Prostate Cancer (PCa) is the second most commonly diagnosed cancer in the United States with 180,890 males diagnosed and is predicted to cause approximately 26,000 deaths in 2016. The current treatment of androgen deprivation therapy (ADT) initially depletes circulating androgens; however, intratumoral androgens rescue androgen receptor (AR) signaling and promotes the development of castration resistant prostate cancer (CRPC). The dysregulation of the Wnt/β-catenin signaling pathway has been implicated in the development of many cancers including PCa. The disruption of this signaling leads to the stabilization of β-catenin which upregulates many genes involved in tumorigenesis. Additionally, β-catenin acts as AR cofactor. Our previous studies show that AR is a direct target of miR-644a. We hypothesized that targeting the expression of both the β-catenin pathway and AR by conventional drugs and/or tumor suppressor miR-644a would have synergistic therapeutic benefits. In this

study, we are investigating miR-644a mediated posttranscriptional downregulation of GSK3-β and β-catenin in the wnt/β-catenin signaling pathway. The effect of miR-644a in combination with inhibitors (β-catenin or GSK3-β) was also assessed using proliferation assays and a significant downregulation was observed. We will further study the posttranscriptional effects of tumor suppressor miR-644a on the wnt/β-catenin pathway and also the processing and regulation of miR-644a in PCa.

Citation Format: Alexis Plaga, Girish C. Shukla. Regulation of cross talk between AR and wnt/beta-catenin pathways in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 478. doi:10.1158/1538-7445.AM2017-478