GST M1 and CYP1A1 gene polymorphism and daily fruit consumption in Turkish patients with non-small cell lung carcinomas
Oztürk, O.; Isbir, T.; Yaylim, I.; Kocatürk, C.I.; Gürses, A.
In Vivo 17(6): 625-632
2003
ISSN/ISBN: 0258-851X PMID: 14758730 Document Number: 563196
In general, the metabolism of carcinogens involves two pathways. The oxidative pathway, which enhances carcinogenesis (phase I), and the protective pathway, in which carcinogens are conjugated with a series of substances such as glutathione to achieve detoxification (phase II). It has been suggested that an increased phase I enzyme activity (CYP1A1) and a decreased phase II enzyme activity (GST M1) could each individually cause an increase in the risk of cancer. In the present study we explored the association between genetic polymorphisms of CYP 1A1 and GST M1 and non-small cell lung cancer (n = 55) and controls(n = 60) in Turkish subjects. We used PCR methods and enzyme restriction for determining polymorphism. A standard food questionnaire was used to determine daily fresh fruit consumption. We found that CYP1A1 mutant variant (Ile/Val) was more highly expressed in Turkish patients and controls than in other Caucasian populations. Our findings were similar to Far Eastern populations (32.7% for patient group, 43.1% for controls). Inspite of the similarity between the groups regarding GST M1 polymorphism, in the patient group, patients with GST M1 null genotype had a statistically significant positive history of exposure to carcinogens other than smoking, such as asbestos, petrochemicals and/or other chemicals (p = 0.01). The patients, who had CYP 1A1 mutant variant, had increased risk of adenocarcinoma (p = 0.046) of lung (8 out of 18 patients) and 6 of them also had GST M1 (-) gene variants together. The patients who consumed less fruit daily had a greater risk of epidermoid carcinoma of lung (p = 0.019). However this study showed that there were no differences between the patient and control groups regarding genetic polymorphism of genes.