p53 Mutation in Lung Cancer in Gejiu and Xuanwei Regions of Yunnan Province
Huang Yanping, Jin Kewei, Gao Qian, Li Baogang. Department of Pathology, Kunming Medical College, Kunming 650031, China
Objective The incidence rates of lung cancer among tin miners in Gejiu and among peasants in Xuanwei are higher than the average incidence rate in Yunnan Province, and the causes of the disease in these two regions have been preliminarily clarified. This study was directed to the molecular biological basis of its pathogenesis.Methods Twenty six specimens of the lung cancers of Gejiu tin miners(GTM) and 15 ones of Xuanwei peasants (XP) were examined by single strand conformation polymorphism analysis of polymerase chain reaction products.Results Using PCR primers for the most highly conserved region of the p53 including exons 5 8, we have identified p53 mutations in 13 lung cnacer tumor DNA samples of GTM and in 4 ones of XP. Nucleotide sequencing of one of the exon 5 mutations of GTM indicated that there was a C to T transition, which resulted in substitution of Val for Ala at amino acid 135, and there was an AAC to TTC transertion in the exon 7 of XP, which resulted in substitution of Phe for Asn at amino acid 247.Conclusion p53 mutation is a frequent incident in lung cancer of GTM and XP, and two new mutation sites were found in p53 gene, which have not been reported before now. There was no statistically significant correlation between the detection of p53 mutation and the patient's age, sex, mining history and histologic type of the cancer.