ABSTRACT
Polycyclic aromatic hydrocarbons of tobacco require activation by phase I enzymes, such as cytochrome-P4501A1 (CYP1A1) to become an ultimate carcinogen, which are subjected to detoxification by phase II enzymes, especially glutathione S-transferases (GSTs). A study was designed to find whether genetic predisposition are risk modifiers of oral pathologies. The study included 102 cases with Oral Cancers (OCs), 68 cases with nonmalignant pathologies, 100 cases as control group. GSTM1 null genotype was associated with increased risk of OCs but not with benign pathologies. Deleted GSTT1 was associated with all pathologies. Both m1m2 and m2m2 polymorphisms of CYP1A1 were associated with oral pathologies.
ABSTRACT
Oral cancer is a lifestyle-related cancer, with tobacco as a primary factor. Progression of oral cancer develops over several years from the stage of leukoplakia, erythroplakia, etc. A micronucleus test was applied to oral mucosal cells, considering them as the target site for carcinogens and cytogenetic damage. The test has been established as a reliable biomarker for differential prevalence of MN indices among oral cancers, pre-cancers, non-malignant oral pathologies, and healthy controls for the first time. Buccal scrapings were collected from 63 patients with cancer and pre-cancerous lesions, 42 with non-malignant oral problems, and 100 healthy controls. The analysis revealed that MN frequencies in cancer and pre-cancerous cases were 4-fold elevated (p < 0.001) and 3.87-fold (p < 0.002) elevated for other non-malignant pathologies. Significant associations between use of tobacco in various forms and development of oral pathologies are also established. The relative cancer risk for smoking healthy controls with a definite MN frequency was also found to be significant. The results indicate the validity of the MN test as a cytogenetic marker for the development of several oral pathologies.
