Abstract
BACKGROUND AND OBJECTIVE: It has been proven that p53 gene was related to many human cancers. The mutations in p53 gene play an important role in carcinogensis and mostly happened in exon 5-8. The aim of this study is to establish a high resolution melting (HRM) assay to detect p53 mutations from patients with non-small cell lung cancer (NSCLC), to investigate the characteristics of p53 gene mutations, and to analyze the relationship between p53 mutations and evolution regularity of pathogenesis. METHODS: p53 mutations in exon 5-8 were detected by HRM assay on DNA insolated from 264 NSCLC samples derived from tumor tissues and 54 control samples from pericancerous pulmonary tissues. The mutation samples by the HRM assay were confirmed by sequencing technique. Samples which were positive by HRM but wild type by sequencing were further confirmed by sub-clone and sequencing. RESULTS: No mutation was found in 54 pericancerous pulmonary samples by HRM assay. 104 of the 264 tumor tissues demonstrated mutation curves by HRM assay, 102 samples were confirmed by sequencing, including 95 point mutations and 7 frame shift mutations by insertion or deletion. The mutation rate of p53 gene was 39.4%. The mutation rate from exon 5-8 were 11.7%, 8%, 12.5% and 10.6%, respectively and there was no statistically significant difference between them (P=0.35). p53 mutations were significantly more frequent in males than that in females, but not related to the other clinicopathologic characteristics. CONCLUSIONS: The results indicate that HRM is a sensitive in-tube methodology to detect for mutations in clinical samples. The results suggest that the arising p53 mutations in NSCLC may be due to spontaneous error in DNA synthesis and repair.