Abstract
Purpose: Radiation therapy has made significant contributions to cancer treatment. However, despite continuous improvements, tumor recurrence and therapy resistance still occur in a high proportion of patients. One underlying reason for this radioresistance might be attributable to the presence of cancer stem cells (CSC). The purpose of this review is to discuss CSC-specific mechanisms that confer radiation resistance.
Conclusions: We focus our discussions on breast cancer and glioblastoma multiforme (GBM) and conclude that both CSC-intrinsic and CSC-extrinsic factors as well as adaptive responses in CSC caused by irradiation and microenvironmental changes all make contributions to CSC-mediated radioresistance. Our discussions emphasize CSC as novel therapeutic targets in order to potentiate radiotherapy efficacy.
Acknowledgements
The work in the authors’ lab was supported, in part, by grants from NIH (R01-CA155693), Department of Defense (W81XWH-13-1-0352), CPRIT (RP120380), and the MDACC Center for Cancer Epigenetics and RNA Center-Laura & John Arnold Foundation grant (D.G.T). K.R was supported in part by an NIH post-doctoral fellowship.
Declaration of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.