The Study On The Chemokine CXCL7 In Clinical Diagnosis And Its Role Of Regulating Proliferation,migration And Invasion In Colorectal Cancer

Objective: To explore the diagnostic value of chemokine CXCL7 in colorectal cancer(CRC).To compare the expression of CXCL7 between cancer tissues and adjacent normal tissues of CRC patients,and study the biological function of CXCL7 on CRC cells.Methods: ELISA method was used to quantify the concentration of serum CXCL7 in280 CRC patients and 280 normal people.First,the levels of serum CXCL7 were compared in two groups,and the correlation between serum CXCL7 and clinical data was also analyzed in CRC patients.The diagnostic efficiency of CXCL7 was analyzed by designing three cohorts,including a test cohort,a verification cohort and a cross-cohort.Then,logistic regression models were established to make a joint diagnostic model,and the diagnostic tests were also conducted by drawing ROC curve,calculating the area under the curve,sensitivity,specificity and other indicators.Next,different subgroups of TNM,I-II and genders CRC patients were used to evaluate the diagnostic efficacy of CXCL7.Furthermore,CRC patients were reselected from other hospitals to test the stability and extension promotion value of CXCL7 as a diagnostic biomarker in CRC diagnosis.The expression of CXCL7 was measured by immunohistochemistry and qPCR in 20 CRC patients both in cancer tissues and adjacent normal tissues.Afterward,the difference of CXCL7 expression was analyzed in cancer tissues and adjacent normal tissues.Lo Vo overexpression and Caco-2 knockdown stable expression cells were constructed by lentivirus transfection.Then,CCK-8,EdU staining and plate clone formation experiments were used to evaluate the effect of CXCL7 on proliferation of CRC cells.Wound-healing assay was adopted to determine the effect of CXCL7 on migration ability of CRC cells.Transwell assay was used to inquire the change of invasion ability by CXCL7.Results: The concentration of serum CXCL7 in the CRC group was significantly higher than that in the control group,and it increased with the TNM stages(P<0.05),and the levels of serum CXCL7 were correlated with gender,TNM stages and T stage in CRC patients(all P<0.05).The diagnostic analysis of test cohort,verification cohort and cross-cohort showed that CXCL7 had the potentiality to diagnose CRC.CXCL7 had a higher diagnostic area under the curve(AUC,0.862)than other four markers(P<0.05),and combined diagnosis improved the diagnostic efficiency,and the stability of CXCL7 was also high in the subgroup analysis.Immunohistochemistry and qPCR analysis showed that the expression of CXCL7 in CRC cancer tissues was higher than that in adjacent normal tissues,and the results of qPCR and ELISA analysis showed that CRC cell lines also highly expressed CXCL7.Furthermore,CXCL7 can regulate the proliferation,migration and invasion of CRC cells.Conclusion: These results suggest that CXCL7 is a better serum biomarker for diagnosis of CRC,and it is also a potential carcinogenic target,which can participate in regulating the malignant phenotypes of CRC.