Downregulated microRNA-26a modulates prostate cancer cell proliferation and apoptosis by targeting COX-2

MicroRNA-26a (miR-26a) is expressed at lower levels in prostate cancer cells compared with normal prostate cells. However, the regulatory mechanism of miR-26a in tumorigenesis and metastasis is not clear. In the present study, the expression profile of cellular miR-26a was analyzed by reverse transcription-quantitative polymerase chain reaction. The potential target of miR-26a was identified by luciferase assay and western blotting. Examination of miR-26a function was performed by transfection with miR-26a mimics and inhibitor. It was found that miR-26a expression was decreased in prostate cancer tissues and cell lines, with androgen-independent prostate cancer (AIPC) showing lower miR-26a expression compared with androgen-dependent prostate cancer (ADPC). Overexpression of miR-26a by transfecting miR-26a mimics could significantly enhance apoptosis, and this upregulation of apoptosis was triggered by cytochrome c oxidase subunit II inhibition. Furthermore, it was found that lower miR-26a density resulted in an evidently poor prognosis. Understanding the important roles of miR-26a in regulating cell apoptosis in human prostate cancer cells may aid the exploration of AIPC transformation mechanisms and contribute to the development of miRNA-based therapy in the future.

Oncology letters. 2016 Jan 31 [Epub]

Jing Zhang, Jinghao Liang, Jianguo Huang

Department of Oncology, Urumqi General Hospital of Lanzhou Military Command of the Chinese People's Liberation Army, Urumqi, Xinjiang 830000, P.R. China., Department of Orthopedics, Urumqi General Hospital of Lanzhou Military Command of the Chinese People's Liberation Army, Urumqi, Xinjiang 830000, P.R. China.