucinyl-leucinyl-leucinal inhibits stress-induced NF-kappa B activation and reverses BFA-induced drug resistance. To test whether NF-kappa B specifically mediates stress-induced drug resistance, an inducible phosphorylation site-deficient mutant of I kappa B alpha (I kappa B alpha M, S32/36A) was introduced into EMT6 cells. In this study, we show that I kappa B alpha M expression inhibits stress-induced NF-kappa B activation and prevents BFA-, hypoxia-, and OA-induced resistance to etoposide. These results indicate that NF-kappa B activation mediates both chemical and physiological drug resistance to etoposide. Furthermore, they imply that coadministration of agents that inhibit NF-kappa B may enhance the efficacy of topoisomerase II inhibitors in clinical cancer chemotherapy.

Authors

Brandes, LM; Lin, ZP; Patierno, SR; Kennedy, KA

MLA Citation

Brandes, L. M., et al. “Reversal of physiological stress-induced resistance to topoisomerase II inhibitors using an inducible phosphorylation site-deficient mutant of I kappa B alpha..” Mol Pharmacol, vol. 60, no. 3, Sept. 2001, pp. 559–67.

PMID

11502888

Source

pubmed

Published In

Molecular Pharmacology

Volume

60

Issue

3

Publish Date

2001

Start Page

559

End Page

567

Hexavalent chromium (Cr (VI)) is reduced intracellularly to Cr (V), Cr (IV) and Cr (III) by ascorbate (Asc), cysteine and glutathione (GSH). These metabolites induce a spectrum of genomic DNA damage resulting in the inhibition of DNA replication. Our previous studies have shown that treatment of DNA with Cr (III) or Cr (VI) plus Asc results in the formation of DNA-Cr-DNA crosslinks (Cr-DDC) and guanine-specific arrests of both prokaryotic and mammalian DNA polymerases. GSH not only acts as a reductant of Cr (VI) but also becomes crosslinked to DNA by Cr, thus, the focus of the present study was to examine the role of GSH in Cr-induced DNA damage and polymerase arrests. Co-incubation of Cr (III) with plasmid DNA in the presence of GSH led to the crosslinking of GSH to DNA. GSH co-treatment with Cr (III) also led to a decrease in the degree of Cr-induced DNA interstrand crosslinks relative to Cr (III) alone, without affecting total Cr DNA binding. DNA polymerase arrests were observed following treatment of DNA with Cr (III) alone, but were markedly reduced when GSH was added to the reaction mixture. Pre-formed polymerase-arresting lesions (Cr-DDC) were not removed by subsequent addition of GSH. Treatment of DNA with Cr (VI), in the presence of GSH, resulted in crosslinking of GSH to DNA, but failed to produce detectable DNA interstrand crosslinks or polymerase arrests. The inhibitory effect of GSH on Cr-induced polymerase arrest was further confirmed in human genomic DNA using quantitative PCR (QPCR) analysis. Treatment of genomic DNA with Cr (III) resulted in a marked inhibition of the amplification of a 1.6 kb target fragment of the p53 gene by Taq polymerase. This was almost completely prevented by co-treatment with GSH and Cr (III). These results indicate that Cr-induced DNA interstrand crosslinks, and not DNA-Cr-GSH crosslinks, are the principal lesions responsible for blocking DNA replication. Moreover, the formation of DNA-Cr-GSH crosslinks may actually preclude the formation of the polymerase arresting lesions.

Authors

O'Brien, T; Xu, J; Patierno, SR

MLA Citation

O’Brien, T., et al. “Effects of glutathione on chromium-induced DNA crosslinking and DNA polymerase arrest..” Mol Cell Biochem, vol. 222, no. 1–2, June 2001, pp. 173–82.

PMID

11678599

Source

pubmed

Published In

Molecular and Cellular Biochemistry

Volume

222

Issue

1-2

Publish Date

2001

Start Page

173

End Page

182

A variety of key events in the molecular apoptotic pathway involve the mitochondria. Cyclosporin A (csA) affects the mitochondria by inhibiting the mitochondrial permeability transition (MPT), thereby preventing disruption of the transmembrane potential. The role of the MPT in apoptosis is not fully understood, but inhibition of the MPT may prevent the release of mitochondrial caspase activators, such as cytochrome c (cyt c), into the cytosol. Certain hexavalent chromium [Cr(VI)] compounds are known occupational respiratory tract toxins and carcinogens. We have previously shown that these compounds induce apoptosis as a predominant mode of cell death and that this effect can be observed in cell culture using soluble Cr(VI). We show here that Cr(VI)-induced apoptosis in Chinese hamster ovary (CHO) cells involves disruption of mitochondrial stability. Using a cyt c-specific monoclonal antibody, we observed a dose-dependent release of mitochondrial cyt c in cytosolic extracts of CHO cells exposed to apoptogenic doses of sodium chromate. Co-treatment of these cells with csA inhibited the release of cyt c and abrogated Cr(VI)-induced apoptosis as determined by a reduction in internucleosomal DNA fragmentation. Co-treatment with csA also markedly increased clonogenic survival of Cr(VI)-treated CHO cells. In contrast, the general caspase inhibitor Z-VAD-FMK markedly inhibited most of the morphological and biochemical parameters of apoptosis but did not prevent cyt c release and did not increase clonogenic survival. These results suggest that the MPT plays an important role in the regulation of mitochondrial cyt c release and that this may be a critical point in the apoptotic pathway in which cells are irreversibly committed to death.

Authors

Pritchard, DE; Singh, J; Carlisle, DL; Patierno, SR

MLA Citation

Pritchard, D. E., et al. “Cyclosporin A inhibits chromium(VI)-induced apoptosis and mitochondrial cytochrome c release and restores clonogenic survival in CHO cells..” Carcinogenesis, vol. 21, no. 11, Nov. 2000, pp. 2027–33. Pubmed, doi:10.1093/carcin/21.11.2027.

PMID

11062164

Source

pubmed

Published In

Carcinogenesis

Volume

21

Issue

11

Publish Date

2000

Start Page

2027

End Page

2033

DOI

10.1093/carcin/21.11.2027

Eicosanoids modulate the interaction of tumor cells with various host components in cancer metastasis. Their synthesis involves the release of arachidonic acid (AA) from cellular phospholipids by phospholipase A2 (PLA2), followed by metabolism by cyclooxygenases (COXs) and lipooxygenases (LOXs). This study aimed to identify the pathway(s) of AA metabolism that are required for the invasion of prostate tumor cells. DU-145 and PC-3 human prostate cancer cell lines were used to test the effect of inhibitors of PLA2, COX, or LOX on the invasion of prostate tumor cells through Matrigel in vitro using the Boyden chamber assay and fibroblast-conditioned medium as the chemoattractant. We used nontoxic doses that did not inhibit simple cell motility and did not decrease clonogenic survival. All of the inhibitors caused a significant reduction in AA release from treated cells compared with control cells, which indicated that the treatments were biochemically active. Invasion through Matrigel was inhibited by the PLA2 inhibitor 4-bromophenacyl bromide (4-BPB), the general COX inhibitor ibuprofen (IB), and the highly selective COX-2 inhibitor NS398. Inhibition of cell invasiveness by 4-BPB (1.0 microM), IB (10.0 microM), and NS398 (10.0 microM) was reversed by the addition of prostaglandin E2 (PGE2). PGE2 alone, however, did not stimulate invasiveness, which suggests that its production is necessary for rendering the cells invasive-permissive but not sufficient for inducing invasiveness. In contrast, we found no significant inhibition of invasion of prostate tumor cells treated with esculetin (1.0 microM) or nordihydroguiaretic acid (1.0 microM), which are specific inhibitors of LOX. We also tested the effect of 4-BPB, IB, NS398, and esculetin on the secretion of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), as key enzymes in the proteolysis of Matrigel during invasion, using gelatin zymograms and Western blots. Cells that received 4-BPB, IB, or NS398, but not esculetin showed a significant reduction in the levels of proMMP-2, MMP-9, and proMMP-9 in the culture medium. DU-145 cells did not secrete TIMP-1, and the drugs did not alter the secretion of TIMP-2. This work highlights the role played by COX in disturbing the balance between MMPs and TIMPs in prostate cancer cells, and it points to the potential use of COX inibitors, especially COX-2 selective inhibitors, in the prevention and therapy of prostate cancer invasion.

Authors

Attiga, FA; Fernandez, PM; Weeraratna, AT; Manyak, MJ; Patierno, SR

MLA Citation

Attiga, F. A., et al. “Inhibitors of prostaglandin synthesis inhibit human prostate tumor cell invasiveness and reduce the release of matrix metalloproteinases..” Cancer Res, vol. 60, no. 16, Aug. 2000, pp. 4629–37.

PMID

10969817

Source

pubmed

Published In

Cancer Research

Volume

60

Issue

16

Publish Date

2000

Start Page

4629

End Page

4637

Authors

Waalkes, MP; Fox, DA; States, JC; Patierno, SR; McCabe, MJ

MLA Citation

Waalkes, M. P., et al. “Metals and disorders of cell accumulation: modulation of apoptosis and cell proliferation..” Toxicol Sci, vol. 56, no. 2, Aug. 2000, pp. 255–61. Pubmed, doi:10.1093/toxsci/56.2.255.

PMID

10910982

Source

pubmed

Published In

Toxicological Sciences

Volume

56

Issue

2

Publish Date

2000

Start Page

255

End Page

261

DOI

10.1093/toxsci/56.2.255

Some forms of hexavalent chromium [Cr(VI)] are known to cause damage to respiratory-tract tissue and DNA and are thought to be human lung carcinogens. In general, Cr(VI) is mutagenic and carcinogenic at doses that also evoke some cell death, and we previously showed that the predominant mode of death is apoptosis. Because p53 has been shown to initiate apoptosis after genotoxic insults, the objective of these experiments was to determine whether p53 is activated in and necessary for apoptosis of normal diploid human lung fibroblasts (HLF cells) after chromium exposure. By using annexin(V) staining and fluorescent microscopy, we found that Cr(VI) caused up to 14% of HLF cells to undergo apoptosis within 24 h after exposure. In addition, by using western blotting, we found that p53 protein levels increased fourfold to sixfold after exposure to sodium chromate. Because the major function of p53 is as a transcription factor, it must be translocated from the cytoplasm to the nucleus after chromate exposure to be active. Immunofluorescence studies using an antibody against p53 showed that, after chromate exposure, p53 was located in the nucleus of the treated HLF cells. The necessity of p53 for chromium-induced apoptosis was examined in two ways. One approach used dermal fibroblasts from p53 wild-type, heterozygous, and null mice, and the other approach used HLF cells that were transiently transfected with the human papilloma virus E6 gene, which targets p53 for degradation and creates a functional p53-null cell. These studies showed that chromium-induced apoptosis was p53 dependent. Mol. Carcinog. 28:111-118, 2000.

Authors

Carlisle, DL; Pritchard, DE; Singh, J; Patierno, SR

MLA Citation

Carlisle, D. L., et al. “Chromium(VI) induces p53-dependent apoptosis in diploid human lung and mouse dermal fibroblasts..” Mol Carcinog, vol. 28, no. 2, June 2000, pp. 111–18.

PMID

10900468

Source

pubmed

Published In

Molecular Carcinogenesis

Volume

28

Issue

2

Publish Date

2000

Start Page

111

End Page

118

Some forms of hexavalent chromium [Cr(VI)] are known to cause damage to respiratory tract tissue, and are thought to be human lung carcinogens. Because Cr(VI) is mutagenic and carcinogenic at doses that evoke cell toxicity, the objective of these experiments was to examine the effect of Cr(VI) on the growth, survival, and mode of cell death in normal human lung fibroblasts (HLF cells). DNA adduct formation was monitored as a marker for bioavailability of genotoxic chromium. We also examined the modulation of these endpoints by vitamins C and E. Long-term Cr(VI) exposures were employed, which decreased clonogenic cell survival by 25% to 95% in a dose-dependent manner. The predominant cellular response to Cr(VI) was growth arrest. We found that Cr(VI) caused up to 20% of HLF cells to undergo apoptosis, and documented apoptotic morphology and the phagocytosis of apoptotic bodies by neighboring cells. P53 levels increased 4- to 6-fold in chromium-treated cells. In contrast with previous studies using CHO cells, the present study using HLFs found that pretreatment with either vitamin C or E did not exhibit a significant effect on Cr-induced apoptosis or clonogenic survival. In addition, pretreatment with vitamin C did not affect the p53 induction observed after chromium treatment. Neither vitamin had any effect on Cr-DNA adduct formation. These data indicate that although pretreatment with vitamin C or E alters the spectrum of cellular and/or genetic lesions induced by chromium(VI), neither vitamin altered the initiation or progression of apoptosis in diploid human lung cells.

Authors

Carlisle, DL; Pritchard, DE; Singh, J; Owens, BM; Blankenship, LJ; Orenstein, JM; Patierno, SR

MLA Citation

Carlisle, D. L., et al. “Apoptosis and P53 induction in human lung fibroblasts exposed to chromium (VI): effect of ascorbate and tocopherol..” Toxicol Sci, vol. 55, no. 1, May 2000, pp. 60–68. Pubmed, doi:10.1093/toxsci/55.1.60.

PMID

10788560

Source

pubmed

Published In

Toxicological Sciences

Volume

55

Issue

1

Publish Date

2000

Start Page

60

End Page

68

DOI

10.1093/toxsci/55.1.60

A novel method for the determination of chromium in suspensions of human lung fibroblast cells is described by using a large bore-direct injection high efficiency nebulizer (LB-DIHEN) with micro scale flow injection analysis and inductively coupled plasma mass spectrometric detection. Chromium(VI)-treated cells were first counted and then suspended in a phosphate buffer saline solution. With the use of the method of standard additions, the relative concentration of Cr in approx. 100 HLF cells/peak was determined at m/z = 50. Because the cells tend to clump and can yield inhomogeneities in the total number analyzed, Mg was used as an internal standard to compensate for the total cell mass. The level of Cr in HLF cells grown in a medium of 100 μM Na2CrO4 for two hours is on the order of 180 fg Cr/cell after correction for the number of cells in each injection.

