Characteristics of apoptosis and dna repair related genes methylation in stepwise gastric cancerogenesis process

DNA repair and apoptosis are two main pathways supporting the integrity of human genome. After the disturbance of these processes the cell survives, despite the accumulation of DNA lesions, and in this way a basis for a subsequent transformation is formed. In our research we evaluated the epigenetic regulation - methylation - aspects of genes participating in DNA repair function (hMLH1 and MGMT) and also of apoptosis-related genes (DAPK-1, CASP8) in relation to a stepwise gastric oncogenesis process. During this investigation a different hMLH1 gene methylation observation frequency in tissues obtained from separate anatomical parts of the stomach in atrophic pangastritis patients was determined for the first time. It was estimated, that hMLH1 gene methylation in tumor-surrounding non-cancerous tissue in gastric cancer patients could be associated with patient age. Results of survival analysis indicated that MGMT gene methylation is an indicator of better prognosis in case of diffuse form of gastric cancer. During the study we determined some additional associations (not described in previous publications) between methylation combinations of analyzed genes and clinical, morphological and prognostic features of oncological illness