Therapeutic Efficacy and Inhibitory Mechanism of Regorafenib Combined With Radiation in Colorectal Cancer
Yu‐Chang Liu, I‐Tsang Chiang, Jing-Gung Chung, Jung-Hung Hsieh, Chih‐Hung Chiang, Mao-Chi Weng, Fei‐Ting Hsu, Yuan‐Hao Lee, Cheng‐Shyong Chang, Song‐Shei Lin
Abstract
BACKGROUND: Although both chemotherapy and radiotherapy (RT) can sufficiently maintain tumor suppression of colorectal cancer (CRC), these treatments may trigger the expression of nuclear factor kappa B (NF-κB) and compromise patients' survival. Regorafenib suppresses NF-κB activity in various tumor types. However, whether regorafenib may act as a suitable radiosensitizer to enhance therapeutic efficacy of RT remains unknown. MATERIALS AND METHODS: Here, we established a CRC-bearing animal model to investigate the therapeutic efficacy of regorafenib in combination with RT, through measurement of tumor growth, body weight, whole-body computed tomography (CT) scan and immunohisto-chemistry staining. RESULTS: Smallest tumor size and weight were found in the combination treatment group. In addition, RT-induced up-regulation of NF-κB and downstream proteins were diminished by regorafenib. Moreover, the body weight and liver pathology in the treated group were similar to those of the non-treated control group. CONCLUSION: Regorafenib may enhance the anti-CRC efficacy of RT.