Authors

McLean, JA; Acon, BW; Montaser, A; Singh, J; Pritchard, DE; Patierno, SR

MLA Citation

McLean, J. A., et al. “Determination of chromium in human lung fibroblast cells using a large bore-direct injection high-efficiency nebulizer with inductively coupled plasma mass spectrometry.” Applied Spectroscopy, vol. 54, no. 5, Jan. 2000, pp. 659–63. Scopus, doi:10.1366/0003702001950120.

Source

scopus

Published In

Applied Spectroscopy

Volume

54

Issue

5

Publish Date

2000

Start Page

659

End Page

663

DOI

10.1366/0003702001950120

The 78 kDa glucose-regulated stress protein GRP78 is induced by physiological stress conditions such as hypoxia, low pH, and glucose deprivation which often exist in the microenvironments of solid tumors. Activation of this stress pathway occurs in response to several pro-apoptotic stimuli. In vitro studies have demonstrated a correlation between induced expression of GRP78 and resistance to apoptotic death induced by topoisomerase II-directed drugs. We were interested in characterizing this protein in human breast lesions for potential implications in chemotherapeutic intervention. Surgical specimens of human breast lesions and paired normal tissues from the same patients were flash frozen for these studies. Total RNA and/or protein were extracted from these tissues and used in northern and/or western blot analyses, respectively, to quantify the relative expression of GRP78. Northern blot analysis indicated that 0/5 benign breast lesions, 3/5 estrogen receptor positive (ER+) breast tumors, and 6/9 estrogen receptor negative (ER-) breast tumors exhibited overexpression of GRP78 mRNA compared to paired normal tissues, with fold overexpressions ranging from 1.8 to 20. Western blot analyses correlated with these findings since 0/5 benign breast lesions, 4/6 ER+ breast tumors, and 3/3 ER- breast tumors overexpressed GRP78 protein with fold overexpressions ranging from 1.8 to 19. Immunohistochemical analysis of these tissues demonstrated that the expression of GRP78 was heterogeneous among the cells comprising different normal and malignant glands, but confirmed the overexpression of GRP78 in most of the more aggressive ER- tumors. These results suggest that some breast tumors exhibit adverse microenvironment conditions that induce the overexpression of specific stress genes that may play a role in resistance to apoptosis and decreased chemotherapeutic efficacy.

Authors

Fernandez, PM; Tabbara, SO; Jacobs, LK; Manning, FC; Tsangaris, TN; Schwartz, AM; Kennedy, KA; Patierno, SR

MLA Citation

Fernandez, P. M., et al. “Overexpression of the glucose-regulated stress gene GRP78 in malignant but not benign human breast lesions..” Breast Cancer Res Treat, vol. 59, no. 1, Jan. 2000, pp. 15–26.

PMID

10752676

Source

pubmed

Published In

Breast Cancer Research and Treatment

Volume

59

Issue

1

Publish Date

2000

Start Page

15

End Page

26

Stress conditions associated with solid tumors lead to the formation of heterogeneous tumor cell subpopulations and insensitivity to cancer chemotherapeutics. In this report, we show that EMT6 mouse mammary tumor cells treated with the chemical stress, brefeldin A (BFA), or the physiological stress, hypoxia, develop resistance to the topoisomerase II (topoII) inhibitors teniposide and etoposide. BFA and hypoxia treatment did not alter intracellular drug concentrations, topoll protein levels, or inhibit topoII activity. BFA and hypoxia did cause the activation of the nuclear transcription factor NF-kappaB. We demonstrate that pretreatment with the synthetic cyclopentenone prostaglandin A1 (PGA1) inhibits stress-induced NF-kappaB activation and reverses BFA- and hypoxia-induced resistance. The reversal of BFA-induced resistance can occur when PGA1 is administered either before or several hours after the induction of stress. Taken together, these data support the involvement of NF-kappaB in stress-induced drug resistance, show that pharmacologic inhibitors of NF-kappaB can disrupt the biological consequences of stress, and imply that inhibitors of NF-kappaB may be useful agents to enhance the clinical efficacy of topoII-directed chemotherapeutics.

Authors

Boller, YC; Brandes, LM; Russell, RL; Lin, ZP; Patierno, SR; Kennedy, KA

MLA Citation

Boller, Y. C., et al. “Prostaglandin A1 inhibits stress-induced NF-kappaB activation and reverses resistance to topoisomerase II inhibitors..” Oncol Res, vol. 12, no. 9–10, 2000, pp. 383–95.

PMID

11697817

Source

pubmed

Published In

Oncology Research

Volume

12

Issue

9-10

Publish Date

2000

Start Page

383

End Page

395

Occupational exposure to certain particulate hexavalent chromium [Cr(VI)] compounds, such as lead chromate, has been associated with lung cancer and respiratory tract toxicity. We have previously shown that apoptosis is a major mode of death in cultured rodent cells treated with soluble sodium chromate and particulate lead chromate. Here we report the cellular and molecular effects of lead chromate and sodium chromate in normal human lung small airway epithelial (HSAE) cells, which may be one of the targets for Cr(VI)-induced lung cancer and respiratory tract toxicity. Phagocytosed lead chromate particles and intracellular lead-inclusion bodies (LIB) were observed by transmission electron microscopy and confirmed by X-ray analysis. HSAE cells exposed to lead chromate and sodium chromate underwent dose-dependent apoptosis. The cellular uptake and genomic interactions of both Cr and lead (Pb) were examined by inductively coupled plasma mass spectrometry (ICPMS) coupled with a novel, direct-injection high-efficiency nebulizer (DIHEN). Using this approach, we have quantitated a dose-dependent formation of Cr-DNA adducts and DNA-associated Pb in lead chromate-treated HSAE cells. The formation of LIB in normal human lung cells exposed to lead chromate indicates that ionic Pb is released from the particles and thus might contribute to the cell toxicity caused by lead chromate. Internalization and dissolution of lead chromate particles and the interaction of ionic Cr and Pb with DNA, may be components of the mechanism of lead chromate carcinogenesis. Lead chromate-induced apoptosis may be a mechanism to eliminate cells with chromium- and/or lead-damaged DNA.

Authors

Singh, J; Pritchard, DE; Carlisle, DL; Mclean, JA; Montaser, A; Orenstein, JM; Patierno, SR

MLA Citation

Singh, J., et al. “Internalization of carcinogenic lead chromate particles by cultured normal human lung epithelial cells: formation of intracellular lead-inclusion bodies and induction of apoptosis..” Toxicol Appl Pharmacol, vol. 161, no. 3, Dec. 1999, pp. 240–48. Pubmed, doi:10.1006/taap.1999.8816.

PMID

10620481

Source

pubmed

Published In

Toxicology and Applied Pharmacology

Volume

161

Issue

3

Publish Date

1999

Start Page

240

End Page

248

DOI

10.1006/taap.1999.8816

A novel method is described for the sensitive detection of chromium-DNA adducts. Chromium-DNA adducts were determined in 1 microgram of DNA from normal human lung fibroblasts exposed to sodium chromate using microscale flow injection analysis with a direct injection high-efficiency nebulizer and inductively coupled plasma mass spectrometry detection. The frequency of Cr-DNA adducts increased in a dose-dependent sigmoidal manner, indicating saturation and toxicity. The low detection limits (on the order of parts per trillion) allows the detection of as few as two Cr adducts per 10,000 bases, which, coupled with the small DNA sample requirement, makes this technique suitable for measuring metal-DNA adducts as biomarkers of exposure to toxic and carcinogenic metals such as Cr, in cultured cells, animals, and humans.

Authors

Singh, J; McLean, JA; Pritchard, DE; Montaser, A; Patierno, SR

MLA Citation

Singh, J., et al. “Sensitive quantitation of chromium-DNA adducts by inductively coupled plasma mass spectrometry with a direct injection high-efficiency nebulizer..” Toxicol Sci, vol. 46, no. 2, Dec. 1998, pp. 260–65. Pubmed, doi:10.1006/toxs.1998.2512.

PMID

10048129

Source

pubmed

Published In

Toxicological Sciences

Volume

46

Issue

2

Publish Date

1998

Start Page

260

End Page

265

DOI

10.1006/toxs.1998.2512

We have previously shown that trivalent chromium, and hexavalent chromium in the presence of one of its primary in vivo reductants, ascorbate, can bind to DNA and form interstrand crosslinks capable of obstructing replication. This effect was demonstrated in vitro by using Sequenase Version 2.0 T7 DNA polymerase; its parent enzyme, the unmodified T7 DNA polymerase; and Escherichia coli polymerase I large (Klenow) fragment; and it was demonstrated ex vivo by using Taq polymerase and DNA from chromium-treated human lung cells as template. This study was performed to determine whether DNA-bound chromium affects mammalian DNA polymerases in the same manner. Two mammalian enzymes, DNA polymerase alpha and DNA polymerase beta, were used. DNA polymerase alpha is a processive enzyme believed to be the primary lagging-stand synthetase, whereas DNA polymerase beta is a non-processive enzyme believed to function in DNA repair by filling single stranded gaps one base at a time. DNA polymerase arrest assays were performed with each of these enzymes to replicate DNA with toxicologically relevant levels of chromium adducts produced by either trivalent chromium or hexavalent chromium and ascorbate. Both enzymes responded to chromium-DNA damage by arresting replication, and the arrests increased in a dose-dependent manner. Furthermore, the guanine-specific pattern of arrests produced when an exonuclease-free preparation of DNA polymerase beta was used corresponded exactly to the arrest patterns produced in vitro by the exonuclease-free enzyme Sequenase and ex vivo by Taq polymerase. These results suggest that replication arrest may be a common response of polymerases to DNA-chromium lesions and provide a plausible mechanism for the inhibition of DNA synthesis and S-phase cell-cycle delay that occurs in mammalian cells treated with genotoxic chromium compounds.

Authors

Bridgewater, LC; Manning, FC; Patierno, SR

MLA Citation

Bridgewater, L. C., et al. “Arrest of replication by mammalian DNA polymerases alpha and beta caused by chromium-DNA lesions..” Mol Carcinog, vol. 23, no. 4, Dec. 1998, pp. 201–06.

PMID

9869448

Source

pubmed

Published In

Molecular Carcinogenesis

Volume

23

Issue

4

Publish Date

1998

Start Page

201

End Page

206

The adverse health effects linked with chromium (Cr) exposure, the role of solubility and chemical speciation of Cr compounds, and the diverse cellular and molecular effects of Cr make the study of Cr carcinogenesis and toxicology very interesting and complex. Certain Cr compounds are prominent metal carcinogens in both occupational and environmental settings. Inhaled particulate forms of hexavalent Cr [Cr(VI)] cause lung cancer as well as lung toxicity. Some of the important factors in determining the biological outcome of Cr exposure include the bioavailability, chemical speciation and solubility of Cr compounds, intracellular reduction, and interaction of Cr with DNA. The stable oxidation states of Cr found in nature are Cr(III) and Cr(VI). Cr(III) is unable to enter cells but Cr(VI) enters into cells through membrane anionic transporters. Intracellular Cr(VI) is metabolically reduced to the ultimate Cr(III). Cr(VI) does not react with macromolecules such as DNA, RNA, proteins and lipids. However, both Cr(III) and the reductional intermediate Cr(V) are capable of co-ordinate covalent interactions with macromolecules. At the genomic level, Cr genotoxicity manifests as gene mutations, several types of DNA lesions and inhibition of macromolecular synthesis. At the cellular level, Cr exposure may lead to cell cycle arrest, apoptosis, premature terminal growth arrest, or neoplastic transformation. Cr-induced DNA-DNA interstrand crosslinks (DDC), the tumor suppressor gene p53 and oxidative processes are some of the major factors that may play a significant role in determining the cellular outcome in response to Cr exposure. We have utilized cellular, molecular, pharmacological, and genetic approaches to understand the interrelationship between Cr-induced genotoxicity, apoptosis and carcinogenesis. This review is based on the results and inferences of this research. We hope this review will clarify existing concepts and also introduce novel perspectives in chromium carcinogenesis research.

Authors

Singh, J; Carlisle, DL; Pritchard, DE; Patierno, SR

MLA Citation

Singh, J., et al. “Chromium-induced genotoxicity and apoptosis: relationship to chromium carcinogenesis (review)..” Oncol Rep, vol. 5, no. 6, Nov. 1998, pp. 1307–18. Pubmed, doi:10.3892/or.5.6.1307.

PMID

9769362

Source

pubmed

Published In

Oncology Reports

Volume

5

Issue

6

Publish Date

1998

Start Page

1307

End Page

1318

DOI

10.3892/or.5.6.1307

Some compounds of hexavalent chromium are well-established carcinogens. Chromium enters mammalian cells in the hexavalent form and is reduced to chromium (III). Treatment of purified DNA with chromium (III) produces DNA-DNA interstrand crosslinks (DDC) which obstruct the progression of DNA polymerases in vitro. DDC were also detected in chromate-treated cultured normal human lung cells using the renaturing agarose gel electrophoresis (RAGE) assay and correlated with base-specific inhibition of DNA replication. Curiously, DDC have gone undetected in studies of cultured cells using the alkaline elution (AE) technique, whereas chromium-mediated DNA-protein crosslinks (DPC) were readily detected by AE. We tested the hypothesis that AE conditions [60 mM tetraethyl ammonium hydroxide (TEA), 20 mM EDTA, pH 12.6, for 16 h at room temperature] dissociate DDC but not DPC using chromium(III)-treated plasmid DNA and the RAGE assay. Dose-dependent chromium-induced DDC were unaffected by TEA (pH 11.8) alone or by more rigorous alkaline denaturation conditions (200 mM NaOH, pH 13.5, for 16 h). DDC were, however, completely disrupted by EDTA (pH 12.6) alone or the combination of TEA and EDTA (pH 12.6). In contrast, DPC remained largely intact under these conditions. Therefore, past AE-based studies which have failed to detect chromium-induced DDC do not prove the absence of this lesion. AE may not be suitable for detecting DDC induced by EDTA-chelatable agents such as metals.

Authors

Singh, J; Bridgewater, LC; Patierno, SR

MLA Citation

Singh, J., et al. “Differential sensitivity of chromium-mediated DNA interstrand crosslinks and DNA-protein crosslinks to disruption by alkali and EDTA..” Toxicol Sci, vol. 45, no. 1, Sept. 1998, pp. 72–76. Pubmed, doi:10.1006/toxs.1998.2489.

