We examined efficacy of the mTOR inhibitor RAD001 to seek novel therapies for synovial sarcoma (SS). Although RAD001 had significant anti-tumor effects, its sensitivity differed among cell lines. Phosphoreceptor tyrosine kinase (RTK) array analyses revealed c-MET phosphorylation in highly mTOR inhibitor-sensitive cells and PDGFR alpha (which induces intrinsic resistance to mTOR inhibitor) activation in less sensitive cells. Combined treatment with RAD001 and the PDGFR inhibitor pazopanib showed anti-tumor effects in xenograft models with less sensitive cells. Thus, evaluating activated RTKs in clinical samples may predict sensitivity to mTOR inhibitors, raising the possibility of a tailored therapy for SS. (C) 2014 Elsevier Ireland Ltd. All rights reserved.