Notch3 regulate invasion and metastasis of hepatic carcinoma by matrix metalloproteinase-2/matrix metalloproteinase-9 mediated by Wnt/β-catenin pathway

Abstract

Objective To observe the effect of Notch3 on invasion and metastasis of hepatocellular carcinoma mediated by Wnt/β-catenin pathway. Methods The Notch3 gene and protein expression was detected by real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) and Immunohistochemistry. Cultured hepatoma cell lines QGY7701, and then cells were divided into three groups: non transfection group (Control), Lipo transfection group (si-NC) and small interfering RNA (siRNA)-Notch3 transfection group (si-N3). Wound healing and transwell assays were used to assess cancer cells the capacity of invasive and metastasis. Western blotting was carried out to analyze the expression of Notch3, β-catenin, matrix metalloproteinase (MMP)-2 and MMP-9 proteins. Results Notch3 gene expression levels were significantly increased in the tumor tissue compared with the normal liver tissue from the same patient. The results of immunohistochemistry showed that Notch3 protein expression was positive in the tumor tissue. Wound healing assay showed that the migrating cells of si-N3 group were less than Control group and si-NC group in 12 h and 24 h, which means the capacity of cell migration inhibited. Compared control group, the invasion capacity of QGY7701 cells was significantly decreased [ (75±8) cells vs. (125±11) cells vs. (118±10) cells, P=0.001, 0.002]. After Notch3 protein silenced, the expression level of β-catenin was upregulated and MMP-2/MMP-9 was downregulated. Conclusion Notch3 expression is activated in hepatocellular carcinoma tumor tissues, and Notch3 can mediate MMP-2/MMP-9 through the Wnt/β-catenin pathway to promote the invasion and metastasis of hepatoma cells. Key words: Notch3; β-catenin; Hepatic cancer; Invasion; Migration; Matrix metalloproteinase-2; Matrix metalloproteinase-9