ABSTRACT
Radiotherapy is one of the most commonly used and effective method to treat malignant tumors in clinical practice. However, there are still some limitations including high radiotherapy doses, harmful side effects on normal tissues, and radiation resistance of tumor cells. Therefore, seeking safe and effective radiotherapy sensitizers to improve radiation sensitivity of tumor cells has been focused for a long time. Histone deacetylase inhibitors (HDACIs), as a kind of epigenetic modifiers, can regulate the sensitivity of tumor cells to ionizing radiation and ultraviolet radiation in addition to the inherent anticancer characteristics. This article reviewed the molecular mechanisms of HDACIs in enhancing radiation sensitivity and by selectively killing tumor cells.