Advance Access publication August 13, 2007 Thimerosal-Induced Apoptosis in Human SCM1 Gastric Cancer Cells:

Thimerosal is a mercury-containing preservative in some vaccines. The effect of thimerosal on human gastric cancer cells is unknown. This study shows that in cultured human gastric cancer cells (SCM1), thimerosal reduced cell viability in a concen-tration- and time-dependent manner. Thimerosal caused apopto-sis as assessed by propidium iodide–stained cells and caspase-3 activation. Although immunoblotting data revealed that thimer-osal could activate the phosphorylation of extracellular signal– regulated kinase, c-Jun NH2-terminal protein kinase, and p38 mitogen-activated protein kinase (p38 MAPK), only SB203580 (a p38 MAPK inhibitor) partially prevented cells from apoptosis. Thimerosal also induced [Ca21]i increases via Ca 21 influx from the extracellular space. However, pretreatment with (bis(o-aminophenoxy)ethane-N,N,N#,N#-tetraacetate)/AM, a Ca21 che