Epigenetic strategies in cancer therapy

Background: Experimental insights into epigenetic regulatory mechanisms have dramatically altered our understanding of malignant diseases and demonstrated that, in addition to genetic alterations, epigenetic changes significantly contribute to cancer development and progression. Consequently, epigenetic mechanisms are considered to be core components of prospective cancer therapies. The first epigenetic cancer drugs have been developed and are already being used in cancer treatment. Predominantly, these epigenetic treatments inhibit enzymes, such as DNA methyltransferase inhibitors and inhibitors of histone deacetylases, which add or remove epigenetic modifications. Some substances have already been approved for the treatment of selected malignancies or are currently undergoing testing in clinical trials. The rationale behind the application of epigenetic inhibitors is to modulate undesired epigenetic DNA and histone modifications in order to restore the normal expression of tumor suppressor genes or restrict the transcriptional activity of oncogenes. Conclusion: Novel epigenetic approaches, such as inhibition of histone methyltransferases and oncogenic chromatin complexes have not yet achieved clinical approval but are being intensively studied in preclinical and clinical trials and represent promising candidates for cancer therapy.