Expression of candidate tumor suppressor gene N-Myc downstream-regulated gene 2 in colon cancer

OBJECTIVE: To analyze the expression level of candidate tumor suppressor gene N-Myc downstream-regulated gene 2 (NDRG2) in human colon cancer. METHODS: Thirty samples of colon cancer tissues with matched normal colon tissues were collected. The NDRG2 mRNA level was detected by semi-quantitive RT-PCR and the NDRG2 protein level was examined by Western blot and immunohistochemistry. RESULTS: Twelve samples of colon cancer tissues had low NDRG2 mRNA level and low protein level. The positive rates of NDRG2 in normal tissues and the tumorous colon tissues were 90.0%(27/30) and 53.3%(16/30) by immunohistochemistry respectively. There was a significant difference between two groups (P<0.05). The NDRG2 expression was not correlated with age, sex, metastasis of lymph node, depth of infiltration, as well as the Dukes staging(P>0.05), while it was correlated to the histology grading. The positive rate of NDRG2 in the well- and moderate-differentiation group was higher than that in the poor-differentiation group(P<0.05). CONCLUSION: The expression of NDRG2 is low in some colon cancer tissues, which indicates that the low level of NDRG2 expression may be engaged in the development of colon cancer.