EGF receptor—mediated intracellular calcium increase in human hepatoma BEL—7404 cells

Epidermal growth factor(EGF) induced intracellular free calcium (Ca^2 ]i) response was studied in fura-2- or fluo-3-loaded human hepatoma cells of BEL-7404 cell line.Single cellCa^2 ]i analysis and Ca^2 ]i measurement in cell populations revealed that EGF triggered a rapidCa^2 ]i increase in the dose-dependent and time-dependent manner.Pretreatment of cells with an endoplasmic reticulum(ER) Ca^2 -ATPase inhibitor,thapsigargin(TG) at 100nM concentration for 20 min,completely abolished EGF-induced Ca^2 ]i increase,and chelating extracellular calcium by excess EGTA partially inhibited the increase.Furthermore,the expression of antisense EGF receptor sequence in BEL-7404 cells suppressed the Ca^2 ]i response to EGF.The results suggest that EGF receptor-mediated Ca^2 ]i increase in the human hepatoma cells is essentially dependent on the Ca^2 storage in ER.

EGF receptor-mediated intracellular calcium increasein human hepatoma BEL-7404 cells

Epidermal growth factor (EGF) induced intracellular free calcium (Ca~(2 )]i) response was studied in fura-2- or fluo-3-loaded human hepatoma cells of BEL-7404 cell line. Single cell Ca2 ]i analysis and Ca2 ], measurement in cell populations revealed that EGF triggered a rapid Ca2 ]iincrease in the dose-dependent and time- dependent manner. Pretreatment of cells with an endoplasmic reticulum (ER) Ca2 -ATPase inhibitor, thapsigargin (TG) at 100 nM concentration for 20 min, completely abolished EGF-induced Ca2 ]i increase, and chelating extracellular calcium by excess EGTA partially inhibited the increase.Furthermore, the expression of antisense EGF receptor sequence in BEL-7404 cells suppressed the Ca2 ]i response to EGF. The results suggest that EGF receptor-mediated Ca2 ]i increase in the human hepatoma cells is essentially dependent on the Ca2 storage in ER.