title: Differential cytotoxic effects of arsenic compounds in human acute promyelocytic leukemia cells.
abstract: 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. The arsenic-exposed cells were stained with annexin V-PE and 7-aminoactinomycin D (7-AAD) and analyzed by flow cytometry in order to detect apoptotic and viable cells while cell morphology was visualized using scanning and transmission electron microscopy. Acridine orange staining and microtubule-associated protein 1 light chain 3 (MAP-LC3) detection were used to recognize autophagic cell death. The results showed that the compounds reduced viable HL-60 cells by inducing apoptosis in a concentration-dependent manner. None of the compounds tested caused a significant change in binding of acridine orange or redistribution of MAP-LC3. Potencies of the six different arsenic compounds tested were ranked as PAO(III)>MMA(III)> or =As(III)>As(V)>MMA(V)>DMA(V). An increase in caspase-3 activity by PAO(III), MMA(III) and DMA(V) implied that these compounds induced apoptosis in HL-60 cells through a caspase-dependent mechanism, but the other arsenic compounds failed to activate caspase-3, suggesting that they induce apoptosis by an alternative pathway.
authors.affiliation: Department of Public Health Sciences, University of Alberta, Edmonton, AB, Canada.
authors.forename: Vichaya
authors.initials: V
authors.lastname: Charoensuk
authors.forename: Wendy P
authors.initials: WP
authors.lastname: Gati
authors.forename: Michael
authors.initials: M
authors.lastname: Weinfeld
authors.forename: X Chris
authors.initials: XC
authors.lastname: Le
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001152:Arsenicals / Q000737:chemistry / Q000494:pharmacology*; D001343:Autophagy / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D005434:Flow Cytometry; D018922:HL-60 Cells; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D001152:Arsenicals; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D053148:Caspase 3