Abstract

Acetaldehyde interacts covalently with DNA to form major stable acetaldehyde–DNA adduct N2- ethyl-2’- de-oxyguanosine, which may be critical initiating event in the multistage process of chemical carcinogenesis primarily observed in gastroesophageal cancers. In the present study, RT-PCR experiment results showed increased expression of ADH and decreased expression of ALDH2 in GE cancerous conditions when compared with the normal GE tissue indicating the variation in the catabolism of acetaldehyde to acetate in the cancerous tissue. These results were further corroborated by enzyme assay where increased ADH enzyme activity was observed (0.445+0.02ìM/ml/minute) in cancerous tissue compared to normal tissue (0.335+0.01 ìM/ml/ minute) whereas; ALDH2 enzyme activity (0.15+0.01 ìM/ml/minute) decreased appreciably in cancerous tissue and compared to normal tissue (0.356+0.04 ìM/ml/minute). Further, SDS-PAGE results too indicated differential expression of 40KD and 55KD proteins in normal and in GE cancerous tissue. Therefore, detection of ADH and ALDH2 expression levels in alcoholics will assist in the early diagnosis of gastro esophageal cancers.