For miR-224, Wang et al.15 had already demonstrated that through targeting to the cellular target of apoptosis inhibitor-5 (API-5) gene, its elevation could stimulate the carcinogenic process. However, the

target gene(s) selleck kinase inhibitor and the underlying regulatory mechanism for the elevation of miR-216a in hepatocarcinogenesis had not yet been addressed, and this is the main topic under investigation in the current study. Increasing evidence for sex steroids affecting the carcinogenic process through regulating specific miRNAs has been documented in breast cancers and prostate cancers.16-19 Our previous studies have identified an intriguing positive regulatory loop between the HBx viral protein and the androgen pathway in male HBV patients.13, 20, 21 It thus raises the possibility that miRNAs could be the candidates affected by the androgen pathway in early hepatocarcinogenesis of HBV-related male HCC. In that case, we expect the candidate miRNAs to show a gender-difference expression pattern in liver tissues at the precancerous stage. Of note, our current study pointed out that miR-216a was preferentially elevated in the precancerous

liver tissues of male HBV-related HCC patients, even in ≈70% of dysplastic nodules, suggesting it as a candidate miRNA regulated by the androgen pathway. This pattern was also noted in HCV-related HCC, although less significantly than that in HBV-related HCC, which is consistent with the fact that the

HCV core viral proteins can also activate the androgen pathway in hepatocytes.22 EGFR inhibitor Aided by our successful identification of the TSS for pri-miR-216a, the effect of AR and HBx on the transcription of pri-miR-216a was investigated. The results indicated that through direct binding to the ARE site within the promoter region of pri-miR-216a (−349 to −335 bp upstream of TSS), the ligand-stimulated AR can increase its transcription and lead to the elevation of miR-216a. It is noteworthy that the elevation of miR-216a in the nontumorous liver tissues of male HCC patients showed a higher risk for mortality (hazard ratio [HR] = 4.62, 95% confidence interval [CI] = 0.74-29.05), suggesting that the levels of miR-216a are associated with the patients’ prognosis. Furthermore, we identified TSLC1 as a putative target gene of miR-216a. TSLC1 is see more a transmembrane glycoprotein, whose major tumor suppressor function is mediated through its extracellular immunoglobulin-like C2 type domains to regulate the cell adhesion activity, which in turn suppresses the tumor invasion and metastasis.23 Some other tumor suppressor functions of TSLC1 were reported to be mediated by its cytoplasmic domain, modulating the cell cycle progression, cell proliferation, and inducing apoptosis.24, 25 The decreased expression of the TSLC1 protein has been identified in a variety of tumors, including lung, prostate, pancreatic, colorectal, and gastric cancers.