Endothelin-1 as an autocrine/paracrine factor for human tumor cell lines.
We determined whether endothelin-1 (ET-1) is produced and secreted by human tumor cell lines and whether ET-1 can affect cytosolic free Ca2+ concentrations ([Ca2+]i) in these cells. Dilution curves of extracts of cultured conditioned media from several human cancer cell lines (HeLa, HEp-2, DLD-1, and Ca9-22) were parallel to those of standard ET-1 in radioimmunoassay (RIA). Amounts of ET-1-like immunoreactivity released into conditioned media were reduced by omitting fetal bovine serum from culture media. Synthetic ET-1 dose-dependently induced gradual and sustained increases in [Ca2+]i in HeLa, HEp-2, GOTO, and Lovo cells, an effect completely abolished by a Ca2+ channel blocker or by chelating extracellular Ca2+. These data suggest an autocrine/paracrine role of ET-1 in human tumor cell lines.
Shichiri
M
M
Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
Hirata
Y
Y
Marumo
F
F
D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D016232:Endothelins / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D011863:Radioimmunoassay; D014407:Tumor Cells, Cultured / Q000378:metabolism
D002121:Calcium Channel Blockers; D016232:Endothelins; D002118:Calcium