Expression of CDX2,PTEN,Ki-67 and their correlativity of DNA ploidy in colorectal carcinoma

Abstract

Objective To investigate the expression of CDX2,PTEN and Ki-67 in colorectal carcinoma,and the correlations among CDX2,PTEN,Ki-67 and DNA ploidy. Methods Fifty samples of human colorectal carcinoma tissue and ten samples of normal mucosa adjacent to carcinoma were examined for CDX2,PTEN as well as Ki-67 by immunohistochmistry,and the flow cytometry was used to detect the status of DNA ploidy jn colorectal carcinoma.Results The expression of CDX2 in colorectal carcinoma and normal mucosa tissue were 82%(41/50) and 100%(10/10) respectively.The expression of CDX2 had significant difference compared to that in normal mucosa tissue.PTEN in colorectal carcinoma and normal mucosa were 64%(32/50)and 90%(9/10) respectively,the expression had significant difference.Both CDX2 and PTEN were related with staging and grading of tumor,metastasis of lymph nodes and infiltrating depth of carcinoma.Expression of CDX2 and PTEN was negatively correlated with the expression of Ki-67(r=-0.254,P＜0.05;r=-0.340,P＜0.01) respectively.The expression of CDX2 was increased in diploid colorectal cancer,as compared with that in heteroploidy colorectal cancer(93.75%and 76.47%).But the expression of PTEN had no difference between diploidy and heteroploidy carcinomas.Conclusion The expression of the CDX2 and of the PTEN were are positive in part of the colorectal carcinoma.Both CDX2 and PTEN's expression negatively correlate with Ki-67.CDX2,intestinal-specific homeobox genes,regulate cell proliferation and differentiation in the continuously renewed intestinal epitheium.PTEN positively regulates CDX2 gene expression.The down regulation of CDX2 protein is concerned with tumor maligancy and bad prognosis. Key words: CDX2; FTEN; Ki-67; DNA ploidy; Colorectal neoplasms; Immunohistochmistry; Flow cytometry