Expression of CCL2 in colorectal cancer and its role in carcinogenesis / 中华普通外科杂志

ABSTRACT

Objective To investigate the expression of CCL2 in colorectal cancer and its carcinogenesis mechanism associated with macrophages.Methods The expression level of CCL2 mRNA in 17 cases of colorectal cancer tissues and corresponding adjacent tissues were analyzed by PCR,and the phenotypes of macrophages in tumor infiltrating lymphocytes (TIL) were analyzed by flow cytometry.Human peripheral blood mononuclear cells were isolated and induced to differentiate into macrophages.After 12 h incubation with CCL2,the phenotypic changes of macrophages were analyzed by flow cytometry.The expression level of VEGF,COX-2 and IL-6 in the supernatant were measured by ELISA assay.Results The expression level of CCL2 in colorectal cancer tissues was significantly higher than that in corresponding adjacent mucosal tissues (t =4.017,P ＜ 0.05),and the macrophages in TIL had a high proportion of CCR2 phenotype.CCL2 was shown to induce increased CCR2 expression in macrophages (t =5.070,P ＜ 0.05),and promote the secretion of the tumor growth-associated factors such as VEGF,COX-2 and IL-6 (all P ＜ 0.05).Conclusion The levels of CCL2 in colorectal cancer were up-regulated suggesting that CCL2 may play a key role in tumor promotion by recruiting macrophages and influencing their function.