PRMT5, regulated by lncRNA ZFAS1/miR-150-5p, promoted androgen-independent prostate cancer migration and invasion

Prostate cancer (PCa) is the most common male genitourinary malignancy in the world. The protein arginine methyltransferase 5 (PRMT5) is one of the main members of the type II PRMT family, which was reported to regulate androgen-dependent PCa cell proliferation. However, the upstream regulators of PRMT5 and its effects on androgen-independent PCa metastasis remained unclear. In the present study, we investigated whether PRMT5 could be a novel diagnostic marker and be used as a therapeutic target in PCa, to explore the possible molecular mechanism, and to understand the clinical importance of PRMT5 in PCa.

The present study evaluated PRMT5 expression levels in PCa and normal prostate samples using public datasets, including TCGA, GEPIA and GSE21032. Furthermore, CCK-8 assay, flow cytometer assay, and transwell assay were conducted to detect the roles of PRMT5. Luciferase reporter assay was used to determine the relationship among ZFAS1/miR-150-5p/PRMT5.

Our results showed that PRMT5 was overexpressed in PCa samples. PRMT5 significantly promoted androgen-dependent PCa proliferation and cell cycle progression and suppressed cell apoptosis. However, PRMT5 did not affect androgen-independent PCa proliferation but it could significantly induce androgen-independent PCa metastasis. Knockdown of PRMT5 suppressed, whereas overexpression of PRMT5 induced, cell migration and invasion in androgen-independent DU145 and PC-3 cells. Moreover, our results showed that the ZFAS1/miR-150-5p axis regulated PRMT5 expression in PCa cells. Furthermore, the study showed that ZFAS1 and PRMT5 were overexpressed and miR-150-5p was down-regulated in PCa samples. Higher expression levels of ZFAS1 and PRMT5 were correlated with shorter disease-free survival time in PCa patients.

These results showed that PRMT5 may be a therapeutic target for PCa.