[Correlation between p53 gene mutation and protein expression in 30 cases of human lung cancer].

OBJECTIVE: To investigate the correlation between p53 gene mutation and protein expression and discuss the sensitivities of immunohistochemistry and PCR-SSCP in detecting p53 abnormalities in lung cancer. METHODS: Immunohistochemistry, PCR-SSCP, and PCR-sequencing were used. RESULTS: 22 of 30 patients showed p53 mutations by PCR-sequencing. Mutations of 8 patients (36%) located on exon 5, 2(9%) on exon 6, 7 (32%) on exon 7, and 5(23%) on exon 8, respectively. 14 patients (64%) showed missense mutations, and 4(18%) neutral mutations, 3(14%) frameshifts and 1(5%) splice site mutation. In all mutations, G:C-->T:A transversions accounted for 41%(9/22). p53 missense mutations were found in all 10 patients whose immunohistochemistry and PCR-SSCP were both positive. Nine of 10 patients whose PCR-SSCP was positive but immunohistochemistry negative had p53 mutations, including 4 patients with neutral mutations, 3 frameshift mutations, 1 missense mutation, and 1 splice site mutation. In 10 patients whose immunohistochemistry was positive but PCR-SSCP negative, only 3 showed p53 missense mutations. CONCLUSION: Most of p53 mutation sites located on exon 5 and exon 7 in lung cancer of China. Missense mutations and G to T transversions were prevalent. If both PCR-SSCP and immunohistochemistry gave the positive results, p53 missense mutations may be expected.