USP39 phase separates into the nucleolus and drives lung adenocarcinoma progression by promoting GLI1 expression

作者：Shaoxuan Cheng, Zhiyuan Qiu, Ziyi Zhang, Yuxuan Li, Yue Zhu, Yuxin Zhou, Yinghui Yang, Yaowen Zhang, Dian Yang, Yingqiu Zhang, Han Liu, Zhaoxia Dai, Shu-Lan Sun, Shuyan Liu · 发表于：Cell Communication and Signaling · 年份：2025 · DOI：10.1186/s12964-025-02059-5 · 被引用次数：8 · 研究领域：RNA Research and Splicing、Nuclear Structure and Function、Ubiquitin and proteasome pathways

BACKGROUND: Intracellular membraneless organelles formed by liquid-liquid phase separation (LLPS) function in diverse physiological processes and have been linked to tumor-promoting properties. The nucleolus is one of the largest membraneless organelle formed through LLPS. Deubiquitylating enzymes (DUBs) emerge as novel therapeutic targets against human cancers. However, the nucleolar phase separation of DUBs and association with lung cancer development have remained incompletely investigated till now. METHODS: GFP-USP39 fusion proteins were analyzed for LLPS properties using immunofluorescence, fluorescence recovery after photobleaching (FRAP) and in vitro LLPS assays. Intrinsically-disordered regions of USP39 were analyzed by PhaSepDB database. Transcriptomic profiling, Western blot, RT-PCR and luciferase reporter assays were conducted to identify targets regulated by USP39. The effects of USP39 depletion on tumor progression were tested using doxycycline-inducible USP39 knockdown and rescue lung adenocarcinoma cells both in vitro and in vivo by performing MTT, colony formation, EdU staining, transwell and tumor xenograft model experiments. RESULTS: USP39 phase separates into nucleoli depending upon its N-terminal disordered region with amino acid residues 1-103. Lung cancer cell growth and migration were dramatically inhibited by USP39 knockdown, which was rescued by exogenous USP39 complementation. Moreover, knockdown of USP39 reduced oncogenic transcription effector GLI1...