Abstract 489: Up-regulation of miR-130b is involved in prostate cancer racial disparity through FHIT pathway inactivation

Purpose: Prostate cancer (PCa) is a common cancer in men. African-American (AfA) men have higher incidence and significantly higher prostate cancer mortality rates than Caucasian-American (CaA) men. In this study, we investigated the biochemical role of miR-130b in this disparity. Methods: We used meta-analyses and data from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). PCa cell lines from CaA (DU145, LNCaP, PC3), AfA (MDA-PCa-2b, E006AA-hT) and a normal epithelial cell line (PWR1E) were used for examining miR-130b expression levels and/or establishing stable miR-130b knock-down clones. Total RNA was extracted from clinical samples and cell lines. miR-130b and mRNA levels of its target genes were determined by quantitative real-time PCR (qPCR). qPCR based gene expression arrays were used to identify miR-130b target genes. Cell proliferation, apoptosis and cell cycle were monitored after stable miR-130b knock down. Western blotting was performed to detect miR-130b target protein expression levels. Results: TCGA data showed up-regulation of miR-130b in AfA PCa tissue samples compared with CaA samples. miR-130b was significantly up-regulated in AfA prostate cancer tissues and cell lines compared to CaA cells and tissues. Utilizing SFVAMC and NDRI patient cohorts, we confirmed that miR-130b expression was linked to a racial difference between AfA/CaA PCa patients. Knock down of miR-130b showed decreased growth and cell cycle arrest, though the effect was less in CaA compared to AfA cells. We found unique changes in biological pathways associated with miR-130b knock down in AfA cells by qPCR array. Evaluation of the altered pathways showed that Fragile Histidine Triad (FHIT) was markedly changed in the AfA compared with CaA cells. Conclusion: These results demonstrate that miR-130b may be a central regulator of key events that contribute racial differences in prostate cancer. FHIT may also be a new AfA specific tumor-suppressive pathway that may be of therapeutic importance in AfA prostate cancer patients. Citation Format: Yutaka Hashimoto, Masrisa Shiina, Taku Kato, Soichiro Yamamura, Yuichiro Tanaka, Shahana Majid, Sharanjot Saini, Varahram Shahryari, Priyanka Kulkarni, Pritha Dasgupta, Divya Bhagiratha, Nadeem Bhat, Guoren Deng, Laura Tabatabai, Deepak Kumar, Rajvir Dahiya. Up-regulation of miR-130b is involved in prostate cancer racial disparity through FHIT pathway inactivation [abstract]. In: Proceedings of the American Association for