Radio Resistance Mechanisms of Cancers: An Overview and Future Perspectives

Abstract

Radiation therapy is widely applied as a standard curative treatment in cancers and the therapeutic techniques have improved remarkably in recent years. However, repopulation of surviving cancer cells is frequently observed during fractionated radiotherapy, which limits the efficacy of radiotherapy. These surviving cells often acquire radio resistance through the deregulation of survival signaling pathways, DNA damage repair mechanisms, post-transcriptional regulation of miRNAs, and epigenetic modifications. Therefore, advances in our understanding of the mechanisms underlying cellular sensitivity to irradiation may provide novel diagnostic markers and therapeutic targets to improve the efficacy of radiotherapy. In this review, we summarize previous studies that report on the radio resistance of various cancer cells.