Expression And Clinical Significance Of Anterior Gradient-2in Colon Adenocarcinoma

AIM：In recent years, the incidence and the rate of death of colon cancer is rising, andthe average age tends to be younger in China, because of the continuous improvementof living standards of the country and changes in habits and composition of diet.Therefore, the research of colon cancer potential tumor marker is particularlyimportant, which may assist the diagnosis, prognosis of tumor metastasis. Anteriorgradient-2AGR2was discovered in the differential express genes of estrogenreceptor positive breast cancer cells, which is located on7p21.3and encodes secretedprotein. Subsequent research indicated AGR2express abnormally in a variety ofhuman tumor tissues and may be closely related to the tumor genesis, progression andmetastasis of tumor. The latest researches demonstrates that AGR2express highly incolon cancer cell lines and in peripheral blood of patients with colon cancer, but theexpression of AGR2in colon cancer tissues is not yet reflected. This study aims toestimate the expression of AGR2in colon cancer tissues and the relationship of itsexpression with clinicopathological factors, to investigate its role in the occurrenceand development of colon adenocarcinoma.METHODS：68cases of colon cancer surgical specimens were selected in the First AffiliatedHospital of Zhengzhou University from October2012to May2013,and all specimenswere dignosed definitely in the department of pathology. The AGR2mRNA level wasdetected by semi-quantitive RT-PCR and the AGR2protein level was examined by Western blot and immunohistochemistry in colon adenocarcinoma andtumor-adjacent non-cancerous tissues.RESULTS：The expression of AGR2mRNA in colon adenocarcinoma was significantlyhigher than that in tumor-adjacent non-cancerous tissues （0.95±0.03vs0.21±0.06，P<0.05）. The expression of AGR2protein in colon adenocarcinoma was significantlyhigher than that in tumor-adjacent non-cancerous tissues （0.93±0.03vs0.31±0.02，P<0.05）. The positive rate of AGR2expression in colon adenocarcinoma wassignificantly higher than those in tumor-adjacent non-cancerous tissues （75%vs29.4%， P<0.05）. The expression of AGR2was correlated with Dukes stage，histopathological grade and lymph node metastasis （all P <0.05），but not with otherclinicopathologic factors.CONCLUSION：Our findings indicate the expression of AGR2is closely related to thetumorigenesis, progression and metastasis of colon adenocarcinoma. AGR2may beused as diagnostic marker for colon adenocarcinoma.