Expression And Significance Of Slug And E-cadherin In Colorectal Adenocarcinoma

ObjectiveTo investigate the expression of transcription factor Slug and E-cadherin by immunohistochemistry in the Colorectal adenocarcinoma,adjacent nontumor tissue and colorectal polyp and colorectal adenoma,the purpose of the presnt study was to examine the significance of Slug and E-cadherin expression in colorectal adenocarcinoma and the correlation between Slug and E-cadherin expression in colorectal carcinoma.Also, to clarify whether Slug and E-cadherin may be used as a novel parameter to predict prognosis in colorectal adenocarcinoma.Materials and methodsFormalin-fixed and paraffin-embedded samples from primary colorectal carcinoma(n=87) were obtained from Department of Pathology,the First Hospital of Shanxi Medical university,from January2011to December2012.Patients’treatment was surgical,not preoperative chemotherapy, radiotherapy, adjuvant therapy,all specimens were pathologically diagnosed as colorectaladenocarcinoma,The patient age ranged from26to85years old;Gende:rmale36cases,female51cases;Tumour location:24cases of right colorectal cancer,left colon in51cases,12cases of rectal cancer; According to the International Union Against Cancer TNM staging (UICC):16cases of stage Ⅰ,37cases of stage Ⅱ,34cases of stageⅢ+Ⅳ. While collecting30cases of adenoma and30cases of hyperplastic polyps as controls,30cases of adjacent tissue (from the tumor at least5cm) as normal control group.All specimens were cut into4μm thicks,which were mounted on glass slides,Immunohistoche-mical staining was performed using EnVision and highpress antigen retrieval technique, sections.E-cadherin mouse anti-human monocolonal antibody(Clone ID:MAB-0589),DAB kit were all purchased from Fuzhou MaximCo,Ltd.Slug mouse anti-human monoeolonal antibody(sc-166476)Was purchased from Santa Cruz Biotechnology.Working dilutions of Slug werel:500.The substrate reactions were performed with DAB solution at room temperature for3min.A hematoxylin counterstain was used. In the negative controls, the primary antibody Was replaced by PBS.All statistical calculations were performed by SPSS version16.O.P values less than0.05were considered statistically significant.Results1Slug was observed mainly in the cytoplasm of the tumour cells,Expression of Slug was considered as positive in42.5%of all patients(37of87samples),Expression of Slug was considered as positive in6.7%(2of30)of tissue adjacent to carcinoma,16.7%(5of30) of hyperplastic polyps and23.3%(7of30)of adenoma.There was significant difference both colorectal adenocarcinoma and adenoma, hyperplastic polyps,tissue adjacent to carcinoma (P<0.05).The positive expression of Slug in the colorectal adenocarcinoma was the higher than other tissues. Slug expression was significantly associated with histology,depth of tumour, lymph node metastasis,and TNM stage(P<0.05),but was not associated with age,gender,tumour location(P>0.05).2Expression of E-cadherin was observed on the cell membrane and borders of the cancer cells. Slug was not reduced in the adjacent to carcinoma.E-cadherin was considered as reduced in41.3%of all patients (36of87),(6.7%(2of30) of hyperplastic polyps and13.3%(4of30)of adenoma.There was significant difference both colorectal adenocarcinoma and adenoma, hyperplastic polyps,tissue adjacent to carcinoma (P<0.05). The reduced expression of E-cadherin in the olorectal adenocarcinoma was the higher than other tissues.Reduced E-cadherin expression was significantly associated with histology,depth of tumour,lymph node metastasis, and TNM stage(P<0.05),but was not associated with age,gender, tumour location(P>0.05).3There were negative correlation in the expression of the Slug and E-cadherin in colorectal adenocarcinoma (P<0.05).Conclusion1The expression of Slug was highly in colorectal adenocarcinoma and it was significant correlation with differentiation,depth of invasion, lymph node metastasis, and clinical stage of colorectal adenocarcinoma, but it was no significant correlation with age, gender, tumor location, Slug may be involved in the development, invasion and metastasis of colorectal adenocarcinoma.2E-cadherin expression in colorectal adenocarcinoma was low, and it was significant correlation with the degree of differentiation,depth of invasion,lymph node metastasis,and clinical stage of colorectal adenocarcinoma, but it was no significant correlation with age, gender, tumor location.3There were negative correlation between the expression of the Slug and the expression of E-cadherin in colorectal adenocarcinoma. two indicators may be more conducive to colorectal cancer diagnosis and prognosis,if we simultaneous detect Slug and E-cadherin in Colorectal adenocarcinoma.