Release of intracellular calcium by prenylamine in human ovarian tumour cells.
The effects of the calcium antagonist prenylamine on intracellular calcium concentration were studied in a human ovarian carcinoma cell line, OVCAR-3. Exposure of cells to 100 microM prenylamine resulted in nearly a 10-fold increase in cytosolic free calcium concentration ([Ca2+]i) as measured by Fura-2 fluorescence. In calcium-free medium, although the increase in [Ca2+]i caused by prenylamine was smaller, it was still substantial compared with the basal level. Efflux experiments with 45Ca showed that 100 microM prenylamine increased calcium efflux by 70% compared with control, indicating active extrusion of the elevated [Ca2+]i. The sluggish nature of calcium release and its independence from the pool activated by ionomycin suggest that the calcium was probably not released from endoplasmic reticulum. These results, although paradoxical, provide a new insight into the possible mechanism of action of prenylamine in causing cancer cell death.
Popper
L D
LD
Department of Obstetrics and Gynecology, University of Lund, Sweden.
Batra
S C
SC
D002118:Calcium / Q000378:metabolism*; D002132:Calcium Radioisotopes; D002460:Cell Line / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D016257:Fura-2; D006801:Humans; D010051:Ovarian Neoplasms / Q000378:metabolism*; D011299:Prenylamine / Q000494:pharmacology*
D002132:Calcium Radioisotopes; D011299:Prenylamine; D002118:Calcium; D016257:Fura-2