ABT-737 Synergizes with Arsenic Trioxide to Induce Apoptosis of Gastric Carcinoma Cells In Vitro and In Vivo

OBJECTIVE: This study investigated the potential synergistic effects of two inducers of apoptosis: the small molecule ABT-737 and arsenic trioxide (ATO). METHODS: Human gastric carcinoma cell lines SGC-7901 and MGC-803 were used to determine the effects of ABT-737 and ATO (alone or in combination) on cell proliferation and apoptosis in vitro. In vivo effects of these drugs were investigated in SGC-7901 solid tumours, grown in immunodeficient mice. RESULTS: ABT-737 and ATO inhibited proliferation and induced apoptosis in SGC-7901 and MGC-803 cells in concentration- and time-dependent manners, and showed a synergistic effect. ABT-737 disturbed the binding of B cell lymphoma (Bcl)-2 homologous antagonist killer and Bcl-extra large; ATO downregulated myeloid cell leukaemia (Mcl)-1 protein and upregulated Mcl-1short, the short splicing variant. ABT-737 and ATO significantly suppressed SGC-7901 xenograft growth, synergistically inhibited tumour growth and induced apoptosis in vivo. CONCLUSIONS: This study provides preclinical evidence that ABT-737 and ATO synergize to induce apoptosis of gastric carcinoma cells, suggesting that further investigation of these agents (as potential treatments for gastric cancer) is warranted.