Cellular senescence in ionizing radiation (Review).

Radiotherapy (RT) is one of most common treatments for cancer. However, overcoming the failure and side effects of RT as well as radioresistance, recurrence and metastasis remains challenging in cancer treatment. Cellular senescence (CS) is permanent arrested state of cell division induced by various factors, including exposure to ionizing radiation (IR). CS induced by IR contributes to tumour cell control and often even causes side effects in normal cells. Improvement of the therapeutic RT ratio is dependent on more cancer cell death and less normal cell damage. In addition, the biological behaviour of tumour cells after IR has also been linked to CS. This review summarizes our understanding of CS in IR, which may be beneficial for providing new insight for improving the therapeutic outcomes of RT.