PMID

9848113

Source

pubmed

Published In

Toxicological Sciences

Volume

45

Issue

1

Publish Date

1998

Start Page

72

End Page

76

DOI

10.1006/toxs.1998.2489

Brefeldin A, an agent that disrupts protein transport from the endoplasmic reticulum to the Golgi, induces the expression of GRP78 and the activation of nuclear factor (NF)-kappaB in cells. Treatment of cells with brefeldin A causes the development of resistance to topoisomerase II-directed agents, such as etoposide and doxorubicin. In this study, we show that treatment of EMT6 mouse mammary tumor cells with brefeldin A strongly induces GRP78 mRNA (8.5-fold) and resistance to teniposide (VM26). Treatment with okadaic acid causes a minor increase in GRP78 mRNA (2.1-fold) yet still induces resistance to VM26 as effectively as brefeldin A. In contrast, cells treated with castanospermine show a moderate increase in GRP78 mRNA (3.9-fold) but no resistance to VM26. These data imply that GRP78 induction does not mediate the development of drug resistance. An alternative mechanism of drug resistance may involve activation of the transcription factor, NF-kappaB, and we show that both brefeldin A and okadaic acid activate NF-kappaB in EMT6 cells. Furthermore, we demonstrate that treatment with the proteasome inhibitor MG-132 blocks the activation of NF-kappaB and prevents the development of resistance to VM26 induced by brefeldin A. Collectively, these results suggest that the resistance to VM26 in EMT6 cells treated with brefeldin A is mediated by the activation of NF-kappaB rather than the induction of GRP78. Our results also suggest that inhibition of NF-kappaB activation in tumor cells may increase the efficacy of topoisomerase II-directed agents in chemotherapy.

Authors

Lin, ZP; Boller, YC; Amer, SM; Russell, RL; Pacelli, KA; Patierno, SR; Kennedy, KA

MLA Citation

Lin, Z. P., et al. “Prevention of brefeldin A-induced resistance to teniposide by the proteasome inhibitor MG-132: involvement of NF-kappaB activation in drug resistance..” Cancer Res, vol. 58, no. 14, July 1998, pp. 3059–65.

PMID

9679971

Source

pubmed

Published In

Cancer Research

Volume

58

Issue

14

Publish Date

1998

Start Page

3059

End Page

3065

We have shown previously that the secretory protein uteroglobin (UG) is highly expressed in normal human prostate tissue but this expression is either lost or altered in human prostate cancer cell lines. Treatment of these cell lines with recombinant human UG inhibits their ability to invade human reconstituted basement membrane by up to 90%, implying that the loss of normal UG expression may be related to the invasive potential of prostate cancer. Because invasion represents a critical step in metastasis, the expression patterns of UG could provide a unique and relevant indicator of cancer progression. In this study, we present the immunohistochemical analyses of fresh frozen prostate tissues from surgical specimens taken from 50 patients. Eight slides per patient were analyzed for UG staining. Slides from 26 patients showed evidence of prostate cancer, whereas slides from the remaining 24 patients showed only benign glands. The results demonstrate UG immunoreactivity in normal prostate, benign prostatic hyperplasia, and prostatic atrophy; low but clearly positive expression in prostatic intraepithelial neoplasia; positive expression in cancerous glands of Gleason's pattern

Authors

Weeraratna, AT; Cajigas, JA; Schwartz, A; Enquist, EG; Manyak, MJ; Patierno, SR

MLA Citation

Weeraratna, A. T., et al. “Loss of uteroglobin expression in prostate cancer: relationship to advancing grade..” Clin Cancer Res, vol. 3, no. 12 Pt 1, Dec. 1997, pp. 2295–300.

PMID

9815627

Source

pubmed

Published In

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research

Volume

3

Issue

12 Pt 1

Publish Date

1997

Start Page

2295

End Page

2300

Certain hexavalent chromium compounds are documented human carcinogens. Exposure of cells to particulate forms of chromium results in cell-enhanced dissolution of particles in the extracellular microenvironment and chronic production of chromium oxyanions, which are taken up by the cell through an anion transport system and are genotoxic and clastogenic. It was previously shown that apoptosis is the mode of cell death of nearly all of the Chinese hamster ovary cells (CHO-AA8 cell line), which die after high-dose, short-term treatments with soluble sodium chromate. In this report the mode of cell killing by particulate lead chromate and of low-dose continuous treaments of soluble sodium chromate designed to mimic conditions of ionic chromate uptake after lead chromate exposure was examined. CHO-AA8 cells were treated for 24 hr with doses of sodium chromate or lead chromate which cause a 50% decrease in survival in colony-forming effeciency assays. Longer treatments (up to 72 hr) at the same doses did not decrease survival further than the 24-hr exposure. Morphological changes indicative of apoptosis, as well as internucleosomal DNA fragmentation, were detectable by 24 hr after treatment with lead chromate or soluble sodium chromate. All of the cells killed by treatments with lead chromate particles underwent apoptosis as the mode of cell death and this was accurately modeled in cell culture by continuous treatments with low-dose soluble sodium chromate. Exposure of cells to hexavalent chromium compounds causes a spectrum of DNA damage which can be selectively altered by pretreatment of cells with antioxidant vitamins prior to chromium exposure. Here we show that ascorbate and alpha-tocopherol markedly inhibited the chromosomal aberrations induced by both particulate and soluble chromate compounds, even though chromium adduct levels were not decreased by either vitamin pretreatment. Cell survival assays showed that ascorbate, but not alpha-tocopherol, protected cells from apoptosis induced by sodium chromate. The results differentiate chromium-induced apoptosis from both chromosomal damage and adduct levels and suggest that other lesions sensitive to ascorbate but not tocopherol are the proximal inducing signal for chromium-induced apoptosis.

Authors

Blankenship, LJ; Carlisle, DL; Wise, JP; Orenstein, JM; Dye, LE; Patierno, SR

MLA Citation

Blankenship, L. J., et al. “Induction of apoptotic cell death by particulate lead chromate: differential effects of vitamins C and E on genotoxicity and survival..” Toxicol Appl Pharmacol, vol. 146, no. 2, Oct. 1997, pp. 270–80. Pubmed, doi:10.1006/taap.1997.8237.

PMID

9344895

Source

pubmed

Published In

Toxicology and Applied Pharmacology

Volume

146

Issue

2

Publish Date

1997

Start Page

270

End Page

280

DOI

10.1006/taap.1997.8237

In order to test the hypothesis that integrin and uteroglobin (UG) expression in cultured endometrial cells are affected by hormone treatment, Ishikawa-CH endometrial cancer cells were cultured and exposed to oestradiol or oestradiol and progesterone regimens and assayed using immunohistochemistry. We evaluated the intensity of immunohistochemical staining for the integrin monomers alpha(v) and beta1, the dimers alpha(v)beta3 and alpha(v)beta6, and for the secretory protein uteroglobin under various experimental conditions. Cells grown in control media stained positively for the integrin monomers alpha(v) and beta1, the dimer alpha(v)beta3, and for UG. Oestradiol and sequential oestradiol/progesterone reversibly suppressed staining for the dimer alpha(v)beta3. Hormone treatment had no effect on the staining of the beta1 and alpha(v) monomers or UG. The alpha(v)beta6 dimer antibody did not stain under any experimental treatment conditions. These data indicate that expression of the integrin complex alpha(v)beta3 is reversibly suppressed by oestradiol in Ishikawa cells and that these cells may be a good model for studying hormone-driven molecular changes in endometrium.

Authors

Widra, EA; Weeraratna, A; Stepp, MA; Stillman, RJ; Patierno, SR

MLA Citation

Widra, E. A., et al. “Modulation of implantation-associated integrin expression but not uteroglobin by steroid hormones in an endometrial cell line..” Mol Hum Reprod, vol. 3, no. 7, July 1997, pp. 563–68. Pubmed, doi:10.1093/molehr/3.7.563.

PMID

9268133

Source

pubmed

Published In

Molecular Human Reproduction

Volume

3

Issue

7

Publish Date

1997

Start Page

563

End Page

568

DOI

10.1093/molehr/3.7.563

In 1992, a simple and sensitive assay for detecting DNA-protein crosslinks was developed [1]. In an effort to facilitate the greater use of the assay, a number of studies were conducted to evaluate its reliability and reproducibility. During this work, the assay was used to assess whether various metals and other compounds could induce crosslinks in cultured human lymphocytes (Epstein-Barr virus-transformed Burkitt's Lymphoma cell line). Potassium permanganate, mercury chloride, lead nitrate, magnesium perchlorate, aluminum chloride, and cadmium chloride did not induce DNA-protein crosslinks at either cytotoxic or non-cytotoxic levels. Copper sulfate, arsenic trioxide, and potassium chromate induced DNA-protein crosslinks only at cytotoxic concentrations. Acute lethality of the cells was assessed immediately after exposure to metals by trypan blue exclusion while long-term lethality was assessed by cell proliferation and trypan blue exclusion following an incubation period of 5 days after exposure to the metal compound. All metals exhibited more toxicity in the long-term lethality assay compared to the short-term assay. The cultured human lymphocytes treated with various doses of lead acetate, cadmium chloride, arsenic trioxide and copper sulfate, as well as cis-platinum and chromate, were sent to four different laboratories to compare the reliability and reproducibility of the DNA-protein crosslink assay. Depending on the chemical studied, there were quantitative differences in the results observed among the various laboratories using the assay. However, all laboratories generally showed that cis-platinum, chromate, arsenic trioxide and copper sulfate induced DNA-protein crosslinks at levels that produced acute cytotoxicity, whereas cadmium chloride and lead acetate did not.

Authors

Costa, M; Zhitkovich, A; Gargas, M; Paustenbach, D; Finley, B; Kuykendall, J; Billings, R; Carlson, TJ; Wetterhahn, K; Xu, J; Patierno, S; Bogdanffy, M

MLA Citation

Costa, M., et al. “Interlaboratory validation of a new assay for DNA-protein crosslinks..” Mutat Res, vol. 369, no. 1–2, July 1996, pp. 13–21. Pubmed, doi:10.1016/s0165-1218(96)90043-9.

PMID

8700178

Source

pubmed

Published In

Mutation Research

Volume

369

Issue

1-2

Publish Date

1996

Start Page

13

End Page

21

DOI

10.1016/s0165-1218(96)90043-9

Previous studies have shown that in vitro treatment of a synthetic double-stranded DNA template with chromium(III), or chromium(VI) in the presence of ascorbate, resulted in guanine-specific DNA polymerase arrests that correlated strongly with DNA-DNA cross-linking. In vivo chromium(VI) undergoes a more complicated intracellular cascade of reductive metabolism than is achievable in an in vitro model. Moreover, in living cells, DNA is highly packaged in the form of chromatin which may alter the accessibility of DNA to chromium. A repetitive primer-extension assay was employed to determine whether chromium forms polymerase-arresting lesions in vivo. Normal human lung fibroblasts treated with chromium(VI) exhibited adduct levels of 0.13-0.92 mmol Cr/mol DNA-nucleotides in the total genome (0.26-1.84 Cr adducts/Kbp DNA) and DNA interstrand cross-links. Genomic DNA was isolated and alphoid sequences (1-5% of the genome) were used as a substrate for repetitive primer extension using Taq polymerase. The results showed a dose-dependent, guanine-specific, replication termination, even at low doses resulting in greater than 90% survival. The same treatment resulted in dose-dependent suppression of thymidine incorporation into DNA immediately after treatment. Thymidine incorporation increased during the first 6 h after the 2-h exposure, probably related to the repair of the single strand breaks, but then returned to high suppression levels at 24 h. The chromate treatments inhibited cell growth by specific blocking of the progression of cells through S-phase of the cell cycle. The results confirmed our studies in cell-free systems and taken together they strongly indicate that guanine-guanine DNA interstrand cross-links induced by chromate in living cells is the lesion responsible for blocking DNA replication processivity.

Authors

Xu, J; Bubley, GJ; Detrick, B; Blankenship, LJ; Patierno, SR

MLA Citation

Xu, J., et al. “Chromium(VI) treatment of normal human lung cells results in guanine-specific DNA polymerase arrest, DNA-DNA cross-links and S-phase blockade of cell cycle..” Carcinogenesis, vol. 17, no. 7, July 1996, pp. 1511–17. Pubmed, doi:10.1093/carcin/17.7.1511.

PMID

8706257

Source

pubmed

Published In

Carcinogenesis

Volume

17

Issue

7

Publish Date

1996

Start Page

1511

End Page

1517

DOI

10.1093/carcin/17.7.1511

The anticancer drug cis-diamminedichloroplatinum(II) (cisplatin) has been shown previously to form adducts preferentially within internucleosomal or linker DNA rather than to DNA within the nucleosome. To determine whether other "open" regions of chromatin have an increased affinity for cisplatin, adduct formation within specific chromatin domains was analyzed. There was a significant increase in cisplatin-DNA adduct formation for DNA associated with the nuclear matrix (NM) compared with other chromatin domains and total unfractionated DNA. In contrast, treatment of the same cells with trans-diamminedichloroplatinum(II) (transplatin) did not result in preferential adduct formation. These findings led to the hypothesis that it might be possible to alter DNA to make it a more favorable target for cisplatin. The effect of arginine butyrate on cisplatin-DNA adduct formation was analyzed in human cancer cells. The combination of arginine butyrate and cisplatin resulted in a concentration-responsive increase in cisplatin-DNA adduct formation in PC-3 cells and an overall increase in cisplatin-DNA adduct formation in three other human cancer cell lines. The same combination also resulted in a significant increase in drug-induced cytotoxicity at a low concentration of cisplatin. These results suggest that chromatin configuration can affect cisplatin adduct formation.

Authors

Bubley, GJ; Xu, J; Kupiec, N; Sanders, D; Foss, F; O'Brien, M; Emi, Y; Teicher, BA; Patierno, SR

MLA Citation

Bubley, G. J., et al. “Effect of DNA conformation on cisplatin adduct formation..” Biochem Pharmacol, vol. 51, no. 5, Mar. 1996, pp. 717–21. Pubmed, doi:10.1016/s0006-2952(95)02256-2.

