Igf2-derived intronic miR-483 promotes mouse hepatocellular carcinoma cell proliferation

Most intronic micro-RNAs are coexpressed with their host genes, suggesting that they may play similar roles. The function of miR-483 remains unknown, although it is embedded in an intron of Igf2 gene, which is an activator of hepatocellular carcinoma proliferation. In the present study, we provide evidence that Igf2-derived miR-483 can induce proliferation in hepatocellular carcinoma cells. The miR-483 promotion of proliferation was analysed by soft agar colony formation assay and proliferation curve assay. The effect of miR-483 on Socs3 expression was examined by Western blot and a reporter assay. Our results revealed that Igf2-derived intronic miR-483 was identified by the application of 94G6, an inhibitor of Igf2 at the transcriptional level. All results from the (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) MTT assay, the proliferation curve assay and the soft agar colony formation assay showed that miR-483 promoted the proliferation of hepatocellular carcinoma cells. Finally, Socs3, a putative target predicted by bioinformatics, was regulated by miR-483 at mRNA and protein levels. Direct binding with the 3' UTR was identified by a luciferase activity assay. Our findings demonstrate that Igf2-derived intronic miR-483, through downregulation of its target Socs3, regulates hepatoma cell proliferation and thus may serve as a potential target for hepatocellular carcinoma therapy.