Detection And Analysis Of CCR6 And IL-17 In Primary And Liver Metastases Of Colorectal Cancer

Objective:To compare the expression of CCR6 and IL-17 in primary lesions and liver metastases of colorectal cancer and explore their biological significances in liver metastasis of colorectal cancer.Methods:Primary tissue,liver metastasis,normal intestinal mucosa and normal liver tissue specimens were collected from 40 colorectal cancer patients with liver metastasis(CRCLM)treated in the Affiliated Tumor Hospital of Guangxi Medical University from January 2013 to October 2018.Since the primary lesions of 13 patient were resected in other hospitals,the specimens from CRCLM patients used in this study were as followed: 27 specimens from primary lesion,27 from normal intestinal mucosa,40 from liver metastasis and 16 from normal liver tissue.Specimens from 35 patients diagnosed with hepatocellular carcinoma(HCC)treated in Tumor Hospital Affiliated to Guangxi Medical University from January 2018 to October 2018 were also collected,including 35 from tumor tissues,and 35 paired normal liver tissue.Expression of CCR6 and IL-17 were detected by immunohistochemistry.Clinical pathological features(sex,age,location of primary tumors,primary tumor size,degree of differentiation of primary tumors,lymph node metastasis,intravascular tumor thrombus,size of metastases,intrahepatic metastases,size of metastases)were also collected.The expressions of CCR6 and IL-17 in each group were analyzed and compared.The association of expression of CCR6 and IL-17 and the clinicopathological information of patients was analyzed.All statistical analysis was conducted with SPSS23.0 statistical software.Chi-square test was used to determine the differences of counting data between two groups.Spearman correlation analysis was used to analyze the correlation.P < 0.05 showed that the difference was statistically significant.Results:1.In CRCLM patients,the positive rate of CCR6 in primary lesions(59.3%)was significantly higher than those in normal intestinal mucosa(22.2%)(P < 0.05).The positive rate of CCR6 in liver metastases(50.0%)was significantly higher compared to normal liver tissues(18.8%)(P < 0.05).The positive rate of CCR6 in primary lesions of HCC patients(42.9%)was significantly higher than those in paired normal liver tissues(8.6%)(P < 0.05).The expression of CCR6 in primary lesion and liver metastasis of CRCLM patients,and tumor tissues of HCC patients were not significantly correlated with clinicopathological features,including gender,age,tumor location,tumor size,differentiation,lymph node metastasis,intravascular tumor thrombus,size of metastasis and numbers of intrahepatic metastasis(P > 0.05).2.2.In patients with liver metastasis of colorectal cancer,the positive rate of IL-17 in primary lesions(85.2%)was significantly higher than that in normal intestinal mucosa(29.6%)(P < 0.05).The positive rate of IL-17 in liver metastases(55.0%)was significantly higher than that in normal liver tissues(25.0%)(P < 0.05).The positive rate of IL-17 in tumor tissues of HCC patients(57.1%)was significantly higher than that in paired normal liver tissues(28.6%)(P < 0.05).The expression of IL-17 in primary lesions and liver metastasis of CRCLM patients,and tumor tissues of HCC patients were not significantly correlated with clinicopathological features,including gender,age,location,size,differentiation degree,lymph node metastasis,intravascular embolism,intrahepatic metastasis and size of metastasis(P > 0.05).The expression of IL-17 in primary lesions of CRCLM patients was associated with the tumor differentiation levels(P < 0.05).3.There was no significant correlation between the expression of CCR6 and IL-17 in primary lesions of colorectal cancer with liver metastasis(r=0.291,P > 0.05).CCR6 was moderately correlated with IL-17 expression in liver metastases of CRCLM patients(r=0.402,P < 0.05).No significant correlation between CCR6 and IL-17 expression was found in tumor tissues of HCC patients(r=-0.067,P>0.05).4.There was no significant difference in the expression of CCR6 between primary and liver metastases of colorectal cancer(P>0.05).There was no significant difference in the expression of CCR6 between colorectal cancer with liver metastasis and primary liver cancer(P > 0.05).The expression of IL-17 in primary and liver metastases of colorectal cancer was significantly different(P < 0.05).There was no significant difference in the expression of IL-17 between colorectal cancer with liver metastasis and primary liver cancer(P > 0.05).Conclusion:1.Compared with normal tissues,CCR6 and IL-17 were highly expressed in both primary lesions and liver metastases of CRCLM patients.Whether CCR6 and IL-17 were related to liver metastasis of colorectal cancer deserved further study.2.CCR6 was both highly expressed in liver metastases of CRCLM patients and tumor tissues of HCC,and the differences between them was not significant.This result suggested that there may be some shared biological characteristics between liver metastasis of CRCLM and primary liver cancer.3.3.The similarity in biological features between liver metastasis of CRC and hepatocellular carcinoma may explain the tendency of some cells to metastasis to liver,but the underlying mechanisms were still need to be explored in the future.