PMID

8615910

Source

pubmed

Published In

Biochemical Pharmacology

Volume

51

Issue

5

Publish Date

1996

Start Page

717

End Page

721

DOI

10.1016/s0006-2952(95)02256-2

Carcinogenesis is considered to require an initiating event that results in an irreversible genetic change in a subpopulation of cells. Based on the available evidence, it seems likely that apoptosis may act to attenuate this process by causing the deletion of genetically damaged cells from the host organism. Nevertheless, the existence of an active pathway leading to apoptotic cell death may be a double-edged sword, simply because it can be overcome. Some cells may exhibit preexisting genetic or epigenetic insensitivity to induction of apoptosis. Surviving cells may contain sub- lethal levels of DNA damage and be induced to proliferate as an indirect result of the carcinogen-induced apoptotic cell death of surrounding tissue. This process would facilitate the acquisition mutations in the genome, possibly resulting in further insensitivity to apoptosis through activation of the bcl-2 oncogene or inactivation of the p53 tumor suppressor gene. In this context, the propensity of a cell to undergo apoptosis could be viewed as a selection pressure that a tumor cell must overcome. For neoplastic growth to occur, an imbalance between proliferation and apoptosis must be established such that cell growth predominates. Genetic mutations or epigenetic factors that diminish the propensity of a cell to undergo apoptosis may therefore confer on that cell a growth advantage.

Authors

Manning, FC; Patierno, SR

MLA Citation

Manning, F. C., and S. R. Patierno. “Apoptosis: inhibitor or instigator of carcinogenesis?.” Cancer Invest, vol. 14, no. 5, 1996, pp. 455–65. Pubmed, doi:10.3109/07357909609018903.

PMID

8816861

Source

pubmed

Published In

Cancer Investigation

Volume

14

Issue

5

Publish Date

1996

Start Page

455

End Page

465

DOI

10.3109/07357909609018903

Authors

Mirsalis, JC; Hamilton, CM; O'Loughlin, KG; Paustenbach, DJ; Kerger, BD; Patierno, S

MLA Citation

Mirsalis, J. C., et al. “Chromium (VI) at plausible drinking water concentrations is not genotoxic in the in vivo bone marrow micronucleus or liver unscheduled DNA synthesis assays.” Environmental and Molecular Mutagenesis, vol. 28, no. 1, 1996, pp. 60–63. Scival, doi:10.1002/(SICI)1098-2280(1996)28:1<60::AID-EM9>3.0.CO;2-I.

Source

scival

Published In

Environmental and Molecular Mutagenesis

Volume

28

Issue

1

Publish Date

1996

Start Page

60

End Page

63

DOI

10.1002/(SICI)1098-2280(1996)28:1<60::AID-EM9>3.0.CO;2-I

Authors

Mirsalis, JC; Hamilton, CM; O'Loughlin, KG; Paustenbach, DJ; Kerger, BD; Patierno, S

MLA Citation

Mirsalis, J. C., et al. “Chromium (VI) at plausible drinking water concentrations is not genotoxic in the in vivo bone marrow micronucleus or liver unscheduled DNA synthesis assays..” Environ Mol Mutagen, vol. 28, no. 1, 1996, pp. 60–63. Pubmed, doi:10.1002/(SICI)1098-2280(1996)28:1<60::AID-EM9>3.0.CO;2-I.

PMID

8698048

Source

pubmed

Published In

Environmental and Molecular Mutagenesis

Volume

28

Issue

1

Publish Date

1996

Start Page

60

End Page

63

DOI

10.1002/(SICI)1098-2280(1996)28:1<60::AID-EM9>3.0.CO;2-I

Chromium(III) complexes currently being sold as dietary supplements were tested for their ability to cause chromosomal aberrations in Chinese hamster ovary cells. Complexes were tested in soluble and particulate forms. Chromium picolinate was found to produce chromosome damage 3-fold to 18-fold above control levels for soluble doses of 0.050, 0.10, 0.50, and 1.0 mM after 24 h treatment. Particulate chromium picolinate doses of 8.0 micrograms/cm2 (corresponding to a 0.10 mM solublized dose) and 40 micrograms/cm2 (0.50 mM) produced aberrations 4-fold and 16-fold above control levels, respectively. Toxicity was measured as a decrease in plating efficiency relative to controls. The above treatments produced > or = 86% survival for all doses except 1.0 mM chromium picolinate, which produced 69 +/- 10% survival. Chromium nicotinate, nicotinic acid, and chromium(III) chloride hexahydrate did not produce chromosome damage at equivalent nontoxic doses. Damage was inferred to be caused by the picolinate ligand because picolinic acid in the absence of chromium was clastogenic. Data are evaluated in terms of their relevance to human exposure based on pharmacokinetic modeling of tissue accumulation and are discussed in terms of literature reporting toxic effects of picolinic acid.

Authors

Stearns, DM; Wise, JP; Patierno, SR; Wetterhahn, KE

MLA Citation

Stearns, D. M., et al. “Chromium(III) picolinate produces chromosome damage in Chinese hamster ovary cells..” Faseb J, vol. 9, no. 15, Dec. 1995, pp. 1643–48.

PMID

8529845

Source

pubmed

Published In

Faseb Journal

Volume

9

Issue

15

Publish Date

1995

Start Page

1643

End Page

1648

The ability of reduced peptide bond analogues of gastrin releasing peptide (GRP) to antagonize small cell lung cancer (SCLC) GRP receptors was investigated. BW462U89, BW1023U90, BW2123U89 and BW2258U89 inhibited binding of (125I-Tyr4) BN to NCI-H345 cells with IC50 values of 5, 6, 140 and 10 nM respectively. The GRP analogues had no effect on basal cytosolic Ca2+ but inhibited the increase caused by 10 nM BN. BW462U89 reversibly blocked the increase in cytosolic Ca2+ caused by BN. The GRP analogues (1 microM) inhibited NCI-H345 colony formation in the absence or presence of 10 nM BN. Also, BW2258U89 (0.4 mg/kg, s.c. daily) inhibited xenograft growth in nude mice. These data indicate that BW2258U89 inhibits SCLC growth in vitro and in vivo.

Authors

Moody, TW; Venugopal, R; Zia, F; Patierno, S; Leban, JJ; McDermed, J

MLA Citation

Moody, T. W., et al. “BW2258U89: a GRP receptor antagonist which inhibits small cell lung cancer growth..” Life Sci, vol. 56, no. 7, 1995, pp. 521–29. Pubmed, doi:10.1016/0024-3205(94)00481-7.

PMID

7869832

Source

pubmed

Published In

Life Sciences

Volume

56

Issue

7

Publish Date

1995

Start Page

521

End Page

529

DOI

10.1016/0024-3205(94)00481-7

We have previously shown that trivalent chromium can bind to purified DNA and form lesions capable of obstructing DNA replication in vitro. Trivalent chromium is not, however, carcinogenic to humans. Rather, it is the end product of the intracellular reduction of hexavalent chromium, which is carcinogenic. The process of chromium reduction yields several reactive intermediates which may also interact with DNA, perhaps producing different lesions than those generated when trivalent chromium binds DNA. The present study was undertaken to determine whether the treatment of DNA with hexavalent chromium in the presence of ascorbate (the intracellular reductant responsible for most in vivo chromium reduction), would also generate DNA lesions capable of obstructing replication. Using increasing chromium concentrations and a constant ascorbate:chromium ratio of 0.5:1 to generate biologically relevant adduct levels, a DNA polymerase arrest assay revealed that polymerase arresting lesions were formed and were indistinguishable from those generated by trivalent chromium, in that the most prominent arrests sites were one base upstream of guanine residues on the template strand. Measurement of the amount of chromium bound to template DNA in relation to the number of arrests demonstrated that only a subset (18.5%) of the chromium adducts were capable of causing polymerase arrest. Arrest assays performed with increasing ratios of ascorbate to chromium showed that high ratios (> or = 5:1) resulted in decreased polymerase arrests. DNA interstrand crosslinks in the arrest assay template were detected by renaturing agarose gel electrophoresis, and were shown to decrease markedly with increasing ascorbate to chromium ratios, whereas chromium binding levels remained unchanged. These results strongly implicate DNA interstrand crosslinks as the polymerase arresting lesion. The present study confirms and extends our previous study with trivalent chromium, and suggests that while the initial chemical nature of the DNA lesions formed by either trivalent chromium or reductive intermediates of hexavalent chromium may differ, their effect on DNA replication is the same.

Authors

Bridgewater, LC; Manning, FC; Patierno, SR

MLA Citation

Bridgewater, L. C., et al. “Base-specific arrest of in vitro DNA replication by carcinogenic chromium: relationship to DNA interstrand crosslinking..” Carcinogenesis, vol. 15, no. 11, Nov. 1994, pp. 2421–27. Pubmed, doi:10.1093/carcin/15.11.2421.

PMID

7955085

Source

pubmed

Published In

Carcinogenesis

Volume

15

Issue

11

Publish Date

1994

Start Page

2421

End Page

2427

DOI

10.1093/carcin/15.11.2421

Lead chromate induces chromosomal damage as a result of extracellular dissolution producing solubilized chromium and lead and we show here that the dissolution process is greatly accelerated by the presence of cells. We have sought to determine which of these ions is involved in lead chromate-induced clastogenicity. Cell-mediated extracellular dissolution of particulate lead chromate resulted in the accumulation of both solubilized chromium and solubilized lead, reaching concentrations in the extracellular medium of 15 and 1.9 microM respectively and reaching concentrations inside the cell of 2700 and 97 microM respectively. Both the extracellular and intracellular accumulation of chromium was time dependent and both the solubilized lead and chromium increased proportionately from a lower dose to a higher dose. Exposing cells to water soluble sodium chromate under conditions which produced similar time-dependent intracellular concentrations of chromium also produced a similar amount and spectrum of chromosome damage as lead chromate. In contrast, exposure to lead glutamate resulted in intracellular lead levels 438-times higher than those produced by lead chromate, but produced no chromosome damage. A higher dose of lead glutamate was weakly clastogenic, but it induced a different spectrum of chromosomal aberrations than lead chromate. Pretreatment of cells with vitamin E had no effect on the uptake of chromium, but reduced both sodium chromate- and lead chromate-induced clastogenesis by 54-93%. Vitamin E pretreatment did not affect lead glutamate-induced clastogenesis. The results of this study indicate that although lead(II) is weakly clastogenic at high doses, hexavalent chromium is the proximate clastogen in lead chromate-induced clastogenesis. Additionally, this is the first report that pretreatment of cells with vitamin E can block clastogenesis induced by particulate chromates.

Authors

Wise, JP; Stearns, DM; Wetterhahn, KE; Patierno, SR

MLA Citation

Wise, J. P., et al. “Cell-enhanced dissolution of carcinogenic lead chromate particles: the role of individual dissolution products in clastogenesis..” Carcinogenesis, vol. 15, no. 10, Oct. 1994, pp. 2249–54. Pubmed, doi:10.1093/carcin/15.10.2249.

PMID

7955062

Source

pubmed

Published In

Carcinogenesis

Volume

15

Issue

10

Publish Date

1994

Start Page

2249

End Page

2254

DOI

10.1093/carcin/15.10.2249

Hexavalent chromium (Cr) compounds are respiratory carcinogens in humans and animals. Treatment of Chinese hamster ovary cells with 150 and 300 microM sodium chromate (Na2CrO4) for 2 hr decreased colony-forming efficiency by 46 and 92%, respectively. These treatments induced dose-dependent internucleosomal fragmentation of cellular DNA beyond 24 hr after chromate treatment. This fragmentation pattern is characteristic of apoptosis as a mechanism of cell death. These treatments also induced an immediate inhibition of macromolecular synthesis and delayed progression of cells through S-phase of the cell cycle. Cell growth (as evidenced by DNA synthesis) was inhibited for at least 4 days and transcription remained suppressed for at least 32 hr. Many of the cells that did progress to metaphase exhibited chromosome damage. Chromate caused the dose-dependent formation of DNA single-strand breaks and DNA-protein cross-links, but these were repaired 8 and 24 hr after removal of the treatment, respectively. In contrast, Cr-DNA adducts (up to 1/100 base-pairs) were extremely resistant to repair and were still detectable even 5 days after treatment. Compared with other regions of the genome, DNA-protein cross-links and Cr adducts were preferentially associated with the nuclear matrix DNA of treated cells, which was 4.5-fold enriched in actively transcribed genes. Chromium adducts, formed on DNA in vitro at a similar level to that detected in nuclear matrix DNA, arrested the progression of a DNA polymerase in a sequence-specific manner, possibly through the formation of DNA-DNA cross-links.(ABSTRACT TRUNCATED AT 250 WORDS)

Authors

Manning, FC; Blankenship, LJ; Wise, JP; Xu, J; Bridgewater, LC; Patierno, SR

MLA Citation

Manning, F. C., et al. “Induction of internucleosomal DNA fragmentation by carcinogenic chromate: relationship to DNA damage, genotoxicity, and inhibition of macromolecular synthesis..” Environ Health Perspect, vol. 102 Suppl 3, Sept. 1994, pp. 159–67. Pubmed, doi:10.1289/ehp.94102s3159.

PMID

7843091

Source

pubmed

Published In

Environmental Health Perspectives

Volume

102 Suppl 3

Publish Date

1994

Start Page

159

End Page

167

DOI

10.1289/ehp.94102s3159

Uteroglobin (UG) is a potent immunomodulatory and antiinflammatory secretory protein with high levels detected in human prostate tissue. We used three human prostate cancer cell lines (DU-145, PC3-M, and LNCaP) to test the hypothesis that UG may modulate invasiveness of prostatic carcinoma cells in the Boyden chamber assay for invasion through a reconstituted basement membrane preparation. Fibroblast-conditioned medium was used as the chemoattractant. The most invasive cell line was DU-145, followed by PC3-M, whereas the androgen-dependent LNCaP cell line exhibited extremely low invasive potential. Pretreatment of DU-145 and PC3-M cells for 24 h with 0.01, 0.1, or 1.0 microM recombinant UG had no effect on basal invasiveness but inhibited fibroblast-conditioned medium-stimulated invasion in a dose-dependent manner, reaching up to 60.2 and 87.9% inhibition of DU-145 and PC3-M, respectively. UG had no effect on either cell-reconstituted basement membrane adhesion or simple chemotaxis in the absence of reconstituted basement membrane. UG also strongly inhibited the biphasic release of [14C]-labeled arachidonic acid from fibroblast-conditioned medium-stimulated DU-145 cells. These results suggest that UG may modulate prostate tumor cell invasiveness and that the mechanism may include inhibition of the arachidonic acid signal cascade.

