DNA demethylating antineoplastic strategies: a comparative point of view.

Despite the involvement of genetic alterations in neoplastic cell transformation, it is increasingly evident that abnormal epigenetic patterns, such as those affecting DNA methylation and histone posttranslational modifications (PTMs), play an essential role in the early stages of tumor development. This finding, together with the evidence that epigenetic changes are reversible, enabled the development of new antineoplastic therapeutic approaches known as epigenetic therapies. Epigenetic modifications are involved in the control of gene expression, and their aberrant distribution is thought to participate in neoplastic transformation by causing the deregulation of crucial cellular pathways. Epigenetic drugs are able to revert the defective gene expression profile of cancer cells and, consequently, reestablish normal molecular pathways. Considering the emerging interest in epigenetic therapeutics, this review focuses on the approaches affecting DNA methylation, evaluates novel strategies and those already approved for clinical use, and compares their therapeutic potential.