Expression of CXC chemokine ligand 16/CXC chemokine receptor 6 in colon cancer and its effect on proliferation, invasion and metastasis of colon cancer

Abstract

Objective To investigate the expression of CXC chemokine ligand 16 (CXCL16)/CXC chemokine receptor 6 (CXCR6) in colon cancer and its effect on the proliferation, invasion and metastasis of colon cancer. Methods Immunohistochemistry was used to detect the expression of CXCL16/CXCR6 in colorectal cancer tissues and para carcinoma tissues, and colon cancer cell lines: SW480, LoVo, HCT116. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect the expression of CXCL16 mRNA and CXCR6 mRNA. The methyl thiazol tetrazolium (MTT) and Transwell were used to analyze the effects of CXCL16/CXCR6 on the proliferation, invasion and metastasis of colon cancer cells by CXCR16-RNA lentiviral vector transfected SW480 cells. Results In 56 cases of colon cancer, there were 48 cases positive for CXCL12 expression, and 47 positive for CXCR6 expression, with the positive expression rate being 85.7% and 83.9% respectively, significantly higher than in the adjacent normal tissues (26.7%, 33.3%), the difference was statistically significant (χ2=18.542, P=0.005; χ2=19.464, P=0.005). CXCL16 and CXCR6 in colon cancer cell lines SW480, LoVo, HCT116 were all positively expressed. The RT-PCR revealed that the expression of CXCL16 and CXCR6 mRNA in cancerous tissues was statistically significantly higher than in the normal tissues adjacent to carcinoma (t=2.592, P=0.008; t=2.364, P=0.003). CXCL16 and CXCR6 mRNA was highly expressed in the cancer cell linves (P=0.232). After transfection with lentivirus vector, MTT experiment showed that the proliferation of CXCL16-short hairpin RNA (shRNA) group was significantly lower than the control group (P=0.002). Transwell experimental results demonstrated that the number of cells in the experimental group and the control group was (14.2±1.68)×105 and (28.7±2.02)×105 respectively, and the difference was statistically significant (t=3.022, P=0.001). Conclusion CXCL16/CXCR6 may be involved in the proliferation, invasion and metastasis of colon cancer. Key words: CXC chemokine ligand 16; CXC chemokine receptor 6; Colon cancer; Proliferation; Invasion