Open AccessABT-737, a Bcl-2 Selective Inhibitor, and Chloroquine Synergistically Kill Renal Cancer Cells
Author(s) -
Ping Yin,
Jin-Peng Jia,
Jijun Li,
Yan Song,
Yiyan Zhang,
Fengkun Chen
Publication year - 2016
Publication title -
oncology research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 57
eISSN - 1555-3906
pISSN - 0965-0407
DOI - 10.3727/096504016x14587366983838
Subject(s) - apoptosis , chloroquine , programmed cell death , cathepsin b , cancer cell , cancer research , cathepsin d , cathepsin , pharmacology , cancer , autophagy , cathepsin l , viability assay , medicine , biology , immunology , biochemistry , enzyme , malaria
Renal cell carcinoma (RCC) is the most common malignancy in the kidney in the world, and the 5-year overall survival for patients remains poor due to the lack of effective treatment strategies. Although ABT-737, as a Bcl-2/Bcl-xL inhibitor, has recently emerged as a novel cancer therapeutic reagent, apoptosis induced by ABT-737 is often blocked in several types of cancer cells. This study investigated whether the combination of the small-molecule BH3 mimetic ABT-737 and the lysosome inhibitor chloroquine was an effective strategy for treating renal cancer cells. We found that the combination of ABT-737 and chloroquine synergistically decreased cell viability when compared to treatment with either single reagent. Cell apoptosis induced by a combined treatment was markedly inhibited by the caspase inhibitors z-DEVD-FMK and z-VAD-FMK. It was also inhibited by cathepsin inhibitor E-64 and CTSI (cathepsin inhibitor), which suggested that apoptosis was dependent on the cascade of caspase activation and cathepsins released from lysosomes. Furthermore, we found that ABT-737 could increase the cell level of ROS, which triggers cathepsin-mediated cell death and augments the role of chloroquine in cell death. So the combination of ABT-737 and chloroquine was an effective strategy for the treatment of renal cancer cells, and this combined strategy may widen the therapeutic window of ABT-737 and chloroquine as well as enhance the clinical efficacy of synergistic drug combinations.