ShRNA knock-down of CXCR7 inhibits tumour invasion and metastasis in hepatocellular carcinoma after transcatheter arterial chemoembolization

Abstract

To investigate the effects of lentiviral vector-mediated shRNA suppressing CXCR7 on tumour invasion and metastasis in hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE). HCCLM3 cell lines were cultured and assigned into the CXCR7-shRNA, negative control (NC) and blank groups. The qRT-PCR and Western blotting were applied to detect the mRNA and protein expressions of CXCR7, CXCR4 and MMP-2 in HCCLM3 cells. Cell proliferation and invasion were evaluated by MTT and Transwell assays. A Buffalo rat model of HCC was established. Fifty model rats were divided into the CXCR7-shRNA + TACE, CXCR7-shRNA, TACE, NC and control groups. Immunohistochemistry was performed to detect the expressions of CXCR7, MMP-2, vascular endothelial growth factor (VEGF) and intratumoral CD31-positive vessel count in tumour tissues of mice. Compared with the blank and NC groups, the mRNA and protein expressions of CXCR7 and MMP-2 were decreased in the CXCR7-shRNA group. The cell proliferation and invasion rates of the CXCR7-shRNA group were lower than the blank and NC groups. At the 4th week after TACE, tumour weight of the CXCR7-shRNA + TACE group increased continuously. The CXCR7-shRNA + TACE group showed longer survival time and smaller tumour sizes than other groups. Compared with other groups, the CXCR7-shRNA + TACE and CXCR7-shRNA groups had less number of lung metastatic nodules and lower expressions of CXCR7, MMP-2, VEGF and CD31-positive vessel count. CXCR7-shRNA inhibits tumour invasion and metastasis to improve the efficacy of TACE in HCC by reducing the expressions of CXCR7, MMP-2 and VEGF.

Keywords: CXCR7; hepatocellular carcinoma; invasion; lentiviral vector; metastasis; shRNA; transcatheter arterial chemoembolization.