Abstract 4155: USP11 regulates UV-induced DNA damage repair and cell survival associated with skin cancer

Abstract

Abstract UV radiation is a major risk factor for skin cancer, the most common cancer in the United States. UV exposure leads to DNA damage by formation of dimers between adjacent pyrimidine bases. The nucleotide excision repair (NER) process is responsible for removal of UV-induced DNA damage. When the damage is left unrepaired due to inefficient NER in disorders like xeroderma pigmentosum, it leads to skin tumorigenesis. Although the main players of the NER pathway have been characterized, the molecular regulation of the pathway is less understood. Understanding the regulation, particularly post-translational regulation, of the NER pathway has the potential to yield modulators of NER efficiency to prevent skin cancer. We found that chronic UV irradiation led to down-regulation of ubiquitin specific peptidase 11 (USP11) in mouse skin tissue. We also found that USP11 is decreased in skin tumors in mice and humans. Moreover, high-throughput proteomics analysis had predicted that USP11 may interact with NER factor XPC. Hence, we undertook this study to determine the role of USP11 in NER and cellular response to UV. We found that USP11 promoted the NER pathway by regulating XPC activity. USP11 promoted XPC deubiquitination and retention at the DNA damage sites. We also found that USP11 interaction with ubiquitinated XPC was enhanced post-UV irradiation, and that USP11 was recruited to the chromatin post-UV damage. Further, squamous cell carcinoma cells showed reduced survival with inhibition of USP11 after UV exposure. Our findings indicate that USP11 plays an important role in maintaining NER capacity, and suggest that USP11 acts as a tumor suppressor via its role in DNA repair. Citation Format: Palak Shah, Lei Qiang, Seungwon Yang, Keyoumars Soltani, Yu-Ying He. USP11 regulates UV-induced DNA damage repair and cell survival associated with skin cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4155.