Expression And Significance Of MiR-29b And Its Target DNMT1 Protein In Colorectal Adenocarcinoma

Objective: To study the expression of miR-29 b and its target DNMT1 protein in colorectal carcinoma and its correlation with clinicopathologic significance in colorectal carcinoma.Methods: In 115 cases of invasive colorectal carcinoma,the expression of miR-29 b was determined by in situ hybridization and DNMT1 proteins were determined by the immunohistochemical staining, respectively. The relationship between these three proteins and clinicopathologic features in colorectal carcinoma was analyzed by χ2 test and Spearman’s rank correlation analysis. The survival analysis was analyzed by Kaplan-Meier’s method and cox regression analysis.Results:(1) In 115 cases of invasive colorectal carcinoma, the positive rates of miR-29 b and its target DNMT1 protein were 35.7%, and 68.7%, respectively,(p<0.05).(2) In situ hybridization showed much lower mi R-29 b positive cells in patients with advanced Dukes stages, or with lymph nodes metastasis than that in lower Dukes stages, or without lymph nodes metastasis(p<0.05).And immunostaining analysis shown more DNMT1 positive cells in patients with advanced Dukes stages, or with lymph nodes metastasis than that in lower Dukes stages, without lymph nodes metastasis(p<0.05).(3) Spearman’s rank correlation analysis shown miR-29 b correlates with DNMT1 negatively.Conclusion:(1) miR-29 b and DNMT1 testing could predict the invasive behavior and higher clinical Dukes stages of colorectal carcinoma;(2) The negative expression of miR-29 b and over-expression of DNMT1 correlates with the metastasis of colorectal carcinoma and unfavorable prognosis.