Acute myeloid leukemia(AML)is a serious disease.The 5-year survival rates remain frustratingly low(65%for children and 26%for adults).Resistance to frontline chemotherapy(usually cytarabine)often develops;therefore a ...Acute myeloid leukemia(AML)is a serious disease.The 5-year survival rates remain frustratingly low(65%for children and 26%for adults).Resistance to frontline chemotherapy(usually cytarabine)often develops;therefore a new treatment modality is needed.Bcl-2 family proteins play an important role in balancing cell survival and apoptosis.The antiapoptotic Bcl-2 family proteins have been found to be dysregulated in AML.ABT-199,a BH3 mimetic,was developed to target antiapoptotic protein Bcl-2.Although ABT-199 has demonstrated promising results,resistance occurs.Previous studies in AML show that ABT-199 alone decreases the association of proapoptotic protein Bim with Bcl-2,but this is compensated by increased association of Bim with prosurvival protein Mcl-1,stabilizing Mcl-1,resulting in resistance to ABT-199.In this study,we investigated the antileukemic activity of the Mcl-1-selective inhibitor A-1210477 in combination with ABT-199 in AML cells.We found that A-1210477 synergistically induced apoptosis with ABT-199 in AML cell lines and primary patient samples.The synergistic induction of apoptosis was decreased upon Bak,Bax and Bim knockdown.While A-1210477 treatment alone also increased Mcl-1 protein levels,combination with ABT-199 reduced binding of Bim to Mcl-1.Our results demonstrate that sequestration of Bim by Mcl-1,a mechanism of ABT-199 resistance,can be abrogated by combined treatment with the Mcl-1 inhibitor A-1201477.展开更多
基金This study was supported by grants from the National Natural Science Foundation of China,NSFC 31671438 and NSFC 31471295the Graduate Innovation Fund of Jilin University,Hyundai Hope On Wheels,the Ring Screw Textron Endowed Chair for Pediatric Cancer Research,Children’s Hospital of Michigan Foundation,Kids Without Cancer,Lafontaine Family/U Can-Cer Vive Foundation,the Decerchio/Guisewite Family,Justin’s Gift,Elana Fund,and the Ginopolis/Karmanos Endowment and supported by Jilin University,Changchun,China,Wayne State University School of Medicine,the China Scholarship Council,and the Barbara Ann Karmanos Cancer Institute.
文摘Acute myeloid leukemia(AML)is a serious disease.The 5-year survival rates remain frustratingly low(65%for children and 26%for adults).Resistance to frontline chemotherapy(usually cytarabine)often develops;therefore a new treatment modality is needed.Bcl-2 family proteins play an important role in balancing cell survival and apoptosis.The antiapoptotic Bcl-2 family proteins have been found to be dysregulated in AML.ABT-199,a BH3 mimetic,was developed to target antiapoptotic protein Bcl-2.Although ABT-199 has demonstrated promising results,resistance occurs.Previous studies in AML show that ABT-199 alone decreases the association of proapoptotic protein Bim with Bcl-2,but this is compensated by increased association of Bim with prosurvival protein Mcl-1,stabilizing Mcl-1,resulting in resistance to ABT-199.In this study,we investigated the antileukemic activity of the Mcl-1-selective inhibitor A-1210477 in combination with ABT-199 in AML cells.We found that A-1210477 synergistically induced apoptosis with ABT-199 in AML cell lines and primary patient samples.The synergistic induction of apoptosis was decreased upon Bak,Bax and Bim knockdown.While A-1210477 treatment alone also increased Mcl-1 protein levels,combination with ABT-199 reduced binding of Bim to Mcl-1.Our results demonstrate that sequestration of Bim by Mcl-1,a mechanism of ABT-199 resistance,can be abrogated by combined treatment with the Mcl-1 inhibitor A-1201477.
