Downregulation of SRC Kinase Signaling Inhibitor 1 (SRCIN1) Expression by MicroRNA-32 Promotes Proliferation and Epithelial–Mesenchymal Transition in Human Liver Cancer Cells

MicroRNAs play an important role in regulating gene expression by binding to the 3′-UTR of target mRNAs. In this study, we have made an attempt to assess the molecular mechanisms by which miR-32 suppresses the expression of SRCIN1, thereby leading to promotion of proliferation and epithelial–mesenchymal transition of human liver cancer cells. Human liver cancer cell line HepG2 was transfected with miR-32 mimics and its control. The HepG2 cells were assessed for miR-32 expression. The transfected cells were then studied for SRCIN1 expression by luciferase assay, effect of transfection on cell proliferation, and epithelial–mesenchymal transition. SRCIN1 expression was downregulated in the human liver cancer cell line HepG2. Overexpression of SRCIN1 inhibited the proliferation of human liver HepG2 cancer cells and blocked epithelial–mesenchymal transition. It was observed that SRCIN1 expression was regulated by miR-32 in human liver cancer cells. Overexpression of miR-32 promoted cell proliferation and epithelial–mesenchymal transition of human liver cancer HepG2 cells. Our data demonstrated that SRCIN1 functions as a tumor suppressor in human liver cancers. Additionally, SRCIN1 functions to inhibit the proliferation and epithelial–mesenchymal transition of human liver cancer HepG2 cells. miRNA-32 was a direct target of SRCIN1. Overexpression of miR-32 promoted cell proliferation and epithelial–mesenchymal transition of human liver cancer HepG2 cells.