Tetraarsenictetrasulfide and Arsenic Trioxide Exert Synergistic Effects on Induction of Apoptosis and Differentiation in Acute Promyelocytic Leukemia Cells

摘要

Since arsenic trioxide (As³⁺) has been successfully used in the treatment of acute promyelocytic leukemia (APL), its adverse effects on patients have been problematic and required a solution. Considering the good therapeutic potency and low toxicity of tetraarsenictetrasulfide (As4S4) in the treatment of APL, we investigated the effects of combining As4S4 and As³⁺ on the apoptosis and differentiation of NB4 and primary APL cells. As4S4, acting similarly to As³⁺, arrested the G1/S transition, induced the accumulation of cellular reactive oxygen species, and promoted apoptosis. Additionally, low concentrations of As4S4 (0.1–0.4 μM) induced differentiation of NB4 and primary APL cells. Compared with the As4S4- or As³⁺-treated groups, the combination of As4S4 and As³⁺ obviously promoted apoptosis and differentiation of NB4 and primary APL cells. Mechanistic studies suggested that As4S4 acted synergistically with As³⁺ to down-regulate Bcl-2 and nuclear factor-κB expression, up-regulate Bax and p53 expression, and induce activation of caspase-12 and caspase-3. Moreover, the combination of low concentrations of As4S₄ and As³⁺ enhanced degradation of the promyelocytic leukemia-retinoic acid receptor α oncoprotein. In summary, As₄S₄ and As³⁺ synergistically induce the apoptosis and differentiation of NB4 and primary APL cells.