BMP-2
BMP-2 is an active inducer of osteoblastic differentiation in immature osteoblasts and less committed cells. Reports have implicated BMP-2 in the induction of tumorigenic factors and the proliferation and aggressiveness of osteosarcoma MSCs (OSMSC) [38]; and elevation of BMP-2 has been linked to overexpression of VEGF, EMMPRIN and MMP-9 in OSMSCs [38]. In contrast, researchers reported BMP-2 downregulated Oct3/4, Sox2 and Nanog expression in osteosarcoma cells and upregulated transcription of osteogenic markers Runx-2 and Collagen Type I, resulting in decreased tumorigenicity [39], and BMP-2 expression has been linked to decreased expression of ki67, potentially inhibiting the proliferation of OSCs [39].