Expression and Significance of NDRG1 Protein in Rectal Adenocarcinoma

Objective To investigate the role of NDRG1 protein in rectal adenocarcinoma development. Methods The expressions of NDRG1 and E-cadherin proteins were detected by immunohisto-chemical technique and Western blot, in 80 cases of rectal adenocarcinoma and 12 cases of rectal adenoma tissues. Results(1)The positive rates of NDRG1 and E-cadherin proteins were significantly diferent between the groups of adenoma (50.0% and 91.7% )and adenocarcinoma (77.5％and 53.8％) respectively (P＜0.05). Positive rate of NDRG1 protein( 95.0％) was higher in the groups of TNMⅢ～Ⅳ and lymph-node metastasis than that in the groups of TNMⅠ～Ⅱand lymph-node metastasis-free(60.0％) (P＜0.05). Expression of NDRG1 protein was more increased in group of serosa invasion (82.8％) than that in group of invasion within the muscular layer (63.6％)(P＜0.05). Positive rate of E-cadherin(58.5％) was higher in the group of well-moderately differentiated rectal adenocarcinoma than that in the group of the poorly differentiated rectal adenocarcinoma(25.0％). Meantime positive rate was lower in the groups of lymph-node metastasis and TNMⅢ～Ⅳ（32.5％）than that in the groups of without lymph node metastasis and TNMⅠ～Ⅱ（75.0％）(P＜0.05). (2)The expression levels of NDRG1 protein detected by western blot were consistent with the results by IHC. Conclusion It was suggested that NDRG1 might be contribute to the progression of rectal adenocarcinoma as a potential oncogene. The identification of both NDRG1 and E-cadherin proteins might be advantageous to analyse biological behaviors of rectal adenocarcinoma.