[Correlation study of allelic gene deletion of nm23-H1 and human colorectal carcinoma metastasis].

In recent years, a tumor suppressor gene nm23 has been found to be associated with decreased tumor metastatic potential. Allelic deletion, mutation and low expression of this gene has been correlated with tumor metastatic potential in a number of tumors. There are two known isotypes of human nm23 gene, named nm23-H1 and nm23-H2. We examined DNA from 23 cases of colorectal carcinomas and their corresponding normal mucosa using Southern blot hybridization with nm23-H1 cDNA probe. Five cases with allelic deletion of nm23-H1 gene were found, with allelic deletion rate of 57. 1% (4/7) in cases with metastasis to lymph node, liver or other organs, and 6.2% (1/16) in cases without metastases (P < 0.005). There is no correlation between allelic deletion and tumor size, location or differentiation. This result indicates that nm23-H1 gene plays an important role in the metastasis of colorectal carcinoma.