Modulation of organotin-induced apoptosis by the water pollutant methyl mercury in a human lymphoblastoid tumor cell line and a marine sponge

Apoptosis is a special form of cell death in which the cells actively participate in the process of dying. We found that the water pollutants tributyltin (> 1 μM) and methyl mercury (MeHg; at concentrations of > 3 μM) induce apoptosis in human T-lymphoblastoid CEM cells and in tissue of the marine sponge Geodia cydonium. At concentrations of > 5 μM, MeHg causes alkaline-labile sites in DNA of CEM cells. At the lower dose of 0.3 μM, MeHg abolishes the tributyltin-induced apoptosis in both CEM cells and sponge tissue. Incubation of sponge tissue with 3 μM of tributyltin induces not only apoptosis but also an increased expression of heat shock protein-70.