ABSTRACT
The p53 gene, which resides on the short arm of chromosome 17, has been described as a tumor suppressor gene playing a role of G1 checkpoint monitering DNA damage, but mutation of this gene has been shown in numerous types of human cancers. The nm23-H1 gene encodes human NDP(nucleotide diphosphate) kinase. The expression of nm23-H1 gene was postulated to inversely correlate with metastatic potential of malignant tumors. We examined immunohistochemical expression in 30 cases of stomach cancers including 10 cases each of early gastric cancers(EGC), advanced gastric cancers without lymph node involvement, and advanced gastric cancers with lymph node involvement, which were stained with mouse monoclonal antibody of p53(PB53-12) and nm23-H1. Positive nuclear staining of p53 was frequently found in advanced gastric cancers with lymph node involvement (80%). The lymph node positive group showed high expression of p53(80%), and low expression of nm23-Hl(30%) than lymph node negative group. There was no significant correlation of p53 and nm23-H1 expression with tumor size, invasion depth, TNM stages, distant metastasis and histologic differentiation. Based on the present study, the expression of p53 and down regulation of nm23-H1 are thought to be correlated with tumor progression and lymph node involvement, and may be a useful prognostic factor in gastric cancers.