Abstract 2371: MicroRNA-99b-5p targets the mTOR/AR axis and induced autophagic cell death in prostate cancer cells

Abstract

Abstract MicroRNAs are the small non-coding regulatory RNA molecules involved in a wide array of cellular and molecular processes. MicroRNAs negatively regulate gene expression via base-pairing with complementary sequences within mRNA molecules. In cancer, the dysregulation of miRNAs expression is associated with cancer development or suppression through the regulation of key gene expression followed by modulation of multiple cell signaling pathways. In the present study, we investigated the role of microRNA-99b-5p (miR-99b) on prostate cancer (PCa) cell survival, cell migration, and apoptosis. Overexpression of miR-99b in PCa cells inhibited cell proliferation, cell colony-forming capability, spheroid formation, and induced cell apoptosis. On the contrary, inactivation of miR-99b by miR-99b inhibitor promotes PCa cell proliferation, cell colony-forming capability, and cell migration. Mechanistically, miR-99b binds with the 3'UTR region of the mammalian target of the rapamycin (mTOR) gene and controls the expression of mTOR. Our preliminary data also suggest that miR-99b also inhibits androgen receptor (AR) activity in LNCaP cells and induced cell apoptosis. Further by inhibition of mTOR, miR-99b induced autophagy in PCa cells and autophagic cell death. Expression of miR-99b and inactivation of mTOR by rapamycin increased the sensitivity of PCa cells to anti-PCa drug docetaxel (DTX). Collectively the data suggest that miR-99b functions as a tumor suppressor in PCa cells, and therefore, miR-99b may be considered as novel biomarkers and therapeutic targets for PCa management in PCa patients. Citation Format: Suryakant Niture, Lucas Tricoli, Kala Hayes, Deepak Kumar. MicroRNA-99b-5p targets the mTOR/AR axis and induced autophagic cell death in prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2371.