Transforming growth factor-beta modulates eicosanoid metabolism in osteogenic osteosarcoma cells

The metabolites of cycloxyegenase and lipoxygenase pathways are known to play an important role in the bone metabolism involving osteoclast and osteoblast interaction, bone resorption and morphogenesis. The recently discovered growth factor TGF-beta is abundant in bone and some of its intracellular and extracellular effects depend on de novo synthesis of eicosanoids. However, the effect of TGF-beta on the synthesis and the release of eicosanoid by bone cells is essentially unknown. In the present study we have identified the main eicosanoid metabolites produced by osteogenic osteosarcoma cell-line SAOS1 and investigated how production and release of these is affected by TGF-beta. We found that the leukotriene C4 is the main metabolite produced by these cells and that TGF-beta induces concentration-dependent, quantitative and qualitative alterations in eicosanoid production and release by human osteogenic osteosarcoma cells SAOS1.