Production and secretion of endothelin-1 by cultured choroid plexus carcinoma cells

Choroid plexus carcinoma is a rare neoplasm derived from the epithelium of the choroid plexus. The production and secretion of endothelin-1 (ET-1) by cultured human choroid plexus carcinoma cells were studied by radioimmunoassay and Northern blot analysis. Immunoreactive (IR)-ET was detected in the culture medium (2.78 ± 0.12 fmol/10⁵ cells/24 h; n = 5; mean ± SEM) but not in the unconditioned medium. Reverse-phase high-performance liquid chromatography of the extract of the culture medium showed a single peak eluting in the position of ET-1. Treatment with tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) or a combination of interferon-γ (IFN-γ), TNF-α, and IL-1β caused significant increases in the IR-ET levels in the culture medium. Northern blot analysis of total RNA showed the expression of ET-1 mRNA in choroid plexus carcinoma cells. The expression levels of ET-1 mRNA were increased by treatment with a combination of IFN-γ, TNF-α, and IL-1β. The present study has shown the production and secretion of ET-1 by cultured human choroid plexus carcinoma cells and suggests the possibility that ET-1 formation is related to the pathophysiology of this tumor.