Authors

Leyton, J; Manyak, MJ; Mukherjee, AB; Miele, L; Mantile, G; Patierno, SR

MLA Citation

Leyton, J., et al. “Recombinant human uteroglobin inhibits the in vitro invasiveness of human metastatic prostate tumor cells and the release of arachidonic acid stimulated by fibroblast-conditioned medium..” Cancer Res, vol. 54, no. 14, July 1994, pp. 3696–99.

PMID

8033085

Source

pubmed

Published In

Cancer Research

Volume

54

Issue

14

Publish Date

1994

Start Page

3696

End Page

3699

The distributions of chromium-DNA adducts and DNA-protein crosslinks induced by treatment of intact CHO cells with carcinogenic chromium were examined in distinct chromatin subfractions: a chromatin subfraction released by digestion of isolated nuclei with micrococcal nuclease (1SF, 14% of total nuclear DNA), bulk chromatin (74% of total DNA) and a nuclear matrix fraction (12% of total DNA). The identity of the matrix fraction was confirmed by hybridization of DNA from each subfraction with a cDNA probe prepared from total mRNA isolated from CHO cells, which showed that the 1SF and nuclear matrix fractions were 2.3- and 3.8-fold enriched in actively transcribed genes respectively, compared to total unfractionated DNA. Immediately following treatment of cells with 150 microM sodium chromate for 2 h the binding of chromium to each chromatin fraction was found to be non-uniform. Compared with total unfractionated nuclei, the nuclear matrix fractions were enriched in chromatin-bound chromium (3.4-fold), whereas the bulk chromatin fraction was relatively depleted (0.5-fold). Approximately 13% of nuclear chromium was associated with the detergent-soluble lipid component of nuclei. A similar distribution of chromatin-bound chromium was also apparent 24 h after the chromate treatment. Immediately after the 2 h chromate treatment, chromium-DNA adducts were detected in all the chromatin subfractions. Total nuclear and bulk chromatin DNA contained similar levels of this type of damage. The 1SF fraction was depleted approximately 3-fold in this type of damage compared with total nuclear DNA. In contrast, the nuclear matrix was markedly enriched in chromium-DNA adducts (approximately 4-fold compared with total nuclear DNA) at this time. As previously demonstrated, chromium-DNA adducts in total nuclear DNA decreased within the first 24 h, but thereafter persisted at a similar level. Chromium-DNA adducts in nuclear matrix DNA also reached maximum levels at the end of the 2 h treatment and decreased to 68% and 39% of this level by 24 and 48 h after treatment respectively. In contrast, the adduct levels in the 1SF and bulk chromatin fractions did not change up to 48 h after treatment. Chromium-induced DNA-protein crosslinks, which were stable to 8 M urea and 2% SDS, occurred almost exclusively in the nuclear matrix fraction. The crosslinks in this fraction reached a maximum level at the end of the 2 h treatment, but returned to control levels 24 h later.(ABSTRACT TRUNCATED AT 400 WORDS)

Authors

Xu, J; Manning, FC; Patierno, SR

MLA Citation

Xu, J., et al. “Preferential formation and repair of chromium-induced DNA adducts and DNA--protein crosslinks in nuclear matrix DNA..” Carcinogenesis, vol. 15, no. 7, July 1994, pp. 1443–50. Pubmed, doi:10.1093/carcin/15.7.1443.

PMID

8033323

Source

pubmed

Published In

Carcinogenesis

Volume

15

Issue

7

Publish Date

1994

Start Page

1443

End Page

1450

DOI

10.1093/carcin/15.7.1443

The role of apoptosis in the mechanism of toxicity of hexavalent chromium, a human carcinogen, was investigated. Chinese hamster ovary (CHO) cells were treated with 150 or 300 microM sodium chromate for 2 hr, doses which decreased colony-forming efficiency to 53 and 5% of control, respectively. Cell growth was inhibited at least up to Day 8 after treatment. DNA synthesis was inhibited to 30 and 19% of control at 1 hr after treatment, and did not begin to recover until Day 4 after treatment. Protein synthesis was inhibited by 52 and 60% in 150 and 300 microM treated cells, respectively, 1 h after treatment, and recovered to 142 and 93%, respectively, at 24 hr. Incubation of cells with nontoxic doses of cycloheximide for 24 hr after treatment produced synergistic toxicity with chromate in colony-forming efficiency assays. Ion gradients persisted to Day 2 as revealed by exclusion of trypan blue dye in 97% of treated cells. Fluorescence microscopy of acridine orange-stained cells revealed morphological features of apoptosis including nuclear fragmentation in more than 90% of detached nonadherent cells and up to 22% of adherent cells by Day 2 after treatment. Untreated cells remained morphologically normal. Transmission electron microscopy of chromate treated cells showed characteristic features of apoptosis including chromatin margination and fragmentation, and cytoplasmic condensation with intact membrane and organelle structure. Internucleosomal DNA fragmentation (IDF) was delayed for at least 24 hr, whereafter it was detected in both adherent and nonadherent cells through Day 5 after treatment. These results indicate apoptosis as the mode of cell death caused by chromium and imply that apoptosis must be considered as a component of chromium-induced multistage carcinogenesis.

Authors

Blankenship, LJ; Manning, FC; Orenstein, JM; Patierno, SR

MLA Citation

Blankenship, L. J., et al. “Apoptosis is the mode of cell death caused by carcinogenic chromium..” Toxicol Appl Pharmacol, vol. 126, no. 1, May 1994, pp. 75–83. Pubmed, doi:10.1006/taap.1994.1092.

PMID

8184436

Source

pubmed

Published In

Toxicology and Applied Pharmacology

Volume

126

Issue

1

Publish Date

1994

Start Page

75

End Page

83

DOI

10.1006/taap.1994.1092

Carcinogenic chromium (Cr6+) enters cells via the sulfate transport system and undergoes intracellular reduction to trivalent chromium, which strongly adducts to DNA. In this study, the effect of adducted trivalent chromium on in vitro DNA synthesis was analyzed with a polymerase-arrest assay in which prematurely terminated replication products were separated on a DNA sequencing gel. A synthetic DNA replication template was treated with increasing concentrations of chromium(III) chloride. The two lowest chromium doses used resulted in biologically relevant adduct levels (6 and 21 adducts per 1,000 DNA nucleotides) comparable with those measured in nuclear matrix DNA from cells treated with a 50% cytotoxic dose of sodium chromate in vivo. In vitro replication of the chromium-treated template DNA using the Sequenase version 2.0 T7 DNA polymerase (United States Biochemical Corp., Cleveland, OH) resulted in dose-dependent polymerase arrest beginning at the lowest adduct levels analyzed. The pattern of polymerase arrest remained consistent as chromium adduct levels increased, with the most intense arrest sites occurring 1 base upstream of guanine residues on the template strand. Replication by the DNA polymerase I large (Klenow) fragment as well as by unmodified T7 DNA polymerase also resulted in similar chromium-induced polymerase arrest. Interstrand cross-linking between complementary strands was detected in template DNA containing 62, 111, and 223 chromium adducts per 1,000 DNA nucleotides but not in template containing 6 or 21 adducts per 1,000 DNA nucleotides, in which arrest nevertheless did occur. Low-level, dose-dependent interstrand cross-linking between primer and template DNA, however, was detectable even at the lowest chromium dose analyzed. Since only 9% of chromium adducts resulted in polymerase arrest in this system, we hypothesized that arrest occurred when the enzyme encountered chromium-mediated interstrand DNA-DNA cross-links between either the template and a separate DNA molecule or the template and its complementary strand in the same molecule. These results suggest that the obstruction of DNA replication by chromium-mediated DNA-DNA cross-links is a potential mechanism of chromium-induced genotoxicity in vivo.

Authors

Bridgewater, LC; Manning, FC; Woo, ES; Patierno, SR

MLA Citation

Bridgewater, L. C., et al. “DNA polymerase arrest by adducted trivalent chromium..” Mol Carcinog, vol. 9, no. 3, Mar. 1994, pp. 122–33.

PMID

8142016

Source

pubmed

Published In

Molecular Carcinogenesis

Volume

9

Issue

3

Publish Date

1994

Start Page

122

End Page

133

The cytotoxicity and transforming activity of nickel subsulfide, nickel oxide and nickel sulfate was studied by assays of colony-forming efficiency and of transformation of rat tracheal epithelial (RTE) cells to enhanced growth variants (EGVs) and immortal growth variants (IGVs). Nickel subsulfide caused dose-dependent cytotoxicity between 1 and 5 micrograms/ml, whereas the cytotoxic range of nickel oxide and nickel sulfate was 50-200 micrograms/ml and 60-130 micrograms/ml, respectively. At lower concentrations, nickel sulfate caused modest (up to 126%) growth stimulation. During the initial 24-h treatment period, internalized nickel subsulfide particles were observed in phagocytic vesicles in cells near the periphery of all RTE cell colonies, whereas nickel oxide particles were not internalized but had adhered to both the cells and the tissue culture dish. After 7-10 days of the transformation assay, nickel subsulfide particles were no longer visible, but nickel oxide particles remained on the dish for the duration of the 5 week assay. During weeks 3-5 of the transformation assay, internalized nickel oxide particles were observed in non-vacuolated cells at the periphery of the colonies. All 3 nickel compounds significantly (p < 0.05) increased the transformation frequency of RTE cells to EGVs at moderately cytotoxic concentrations; the order of potency was Ni3S2 > NiO = NiSO4. MNNG, the positive control, was twice as active as nickel subsulfide at 1/3 the concentration and 1/6 the duration of treatment. EGVs induced by MNNG, nickel subsulfide and nickel sulfate were cloned and converted to IGVs at frequencies of 44, 24 and 43%, respectively. In contrast, EGVs transformed by nickel oxide rarely converted to IGVs (13%). All nickel-induced IGVs were immunohistochemically epithelial, mitotically active, aneuploid and exhibited high plating efficiencies. Our results suggest that respiratory epithelial cells are targets for the transforming capabilities of several nickel compounds but that the potency and mechanism of transformation by various forms of nickel may be different according to the physico-chemical properties of each compound.

Authors

Patierno, SR; Dirscherl, LA; Xu, J

MLA Citation

Patierno, S. R., et al. “Transformation of rat tracheal epithelial cells to immortal growth variants by particulate and soluble nickel compounds..” Mutat Res, vol. 300, no. 3–4, Aug. 1993, pp. 179–93. Pubmed, doi:10.1016/0165-1218(93)90049-j.

PMID

7687017

Source

pubmed

Published In

Mutation Research

Volume

300

Issue

3-4

Publish Date

1993

Start Page

179

End Page

193

DOI

10.1016/0165-1218(93)90049-j

A nuclear scaffold (NS) protease has previously been implicated in production of the M(r) 46,000 ATP-binding protein in NS (which may acquire nucleoside triphosphatase activity and participate in nucleocytoplasmic transport) by cleavage of a subset of lamins A/C. In a preceding paper (G. Clawson, L. Norbeck, C. Hatem, C. Rhodes, P. Amiri, J. McKerrow, S. Patierno, and G. Fiskum, Cell Growth & Differ., 3: 827-838), this NS protease was identified as a novel, Ca(2+)-regulated serine protease, which was found only in the NS and which appears to represent a unique multicatalytic protease complex. Based upon its predominantly chymotrypsin-like substrate preference, a peptide-chloromethylketone inhibitor (succinyl-AAPF-chloromethylketone, AAPFcmk) was identified. AAPFcmk showed a KI = 56 nM for the NS protease versus 1.4 microM for the endoplasmic reticulum activity. Treatment of C3H/10T1/2 mouse embryo fibroblast cells with 1 microM AAPFcmk produced effects which were confined to the nuclear (and to a lesser extent the endoplasmic reticulum) compartment. In this report, we examine the effects of the AAPFcmk inhibitor on cellular transformation and growth. Growth of C3H/10T1/2 cells was decreased by 34% and 56% at 25 microM and 50 microM AAPFcmk, respectively. Growth inhibition occurred without any major change in DNA content distribution, suggesting effects throughout the cell cycle. Growth inhibition was not observed at lower (< or = 10 microM) concentrations, which decreased transformation of C3H/10T1/2 fibroblasts in a dose-dependent manner by up to 90%, even at femtomolar concentrations of AAPFcmk (in the absence of growth inhibition). Inclusion of irrelevant inhibitors was without affect.(ABSTRACT TRUNCATED AT 250 WORDS)

Authors

Clawson, GA; Norbeck, LL; Wise, JP; Patierno, SR

MLA Citation

Clawson, G. A., et al. “An inhibitor of nuclear scaffold protease blocks chemical transformation of fibroblasts..” Cell Growth Differ, vol. 4, no. 7, July 1993, pp. 589–94.

PMID

8398899

Source

pubmed

Published In

Cell Growth & Differentiation : the Molecular Biology Journal of the American Association for Cancer Research

Volume

4

Issue

7

Publish Date

1993

Start Page

589

End Page

594

Chromium metal salts are considered to be human carcinogens, especially the salts of low solubility. Lead chromate, a highly insoluble chromium metal salt, has been shown to be tumorigenic, genotoxic and clastogenic. In this study, the roles of particle-cell contact, particle dissolution and particle uptake in the clastogenic activity of lead chromate were investigated. Using Pb51CrO4 it was found that lead chromate particles (1.2 microns mean diameter, -28 mV surface charge) were slightly soluble in water; solubility increased 2-fold when particles were incubated in culture medium, but was not increased further by the addition of serum. The extracellular concentration of chromium increased 7-fold when lead chromate was incubated in the presence of Chinese hamster ovary (CHO) cells compared with culture medium alone. The intracellular concentration of ionic chromium increased in a dose-dependent manner following exposure of CHO cells to clastogenic doses of lead chromate reaching estimated levels as high as 1.2 mM per cell. Treatment of cells with lead chromate particles in the presence of a nontoxic dose of vitamin C blocked uptake of ionic chromium and eliminated the clastogenic activity of the particles. Transmission electron microscopy showed that lead chromate particles were internalized by CHO cells in phagocytic vacuoles in as little as 1 h; internalization was unaffected by co-treatment with vitamin C. It was demonstrated that particle-cell contact was required for lead chromate-induced clastogenesis. These data show that although phagocytic particle uptake occurs, particle-cell contact and extracellular dissolution are responsible for the clastogenic activity of lead chromate. These data also demonstrate that the genotoxicity of particulate hexavalent chromates can be blocked by vitamin C.

