Research On The Expression Of CXCR3 And Its Functionin Colorectal Cancer

Objective To investigate the expression of chemokine CXCR3(CXCR3-A and CXCR3-B)and its function in colorectal cancer.To clarify its mechanism of occurrence and development of colorectal cancer,to lay the foundation for the search for new targets.Methods The expressions of CXCR3-A and CXCR3-B in colorectal cancer tissues and cells were detected by immunocytochemistry(IHC)and Western-blot.The proliferation,invasion and migration of CXCR3-A and CXCR3-B were analyzed by Transwell and CCK-8(Cell Counting Kit 8),Transwell assay and scratch test.The effect of CXCR3-A and CXCR3-B on the tumorigenic ability of colon cancer cells was analyzed by subcutaneous tumorigenesis in nude mice.The expression of Ki67 was detected by immunohistochemistry.Results1.The expression of CXCR3-A was significantly higher in 50 CRC samples than that in adjacent tissues(adjacent tissues≥5cm)(P <0.001),while the expression of CXCR3-B in the adjacent tissues was significantly higher than tumor tissue(P<0.001).The clinicopathological factors showed that CXCR3-A and CXCR3-B were correlated with the differentiation,staging and metastasis of colorectal cancer(P <0.001),but not with the location of the tumor(P>0.05).CXCR3-A gradually increased with TNM staging and CXCR3-B decreased gradually.2.The expression of CXCR3-A in lymph node metastasis colon cancer cells SW620(P <0.001)and LOVO(P <0.001)was higher than that in situ Colon cancer cells HCT116(P<0.01),LS174T(P <0.01),SW480(P <0.01)and normal intestinal epithelial cells NCM460.The expression of CXCR3-B in normal intestinal epithelial cells was higher than that inmetastatic carcinoma cells.The difference was statistically significant in CXCR3-A and CXCR3-B.3.CCK-8 proliferation assay showed that overexpressing CXCR3-A in HCT116 and LOVO cells promote proliferation,when the cells grow to the next day began to show differences(P <0.05),the most obvious difference occurred in the third day(P <0.001).Overexpression CXCR3-B significantly inhibited the growth of HCT116 and LOVO cells.In addition,CXCR3-A and CXCR3-B had no significant effect on NCM460 cell.CXCR3-A and CXCR3-B show the opposite effect on cell proliferation.4.Transwell invasion assay showed that CXCR3-A promoted the invasion of HCT116(P <0.01)and LOVO(P <0.001)cells,and the inhibitory effect of overexpression of CXCR3-B on HCT116 and LOVO cells was no significant.5.Cell scratch test showed that CXCR3-A promoted HCT116(P <0.001)and LOVO(P <0.001)cell migration,and CXCR3-A and CXCR3-B were different between NCM460(P <0.001),HCT116(P <0.001)and LOVO(P <0.001).Transwell migration experiments were consistent with the scratch test results.6.Nude mice tumorigenesis experiment showed the tumor size of overexpressing CXCR3-A group was significantly higher than that of the control group(P <0.01)and the tumor size of overexpressing CXCR3-B group was significantly reduced than control group.(P <0.001).The expression of Ki67 in overexpressing CXCR3-A tumor group was higher than that in the control group(P <0.001),the expression of Ki67 in overexpressing CXCR3-B tumor group was lower than that in control group(P <0.001).This suggests that CXCR3-A and CXCR3-B have different effects on tumor proliferation.7.Overexpressing CXCR3-A competes down-regulation of CXCR3-B expression,overexpressing CXCR3-B down-regulation of CXCR3-A expression.Overexpressing CXCR3-A in the NCM460 cell line,we detected that CXCR3-B was downregulated,with astatistically significant difference(P<0.001).CXCR3-A was down-regulated after overexpressing CXCR3-B in HCT116(P <0.001)and LOVO(P <0.01)cell lines.ConclusionChemokine receptor 3(CXCR3)plays a variety of roles in different stages of colorectal cancer(CRC).CXCR3-A and CXCR3-B may be involved in a competitive antagonistic mechanism in colorectal cancer.The balance of CXCR3-A / CXCR3-B may cause the proliferation,infiltration and migration of CRC in the process of colorectal cancer.This provides a new way to study the pathogenesis of CRC,which provides a theoretical basis for target therapy.