p53 Gene Mutation in Gastric Cancer Tissue

PURPOSE: p53 is one of the most commonly mutated genes in human tumors. The aim of this study was to analyze p53 mutation in gastric cancer and its correlations with the clinicopathologic variables to clarify the usefulness of p53 mutation as a prognostic factor. MATERIALS AND METHODS: Specimens from 331 patients with gastric cancer who underwent a gastrectomy between March 1999 and April 2001 at the Kyungpook National University Hospital were used. p53 gene mutations were assessed by using a polymerase chain-reaction single-strand conformation polymorphism (PCR-SSCP) analysis. The correlations between p53 gene mutation and clinocopathologic parameters were analyzed. RESULTS: p53 mutations were found in 66 (19.9%) tumors. Among those 66 cases, mutations were seen in 23 tumors at exon 5, in 8 at exon 6, in 21 at exon 7, and in 17 at exon 8. Two mutations were shown in 3 tumors. Thirty-six (23.1%) of 156 intestinal-type tumors and 19 (13.1%) of 145 diffuse-type tumors showed p53 gene mutation (P=0.007). The frequency of p53 gene mutation didn't show any significant differences according to age, sex, stage, location, or gross type. Exon 5 mutations showed more frequently in intestinal-type tumors than in diffuse-type tumors (9.7% vs. 2.8%, P=0.024), and p53 mutation were more frequent in lymph nodes metastasis group than lymph nodes non-metastasis group with statistical significance (25.0% vs 15.6%, P=0.034). The five-year survival rate showed no statistically significant difference with p53 mutation (P=0.704). CONCLUSION: p53 mutations assessed by PCR-SSCP had little value as a prognostic factor after gastrectomy in patients with gastric cancer.

p53 Mutation of Head and Neck Squamous Cell Carcinoma Cell Lines / 대한암학회지

PURPOSE: Structural alterations of p53 and overexpression of the p53 protein are the most common genetic abnormalities in various kinds of human cancers. In this study, we examined the mutational status and the frequency of p53 mutations in head and neck squamous cell carcimona (HNSCC) cell lines. MATERIALS AND METHODS: 7 human head and neck squamous cell carcinoma cell lines were included in this analysis. Using polymerase chain reaction(PCR), single strand confonmation polymorphism(SSCP) and PCR-DNA sequencing analysis, we tested the mutational status of 7 cell lines. Exon 4~9 of the p53 gene was amplified for the direct DNA sequencing analysis. RESULTS: Our results showed 100% nuclear p53 immunostaining and 3 electrophoretic abnomalities by PCR-SSCP in three cancer cell lines and mutations of the p53 gene including 2 base substitutions and 1 base deletion were detected in 3 cancer cell lines using PCR directed DNA sequencing analysis. CONCLUSION: 7 HNSCC cell lines examined in this study provide excellent systems for study of gene therapy using p53 gene.