Molecular Biology of Tumor Radioresistance

Surgery, radiation and chemotherapy are the major therapeutic options for treatment of human malignancies. In particular, more than 50% of newly diagnosed cancer patients worldwide receive radiotherapy (alone or in combination with chemotherapy or surgery) at some point during their treatment (Nygren et al., 2001). However, the curative potential of radiotherapy is often limited by intrinsic radioresistance of cancer cells and normal tissue toxicity (Bischoff et al., 2009). Therefore, there is increasing interest in enhancing the radiosensitivity of cancer cells for development of effective therapies. The Notch signaling pathway is an evolutionary conserved signaling pathway, which is also frequently activated in several human malignancies. In this review, we discuss the use of Notch inhibitors as radiosensitizers in cancer treatment.