Both cell-surface and secreted CSF-1 expressed by tumor cells metastatic to bone can contribute to osteoclast activation

摘要: Tumors metastatic to the bone produce factors that cause massive resorption mediated by osteoclasts in microenvironment. Colony stimulating factor (CSF-1) is strictly required for formation and survival of active osteoclasts, frequently produced tumor cells. Here we hypothesize CSF-1 made cells contributes destruction osteolytic metastases. We show high level protected from suppressive effects transforming growth beta (TGF-beta). r3T cells, a mouse mammary cell line forms metastases, express abundant vitro as both secreted membrane-spanning cell-surface glycoprotein, form can support osteoclast co-culture experiments presence RankL. Mice with metastases have elevated levels circulating bone-associated CSF-1, majority found associated These results idea tumor-cell development metastasis.