The impact of combined genotypes of the CYP1A1 Ile/Val polymorphism and GSTM1 on mutation of K-ras was also analyzed, and a higher risk of having a mutated K-ras gene was found for both the CYP1A1 Ile/Ile and GSTM1(-) (OR, 6.32; p=0.021; 95% CI, 1.33-30.19) and CYP1A1 Ile/Val and GSTM1(-) (OR, 6.09; p=0.042; 95% CI, 1.07-34.72) genotype combinations in patients with adenocarcinoma.
GSTM1, GSTT1, GSTP1 and CYP1A1 genetic polymorphisms and susceptibility to esophageal cancer in a French population: different pattern of squamous cell carcinoma and adenocarcinoma.
In agreement with past experimental and epidemiological data, the associations found in this study between CYP1A1 and lung SCC and between CYP2E1 and lung AC suggest a certain specificity of tobacco smoke PAHs for lung SCC and tobacco-specific nitrosamines for lung ACs.
Second, the two polymorphisms of CYP1A1 were examined among current or ex-smokers with three differentiation grades, and we found that poorly differentiated adenocarcinoma showed significantly high frequencies of genotypes C and Val/Val, which have been found to be 'susceptible' in squamous cell carcinoma of the lung.
Because of its potential significance in human lung cancer, we investigated the expression of the CYP1A1 structural gene in 24 established human lung cancer cell lines including 15 non-small cell (eight adenocarcinomas, three large cell undifferentiated carcinomas, two bronchioloalveolar cell carcinomas, and two squamous cell carcinomas) and nine small cell lung carcinomas.