Steven Patierno

Triple-negative breast cancers (TNBCs) tend to become invasive and metastatic at early stages in their development. Despite some treatment successes in early stage localized TNBC, the rate of distant recurrence remains high, and long-term survival outcomes remain poor. In a search for new therapeutic targets for this disease, we observed that elevated expression of the serine/threonine kinase calcium/calmodulin (CaM)-dependent protein kinase kinase 2 (CaMKK2) is highly correlated with tumor invasiveness. In validation studies, genetic disruption of CaMKK2 expression or inhibition of its activity with small molecule inhibitors disrupted spontaneous metastatic outgrowth from primary tumors in murine xenograft models of TNBC. High-grade serous ovarian cancer (HGSOC), a high-risk, poor prognosis ovarian cancer subtype, shares many features with TNBC, and CaMKK2 inhibition effectively blocked metastatic progression in a validated xenograft model of this disease. Mechanistically, CaMKK2 increased the expression of the phosphodiesterase PDE1A which hydrolyzed cyclic guanosine monophosphate (cGMP) to decrease the cGMP-dependent activity of protein kinase G1 (PKG1). Inhibition of PKG1 resulted in decreased phosphorylation of vasodilator stimulated phosphoprotein (VASP), which in its hypophosphorylated state binds to and regulates F-actin assembly to facilitate cell movement. Together, these findings establish a targetable CaMKK2-PDE1A-PKG1-VASP signaling pathway that controls cancer cell motility and metastasis by impacting the actin cytoskeleton. Further, it identifies CaMKK2 as a potential therapeutic target that can be exploited to restrict tumor invasiveness in patients diagnosed with early-stage TNBC or localized HGSOC.

<jats:title>Abstract</jats:title> <jats:p>BACKGROUND: Patient satisfaction (PS) is an important outcome measure of quality of cancer-related care. PS was one of the four core study outcomes of the National Cancer Institute and American Cancer Society funded $25 million multicenter Patient Navigation Research Program (PNRP) to reduce disparities in cancer care. A Patient Satisfaction with Cancer Care (PSCC) measure was developed and validated for the PNRP using classical test theory and principal components analysis (PCA).</jats:p> <jats:p>OBJECTIVE: To calibrate items of the PSCC to facilitate the development of a computerized adaptive testing (CAT) system, which can be used to tailor the PSCC to patients’ satisfaction level based on properties of the items.</jats:p> <jats:p>METHODS: The PCA revealed a unidimensional PSCC measure. Thus, we applied unidimensional item response theory (IRT) models to the 18-item PSCC data from 1,296 participants (73% female; age 18 to 86 years). We fitted two IRT models to the data: An unconstrained graded response model (GRM) and a constrained GRM (i.e., Rasch Model) where all discrimination parameters across items were fixed to be equal. We obtained model fit indices (log-likelihood, AIC &amp; BIC) and performed model comparison through likelihood ratio (LR) test between the unconstrained GRM and the Rasch model. We obtained item and latent trait (i.e., patient satisfaction) parameter estimates, category characteristic curves, operating characteristic curves, and test information curves for the better fitting model.</jats:p> <jats:p>RESULTS: The unconstrained GRM fitted the data significantly better (LR = 828, df = 17, p &amp;lt; 0.001). Item parameter estimates showed strong items discriminating power (α = 0.94 to 2.18). Standard errors (SE) of the item parameter estimates were also small (i.e., mostly around 0.1 for the threshold parameters, and between 0.1 to 0.2 for the discrimination parameters), confirming the precision of the item parameter estimates obtained.</jats:p> <jats:p>CONCLUSIONS: The PSCC is suitable to be delivered through a CAT system where patients will receive tailored optimally selected items to measure their satisfaction levels, and scores will be equated across different subsets of items (i.e., test forms). An IRT-based PSCC CAT system will provide key patient reported outcome data to help improve patient-centered cancer care and satisfaction for medically underserved populations.</jats:p> <jats:p>Citation Format: Pascal Jean-Pierre, Ying Cheng, Steven Patierno, Peter Raich, Richard Roetzheim, Steven Rosen, Donald Dudley, Karen Freund, Victoria Warren-Mears, Electra Paskett, Kevin Fiscella. Item response theory analysis of the patient satisfaction with cancer-related care: psychometric validation in a multicultural sample of 1,296 participants. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1367. doi:10.1158/1538-7445.AM2013-1367</jats:p>

