Nat Med：去泛素酶USP15是潜在抗癌治疗靶标

Pieter J A Eichhorn, Laura Rodón, Alba Gonzàlez-Juncà, Annette Dirac, Magüi Gili, Elena Martínez-Sáez, Claudia Aura, Ignasi Barba, Vicente Peg, Aleix Prat, Isabel Cuartas, Jose Jimenez, David García-Dorado, Juan Sahuquillo, Réné Bernards, José Baselga & Joan Seoane

In advanced cancer, including glioblastoma, the transforming growth factor β (TGF-β) pathway acts as an oncogenic factor and is considered to be a therapeutic target. Using a functional RNAi screen, we identified the deubiquitinating enzyme ubiquitin-specific peptidase 15 (USP15) as a key component of the TGF-β signaling pathway. USP15 binds to the SMAD7–SMAD specific E3 ubiquitin protein ligase 2 (SMURF2) complex and deubiquitinates and stabilizes type I TGF-β receptor (TβR-I), leading to an enhanced TGF-β signal. High expression of USP15 correlates with high TGF-β activity, and the USP15 gene is found amplified in glioblastoma, breast and ovarian cancer. USP15 amplification confers poor prognosis in individuals with glioblastoma. Downregulation or inhibition of USP15 in a patient-derived orthotopic mouse model of glioblastoma decreases TGF-β activity. Moreover, depletion of USP15 decreases the oncogenic capacity of patient-derived glioma-initiating cells due to the repression of TGF-β signaling. Our results show that USP15 regulates the TGF-β pathway and is a key factor in glioblastoma pathogenesis.