Imbalance of the reciprocally inhibitory loop between the ubiquitin-specific protease USP43 and EGFR/PI3K/AKT drives breast carcinogenesis  

作　　者：Lin He Xinhua Liu Jianguo Yang Wanjin Li Shumeng Liu Xujun Liu Ziran Yang Jie Ren Yue Wang Lin Shan Chengjian Guan Fei Pei Liandi Lei Yu Zhang Xia Yi Xiaohan Yang Jing Liang Rong Liu Luyang Sun Yongfeng Shang 

机构地区：[1]Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China [2]Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China [3]Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China [4]Department of Hepatoblliary and Pancreatic Surgical Oncology, Chinese People's Liberation Army General Hospital, Beijing 1 00853, China [5]Department of Pathology, Schoo) of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China [6]Laboratory of Molecular Imaging, Peking University Health Science Center, Beijing 100191, China

出　　处：《Cell Research》2018年第9期934-951,共18页细胞研究（英文版）

基　　金：This work was supported by grants （91219201 and 81530073 to Y.S., and 81372223, 81422034 and 31571340 to L.S.） from the National Natural Science Foundation of China, and grants （2016YFC1302304 to Y.S. and 2014CB542004 to L.S.） from the Ministry of Science and Technology of China.

摘　　要：Hyperactivation of EGFR/PI3K/AKT is a prominent feature of various human cancers. Thus, understanding how this molecular cascade is balanced is of great importance. We report here that the ubiquitin-specific protease USP43 is physically associated with the chromatin remodeling NuRD complex and catalyzes H2BK120 deubiquitination. Functionally this coordinates the NuRD complex to repress a cohort of genes, including EGFR, which are critically involved in cell proliferation and carcinogenesis. We show that USP43 strongly suppresses the growth and metastasis of breast cancer in vivo. Interestingly, USP43 also exists in the cytoplasm, where it is phosphorylated by AKT, enabling its binding to the 14-3-3β/ε heterodimer and sequestration in the cytoplasm. Significantly, hyperactivation of EGFR/PI3K/AKT in breast cancer is associated with the cytoplasmic retention of USP43 and thus, the inhibition of its transcriptional regulatory function. Moreover, cancer-associated mutations of USP43 affect its subcellular localization and/or epigenetic regulatory functions. Nuclear USP43 is significantly reduced in breast carcinomas and is associated with EGFR accumulation and AKT hyperactivation. A low level of nuclear USP43 correlates with higher histologic grades and poor prognosis. Our study identifies USP43 to be an H2BK120 deubiquitinase and a potential tumor suppressor and reveals a reciprocally inhibitory loop between USP43 and EGFR/PI3K/AKT, whose imbalance drives breast carcinogenesis.

关 键 词：不平衡 驱动器 循环 酶 EGFR 细胞质 VIVO AKT 

分 类 号：Q55[生物学—生物化学] TH113.25[机械工程—机械设计及理论]