Abstract LB-209: RON kinase: a target for treatment of cancer-induced bone destruction and osteoporosis

Abstract

Abstract Bone destruction occurs in aging and numerous diseases, including osteoporosis and cancer. Many cancer patients have bone osteolysis that is refractory to state-of-the-art treatments, which block osteoclast activity with bisphosphonates or by inhibiting the RANKL pathway. We previously showed that macrophage-stimulating protein (MSP) signaling, which is elevated in approximately 40% of breast cancers, promotes osteolytic bone metastasis, but it was unknown whether this was due to activation of the MSP signaling pathway in the tumor cells or in the bone microenvironment. Here we show that MSP signals through host expression of its receptor, RON tyrosine kinase, to directly activate osteoclasts by a previously undescribed pathway that is complementary to RANKL signaling and converges on SRC. Genetic or pharmacologic inhibition of RON kinase blocked cancer-mediated bone destruction and osteoporosis in several mouse models. Furthermore, the RON kinase inhibitor BMS-777607/ASLAN002 altered markers of bone turnover in a first-in-human clinical cancer study, indicating potential for normalizing bone loss in patients. These findings uncover a new therapeutic target for pathogenic bone loss and provide a rationale for treatment of bone destruction in various diseases with RON inhibitors. Citation Format: Kelsi Andrade, Jaime Fornetti, Ling Zhao, Scott C. Miller, Lor R. Randall, Neysi Anderson, Susan E. Waltz, Mark McHale, Alana L. Welm. RON kinase: a target for treatment of cancer-induced bone destruction and osteoporosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-209. doi:10.1158/1538-7445.AM2017-LB-209