Suchergebnisse

Sarcomas are mesenchymal cancers with poor prognosis, representing about 20% of all solid malignancies in children, adolescents, and young adults. Radio- and chemoresistance are common features of sarcomas warranting the search for novel prognostic and predictive markers. GARP/LRRC32 is a TGF-β-activating protein that promotes immune escape and dissemination in various cancers. However, if GARP affects the tumorigenicity and treatment resistance of sarcomas is not known. We show that GARP is expressed by human osteo-, chondro-, and undifferentiated pleomorphic sarcomas and is associated with a significantly worse clinical prognosis. Silencing of GARP in bone sarcoma cell lines blocked their proliferation and induced apoptosis. In contrast, overexpression of GARP promoted their growth in vitro and in vivo and increased their resistance to DNA damage and cell death induced by etoposide, doxorubicin, and irradiation. Our data suggest that GARP could serve as a marker with therapeutic, prognostic, and predictive value in sarcoma. We propose that targeting GARP in bone sarcomas could reduce tumour burden while simultaneously improving the efficacy of chemo- and radiotherapy. ; Instituto de Salud Carlos III ; European Union (EU) PI15/00794 PI18/00826 CPII15/00032 PI15/02015 ; Junta de Andalucía C-0013-2018 ; Spanish Government PEJ-2014-A-46314 ; Agencia Estatal de Investigación (AEI) [MICINN/Fondo Europeo de Desarrollo Regional (FEDER)] SAF-2016-75286-R ; ISCIII/FEDER [Miguel Servet Program] CPII16/00049 ; ISCIII/FEDER [Sara Borrell Program] CD16/00103 ; Servicio de Salud del Principado de Asturias, Instituto de Salud Carlos III PT17/0015/0023 ; Fundación Bancaria Cajastur PT17/0015/0023 ; ISCIII/FEDER [Consorcio CIBERONC] CB16/12/00390

Multipotent mesenchymal stromal cells (MSCs) have emerged as a promising cell therapy in regenerative medicine and for autoimmune/inflammatory diseases. However, a main hurdle for MSCs-based therapies is the loss of their proliferative potential in vitro. Here we report that glycoprotein A repetitions predominant (GARP) is required for the proliferation and survival of adipose-derived MSCs (ASCs) via its regulation of transforming growth factor-β (TGF-β) activation. Silencing of GARP in human ASCs increased their activation of TGF-β which augmented the levels of mitochondrial reactive oxygen species (mtROS), resulting in DNA damage, a block in proliferation and apoptosis. Inhibition of TGF-β signaling reduced the levels of mtROS and DNA damage and restored the ability of GARP-/low ASCs to proliferate. In contrast, overexpression of GARP in ASCs increased their proliferative capacity and rendered them more resistant to etoposide-induced DNA damage and apoptosis, in a TGF-β-dependent manner. In summary, our data show that the presence or absence of GARP on ASCs gives rise to distinct TGF-β responses with diametrically opposing effects on ASC proliferation and survival. ; This work has been financed by the Instituto de Salud Carlos III, Spain (www.isciii.es) and Fondo Europeo de Desarrollo Regional (FEDER), from the European Union, through the research grants PI15/00794, PI18/00826, and the contract CPII15/00032 (P.A), PI15/02015, PI18/00337, and ISCIII Red de Terapia Celular (RD12/0019/0006) (F.M.). P.A. is supported by the Consejería de Salud - Junta de Andalucía through the contract "Nicolás Monardes (C-0013-2018). F.M. is supported by the Fundación Progreso y Salud (Consejería de Salud—Junta de Andalucía). A.B.C.-G. is supported by the Ministerio de Ciencia y Tecnología, through the contract PEJ-2014-A-46314. V.A. is funded by the L'Oréal-UNESCO For Women In Science Program. V.R.-M. is supported by a Miguel Servet II contract FIS/FEDER (CPII17/00032) and ISCIII/FEDER PI17/01574. S.G-P. is supported by a Miguel Servet I contract FIS/FEDER (CP14/00197). P.M. is supported by the Fundación Andaluza Progreso y Salud (Consejería de Salud—Junta de Andalucía). ; Yes