M-3M3FBS (2,4,6-trimethyl-N-(meta-3-trifluoromethyl-phenyl)-benzenesulfonamide is a presumed phospholipase C activator which induced Ca^(2+) movement and apoptosis in different cell models. However, the effect of m-3M3FBS on cytosolic free Ca^(2+) concentrations ([Ca^(2+)]i) and apoptosis in SCM1 human gastric cancer cells is unclear. This study explored whether m-3M3FBS elevated basal [Ca^(2+)]i levels in suspended cells by using fura-2 as a Ca^(2+)-sensitive fluorescent dye. M-3M3FBS at concentrations between 5-50 μM increased [Ca^(2+)]i in a concentration-dependent manner. The Ca^(2+) signal was reduced by half by removing extracellular Ca^(2+). M-3M3FBS-induced Ca^(2+) influx was inhibited by nifedipine, econazole, SK&F96365, aristolochic acid, and GF109203X. In Ca^(2+)-free medium, 50 μM m-3M3FBS pretreatment inhibited the [Ca^(2+)]i rise induced by the endoplasmic reticulum Ca^(2+) pump inhibitor thapsigargin. Conversely, pretreatment with thapsigargin partly reduced m-3M3FBS-induced [Ca^(2+)]i rise. Suppression of inositol 1,4,5-trisphosphate production with U73122 did not change m-3M3FBSinduced [Ca^(2+)]i rise. At concentrations between 25 and 50 μM m-3M3FBS killed cells in a concentrationdependent manner. The cytotoxic effect of m-3M3FBS was not reversed by prechelating cytosolic Ca^(2+) with acetoxy-methyl ester of bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA/AM). Annexin V/propidium iodide staining data suggest that m-3M3FBS induced apoptosis at 25 and 50 μM. M-3M3FBS also increased levels of superoxide. Together, in human gastric cancer cells, m-3M3FBS induced a [Ca^(2+)]i rise by inducing phospholipase C-independent Ca^(2+) release from the endoplasmic reticulum and Ca^(2+) entry via protein kinase C-sensitive store-operated Ca^(2+) channels. M-3M3FBS induced cell death that might involve apoptosis via reactive oxygen species production.
為了持續優化網站功能與使用者體驗,本網站將Cookies分析技術用於網站營運、分析和個人化服務之目的。
若您繼續瀏覽本網站,即表示您同意本網站使用Cookies。