Cancer stem cells and signaling pathways in radioresistance

// Lei Chang 1,2 , Peter Graham 1,2 , Jingli Hao 1,2 , Jie Ni 1,2 , Junli Deng 1,2 , Joseph Bucci 1,2 , David Malouf 3 , David Gillatt 3,4 and Yong Li 1,2 1 Cancer Care Centre, St George Hospital, Kogarah, NSW, Australia 2 St George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales, Kensington, NSW, Australia 3 Department of Urology, St George Hospital, Kogarah, NSW, Australia 4 Australian School of Advanced Medicine, Macquarie University, Sydney, NSW, Australia Correspondence to: Yong Li, email: // Keywords : cancer, radiotherapy, radioresistance, CSC, signaling pathway Received : October 13, 2015 Accepted : December 22, 2015 Published : December 24, 2015 Abstract Radiation therapy (RT) is one of the most important strategies in cancer treatment. Radioresistance (the failure to RT) results in locoregional recurrence and metastasis. Therefore, it is critically important to investigate the mechanisms leading to cancer radioresistance to overcome this problem and increase patients’ survival. Currently, the majority of the radioresistance-associated researches have focused on preclinical studies. Although the exact mechanisms of cancer radioresistance have not been fully uncovered, accumulating evidence supports that cancer stem cells (CSCs) and different signaling pathways play important roles in regulating radiation response and radioresistance. Therefore, targeting CSCs or signaling pathway proteins may hold promise for developing novel combination modalities and overcoming radioresistance. The present review focuses on the key evidence of CSC markers and several important signaling pathways in cancer radioresistance and explores innovative approaches for future radiation treatment.