A hypoxia-responsive TRAF6-ATM-H2AX signalling axis promotes HIF1 alpha activation, tumorigenesis and metastasis

作者:Rezaeian Abdol Hossein*; Li Chien Feng; Wu Ching Yuan; Zhang Xian; Delacerda Jorge; You M James; Han Fei; Cai Zhen; Jeong Yun Seong; Jin Guoxiang; Phan Liem; Chou Ping Chieh; Lee Mong Hong; Hung Mien Chie; Sarbassov Dos; Lin Hui Kuan*
来源:Nature Cell Biology, 2017, 19(1): 38-51.
DOI:10.1038/ncb3445

摘要

The understanding of how hypoxia stabilizes and activates HIF1 alpha in the nucleus with related oncogenic signals could revolutionize targeted therapy for cancers. Here, we find that histone H2AX displays oncogenic activity by serving as a crucial regulator of HIF1 alpha signalling. H2AX interacts with HIF1 alpha to prevent its degradation and nuclear export in order to allow successful VHL-independent HIF1 alpha transcriptional activation. We show that mono-ubiquitylation and phosphorylation of H2AX, which are strictly mediated by hypoxia-induced E3 ligase activity of TRAF6 and ATM, critically regulate HIF1 alpha-driven tumorigenesis. Importantly, TRAF6 and gamma H2AX are overexpressed in human breast cancer, correlate with activation of HIF1 alpha signalling, and predict metastatic outcome. Thus, TRAF6 and H2AX overexpression and gamma H2AX-mediated HIF1 alpha enrichment in the nucleus of cancer cells lead to overactivation of HIF1 alpha-driven tumorigenesis, glycolysis and metastasis. Our findings suggest that TRAF6-mediated mono-ubiquitylation and subsequent phosphorylation of H2AX may serve as potential means for cancer diagnosis and therapy.