Authors

Wise, JP; Orenstein, JM; Patierno, SR

MLA Citation

Wise, J. P., et al. “Inhibition of lead chromate clastogenesis by ascorbate: relationship to particle dissolution and uptake..” Carcinogenesis, vol. 14, no. 3, Mar. 1993, pp. 429–34. Pubmed, doi:10.1093/carcin/14.3.429.

PMID

8453719

Source

pubmed

Published In

Carcinogenesis

Volume

14

Issue

3

Publish Date

1993

Start Page

429

End Page

434

DOI

10.1093/carcin/14.3.429

The nuclear scaffold (NS) is a proteinaceous network of orthogonally arrayed intermediate filament proteins, termed lamins, which is responsible for nuclear structure. Recent work has demonstrated that a subset of lamins A/C is proteolytically cleaved to produce an ATP-binding protein. This proteolytic cleavage is accomplished by a NS protease activity, which shows a considerable selectivity for lamins A/C and is stringently regulated by Ca2+ in vitro, suggesting that it might also participate in control of NS breakdown in various scenarios. Here, we identify the major NS protease as a novel serine protease with a predominantly chymotryptic-like substrate preference, and we show that even transient perturbations in cytosolic Ca2+ have significant effects on the NS protease activity. This NS protease activity shows extensive similarities to the multicatalytic proteinase complex. In addition to a potential role in control of NS breakdown at mitosis and/or under pathological conditions, this NS protease is also strategically located for other functions, such as inactivation of various oncogenic proteins or maturation-promoting factor.

Authors

Clawson, GA; Norbeck, LL; Hatem, CL; Rhodes, C; Amiri, P; McKerrow, JH; Patierno, SR; Fiskum, G

MLA Citation

Clawson, G. A., et al. “Ca(2+)-regulated serine protease associated with the nuclear scaffold..” Cell Growth Differ, vol. 3, no. 11, Nov. 1992, pp. 827–38.

PMID

1467310

Source

pubmed

Published In

Cell Growth & Differentiation : the Molecular Biology Journal of the American Association for Cancer Research

Volume

3

Issue

11

Publish Date

1992

Start Page

827

End Page

838

Particulate lead chromate is a highly water-insoluble cytotoxic and carcinogenic agent, but its mechanism of action remains obscure. We investigated its effects on DNA damage in CHO cells after a 24-h exposure using alkaline or neutral filter elution and cytogenetic studies. Concentrations (0.08, 0.4 and 0.8 micrograms/cm2), which reduced the colony-forming efficiency of CHO cells to 94, 50 and 10%, respectively, produced dose-dependent DNA single-strand breaks and DNA-protein crosslinks, but no DNA double-strand breaks or DNA-DNA crosslinks were observed. The single-strand breaks were absent from cells given a 24-h recovery period after removal of the treatment medium, even though most of the particles remained adhered to cells and to the culture dish. In contrast, both the DNA-protein crosslinks and chromosomal aberrations persisted even after the 24-h recovery period. These results suggest that the mechanism of the particle-induced early DNA single-strand breaks may be different from DNA-protein crosslinks and the lesions leading to chromosomal aberrations, or alternatively, that the repair of single-strand breaks is more efficient than the repair of DNA-protein crosslinks in the unavoidable continuing presence of carcinogen. These results also suggest that the chromosome damage may be related to the persistent DNA-protein crosslinks, and further confirm the genotoxic activity of carcinogenic lead chromate particles.

Authors

Xu, J; Wise, JP; Patierno, SR

MLA Citation

Xu, J., et al. “DNA damage induced by carcinogenic lead chromate particles in cultured mammalian cells..” Mutat Res, vol. 280, no. 2, Aug. 1992, pp. 129–36. Pubmed, doi:10.1016/0165-1218(92)90008-n.

PMID

1378537

Source

pubmed

Published In

Mutation Research

Volume

280

Issue

2

Publish Date

1992

Start Page

129

End Page

136

DOI

10.1016/0165-1218(92)90008-n

Several insoluble compounds of chromium, such as lead chromate, are respiratory carcinogens in experimental animals and suspected to be so in humans. Lead chromate induces neoplastic transformation in cultured cells but the mechanism of genotoxicity is unknown. We examined the effect of lead chromate on the integrity of chromosomes of Chinese hamster ovary (CHO) and human foreskin fibroblasts (HFF) after a 24-h exposure. At 0.4 microgram/cm2, 0.8 microgram/cm2, 2 microgram/cm2 and 8 microgram/cm2 lead chromate particles reduced survival of CHO cells to 86%, 62%, 2% and less than 1% respectively. These concentrations induced a dose-dependent 4-19-fold increase in the percent metaphases with damage. The HFF cells exhibited higher sensitivity in both cytotoxicity and clastogenicity. The spectrum of damage observed for both cell types was primarily achromatic lesions affecting one or both chromatids. To test for particle dissolution effects, CHO cells were treated for 24 h with either clarified medium that had been incubated for 24 h with lead chromate particles, or clarified medium that had been pre-conditioned by CHO cells treated with lead chromate particles for 24 h. No damage was detected in these cells, indicating that extracellular dissolution into ionic lead and chromate did not contribute to the genotoxicity. This is consistent with a previous study in which scanning electron micrographs illustrated internalization of the particles. These results suggest that clastogenesis may be a mechanism for lead chromate induced carcinogenesis.

Authors

Wise, JP; Leonard, JC; Patierno, SR

MLA Citation

Wise, J. P., et al. “Clastogenicity of lead chromate particles in hamster and human cells..” Mutat Res, vol. 278, no. 1, Jan. 1992, pp. 69–79. Pubmed, doi:10.1016/0165-1218(92)90287-a.

PMID

1370121

Source

pubmed

Published In

Mutation Research

Volume

278

Issue

1

Publish Date

1992

Start Page

69

End Page

79

DOI

10.1016/0165-1218(92)90287-a

Hexavalent chromium compounds are carcinogenic to humans, are potent inducers of tumors in experimental animals, and can neoplastically transform cells in culture. In this study, the effects of sodium chromate on the expression of the 78-kDa glucose-regulated protein (GRP78) gene and on general transcription were investigated with respect to the DNA damage induced by this agent. DNA single-strand breaks, DNA-protein cross-links, and chromium-DNA adducts were present in CHO cells immediately after 2 h of treatment with sodium chromate. Subsequently, these types of damage were repaired at different rates. Single-strand breaks were essentially repaired after 8 h. By 24 h posttreatment, no cross-links remained in cells exposed to 30 or 150 microM chromate, although cells treated with the 300-microM concentration still contained cross-links at that time. DNA-chromium adducts remained unrepaired for at least 32 h. The moderate constitutive level of GRP78 mRNA was not affected by chromate. Chromate did, however, suppress induction of this gene by tunicamycin in a concentration-and time-dependent manner. Thirty micromolar sodium chromate (96% survival), which caused the least DNA damage, had no effect on GRP78 induction, general RNA synthesis, or mRNA synthesis. Induction of GRP78 was suppressed immediately and 12 h after treatment with 150 microM chromate (54% survival), although there was a partial recovery of induction at 24 h after treatment, which correlated with the repair of DNA-protein cross-links. In contrast, both total cytoplasmic RNA and mRNA synthesis were suppressed by approximately 60-75% for at least 32 h by 150 microM chromate. At the 300-microM concentration (8% survival), where DNA-protein cross-links persisted beyond 24 h, GRP78 induction was totally suppressed for at least 24 h, while total RNA and mRNA synthesis were suppressed by 80-90% for at least 32 h. Overall, the effects of chromate on GRP78 induction correlated most closely with the presence of DNA-protein cross-links, but suppression of total RNA and mRNA synthesis correlated with the presence of DNA-chromium adducts. These results indicate that chromate exerts differential effects on the induction of the GRP78 gene and on general transcription.

Authors

Manning, FC; Xu, J; Patierno, SR

MLA Citation

Manning, F. C., et al. “Transcriptional inhibition by carcinogenic chromate: relationship to DNA damage..” Mol Carcinog, vol. 6, no. 4, 1992, pp. 270–79.

PMID

1283064

Source

pubmed

Published In

Molecular Carcinogenesis

Volume

6

Issue

4

Publish Date

1992

Start Page

270

End Page

279

Authors

Patierno, SR

MLA Citation

Patierno, S. R. “Role of chemical delivery modes in toxicological studies.” Toxic Substances Journal, vol. 11, no. 2, Dec. 1991, pp. 111–48.

Source

scopus

Published In

Toxic Substances Journal

Volume

11

Issue

2

Publish Date

1991

Start Page

111

End Page

148

Soluble CaCrO4 and insoluble PbCrO4 were tested for induction of mutation to 6-thioguanine (base-substitution, deletion, addition, and frameshift mutations) or ouabain (base-substitution mutations) resistance in Chinese hamster ovary cells and morphological transformation in C3H/10(1/2) mouse embryo cells. CaCrO4 induced dose-dependent cytotoxicity and mutation to 6-thioguanine resistance, but did not induce mutation to ouabain resistance or morphological transformation. Highly cytotoxic amounts of CaCrO4 induced conversion of 10T1/2 cells to adipocytes, but cell lines derived from such cells were not transformed. PbCrO4 was not mutagenic in either mutation assay but induced a dose-dependent, low frequency of focus formation. Cell lines established from these foci had a 3-5-fold increased saturation density, grew in soft agarose, and were tumorigenic in nude mice. Chronic exposure to CaCrO4 or PbCl2 did not induce transformation, PbCl2 was inactive even at acutely cytotoxic concentrations, and sequential treatments with CaCrO4 and PbCl2 did not induce transformation. Light and scanning electron microscopy showed progressive cytoplasmic engulfment of PbCrO4 particles and extensive vacuolization of cells in contact with the particles. No particles were observed inside of vacuoles. We suggest that internalization of PbCrO4 and the associated cellular stress response may be related to PbCrO4-induced neoplastic transformation of 10T1/2 cells.

Authors

Patierno, SR; Landolph, JR

MLA Citation

Patierno, S. R., and J. R. Landolph. “Soluble vs insoluble hexavalent chromate. Relationship of mutation to in vitro transformation and particle uptake..” Biol Trace Elem Res, vol. 21, July 1989, pp. 469–74.

PMID

2484629

Source

pubmed

Published In

Biological Trace Element Research

Volume

21

Publish Date

1989

Start Page

469

End Page

474

Use of the analgesic compounds acetylsalicylic acid (aspirin), phenacetin, and acetaminophen has been correlated with increased risk of renal cancer in humans. Hence, we studied these compounds for ability to induce cytotoxicity, mutation to ouabain resistance, and morphological transformation in cultured C3H/10T1/2 clone 8 (10T1/2) mouse embryo cells. All three compounds were cytotoxic from 0.5-mg/ml to 2-mg/ml concentrations as evidenced by decreased plating efficiency. None of the compounds induced detectable base substitution mutations to ouabain resistance even at cytotoxic concentrations. Aspirin did not induce morphological transformation. Both phenacetin and acetaminophen induced low but concentration-dependent numbers of atypical, weak type II morphologically transformed foci; at equimolar concentrations, phenacetin was 1.1- to 3.0-fold more active in inducing these foci. Neither phenacetin nor acetaminophen was cotransforming with 3-methylcholanthrene, and neither compound promoted cell transformation when added to 3-methylcholanthrene-initiated 10T1/2 cells. The focus-inducing potency of both compounds was increased by addition of an Arochlor-induced hamster liver S9 fraction as an exogenous metabolizing system. However, seven putative metabolites of phenacetin and acetaminophen that were tested--N-hydroxyphenacetin, p-phenetidine, p-aminophenol, p-nitrosophenol, benzoquinone, acetamide, and N-acetyl-p-benzoquinoneimine--were inactive in transformation assays at the concentrations reducing plating efficiency of treated cells to 50% of the plating efficiency of nontreated (control) cells. Several acetaminophen- and phenacetin-induced foci were cloned, expanded into cell lines, and characterized. These cell lines stably formed type II foci when maintained at confluence for 2 to 4 wk in reconstruction experiments with nontransformed 10T1/2 cells; however, they did not exhibit significantly increased saturation density compared to 10T1/2 cells, and they did not grow in soft agarose. These results suggest that metabolic intermediates of high concentrations of phenacetin and acetaminophen induce a low frequency of nonneoplastic morphological transformation of 10T1/2 mouse embryo cells.

Authors

Patierno, SR; Lehman, NL; Henderson, BE; Landolph, JR

MLA Citation

Patierno, S. R., et al. “Study of the ability of phenacetin, acetaminophen, and aspirin to induce cytotoxicity, mutation, and morphological transformation in C3H/10T1/2 clone 8 mouse embryo cells..” Cancer Res, vol. 49, no. 4, Feb. 1989, pp. 1038–44.

