Impact of elevated anti-apoptotic MCL-1 and BCL-2 on the development and treatment of MLL-AF9 AML in mice
- Author(s)
- Anstee, NS; Bilardi, RA; Ng, AP; Xu, Z; Robati, M; Vandenberg, CJ; Cory, S;
- Journal Title
- Cell Death and Differentiation
- Publication Type
- Journal Article
- Abstract
- Many acute myeloid leukaemias (AMLs) express high levels of BCL-2 and MCL-1, especially after therapy. To test the impact of these anti-apoptotic proteins on AML development and treatment, we used haemopoietic reconstitution to generate MLL-AF9 AMLs expressing BCL-2 or Mcl-1 transgenes. AMLs with elevated BCL-2 or MCL-1 had a higher proportion of mature myeloid cells but, like conventional MLL-AF9 AMLs, were readily transplantable. Short-term cell lines established from multiple primary AMLs of each genotype were tested in vitro for susceptibility to chemotherapeutics currently used for treating AML (daunorubicin, etoposide, cytarabine); the proteasome inhibitor bortezomib; CDK7/9 inhibitors; and BH3 mimetics, which bind and inhibit pro-survival proteins. The BH3 mimetics tested, alone and in combination with the other drugs, were: ABT-737 which, like its clinical counterpart navitoclax, targets BCL-2, BCL-XL and BCL-W; BCL-2-specific ABT-199 (venetoclax); BCL-XL-specific A-1331852; and S63845, a new MCL-1-specific BH3 mimetic. As single agents, daunorubicin and bortezomib had the greatest efficacy. Elevated MCL-1 or BCL-2 reduced sensitivity to daunorubicin but, surprisingly, not to bortezomib. MCL-1 markedly enhanced resistance to ABT-737 and ABT-199 but not S63845, and BCL-2 increased resistance to S63845 but not to ABT-737 or ABT-199. Notable synergies were achieved by combining BH3 mimetics with daunorubicin: S63845 increased the sensitivity of both MCL-1 and BCL-2 overexpressing MLL-AF9 AMLs, and ABT-737 aided in killing those overexpressing BCL-2. Synergy between daunorubicin and ABT-199 was also apparent in vivo, although not curative. Impressive synergistic responses were achieved for human MLL-fusion AML cell lines treated with daunorubicin plus either ABT-737, ABT-199 or S63845, and with ABT-199 plus S63845, with or without daunorubicin. Our data suggest that AML patients may benefit from combining conventional cytotoxic drugs with BH3 mimetics targeting BCL-2 or MCL-1 or, if tolerated, both these agents.
- Research Division(s)
- Molecular Genetics Of Cancer; Cancer And Haematology
- PubMed ID
- 30470795
- Publisher's Version
- https://doi.org/10.1038/s41418-018-0209-1
- Open Access at Publisher's Site
https://doi.org/10.1038/s41418-018-0209-1- NHMRC Grants
- NHMRC/1016701, NHMRC/1058746, NHMRC/1122783,
- Terms of Use/Rights Notice
- Refer to copyright notice on published article.
Creation Date: 2018-12-18 02:54:27
Last Modified: 2018-12-18 03:10:00