Prostaglandin and thromboxane synthesis by human intracranial tumors

Prostaglandin (PG) and thromboxane (TX) production by homogenates of human intracranial tumors (33 gliomas, 32 meningiomas, six brain metastases) and 'normal' brain (n = 26) from tumor-bearing patients was studied. PGF(2α), PGE₂, PGD₂, 6-keto-PGF(1α) (the hydrolysis product of PGI₂) and TXB₂ (the hydrolysis product of TXA₂) were determined by high-resolution gas chromatography-mass spectrometry after ex vivo metabolism of endogenous arachidonic acid. Prostanoid profiles (relative abundance of each metabolite) were different for gliomas and meningiomas, but similar for gliomas and their nontumoral counterpart, i.e., 'normal' brain. Mean overall prostanoid production was significantly higher in gliomas (539 ± 95) and meningiomas (523 ± 69) than in 'normal' brain (198 ± 23). Prostanoid synthesis significantly increased with anaplastic grade (glioblastomas > anaplastic astrocytomas > slow-growing astrocytomas > 'normal' brain), while profiles did not substantially change (TXB₂ was the most and 6-keto-PGF(1α) the least abundant product). Meningioma profiles showed no marked prevalence of any particular metabolite and no major differences between histological subgroups. All brain metastases from different carcinomas (n = 5) showed a prevalence of TXB₂ and PGE₂ and very low PGD₂ synthesis.