Involvement of BMP-2 signaling in a cartilage cap in osteochondroma

This study describes the distributions of bone morphogenetic protein (BMP)-2 as well as mRNAs for BMP receptor type IB (BMPRIB). collagen types II (Col II) and III (Col III) in a growing "cartilage cap" of osteochondroma. In situ hybridization and immunohistochemical study were performed using histological sections obtained during surgery. BMP-2 was detected in mesenchymal cells in the outer fibrous layer and chondrocytes in the inner cartilaginous matrix, positive for Col III and Col II, respectively. BMPRIB mRNA was distributed in chondrocytes. This is the first study to provide observational evidence of the involvement of BMP-2 signaling in the pathogenesis of cartilage cap of osteochondroma. and suggests the role of BMP-2 in the growth of cartilage cap in osteochondroma.