TY - JOUR AB - Osteosarcoma is a highly malignant bone tumor in children and adolescents. Aprepitant is a selective high‑affinity antagonist of the human neurokinin‑1 (NK‑1) receptor (NK1R) with robust antitumor activity. No data exist on the presence of NK1R in osteosarcoma and whether this tumor responds to NK1R antagonists. Here, we analyzed the expression of NK1R in the human osteosarcoma cell line MG-63 with western blot analysis and PCR and found significant expression both at the protein and mRNA levels. We further studied the growth inhibitory capacity of aprepitant and other NK1R antagonists on MG-63 in vitro using an MTS cytotoxicity assay and DAPI staining. All antagonists induced tumor growth inhibition and apoptosis. Synergism was observed for the combination of L-733,060 with common cytostatic drugs in MG-63, but not in non-malignant HEK293 cells. Pretreatment of HEK293 with L-733,060 prior to exposure to cytostatic drugs partially protected HEK293 cells from inhibition by these drugs. Furthermore, nanomolar concentrations of substance P (SP), the natural ligand of the NK1R, increased the growth rate of MG‑63 cells and micromolar concentrations of aprepitant inhibited SP-induced growth in a dose‑dependent manner. In vivo, a xenograft for MG-63 was created in nude mice and treated with peritumoral s.c. injections of fosaprepitant, which resulted in a significant reduction of tumor volume. Collectively, we demonstrated for the first time that the NK1R is expressed in human osteosarcoma cell line MG‑63 and that this receptor can be targeted with NK1R antagonists both in vitro as well as in vivo. AD - Virgen del Rocío University Hospital, Research Laboratory on Neuropeptides, Seville, Spain Division of Pediatric Infectious Disease and Immunopathology, Virgen del Rocío Children's Hospital, Institute of Biomedicine, Seville, Spain Deparment of Pathology, Virgen del Rocío University Hospital, Seville, Spain Laboratory of Neuroanatomy of the Peptidergic Systems, Institute of Neurosciences of Castilla y León, Salamanca, Spain AU - Muñoz,Miguel AU - Berger,Michael AU - Rosso,Marisa AU - Gonzalez-Ortega,Ana AU - Carranza,Andrés AU - Coveñas,Rafael DA - 2014/01/01 DO - 10.3892/ijo.2013.2164 EP - 146 IS - 1 JO - Int J Oncol KW - neurokinin-1 receptor aprepitant substance P antitumor target osteosarcoma tumor cell lines xenograft L-733 060 L-732 138 apoptosis fosaprepitant PY - 2014 SN - 1019-6439 1791-2423 SP - 137 ST - Antitumor activity of neurokinin-1 receptor antagonists in MG-63 human osteosarcoma xenografts T2 - International Journal of Oncology TI - Antitumor activity of neurokinin-1 receptor antagonists in MG-63 human osteosarcoma xenografts UR - https://doi.org/10.3892/ijo.2013.2164 VL - 44 ER -