MicroRNAs (miRNAs) play vital roles in cell proliferation, differentiation and apoptosis in hepatocellular carcinoma (HCC). miR-26b has been confirmed as an important regulator in carcinogenesis and other pathological processes. miR-26b-5p is one member of the mature miR-26 family, and its functional role in proliferation, angiogenesis and apoptosis in HCC remains unknown. Here, we demonstrate that miR-26b-5p expression was significantly decreased in HCC tissues and HCC cell lines compared with normal liver tissues and liver cells by quantitative real-time polymerase chain reaction (qRT-PCR). The relationships between miR-26b-5p and the clinical characteristics of HCC patients were further analysed, and miR-26b-5p was positively correlated with the differentiation of HCC cells. Computational searches were further used to identify the downstream targets and signalling pathways of miR-26b-5p in HCC cells. Cell viability, proliferation and tube formation abilities were assessed by scrape, 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and three-dimensional culture assays to confirm that miR-26b-5p inhibited HCC cell growth and impaired the tube formation ability of the HCC cells. Both in vitro and in vivo studies showed that miR-26b-5p could suppress vascular mimicry (VM) and angiogenesis by down-regulating the expression of VE-cadherin, Snail and MMP2 and could inhibit the apoptosis of HCC cells. Using mouse models, we revealed that tumours derived from miR-26b-5p-expressing HCC cells displayed a significant decrease in microvessel density compared with those derived from control cells. Therefore, our data provide further insight into the role of miR-26b-5p as a negative regulator of proliferation, angiogenesis, and apoptosis in HCC.
Keywords: Angiogenesis; Apoptosis; Hepatocellular carcinoma; miR-26b-5p.