RESUMEN
We showed that microtubule-associated tumor suppressor gene (MTUS1/ATIP) downregulation correlated with poor survival in head and neck squamous cell carcinoma (HNSCC) patients and that MTUS1/ATIP1 was the most abundant isoform in HNSCC tissue. However, the location and function of MTUS1/ATIP1 have remain unclear. In this study, we confirmed that MTUS1/ATIP1 inhibited proliferation, growth and metastasis in HNSCC in cell- and patient-derived xenograft models in vitro and in vivo. MTUS1/ATIP1 localized in the outer mitochondrial membrane, influence the morphology, movement and metabolism of mitochondria and stimulated oxidative stress in HNSCC cells by directly interacting with MFN2. MTUS1/ATIP1 activated ROS, recruiting Bax to mitochondria, facilitating cytochrome c release to the cytosol to activate caspase-3, and inducing GSDME-dependent pyroptotic death in HNSCC cells. Our findings showed that MTUS1/ATIP1 localized in the outer mitochondrial membrane in HNSCC cells and mediated anticancer effects through ROS-induced pyroptosis, which may provide a novel therapeutic strategy for HNSCC treatment.
Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Mitocondrias , Piroptosis , Carcinoma de Células Escamosas de Cabeza y Cuello , Proteínas Supresoras de Tumor , Animales , Humanos , Ratones , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/genética , Línea Celular Tumoral , Proliferación Celular , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/genética , Ratones Desnudos , Mitocondrias/metabolismo , Membranas Mitocondriales/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Proteínas Supresoras de Tumor/metabolismo , Proteínas Supresoras de Tumor/genéticaRESUMEN
Glioblastoma (GBM) is a highly aggressive brain tumor. Resistance mechanisms in GBM present an array of challenges to understand its biology and to develop novel therapeutic strategies. We investigated the role of a TSG, MTUS1/ATIP1 in glioma. Glioma specimen, cells and low passage GBM sphere cultures (GSC) were analyzed for MTUS1/ATIP1 expression at the RNA and protein level. Methylation analyses were done by bisulfite sequencing (BSS). The consequence of chemotherapy and irradiation on ATIP1 expression and the influence of different cellular ATIP1 levels on survival was examined in vitro and in vivo. MTUS1/ATIP1 was downregulated in high-grade glioma (HGG), GSC and GBM cells and hypermethylation at the ATIP1 promoter region seems to be at least partially responsible for this downregulation. ATIP1 overexpression significantly reduced glioma progression by mitigating cell motility, proliferation and facilitate cell death. In glioma-bearing mice, elevated MTUS1/ATIP1 expression prolonged their survival. Chemotherapy, as well as irradiation, recovered ATIP1 expression both in vitro and in vivo. Surprisingly, ATIP1 overexpression increased irradiation-induced DNA-damage repair, resulting in radio-resistance. Our findings indicate that MTUS1/ATIP1 serves as TSG-regulating gliomagenesis, progression and therapy resistance. In HGG, higher MTUS1/ATIP1 expression might interfere with tumor irradiation therapy.