Downregulation of ARID4A and ARID4B promote tumor progression and directly regulated by microRNA-30d in patient with prostate cancer.

AT-rich interaction domain 4A (ARID4A) and AT-rich interaction domain 4B (ARID4B), which are both the AT-rich interaction domain (ARID) family, have been reported to be oncogene or tumor suppressor gene in various human malignances, but there is no involvement about their functions in prostate cancer (PCa). Our previous study has reported that microRNA-30d (miR-30d) expression can predicted poor clinical prognosis in PCa, however, the underlying mechanisms of miR-30d have not been fully described. The aim of our study is to investigate the expression relevance between miR-30d and ARID4A or ARID4B, and examine the clinical significance and biological function of ARID4A and AIRD4B in PCa. In this study, both ARID4A and ARID4B were identified as the target genes of miR-30d. In addition, the mRNA expression of miR-30d in PCa tissues were significantly negative correlated with ARID4A (Pearson correlation coefficient = -0.313, P = 0.001) and ARID4B (Pearson correlation coefficient = -0.349, P < 0.001), while there was a positive correlation between ARID4A and ARID4B (Pearson correlation coefficient = 0.865, P < 0.001). Moreover, both ARID4A and ARID4B were significantly downregulated in PCa tissues with high Gleason scores (P = 0.005, P = 0.033), PSA failure (P = 0.012, P = 0.05) and short biochemical recurrent-free survival (P = 0.033, P = 0.031). Furthermore, the knockout expression of ARID4A and ARID4B promoted PCa cell proliferation, migration and invasion in vitro. In conclusion, our results indicated that ARID4A and ARID4B may serve as tumor suppressor in PCa progression, suggesting that they might be the potential therapeutic targets in prostate cancer.