[Analysis of aromatic DNA adducts in oral cavity and pharyngeal cancer]

An exposure to tobacco smoke carcinogens is followed by an interaction of chemical carcinogens with DNA molecule resulted by the formation of carcinogen: DNA adducts. The study subjects were 40 oral and pharyngeal cancer patients with primary tumours diagnosed as squamous cell carcinoma. The biological samples purchased for analysis included tumour biopsy, the surrounding tissue (histopathologically recognised as non-malignant) and peripheral blood leucocytes. For DNA adducts analysis first DNA was isolated using phenol detergent extraction followed by 32P-postlabelling assay including P1 nuclease enhancement. Aromatic DNA adducts were found in all studied tissues. The average levels of DNA adducts in tumour and non-tumour tissues were found higher than in leucocytes. Biopsies from pharynx contained higher levels of DNA adducts than from oral cavities. Confounding effect of tobacco smoking and alcohol consumption on DNA adducts level was observed but it has not reached statistical significance. Formation of DNA adducts was not depended on such factors as patients age, sex, pulmonary tuberculosis, cancer progression (TNM), environmental pollution and mechanical irritation.