Mounting evidence has shown that microRNAs (miRNAs), a class of small non-coding RNAs, are frequently deregulated in human malignancies and have pivotal roles in diverse biological processes including cancer cell proliferation. Herein, we investigated the expression pattern of miR-383 in 64 hepatocellular carcinoma (HCC) tissues and 4 HCC cell lines and found that miR-383 was downregulated in HCC tissues and cell lines. Moreover, miR-383 expression in HCC was significantly correlated with tumor size and tumor-node-metastasis (TNM) stage. Kaplan-Meier analysis showed that decreased miR-383 expression was associated with poor overall survival of HCC patients. In addition, Cox regression analysis indicated that miR-383 was an independent prognostic factor for HCC patients. Then, functional studies demonstrated that ectopic miR-383 expression could significantly suppress the in vitro proliferation of HCC cells, as well as induce cell cycle arrest and cell apoptosis. Luciferase reporter assay further identified that a proliferation-inducing ligand (APRIL), a member in the tumor necrosis factor (TNF) superfamily, was a novel target gene for miR-383. Subsequent investigation revealed that miR-383 expression was inversely correlated with APRIL messenger RNA (mRNA) expression in HCC tissues. Besides, recombinant human APRIL (rhAPRIL) could rescue HCC cell proliferation inhibited by miR-383. Taken together, our present study provided the first evidence that miR-383 was decreased in HCC and associated with tumor progression and prognosis of HCC patients. Furthermore, our findings confirmed that miR-383 might inhibit HCC cell proliferation partially via downregulating APRIL expression. Thus, this study might provide a promising strategy by targeting with the miR-383-APRIL axis in the treatment of HCC.
Keywords: APRIL; Apoptosis; Cell cycle; Cell proliferation; Hepatocellular carcinoma; miR-383.