PMID

2912548

Source

pubmed

Published In

Cancer Research

Volume

49

Issue

4

Publish Date

1989

Start Page

1038

End Page

1044

We studied induction of cytotoxicity and morphological transformation in C3H/10T1/2 Cl 8 (10T1/2) mouse embryo fibroblasts by soluble and insoluble carcinogenic nickel compounds. Soluble nickel sulfate and nickel chloride caused dose-dependent cytotoxicity in the concentration range from 0.5 microM to 100 microM after 48 hr treatments, but neither compound induced morphological transformation even at concentrations causing up to 94% cytotoxicity. Insoluble nickel subsulfide, nickel monosulfide, and nickel oxide caused dose-dependent cytotoxicity and a low, dose-dependent frequency of morphological transformation in the concentration ranges from 0.5 to 40 microM, 5 to 50 microM, and 50 to 400 microM, respectively, after 48 hr exposure of cells to these compounds. Foci were predominantly of type II morphology; type III foci were rare. The insoluble nickel compounds studied caused no induction of base substitution mutations to ouabain resistance in 10T1/2 cells over concentration ranges that induced morphological transformation. Nickel subsulfide and nickel monosulfide were taken into cells by phagocytosis, since particles were visible in intracytoplasmic vacuoles. Numerous nickel oxide particles were found associated with cells, but true phagocytic uptake was difficult to detect since no vacuoles were observed. We twice cloned type II and type III foci induced by insoluble nickel compounds, established independent cell lines, and characterized their phenotypes. Four of seven of these cell lines had three- to fourfold increased saturation densities compared to 10T1/2 cells, formed type II and type III foci in reconstruction assays, and grew in soft agarose. One cell line induced by nickel oxide formed tumors in nude mice. These data indicate that insoluble carcinogenic nickel compounds induced type II foci in 10T1/2 cells, some of which were tumorigenic, and that the 10T1/2 cell system is suitable for studying mechanisms of nickel compound-induced morphological transformation in mammalian cells.

Authors

Miura, T; Patierno, SR; Sakuramoto, T; Landolph, JR

MLA Citation

Miura, T., et al. “Morphological and neoplastic transformation of C3H/10T1/2 Cl 8 mouse embryo cells by insoluble carcinogenic nickel compounds..” Environ Mol Mutagen, vol. 14, no. 2, 1989, pp. 65–78.

PMID

2548861

Source

pubmed

Published In

Environmental and Molecular Mutagenesis

Volume

14

Issue

2

Publish Date

1989

Start Page

65

End Page

78

The genotoxicity of soluble and insoluble hexavalent chromium compounds was studied in mammalian cell assays which detect base substitution, deletion, addition, and frameshift mutations [6-thioguanine resistance in Chinese hamster ovary cells], primarily base substitution mutations [ouabain resistance in Chinese hamster ovary and C3H/10T 1/2 Cl 8 mouse embryo fibroblasts (10T 1/2 )] and morphological transformation [focus formation] in 10T 1/2 cells. Soluble hexavalent CaCrO4, administered in either acute (5-h) or subacute (24-h) dosing regimens, induced dose-dependent cytotoxicity and mutation to 6-thioguanine resistance in Chinese hamster ovary cells but no mutation to ouabain resistace or focus formation in transformation assays, although the acute treatment induced a high frequency of conversion of 10T 1/2 cells to adipocytes. Cell lines established from cloned adipocytic cells were not morphologically transformed and did not grow in soft agarose. PbCrO4 did not induce mutationto either 6-thioguanine or ouabain resistance but did induce a reproducible dose-dependent, low frequency of focus formation in 10T 1/2 cells. Cell lines established from PbCrO4-induced foci stably formed foci when coseeded with 10T 1/2 cells, had 3-5-fold increased saturation densities releative to nontransformed 10T 1/2 cells, and formed colonies in soft agarose, indicating their likelihood to be neoplastic. Long term exposure of 10T 1/2 cells to either CaCrO4 or PbCl2, even at 85% cytotoxic concentrations, or pretreatment of cells with either CaCrO4 or PbCl2 followed by treatment with the alternate compound, did not induce morphological transformation. Treatment of cells with insoluble hexavalent PbCrO4 resulted in progressive and extensive vacuolization of cells in contact with the particles. Progressive cytoplasmic engulfment of PbCrO4 particles was observed using scanning electron microscopy, although PbCrO4 particles were not observed inside vacuoles. These results indicated that the soluble clastogens K2Cr2O7 and CaCrO4 were probably mutagenic by a non-base substitution mechanism but could not transform 10T 1/2 cells. In contrast, PbCrO4 was not detectably mutagenic but induced transformation, which could not be explained solely by acute or chronic exposure to dissolution products of either lead or chromate alone. Since PbCrO4 particles were found to be intracytoplasmic in extensively vacuolated cells, we suggest that the unique physicochemical properties of PbCrO4 particles, leading the their internalization and the resultant associated cellular stress response, may be related to the transformation induced by this compound.

Authors

Patierno, SR; Banh, D; Landolph, JR

MLA Citation

Patierno, S. R., et al. “Transformation of C3H/10T 1/2 mouse embryo cells to focus formation and anchorage indepence by insoluble lead chromate but not soluble calcium chromate: Relationship to mutagenesis and internalization of lead chromate particles.” Cancer Research, vol. 48, no. 18, 1988, pp. 5280–88.

Source

scival

Published In

Cancer Research

Volume

48

Issue

18

Publish Date

1988

Start Page

5280

End Page

5288

Expression of the gene coding for the Mr 78,000 glucose-regulated protein (GRP78) was examined in nontransformed and chemically and radiation-transformed C3H 10T1/2 Cl 8 mouse embryo cells. When cells were grown in complete medium with 10% fetal bovine serum, GRP78 mRNA was increased 4- to 9-fold in 3-methylcholanthrene (MCA; Clones 15 and 16)-, bleomycin (Bleo 1)-, and ultraviolet light (UV-C3)-transformed cell lines compared to nontransformed 10T1/2 clone 8 cells (Cl 8) at similar cell number and growth phase. Increased steady-state levels of GRP78 protein in MCA Cl 15 compared to Cl 8 cells were confirmed by 2-dimensional gel electrophoresis. Under these conditions transformed MCA Cl 15 exhibited increased GRP78 RNA within 24 h after addition of fresh glucose-containing medium, whereas nontransformed Cl 8 cells did not increase expression of this gene even after 5 days of culture in conditioned medium. Incubation of Cl 8 and MCA Cl 15 in glucose-free medium for 16 h caused a 3- and 15-fold induction of GRP78 RNA, respectively. In addition, chemically transformed cells were highly sensitive to glucose deprivation and responded by rounding up and detaching from the substratum. Cl 8 cells exhibited no such sensitivity to glucose deprivation. These results extend earlier reports on virally transformed cells to include chemically and radiation-transformed cells and expand earlier reports to include mRNA expression and 2-dimensional gel electrophoresis of GRP78 protein.

Authors

Patierno, SR; Tuscano, JM; Kim, KS; Landolph, JR; Lee, AS

MLA Citation

Patierno, S. R., et al. “Increased expression of the glucose-regulated gene encoding the Mr 78,000 glucose-regulated protein in chemically and radiation-transformed C3H 10T1/2 mouse embryo cells..” Cancer Res, vol. 47, no. 23, Dec. 1987, pp. 6220–24.

PMID

2445468

Source

pubmed

Published In

Cancer Research

Volume

47

Issue

23

Publish Date

1987

Start Page

6220

End Page

6224

An intracellular effect of nickel(II) which may be involved in its carcinogenic action is the alteration of normal DNA-protein binding. This effect of ionic nickel was studied in Chinese hamster ovary cells using several chromatin isolation methods in combination with SDS-polyacrylamide gel electrophoresis. DNA from cells incubated with (35S)-methionine or (35S)-cysteine to radiolabel protein was prepared by three methods: (solation of nuclei or nucleoids followed by chloroform-isoamyl alcohol (24:1 v/v) extraction and in some cases an additional extraction in the absence or presence of 2M NaCl, 40 mM EDTA or SDS; by isopycnic centrifugation through Cs2SO4 gradients containing 0.8% sarkosyl, 2.2 MCs2SO4, 1 mM NaCl and 10 mM EDTA; or by chromatin disaggregation and denaturation using 9 M urea, 2% 2-mercaptoethanol, 4% Nonidet P-40 +/- 2 M NaCl. DNA from nickel-treated cells consistently had more (35S)-methionine radioactivity associated with it than did DNA from untreated cells. This radioactivity was resistant to ribonuclease but sensitive to protease. Differential extraction using denaturing agents and high ionic strength followed by SDS-polyacrylamide gel electrophoresis revealed that most of the tightly bound proteins were nonhistone chromosomal proteins, and possibly histone 1. The enhancement of DNA-protein binding from nickel-treated cells was disrupted by SDS, suggesting that nickel ions do not function as classical bifunctional crosslinking agents. Since regulation of DNA replication and gene expression is dependent upon DNA-protein interactions, the effect of nickel in altering the extent of DNA-protein binding may interfere with this regulation and may contribute to the carcinogenic activity of nickel compounds.

Authors

Patierno, SR; Costa, M

MLA Citation

Patierno, S. R., and M. Costa. “Effects of nickel(II) on nuclear protein binding to DNA in intact mammalian cells..” Cancer Biochem Biophys, vol. 9, no. 2, May 1987, pp. 113–26.

PMID

3621137

Source

pubmed

Published In

Cancer Biochemistry Biophysics

Volume

9

Issue

2

Publish Date

1987

Start Page

113

End Page

126

Ten nickel oxides and nickel-copper oxides, which all contained NiO (bunsenite) as the predominant crystalline phase, were assayed as follows: in vitro dissolution tests in water and body fluids; in vitro phagocytosis tests in Chinese hamster ovary and C3H-10T1/2 cells; morphological transformation and cytotoxicity tests in cultured Syrian hamster embryo (SHE) cells; erythropoiesis stimulation assay by intrarenal administration to Fischer-344 rats; and scoring the renal histopathologic responses in rats killed 3 months post-injection. The test compounds differed substantially in their biological effects when tested in the various experimental systems. Based upon highly significant concordance of ranked results in the assays (P less than 0.001), six colligative biological attributes of the compounds were identified: (i) dissolution half-times in rat serum and renal cytosol; (ii) phagocytosis by C3H-10T1/2 cells; (iii) morphological transformation of SHE cells; (iv) erythropoiesis stimulation in rats; (v) induction of tubular hyperplasia in rat kidneys; and (vi) induction of arteriosclerosis in rat kidneys. Strong rank correlation (P less than 0.01) between results of the cell transformation and erythropoiesis stimulation assays is especially notable, since the compounds were tested by blind protocols in independent laboratories. The presence of high surface area and demonstrable Ni(III) were two physicochemical characteristics that were associated with the greatest biological effects of nickel oxides.

Authors

Sunderman, FW; Hopfer, SM; Knight, JA; McCully, KS; Cecutti, AG; Thornhill, PG; Conway, K; Miller, C; Patierno, SR; Costa, M

MLA Citation

Sunderman, F. W., et al. “Physicochemical characteristics and biological effects of nickel oxides..” Carcinogenesis, vol. 8, no. 2, Feb. 1987, pp. 305–13. Pubmed, doi:10.1093/carcin/8.2.305.

PMID

3802416

Source

pubmed

Published In

Carcinogenesis

Volume

8

Issue

2

Publish Date

1987

Start Page

305

End Page

313

DOI

10.1093/carcin/8.2.305

Nuclear uptake and chromatin binding of nickel(II) was investigated in Chinese hamster ovary (CHO) cells. The cytoplasmic:nuclear ratio of nickel immediately following treatment was 5:1, but by 24 and 48 hours this ratio decreased to 4:1 and 2:1, respectively, indicating that nickel is retained longer in the nucleus than cytoplasmic nickel. Chromatin was fractionated by sonication and centrifugation into fast-sedimenting, magnesium-insoluble, or magnesium-soluble components. The magnesium-insoluble portion bound more nickel ions and retained the metal longer than either the magnesium-soluble or the fast-sedimenting fractions. Treatment of cells with nickel chloride (NiCl2) decreased the amount of DNA in the magnesium-insoluble fraction but increased the amount of DNA in the fast-sedimenting chromatin fraction. The magnesium-insoluble fraction isolated from nickel-treated cells contained approximately ten times more [35-S]-methionine-labeled protein per milligram DNA compared with untreated cells. The magnesium-soluble and the fast-sedimenting fractions isolated from the nickel-treated cells did not exhibit a similar increase in [35-S]-methionine-labeled protein per milligram of DNA. Nickel treatment suppressed [14-C]-thymidine incorporation into total DNA by 30% compared with untreated cells. However, the magnesium-insoluble chromatin fraction from nickel-treated cells had a tenfold to 20-fold increase in thymidine incorporation, while the other chromatin fractions did not exhibit an increase in thymidine incorporation. These findings indicate that nickel induced widespread alterations in chromatin conformation and preferentially interacted with an Mg-insoluble component of chromatin.

Authors

Patierno, SR; Sugiyama, M; Costa, M

MLA Citation

Patierno, S. R., et al. “Effect of nickel(II) on DNA-protein binding, thymidine incorporation, and sedimentation pattern of chromatin fractions from intact mammalian cells..” J Biochem Toxicol, vol. 2, 1987, pp. 13–23.

PMID

3508470

Source

pubmed

Published In

Journal of Biochemical Toxicology

Volume

2

Publish Date

1987

Start Page

13

End Page

23

Alkaline elution studies demonstrated CaCrO4-induced DNA single strand breaks and DNA-protein crosslinks. DNA single strand breaks increased following treatment with 10-400 microM CaCrO4 in Chinese hamster ovary cells maintained with a minimal salts/glucose medium. DNA single strand breaks were rapidly repaired when extracellular CaCrO4 was removed even following exposure levels of CaCrO4 (200 microM for 2 hr) which reduced survival to 0.6%. Under these exposure conditions the trypan blue exclusion was greater than 80%, whereas cell growth was inhibited by 46% within 24 hr. The DNA-protein crosslinks induced by 10 microM CaCrO4 were repaired in the absence of metal within 24 hr. In contrast, the amount of DNA-protein crosslinks measured 24 hr after a 2-hr treatment with 50, 100, and 200 microM CaCrO4 remained unchanged at the 50 microM level or increased at the two higher concentrations. Thus, at concentrations of 50 microM or greater there was no repair of the DNA protein crosslinks, and this may have been due to cytotoxicity of the metal. CaCrO4 at 10 or 25 microM exposure for 6 hr also induced DNA-protein crosslinking in Chinese hamster ovary cells maintained in normal tissue culture growth media. The lack of repair of DNA-protein crosslinks at the 25 microM level, which did not substantially reduce cell survival, indicated the persistence of these lesions in a noncytotoxic form. Uptake of CaCrO4 was linear with all of the concentrations tested. Analysis of the cell cycle sensitivity to CaCrO4 revealed that cells in early S phase were the most sensitive to the cytotoxic and strand breaking activity of CaCrO4. Compared with other phases of the cell cycle, there was also an elevated level of DNA-protein crosslinks when cells were treated in early S phase and incubated 24 hr without CaCrO4. These results implicate the DNA-protein crosslink as an important lesion that may be responsible for the cytotoxic and carcinogenic properties of chromate.

