RP1-59D14.5 triggers autophagy and represses tumorigenesis and progression of prostate cancer via activation of the Hippo signaling pathway

Abstract

Prostate cancer (PCa) is one of the major malignant tumors among men worldwide. Long noncoding RNAs (lncRNAs) have been documented as important modulators in human cancers, including PCa. In our study, we investigated the role and potential mechanism of RP1-59D14.5 in PCa. RP1-59D14.5 expressed at a low level in PCa cells. Gain-of-function assays including colony formation and transwell assays displayed that RP1-59D14.5 overexpression repressed PCa cell proliferation, migration, and invasion. Besides, RP1-59D14.5 up-regulation induced autophagy in PCa cells. Mechanically, luciferase reporter assays and western blot verified that RP1-59D14.5 activated the Hippo pathway in PCa cells. Through RNA-binding protein immunoprecipitation (RIP) and RNA pull-down assays, we validated that RP1-59D14.5 functioned as a competing endogenous RNA (ceRNA) to regulate large tumor suppressor kinase 1/2 (LATS1/2) via targeting miR-147a. Moreover, RP1-59D14.5 recruited HUR to promote casein kinase 1 (CK1) expression. Collectively, RP1-59D14.5 promoted yes-associated protein (YAP) degradation to activate the Hippo pathway in PCa progression via targeting the miR-147a/LATS1/2 axis and recruiting HUR to promote the interaction of CK1 and β-transducin repeat-containing protein (βTrCP). These results implied that RP1-59D14.5 acted as a tumor suppressor in PCa, which might be a target for PCa treatment.