Research Paper|Volume 12, Issue 20|pp 20445—20456

Dual inhibition of DNA-PKcs and mTOR by CC-115 potently inhibits human renal cell carcinoma cell growth

Bing Zheng¹, Xu Sun², Xin-Feng Chen¹, Zhan Chen¹, Wei-li Zhu³, Hua Zhu¹, Dong-Hua Gu¹

¹Department of Urology, The Second Affiliated Hospital of Nantong University, Nantong, China
²Department of Hand and Foot Surgery, Hospital Affiliated 5 to Nantong University, Taizhou People’s Hospital, Taizhou, China
³Port Clinic, Changshu Customs, Changshu, China

* Equal contribution

Received: February 18, 2020Accepted: July 20, 2020Published: October 27, 2020

Copyright: © 2020 Zheng et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

CC-115 is a dual inhibitor of DNA-PKcs and mTOR, both are valuable therapeutic targets for renal cell carcinoma (RCC). Our results showed that CC-115 inhibited survival and proliferation of established RCC cell lines (786-O and A489) and primary human RCC cells. The dual inhibitor induced selective apoptosis activation in RCC cells, as compared to no cytotoxicity nor apoptotic effects toward normal renal epithelial cells. CC-115 inhibited DNA-PKcs and mTORC1/2 activation in RCC cells. It was however ineffective in DNA-PKcs-mTOR double knockout (DKO) 786-O cells. CC-115 induced feedback autophagy activation in RCC cells. Autophagy inhibitors or Beclin-1/Light chain 3 (LC3) silencing potentiated CC-115-induced anti-RCC cell activity. Conversely, ectopic overexpression of Beclin-1 inhibited CC-115-induced cytotoxicity. At last CC-115 oral administration inhibited 786-O subcutaneous xenograft growth in nude mice. Taken together, dual inhibition of DNA-PKcs and mTOR by CC-115 potently inhibited RCC cell growth.