Authors

Sugiyama, M; Patierno, SR; Cantoni, O; Costa, M

MLA Citation

Sugiyama, M., et al. “Characterization of DNA lesions induced by CaCrO4 in synchronous and asynchronous cultured mammalian cells..” Mol Pharmacol, vol. 29, no. 6, June 1986, pp. 606–13.

PMID

3713704

Source

pubmed

Published In

Molecular Pharmacology

Volume

29

Issue

6

Publish Date

1986

Start Page

606

End Page

613

c-abl, c-fos, c-Ha-ras, c-myc, and c-mos were expressed whereas c-sis, c-fms, c-rel, c-src, and c-myb expression was not detectable in C3H/10T1/2 Cl 8 (10T1/2) cells and in eight chemically and radiation-transformed 10T1/2 cell lines. The expression of c-abl, c-fos, c-Ha-ras, and c-myc was growth-related in nontransformed 10T1/2 cells. c-abl and c-fos expression increased at confluence by 5- and 9-fold, respectively, compared to that in log phase cells. c-Ha-ras and c-myc transcripts were most abundant in log phase cells and decreased by 70 and 50%, respectively, in confluent cells. There were no significant growth-related changes in the expression of c-Ha-ras, c-myc, or c-abl in methylcholanthrene-transformed Cl 15 cells. The c-fos transcript was not detected in Cl 15 cell cultures. c-abl, c-fos, c-ras, and c-myc were expressed in whole C3H mouse embryo tissue, mouse liver, and 10T1/2 cells. Sizes of these protooncogene transcripts in 10T1/2 cells were the same as those in whole embryo tissue, except that 10T1/2 cells did not express the 8.2-kilobase abl transcript. At subconfluence, equivalent low levels of c-mos expression were observed in nontransformed and in the eight transformed 10T1/2 cell lines. The level of c-abl expression was similar in the nontransformed and in the eight transformed cell lines, but there was a new 8.2-kilobase transcript in the transformed MCA Cl 15 cell line. c-fos was expressed in 10T1/2 cells but was not detectable or greatly reduced in eight transformed cell lines. c-Ha-ras was expressed to a similar extent in eight transformed cell lines and in nontransformed 10T1/2 cells. In the UVC-4 transformed cell line, extra 3.3-kilobase Ha-ras and 7.5-kilobase Ki-ras transcripts were observed. c-myc was expressed at 4- to 7-fold higher levels in six transformed cell lines compared to 10T1/2 cells. There were no major rearrangements in or amplification of the c-myc gene in three transformed cells overexpressing this gene 5-fold. These studies show that enhanced expression of c-myc and decreased expression of c-fos correlate with the chemically and radiation transformed states of 10T1/2 cells. Changes in c-fos and c-myc oncogene expression may be causally linked to late stages of neoplastic transformation in these chemically and radiation transformed 10T1/2 cell lines.

Authors

Shuin, T; Billings, PC; Lillehaug, JR; Patierno, SR; Roy-Burman, P; Landolph, JR

MLA Citation

Shuin, T., et al. “Enhanced expression of c-myc and decreased expression of c-fos protooncogenes in chemically and radiation-transformed C3H/10T1/2 Cl 8 mouse embryo cell lines.” Cancer Research, vol. 46, no. 10, 1986, pp. 5302–11.

Source

scival

Published In

Cancer Research

Volume

46

Issue

10

Publish Date

1986

Start Page

5302

End Page

5311

Intracellular nickel ions (Ni2+) have been shown to cause single-strand breaks in DNA, that were rapidly repaired, and DNA-protein cross-links, that persisted for at least 24 h following removal of extracellular ionic nickel. In this study, we have used the techniques of alkaline elution, chromatin fractionation, and sodium dodecyl sulfate:polyacrylamide gel electrophoresis to examine the DNA-protein cross-linking induced by NiCl2 in Chinese hamster ovary cells. Continuous treatment of logarithmically growing Chinese hamster ovary cells with 2.5 mM NiCl2 in complete medium resulted in DNA single-strand breaks within 1 h, followed by a time-dependent increase in the induction of DNA-protein cross-links at 2, 3, and 6 h. Since the entry of nickel into cells was maximal within 2 h of exposure, the time delay for the formation of DNA-protein cross-links was not limited by metal uptake. The nickel-induced DNA-protein cross-linking appeared to require active cell cycling, since single-strand breaks but no cross-linking could be detected in confluent cells treated with 1, 2.5, or 5 mM NiCl2 for 3 h. DNA-protein cross-linking induced by nickel occurred in late S phase of the cell cycle. High-molecular-weight nonhistone chromatin proteins and possibly histone H1 migrating at the Mr 30,000 range became cross-linked to DNA after treatment of cells with NiCl2. All nickel-cross-linked proteins were concentrated in the magnesium-insoluble regions of fractionated chromatin and were stable to urea, 2-mercaptoethanol, and Nonidet P-40. Some proteins (Mr 48,000, 52,000, 55,000, 70,000, and 95,000), the association of which with DNA was also stable to Sarkosyl, salt, and EDTA, were detectable in DNA rigorously fractionated from untreated cells. Nickel therefore appeared to cause the cross-linking of proteins that normally reside in close association with DNA. Alterations of the normal association of these proteins with DNA by nickel may be an early event in the nickel transformation process.

Authors

Patierno, SR; Sugiyama, M; Basilion, JP; Costa, M

MLA Citation

Patierno, S. R., et al. “Preferential DNA-protein cross-linking by NiCl2 in magnesium-insoluble regions of fractionated Chinese hamster ovary cell chromatin..” Cancer Res, vol. 45, no. 11 Pt 2, Nov. 1985, pp. 5787–94.

PMID

4053050

Source

pubmed

Published In

Cancer Research

Volume

45

Issue

11 Pt 2

Publish Date

1985

Start Page

5787

End Page

5794

The carcinogenic activity of crystalline NiS has been attributed to phagocytosis and intracellular dissolution of the particles to yield Ni2+ which is thought to enter the nucleus and damage DNA. In this study the extent and type of DNA damage in Chinese hamster ovary CHO cells treated with various nickel compounds was assessed by alkaline elution. Both insoluble (crystalline NiS) and soluble (NiCl2) nickel compounds induced single strand breaks and DNA protein cross-links. The single strand breaks were repaired relatively quickly but the DNA-protein cross-links were present and still accumulating 24 h after exposure to nickel. Single strand breakage occurred at both non-cytotoxic and cytotoxic concentrations of nickel, however, DNA-protein cross-linking was absent when cells were exposed to toxic nickel levels. The concentration of nickel that induced DNA-protein cross-linking correlated with those metal concentrations that reversibly inhibited cellular replication.

Authors

Patierno, SR; Costa, M

MLA Citation

Patierno, S. R., and M. Costa. “DNA-protein cross-links induced by nickel compounds in intact cultured mammalian cells..” Chem Biol Interact, vol. 55, no. 1–2, Oct. 1985, pp. 75–91.

PMID

4064195

Source

pubmed

Published In

Chemico Biological Interactions

Volume

55

Issue

1-2

Publish Date

1985

Start Page

75

End Page

91

Authors

Patierno, SR; Conway, K; Costa, M

MLA Citation

Patierno, S. R., et al. “Analysis of DNA-protein crosslinking by carcinogenic nickel compounds.” Proceedings of the American Association for Cancer Research, vol. VOL. 26, Jan. 1985.

Source

scopus

Published In

Proceedings of the American Association for Cancer Research

Volume

VOL. 26

Publish Date

1985

Authors

Pellis, NR; Johnson, S; Patierno, SR; Costa, M

MLA Citation

Pellis, N. R., et al. “Immunobiology of tumors induced with beta nickel sulfide (B-NiS).” Proceedings of the American Association for Cancer Research, vol. VOL. 26, Jan. 1985.

Source

scopus

Published In

Proceedings of the American Association for Cancer Research

Volume

VOL. 26

Publish Date

1985

Authors

Patierno, SR; DeMars, M; Costa, M

MLA Citation

Patierno, S. R., et al. “Crosslinking of specific tightly bound nuclear proteins (TbNP) to DNA of intact cells treated with carcinogenic nickel compounds.” Federation Proceedings, vol. 43, no. 7, Jan. 1984.

Source

scopus

Published In

Federation Proceedings

Volume

43

Issue

7

Publish Date

1984

Essential and non-essential metal ions were compared on the basis of their growth-inhibitory potency and their mediation of metallothionein induction in a Chinese hamster ovary cell line resistant to cadmium. Cadmium-resistant cells were found to be 20-fold and 6-fold more resistant than wild-type Chinese hamster ovary cells to the non-essential metals CdCl2 and HgCl2, respectively. In contrast, cadmium-resistant cells showed 2-fold or less resistance to growth inhibition due to the metals with known or possible biological essentiality, ZnCl2, CuSO4, CoCl2, and NiCl2. Resistance to either cadmium or mercury was not due to decreased uptake as measured isotopically or by X-ray fluorescence. At concentrations near the threshold of growth inhibition, CdCl2 and ZnCl2 induced metallothionein 8- to 10-fold above background levels in cadmium-resistant cells within 8-10 hr. A 2- to 3-fold induction of this protein was produced in resistant cells by levels of HgCl2, CuSO4, and CoCl2 near the threshold of growth inhibition whereas NiCl2 produced no measurable elevations of metallothionein at concentrations below, near, and above those that inhibit cell growth. Induction of metallothionein was measured by a modified 203Hg binding assay and by [35S]cysteine incorporation. No measurable induction of metallothionein was evident in wild-type cells with any metal treatment using a reasonable quantity of cells consistent with our assay. These results in cadmium-resistant cells demonstrate selective induction of metallothionein by various metals and suggest that induction of this protein alone is not solely responsible for differences in the growth-inhibitory potential of these elements.

Authors

Evans, RM; Patierno, SR; Wang, DS; Cantoni, O; Costa, M

MLA Citation

Evans, R. M., et al. “Growth inhibition and metallothionein induction in cadmium-resistant cells by essential and non-essential metals..” Mol Pharmacol, vol. 24, no. 1, July 1983, pp. 77–83.

PMID

6865929

Source

pubmed

Published In

Molecular Pharmacology

Volume

24

Issue

1

Publish Date

1983

Start Page

77

End Page

83

A sensitive and rapid method to estimate concentrations of functional metallothionein in small biological samples, based upon the acid stability of 203Hg binding and solubility of this protein in trichloroacetic acid is described. Sephadex G-10 minicolumns supported in centrifuge tubes afforded separation and quantitation of isotope bound metallothionein from unbound metal. Elution of metallothionein bound 203Hg was achieved by short term-low speed centrifugation that segregated chelator-ligand complex into the eluate while unbound ligand remained in the gel. A well characterized standard of pure metallothionein protein was utilized to verify the specificity and sensitivity of the modified assay. Metallothionein levels were estimated by 203Hg binding in extracts of wild type and cadmium resistant Chinese hamster ovary cells treated with maximum tolerable concentrations of CdCl2. Similar separation methods demonstrated [35S]-cysteine incorporation into induced metallothionein. Additionally, induction of metallothionein was observed after treatment with particulate CdS but not crystalline NiS particles. These results demonstrate that the modified assay system is easily applied to serial measurement of metallothionein levels in multiple small biological samples.

Authors

Patierno, SR; Pellis, NR; Evans, RM; Costa, M

MLA Citation

Patierno, S. R., et al. “Application of a modified 203Hg binding assay for metallothionein..” Life Sci, vol. 32, no. 14, Apr. 1983, pp. 1629–36. Pubmed, doi:10.1016/0024-3205(83)90870-6.

PMID

6835007

Source

pubmed

Published In

Life Sciences

Volume

32

Issue

14

Publish Date

1983

Start Page

1629

End Page

1636

DOI

10.1016/0024-3205(83)90870-6

Parenteral administration of adrenal corticosteroids or particular transition metal salts are known to protect mice from the lethal effects of bacterial lipopolysaccharides (LPS). To determine if both groups of substances act through similar biologic mechanisms, their capacity to protect macrophages from the direct toxic effects of LPS was examined in vitro. When added simultaneously with LPS at culture initiation, 10 to 100 microM cortisone increased the viability of normal peritoneal macrophages as determined by trypan blue exclusion. Prednisolone and corticosterone protected LPS-treated macrophages at even lower concentrations (0.1 to 1 microM); estradiol and testosterone failed to alter cell viability at any concentration tested. Protection was dependent on de novo synthesis because inclusion of 20 nM actinomycin C1 or 1 microM cycloheximide with 10 microM corticosterone during a 4-hr pretreatment period blocked induction of the protective effect. Murine macrophages were also protected by micromolar concentrations of zinc, cadmium, mercury, and manganese, but not by calcium or lead. As was obtained with corticosteroids, heavy metal-induced protection depended on de novo RNA and protein synthesis. Because all substances that protected against LPS are known inducers of metallothionein in somatic cells, peritoneal macrophages were assayed for the presence of this unique, cytoplasmic protein. Within 2 to 8 hr, 10 microM cadmium caused three to fivefold increases in the incorporation of 35S-cysteine and in the binding of 203Hg into the TCA-soluble fraction of cell lysates that was excluded on centrifugally accelerated Sephadex G-10 columns. These results suggest macrophages may be protected from LPS-mediated cytotoxicity through synthesis of a sulfhydryl-rich, metal-binding protein. Although its mechanism of action remains unknown, it is proposed that metallothionein may function homeostatically by altering intracellular concentrations of zinc or may play a regulatory role by facilitating transfer of heavy metals among metal-requiring apoproteins.

Authors

Patierno, SR; Costa, M; Lewis, VM; Peavy, DL

MLA Citation

Patierno, S. R., et al. “Inhibition of LPS toxicity for macrophages by metallothionein-inducing agents..” J Immunol, vol. 130, no. 4, Apr. 1983, pp. 1924–29.

PMID

6187825

Source

pubmed

Published In

The Journal of Immunology

Volume

130

Issue

4

Publish Date

1983

Start Page

1924

End Page

1929