Abstract: | The role of DNA methylation in functioning of a normal and cancer cell is shown in this review. The value of methylation in functioning of the systems which are involved in the process of formation of malignant cells drug resistance phenotype (regulator proteins of cellular cycle, DNA-adducts reparation, transport systems, systems of detoxication and adhesion) is explicated. The prospects of the antineoplastic therapy directed to regulation of DNA methylation by means of homocysteine and demethylation agents are analyzed. |