The mechanism and biological function of chemokine receptor CXCR4 and its ligand CXCL12 in hepatocellular carcinoma / 天津医药

ABSTRACT

Objective To investigate the mechanism and function of chemokine receptor CXCR4 and its ligand CXCL12 (CXCL12 / CXCR4) in primary hepatocellular carcinoma (PHC). Methods Western blot assay, immunohistochemistry and Real-time PCR were used to detect the protein and mRNA expressions of CXCL12/CXCR4 in 60 PHC and corresponding paracancerous tissue samples. Four kinds of hepatoma cells (Huh7, MHCC97h, HepG2 and Hep3B) and normal hepatocytes (7702) were routinely cultured, and then real-time PCR was performed to detect the mRNA expressions of CXCL12/CXCR4 in these cells to screen suitable experimental cells. CXCR4 interference plasmid (sh-CXCR4) and corresponding empty vector (sh-control) were transfected into MHCC97h to construct stable transfected cell lines. The ability of invasion, migration, and proliferation of the 2 groups of cells were detected by Tanswell invasion experiment, cell scratch test and MTT test. The stably expressed sh-control and sh-CXCR4 MHCC97h cells were taken into the subcutaneous of six nude mice, and the growth of the tumor was observed. Western blot assay was used to detect the expressions of vascular endothelial growth factor-C (VEGF-C) in sh-control and sh-CXCR4 MHCC97h cell lines and corresponding xenografts in nude mice, as the same in MHCC97h, which was transfected with CXCR overexpressed plasmid. Results (1) The results of Western blot assay, immunohistochemistry and Real-time PCR showed that the expressions of CXCL12/CXCR4 protein and mRNA were significantly higher in liver cancer tissues than those of paracancerous tissues. (2) The expression levels of CXCL12/CXCR4 mRNA were higher in Huh7, MHCC97h, HepG2 and Hep3B cells than those of 7702 cells. MHCC97h was selected as the experimental cells. The ability of invasion, migration and proliferation of MHCC97h cells transfected with sh-CXCR4 were significantly lower than those of sh-control group. Meanwhile, the growth rate of nude mice transplanted with sh-CXCR4 MHCC97h cells was also significantly lower than that of sh-control group. (3) Both in vitro and in vivo experiments showed that the expression of VEGF-C was lower in sh-CXCR4 group than that in sh-control group, and the expression of VEGF-C was obviously up-regulated after overexpression of CXCR4. Conclusion High expressions of CXCL12/CXCR4 are found in primary cancer tissues and hepatoma cells. CXCL12/CXCR4 may inhibit the proliferation and invasion of hepatoma cells by regulating the expression of VEGF-C protein.