Edited by Tamas DalmayKeywords: miR-219-5p Glypican-3 Hepatocellular carcinoma Cell proliferation miRNA a b s t r a c t MicroRNAs (miRNAs) have been linked to the molecular pathogenesis of many cancers. In this study, we found that miR-219-5p was significantly downregulated in 83 HCC tissues and three HCC cell lines, compared to their non-tumor counterparts. MiR-219-5p expression correlated with tumor size, histological differentiation, and overall survival time in HCC patients. We also found that miR-219-5p could inhibit cell proliferation in vitro and arrest cell cycle at the G1 to S transition. Further studies identified that miR-219-5p reduced both the mRNA and protein levels of glypican-3 (GPC3). These findings indicate that miR-219-5p exerts tumor-suppressive effects in hepatic carcinogenesis through negative regulation of GPC3 expression.

Taken together, our results suggest that miR-153 play an important role in promoting proliferation of human prostate cancer cells and present a novel mechanism of microRNA-mediated direct suppression of PTEN expression in prostate cancer cells.

BackgroundMicroRNAs have recently emerged as key regulators of cancers, miR-329 located on 14q32.31 is one of down-regulated miRNAs in glioma, but the function and molecular mechanisms of miR-329 in determining the malignant phenotype of human glioma are elusive. This study therefore was conducted to investigate the role of miR-329 in biological behaviors of human glioma LN18 and T98G cell lines and its molecular mechanisms.MethodsNine patients with GBM were analyzed for the expression of miR-329 by quantitative RT–PCR. MiR-329 overexpression was established by transfecting miR-329 precursor into LN18 and T98G cells, and its effects on cell proliferation were studied using MTT assay, anchorage-independent growth ability assay, colony formation assays, Bromodeoxyuridine labeling and immunofluorescence.The effects of miR-329 on cell cycle were studied by flow cytometry. The target of miR-329 was determined by luciferase assays. The regulation of miR-329 on Akt pathway was determined by western blot.ResultsThe E2F1 was identified as the target of miR-329. Overexpression of miR-329 blocked G1/S transition in LN18 and T98G cell lines, dramatically suppressed cell proliferation and the ability of colony formation. MiR-329 significantly decreased the phosphorylation levels of intracellular kinases Akt and expression of cyclin D1, but the expression of p21 was upregulated, cell growth was suppressed by inhibiting E2F1-mediated Akt pathway.ConclusionsMiR-329 may inhibit cell proliferation in human glioma cells through regulating E2F1-mediated suppression of Akt pathway.

microRNAs (miRNAs/miRs) are a conserved class of endogenous, short non-coding RNAs that post-transcriptionally regulate the expression of genes involved in diverse cellular processes. miR-214 has been reported to be associated with several cancers, including human colon cancer. However, the function of miR-214 in colon cancer development is poorly understood. In the current study, miR-214 was demonstrated to be downregulated in colon cancer tissues compared with healthy colon tissues. Functional studies showed that miR-214 overexpression results in the inhibition of cell viability, colony formation and proliferation, and the induction of cell apoptosis. ADP-ribosylation factor-like protein 2 (ARL2) is predicted to be a target candidate of miR-214. A luciferase reporter assay, western blot analysis and quantitative polymerase chain reaction were performed, which revealed that miR-214 negatively regulates ARL2 expression by targeting its 3′ untranslated region directly. In conclusion, the results of the present study revealed that miR-214 suppresses colon cancer cell growth via the suppression of ARL2, and indicated that miR-214 may present a significant potential therapeutic target for colon cancer.