Genetic polymorphism of carcinogen metabolic enzymes in oral submucous fibrosis

Abstract

Background: Biotransformation plays a crucial role in carcinogen activity. Genetic polymorphisms in xenobiotic-metabolizing enzymes crucial to a carcinogen and drug metabolism lead to variations in their activity. These enzymes increase cancer risk by an altered action on environmental carcinogens. The objective of this study was to analyze the significance of genetic polymorphisms in CYP1A1 and GSTM1 (carcinogen-metabolizing enzymes) genes in patients with oral submucous fibrosis (OSMF). Method: The study subjects included 50 patients. Twenty-five were diagnosed with OSMF, 5 with malignant transformation in OSMF, and 20 age and sex-matched healthy controls. Genotypes of CYP1A1 and GSTM1 were determined by polymerase chain reaction-restricted frequency length polymorphism. Results: 10%, 40%, and 60% GSTM1 null genotype were observed in normal subjects, OSMF patients, and OSMF patients with malignancy, respectively. 15%, 48%, and 40% CYP1A1 polymorphism were noted in normal subjects, OSMF patients, and OSMF with malignancy, respectively. Conclusion: Polymorphism in CYP1A1 and GSTM1 null genotype may increase the risk of OSMF. Combined polymorphisms may be an increased risk factor than single-gene polymorphism.