Abstract C028: Hypoxia-associated genes on disparities in the aggressiveness of prostate cancer

Abstract

Abstract The incidence of prostate cancer (PCa) is 70% greater and the mortality rate 137% higher in African-American men (AAM) relative to Caucasian-American men (CAM) (Siegel et al., 2016). AAM also show faster tumor growth, higher levels of PSA, and more aggressive disease relative to CAM (Martin et al., 2013). These data, related to the biology of PCa, suggest that biologic mechanisms contribute to PCa health disparities. Because stratification by clinical parameters alone is not sufficient to predict aggressive PCa, there is an unmet need of reliable biomarkers to anticipate outcome and disease progression. This study was designed to identify hypoxia-associated genes with the potential to anticipate the risk of aggressive PCa in a race-specific manner. Seventy annotated cases with documented follow-up for evidence of biochemical recurrence (BCR) were located. Of these, 22 were AAM (8 with BCR and 14 without BCR) and 48 were CAM (31 with BCR and 17 without BCR). Next, we performed a global sequencing analysis in RNA extracted from formalin-fixed, paraffin-embedded blocks. Among 27 hypoxia-associated genes associated with race and PCa by use of Cox proportional hazards regression analysis (p ≤ 0.05), we identified three genes related with BCR and race: regulator of G-protein signaling 1 (RGS1), nuclear receptor subfamily 3, group C, member 1-glucocorticoid receptor (NR3C1), and myosin light chain kinase (MYLK). A race-independent in silico analysis utilizing TCGA data suggested tumor-specific association between transcripts of RGS1, NR3C1, and MYLK and Gleason score. Likewise, low expression of these transcripts was suggestive of poor survival. Currently, we are analyzing transcripts of these three hypoxia-associated genes by independent techniques. Integration of gene expression data with clinical parameters of prognosis will allow us to develop predictive scores. These studies may enable race-specific differentiation of patients at higher and lower risk of BCR. Our findings underscore the prognostic value of hypoxia-regulated genes in aggressive PCa. They also warrant studies to establish the relevance of RGS1, NR3C1, and MYLK as race-specific markers. Funding sources: GMaP 2 Pilot Grant (IE). Citation Format: Ingrid C. Espinoza, Carlos S. Moreno, Christian R. Gomez. Hypoxia-associated genes on disparities in the aggressiveness of prostate cancer [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C028.