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Shields BJ, Jackson JT, Metcalf D, Shi W, Huang Q, Garnham AL, Glaser SP, Beck D, Pimanda JE, Bogue CW, Smyth GK, Alexander WS, McCormack MP. Acute myeloid leukemia requires Hhex to enable PRC2-mediated epigenetic repression of Cdkn2a. Genes Dev 2016; 30:78-91. [PMID: 26728554 PMCID: PMC4701980 DOI: 10.1101/gad.268425.115] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Here, Shields et al. demonstrate that the hematopoietically expressed homeobox gene Hhex is overexpressed in acute myeloid leukemia (AML) and is essential for the initiation and propagation of MLL-ENL-induced AML but dispensable for normal myelopoiesis, indicating a specific requirement for Hhex for leukemic growth. The findings in this study describe for the first time a nonclustered homeobox transcription factor that is essential for AML initiation and maintenance and provide mechanistic insight into these processes. Unlike clustered HOX genes, the role of nonclustered homeobox gene family members in hematopoiesis and leukemogenesis has not been extensively studied. Here we found that the hematopoietically expressed homeobox gene Hhex is overexpressed in acute myeloid leukemia (AML) and is essential for the initiation and propagation of MLL-ENL-induced AML but dispensable for normal myelopoiesis, indicating a specific requirement for Hhex for leukemic growth. Loss of Hhex leads to expression of the Cdkn2a-encoded tumor suppressors p16INK4a and p19ARF, which are required for growth arrest and myeloid differentiation following Hhex deletion. Mechanistically, we show that Hhex binds to the Cdkn2a locus and directly interacts with the Polycomb-repressive complex 2 (PRC2) to enable H3K27me3-mediated epigenetic repression. Thus, Hhex is a potential therapeutic target that is specifically required for AML stem cells to repress tumor suppressor pathways and enable continued self-renewal.
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Affiliation(s)
- Benjamin J Shields
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia
| | - Jacob T Jackson
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Donald Metcalf
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia
| | - Wei Shi
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia; Computing and Information Systems, University of Melbourne, Parkville, Victoria 3050, Australia
| | - Qiutong Huang
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Alexandra L Garnham
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia
| | - Stefan P Glaser
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia
| | - Dominik Beck
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - John E Pimanda
- Lowy Cancer Research Centre and the Prince of Wales Clinical School, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Clifford W Bogue
- Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Gordon K Smyth
- Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia; Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3050, Australia
| | - Warren S Alexander
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia
| | - Matthew P McCormack
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3050, Australia
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Ali D, Jönsson-Videsäter K, Deneberg S, Bengtzén S, Nahi H, Paul C, Lehmann S. APR-246 exhibits anti-leukemic activity and synergism with conventional chemotherapeutic drugs in acute myeloid leukemia cells. Eur J Haematol 2011; 86:206-15. [PMID: 21114538 DOI: 10.1111/j.1600-0609.2010.01557.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND APR-246 belongs to a new generation of the compounds that restore normal p53 function in cells with mutated or wild type p53. The purpose of this study was to examine the effects of APR-246 alone and in combination with other drugs in acute myeloid leukemia (AML) cells. METHODS Primary leukemic cells from patients with AML and AML cell lines were studied with respect to cytotoxic and apoptotic effects and mechanism of action of APR-246, alone and in combination with Ara-C, daunorubicin and fludarabine. RESULTS APR-246 showed dose-dependent cytotoxic and apoptotic effects in AML cell lines as well as in primary AML patient cells. Cells from patients with TP53 mutation and complex karyotype were more resistant to conventional drugs while these factors did not significantly affect the sensitivity to APR-246. APR-246 increased active caspase-3, upregulated p53 protein levels, and increased the bax/bcl-2 ratio independently of TP53 mutational status in patient cells sensitive to APR-246. AML cells with high p14(ARF) expression were significantly more sensitive to APR-246. APR-246 induced significant synergistic effects in combination with conventional chemotherapeutic agents. Pre-incubation with APR-246 induced more synergistic effects compared to other schedules. In patient cells, pronounced synergism was found when combining APR-246 with danuorubicin. CONCLUSION We conclude that APR-246 is effective in AML cells irrespectively of TP53 mutational status and that it has promising properties for combination studies in AML.
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Affiliation(s)
- Dina Ali
- Hematology Centre, Karolinska University Hospital, Huddinge, Stockholm, Sweden
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Bacher U, Haferlach C. Molecular determinants of prognosis in acute myeloid leukemia (AML) with normal karyotype. Leuk Lymphoma 2009; 50:1403-5. [PMID: 19811325 DOI: 10.1080/10428190903216861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Ulrike Bacher
- Clinic for Stem Cell Transplantation, University Cancer Center Hamburg, Hamburg, Germany
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