DUB1 Suppresses Hippo Signaling Via Modulating TAZ Protein in Gastric Cancer

Background The Hippo pathway functions as a tumor-suppressor pathway in human cancers, while the dys-function of Hippo pathway is frequently observed in malignancies. Although the YAP/TAZ activity is tightly controlled by the phosphorylation cascade of MST-LATS-YAP/TAZ axis, it is still unclear why YAP/TAZ protein is activated in human cancers, even Hippo pathway is still active. Besides phosphorylation, recent studies implicate that several post-translational modifications also play critical roles in modulating TAZ function, including ubiquitination. Methods We work on the ER alpha positive breast cancer cell lines and performed western blots, real-time PCR, immuno-precipitation assay, in vitro ubiquitin assay and xenograft mice studies Results Here, by a DUB (Deubiquitinases) siRNA screening library, we discovered DUB1 as a critical modulator to facilitate gastric cancer stemness and progression, which deubiquitinated and activated TAZ protein. We also identified DUB1 was elevated in gastric cancer, which correlated with TAZ activation and poor survival. DUB1 associated with TAZ protein and deubiquitinated TAZ at several lysine sites, which subsequently stabilized and facilitated TAZ function. Conclusions Our study revealed a novel deubiquitinase of Hippo/TAZ axis and one possible therapeutic target for Hippo-driven gastric cancer.