GARP promotes the proliferation and therapeutic resistance of bone sarcoma cancer cells through the activation of TGF-β Carrillo Gálvez, Ana Belén Esteban Quintero, Juan González Correa, Juan Elías Sánchez Hernández, Sabina Muñoz Rivas, María Pilar Zurita Martínez, Federico Martín, Francisco Rodríguez Manzaneque, Juan Carlos Anderson, Per Olof 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. 2021-02-02T12:27:17Z 2021-02-02T12:27:17Z 2020-11-17 journal article Carrillo-Gálvez, A. B., Quintero, J. E., Rodríguez, R., Menéndez, S. T., González, M. V., Blanco-Lorenzo, V., ... & Anderson, P. (2020). GARP promotes the proliferation and therapeutic resistance of bone sarcoma cancer cells through the activation of TGF-β. Cell death & disease, 11(11), 1-12. [DOI: 10.1038/s41419-020-03197-z] http://hdl.handle.net/10481/66228 10.1038/s41419-020-03197-z eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Springer Nature