The pivotal role of DNA methylation in the radio-sensitivity of tumor radiotherapy.

Radiotherapy is an important modality for treatment of carcinomas; however, radio-resistance is still a difficult problem. Aberrant epigenetic alterations play an important role in cancer development. Among epigenetic parameters, DNA methylation has arguably attracted the most attention in the radio-resistance process. To determine the role of DNA methylation in radiation resistance, several studies were conducted. We summarized previous studies on the role of DNA methylation in radiotherapy. We observed this significant role of DNA methylation in genes related to DNA repair, cell proliferation, cell cycle process, and re-oxygenation. Furtherly, we also conclude the predictive effect of DNA methylation on tumor radio-sensitivity and the using of DNA methyltransferase inhibitors in clinical practice. DNA methylation plays a pivotal role in the radio-sensitivity of tumor radio-therapy. While hyper-methylation or hypo-methylation of genes is related to gene functions.