Organotellurium compound toxicity in a promyelocytic cell line compared to non-tellurium-containing organic analog.

Two substituted aryl organotellurium compounds and a tellurium-free analog of one of these were evaluated for in vitro cytotoxicity using human promyelocytic (HL-60) cells as an experimental system. Both tellurium-containing toxicants (2,2(')-dimethoxydiphenyl ditelluride and 2,2(')-diamino-3,3('),5,5(')-tetramethyldiphenyl ditelluride) were cytotoxic at concentrations as low as 5 x 10(-6) M and the dimethoxydiphenyl compound produced significant numbers of apoptotic cells at a concentration of only 1 x 10(-6) M after 8 h. Data indicate that 2,2(')-dimethoxydiphenyl ditelluride and 2,2(')-diamino-3,3('),5,5(')-tetramethyldiphenyl ditelluride induce apoptosis in both a time and dose dependent manner; however, 2,2(')-dimethoxybiphenyl, structurally comparable to the first of these but without the tellurium bridge, did not produce apoptosis under the concentrations and time course studied. Therefore the telluride moiety was apparently an important factor in the apoptotic effect.