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

摘要

Epidermal growth factor(EGF) induced intracellular free calcium ([Ca2+]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+]i measurement in cell populations revealed that EGF triggered a rapid[Ca2+]i increase in the dose-dependent and time-dependent manner.Pretreatment of cells with an endoplasmic reticulum(ER) Ca2+-ATPase inhibitor,thapsigargin(TG) at 100nM 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.