Prostaglandin E2 synthesis by human primary and metastatic bone tumors in culture

Prostaglandin E2 (PGE2) is known to stimulate osteolysis in vitro and has been implicated in mediating bone resorption in several animal and human tumors. Little attention has yet to be directed toward local humoral control (including PGE2) of bone resorption in primary and metastatic bone tumors. For investigation of whether histologically identified areas of osteolytic or osteoblastic bone tumors differentially secrete PGE2 under in vitro conditions, culture media from explants of central and peripheral areas of tissue were sterilely collected from 13 surgical specimens of primary and metastatic bone tumors and assayed for (PGE2) radioimmunoassay. The results indicate a marked heterogeneity in the concentration of immunoreactive (I-PGE2) synthesis by tumors of different as well as similar cell type. PGE2 production was time-dependent in culture, and at 72 hours substantial increases were apparent compared to cultures of non-neoplastic fascia controls. Significantly higher levels of I-PGE2 were found in cultures derived from "bone-destructive" tumors. No difference in I-PGE2 synthesis was found between explants of peripheral versus central tissue of the same tumors. PGE2 is synthesized in culture by bone tumors characterized as destructive of bone at higher levels than "bone-forming" tumors, and this synthesis is inhibited by indomethacin.