bioRxiv preprint doi: https://doi.org/10.1101/2020.09.28.316810; this version posted October 9, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Deubiquitinase UCHL1 Maintains Protein Homeostasis through PSMA7-APEH- Proteasome Axis in High-Grade Serous Ovarian Carcinoma Apoorva Tangri1*, Kinzie Lighty1*, Jagadish Loganathan1, Fahmi Mesmar2, Ram Podicheti3, Chi Zhang1, Marcin Iwanicki4, Harikrishna Nakshatri1,5, Sumegha Mitra1,5,# 1 Indiana University School of Medicine, Indianapolis, IN, USA 2 Indiana University, Bloomington, IN, USA 3Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN, USA 4Stevens Institute of Technology, Hoboken, NJ, USA 5Indiana University Melvin & Bren Simon Cancer Center, Indianapolis, USA *Equal contribution # corresponding author; to whom correspondence may be addressed. E-mail:
[email protected] 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.09.28.316810; this version posted October 9, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Abstract High-grade serous ovarian cancer (HGSOC) is characterized by chromosomal instability, DNA damage, oxidative stress, and high metabolic demand, which exacerbate misfolded, unfolded and damaged protein burden resulting in increased proteotoxicity. However, the underlying mechanisms that maintain protein homeostasis to promote HGSOC growth remain poorly understood. In this study, we report that the neuronal deubiquitinating enzyme, ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) is overexpressed in HGSOC and maintains protein homeostasis. UCHL1 expression was markedly increased in HGSOC patient tumors and serous tubal intraepithelial carcinoma (HGSOC precursor lesions).