Dysregulation of alternative splicing is a key molecular hallmark of cancer. However, the common features and underlying mechanisms remain unclear. Here, we report an intriguing length-dependent splicing regulation in cancers. By systematically analyzing the transcriptome of thousands of cancer patients, we found that short exons are more likely to be mis-spliced and preferentially excluded in cancers. Compared to other exons, cancer-associated short exons (CASEs) are more conserved and likely to encode in-frame low-complexity peptides, with functional enrichment in GTPase regulators and cell adhesion. We developed a CASE-based panel as reliable cancer stratification markers and strong predictors for survival, which is clinically useful because the detection of short exon splicing is practical. Mechanistically, mis-splicing of CASEs is regulated by elevated transcription and alteration of certain RNA binding proteins in cancers. Our findings uncover a common feature of cancer-specific splicing dysregulation with important clinical implications in cancer diagnosis and therapies.

<jats:title>Abstract</jats:title> <jats:p>African American (AA) men exhibit 2-3 times higher mortality from prostate cancer compared with Caucasian American (CA) men. Factors contributing to the disparity include societal-, neighborhood- and institutional-level determinants of health. In addition, a number of studies have reported individual-level ancestry-related biological differences, including in mutations, copy number variation, aggregate gene expression and response to treatment between AA and CA prostate cancer patients. Previously, by comparing the transcriptome between 20 AA and 15 CA prostate cancer patients, we identified a large number of race-related Alternative RNA Splicing (ARS) events. Among these, we further demonstrated that an exon skipping event involving exon 20 within PIK3CD increased tumor growth rate, metastatic potential and drug resistance in prostate cancer. To expand our previous findings, we collected non-neoplastic and tumor-paired tissue from 37 AA and 40 CA prostate cancer patients with different Gleason score categories: 14 high grade (4 AA and 10 CA), 22 low grade (10 AA and 12 CA), and 41 intermediate grade (23 AA and 18 CA). DNA and RNA were isolated for ancestral genotyping and RNA seq analysis, respectively. To achieve RNA sequencing depth adequate for ARS analysis, we performed RNA seq of 150 bp paired-end and an average of 5 × 106 reads per sample. The read alignment was done using Star 2 TwoPass pipeline. The rMATS pipeline was used for ARS annotation and quantification. We identified 105,403 ARS events, including 60,657 exon skipping, 17,439 alternative acceptor, 12,737 alternative donor, 9,555 retained intron and 5,015 mutually exclusive exon. Using the Wilcoxon rank-sum test, we compared the Percent Spliced In (PSI) between AA and CA of the same Gleason score category and identified ARS events exhibiting ΔPSI &amp;gt; 15% and p-value &amp;lt; 0.05. Specifically, we identified 536 race-related ARS events in high grade, 492 race-related ARS events in low grade, and 447 race-related ARS events in intermediate grade. Gene Ontology analysis demonstrated that the genes undergoing race-related ARS events function in cellular processes relevant to cancer biology, including metabolic processes in low grade, NF-kappaB signaling in intermediate grade and cell motility in high grade. Specific examples of these genes include ERG and PARP2 in high grade, KLK2 and DNMT1 in intermediate grade, and AURKA and SEMA3A in low grade. These findings support a potential role for the ARS process in diversifying gene expression, potentially contributing to prostate cancer aggressiveness in AA patients. The race-related ARS events identified in our work represent potential biomarkers and/or therapeutic targets for precision oncology in the context of prostate cancer. Further analysis of the function of prioritized race-related ARS events and their association with local ancestry is ongoing. Funding: DoD Prostate Cancer Research Program Health Disparity Research Award. NIH Basic Research in Cancer Health Disparities R01 Award. Prostate Cancer Foundation Movember Challenge Award.</jats:p> <jats:p>Citation Format: Muthana Al Abo, Wen-Chi Foo, Daniel J. George, Steven R. Patierno, Jennifer A. Freedman. Comparative transcriptomic analysis of prostate cancer from African American and Caucasian American men by Gleason score and race [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-137.</jats:p>