Targeting RNA binding protein in prostate cancer

Long non-coding RNA DNMBP-AS1 promotes prostate cancer development by regulating LCLAT1

Prostate cancer (PCa) is as a serious threat to male's health around the world. Recent studies have indicated that long non-coding RNAs (lncRNAs) occupy an important position in various human cancers. However, the function and mechanism of lncRNA DNMBP antisense RNA 1 (DNMBP-AS1) in PCa is rarely investigated. RT-qPCR analysis was used to test gene expression. CCK-8, colony formation, EdU staining and transwell assays were conducted to assess the function of DNMBP-AS1 on PCa cell behaviors. RNA pull down, RIP and luciferase reporter assays were implemented to verify the mechanism of DNMBP-AS1. DNMBP-AS1 was obviously up-regulated in PCa cell lines. Functionally, DNMBP-AS1 knockdown weakened cell proliferation, migration and invasion of PCa. Mechanistically, DNMBP-AS1 sponged microRNA-6766-3p (miR-6766-3p) to regulate lysocardiolipin acyltransferase 1 (LCLAT1) expression. Furthermore, DNMBP-AS1 could stabilize LCLAT1 expression by recruiting ELAV like RNA binding protein 1 (ELAVL1). Consequently, rescue assays demonstrated that DNMBP-AS1 regulated PCa cell proliferation, migration and invasion through enhancing LCLAT1 expression. Collectively, we elucidated the function and regulatory mechanism of DNMBP-AS1 and provided the first evidence of DNMBP-AS1 as a driver for PCa.

RNA-binding protein Musashi2 stabilizing androgen receptor drives prostate cancer progression

The androgen receptor (AR) pathway is critical for prostate cancer carcinogenesis and development; however, after 18‐24 months of AR blocking therapy, patients invariably progress to castration‐resistant prostate cancer (CRPC), which remains an urgent problem to be solved. Therefore, finding key molecules that interact with AR as novel strategies to treat prostate cancer and even CRPC is desperately needed. In the current study, we focused on the regulation of RNA‐binding proteins (RBPs) associated with AR and determined that the mRNA and protein levels of AR were highly correlated with Musashi2 (MSI2) levels. MSI2 was upregulated in prostate cancer specimens and significantly correlated with advanced tumor grades. Downregulation of MSI2 in both androgen sensitive and insensitive prostate cancer cells inhibited tumor formation in vivo and decreased cell growth in vitro, which could be reversed by AR overexpression. Mechanistically, MSI2 directly bound to the 3′‐untranslated region (UTR) of AR mRNA to increase its stability and, thus, enhanced its transcriptional activity. Our findings illustrate a previously unknown regulatory mechanism in prostate cancer cell proliferation regulated by the MSI2‐AR axis and provide novel evidence towards a strategy against prostate cancer.