MiRNA-30a-3p inhibit the invasion and metastasis of liver cancer cells through down-regulating Atg3-mediated autophagy pathway

Objective\r\nTo investigate the effect of miRNA-30a-3p on the proliferation, invasion and metastasis of liver cancer cells by targeting Atg3-mediated autophagy pathway.\r\n\r\n\r\nMethods\r\nThe immunohistochemical staining was used to detect content of miRNA-30a-3p and Atg3 and their correlation in human hepatocellular carcinoma. Liver cancer cells were cultured in vitro and hunger environment was used to induce autophagy. RFP-GFP-LC3 double-labeled adenovirus infected hepatoma cells were used to detect autophagosomes in hepatoma cells. The expressions of autophagy-related proteins (autophagocytosis associated protein (Atg3), polyubiquitin-binding protein p62, autophagy microtubule-associated protein light chain 3(LC3)) and EMT-related proteins (N-cadherin, vimentin, snail, ZO-1) were detected by Western blot. Platelet cloning assay and transwell assay were carried out to detect the proliferation, invasion and metastasis of carcinoma cell. CCK-8 kit was used to detect hepatocarcinoma cells′ viability.\r\n\r\n\r\nResults\r\nThe expression of miRNA-30a-3p was down-regulated. The expression of Atg3, E-cadherin and N-cadherin in miRNA-30a-3p high-expressed hepatocellular carcinoma was lower than that in miRNA-30a-3p low-expressed hepatocellular carcinoma. Increasing the expression of miRNA-30a-3p in hepatocellular carcinoma cells can decrease the expression of Atg3 and LC3, increase the expression of p62 and inhibit the formation of autophagosomes; otherwise, Atg3 and LC3 were increased, p62 was decreased and the formation of autophagosomes was promoted. Inhibition of Atg3 expression could decrease the expression of EMT-related proteins. When miRNA-30a-3p was inhibited, the cell viability of HCC was increased at each time point(F1=10.314, P\u003c0.05). When miRNA-30a-3p and Atg3 were inhibitor together, the cell viability of HCC was decreased at each time point(F2=6.599, P\u003c0.05).\r\n\r\n\r\nConclusion\r\nmiRNA-30a-3p can inhibit Atg3-mediated autophagy pathway and reduce cell autophagy activity, thus inhibiting the proliferation, invasion and metastasis of hepatocarcinoma cells.\r\n\r\n\r\nKey words: \r\nCarcinoma, hepatocellular; MicoRNAs; Autophagy; Neoplasm metastasis