Differential cytotoxic effects of arsenic compounds in human acute promyelocytic leukemia cells.

Arsenic trioxide, As(2)O(3), has successfully been used to treat acute promyelocytic leukemia (APL). Induction of apoptosis in cancerous cells has been proposed to be the underlying mechanism for the therapeutic efficacy of arsenic. To further understand the cytotoxicity of arsenic compounds in APL cells, HL-60 cells were exposed to graded concentrations of the following arsenicals for up to 48 h: arsenic trioxide (As(III)), sodium arsenate (As(V)), phenylarsine oxide (PAO(III)), monomethylarsonous acid (MMA(III)), monomethylarsonic acid (MMA(V)) and dimethylarsinic acid (DMA(V)), and the viability and modes of cell death assessed.