Carboxyamidotriazole-induced inhibition of mitochondrial calcium import blocks capacitative calcium entry and cell proliferation in HEK-293 cells Article (Web of Science)

abstract

  • Blocking calcium entry may prevent normal and pathological cell proliferation. There is evidence suggesting that molecules such as carboxyamidotriazole, widely used in anti-cancer therapy based on its ability to block calcium entry in nonexcitable cells, also have antiproliferative properties. We found that carboxyamidotriazole and the capacitative calcium entry blocker 2-aminoethoxydiphenyl borate inhibited proliferation in HEK-293 cells with IC50 values of 1.6 and 50 μM, respectively. Capacitative calcium entry is activated as a result of intracellular calcium store depletion. However, non-capacitative calcium entry pathways exist that are independent of store depletion and are activated by arachidonic acid and diacylglycerol, generated subsequent to G protein coupled receptor stimulation. We found that carboxyamidotriazole completely inhibited the capacitative calcium entry and had no effect on the amplitude of arachidonic-acid-activated non-capacitative calcium entry. However, investigation of the effects of carboxyamidotriazole on mitochondrial calcium dynamics induced by carbachol, capacitative calcium entry and exogenously set calcium loads in intact and digitonin-permeabilized cells revealed that carboxyamidotriazole inhibited both calcium entry and mitochondrial calcium uptake in a time-dependent manner. Mitochondrial inner-membrane potential was altered by carboxyamidotriazole treatment, suggesting that carboxyamidotriazole antagonizes mitochondrial calcium import and thus local calcium clearance, which is crucial for the maintenance of capacitative calcium entry.

authors

  • Mignen, Olivier
  • Brink, Christine
  • Enfissi, Antoine
  • Nadkarni, Aditi
  • Shuttleworth, Trevor J.
  • Giovannucci, David
  • Capiod, Thierry

publication date

  • 2005

webpage

published in

number of pages

  • 8

start page

  • 5615

end page

  • 5623

volume

  • 118

issue

  • 23