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E3 ligase SCF SKP2 ubiquitinates and degrades tumor suppressor C/EBPα in acute myeloid leukemia. Life Sci 2020; 257:118041. [PMID: 32622945 DOI: 10.1016/j.lfs.2020.118041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/18/2020] [Accepted: 06/29/2020] [Indexed: 12/23/2022]
Abstract
AIM Transcription factor CCAAT/Enhancer binding protein alpha (C/EBPα) is a key regulator of myeloid differentiation, granulopoiesis in particular. Although CEBPA mutations are found in more than 10% in AML, functional inhibition of C/EBPα protein is also widely observed in AML. Here, we sought to examine if SKP2, an aberrantly enhanced E3 ubiquitin ligase in primary AMLs inhibits C/EBPα stability to induce differentiation block. MAIN METHODS Here we employed cell based assays such as transfections, immunoblotting, co-immunoprecipitation, luciferase and gel shift assays along with differentiation assays to investigate SKP2 regulated C/EBPα protein stability in acute myeloid leukemia. KEY FINDINGS Here we discovered that oncogenic E3 ubiquitin ligase SCFskp2 ubiquitinates and destabilizes C/EBPα in a proteasome-dependent manner. Our data demonstrates that SKP2 physically interacts with C-terminal of C/EBPα and promotes its K48-linked ubiquitination-mediated degradation leading to its reduced transactivation potential, DNA binding ability and cellular functions. We further show that while overexpression of SKP2 inhibits both ectopic as well as endogenous C/EBPα in heterologous (HEK293T) as well as myeloid leukemia cells respectively, SKP2 depletion restores endogenous C/EBPα leading to reduced colony formation and enhanced myeloid differentiation of myeloid leukemia cells. Using Estradiol-inducible K562-C/EBPα-ER cells as yet another model of granulocytic differentiation, we further confirmed that SKP2 overexpression indeed inhibits granulocytic differentiation by mitigating C/EBPα stability. SIGNIFICANCE Our findings identify SKP2 as a potential negative regulator of C/EBPα stability and function in AML which suggests that SKP2 can be potentially targeted in AML to restore C/EBPα and overcome differentiation block.
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Thacker G, Mishra M, Sharma A, Singh AK, Sanyal S, Trivedi AK. CDK2 destabilizes tumor suppressor C/EBPα expression through ubiquitin‐mediated proteasome degradation in acute myeloid leukemia. J Cell Biochem 2019; 121:2839-2850. [DOI: 10.1002/jcb.29516] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 10/08/2019] [Indexed: 12/23/2022]
Affiliation(s)
- Gatha Thacker
- Division of Cancer BiologyCSIR‐Central Drug Research Institute Lucknow UP India
| | - Mukul Mishra
- Division of Cancer BiologyCSIR‐Central Drug Research Institute Lucknow UP India
| | - Akshay Sharma
- Division of Cancer BiologyCSIR‐Central Drug Research Institute Lucknow UP India
| | | | - Sabyasachi Sanyal
- Division of Cancer BiologyCSIR‐Central Drug Research Institute Lucknow UP India
| | - Arun Kumar Trivedi
- Division of Cancer BiologyCSIR‐Central Drug Research Institute Lucknow UP India
- Academy of Scientific and Innovative Research (AcSIR), CSIR‐CDRI Lucknow UP India
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Wurm AA, Zjablovskaja P, Kardosova M, Gerloff D, Bräuer-Hartmann D, Katzerke C, Hartmann JU, Benoukraf T, Fricke S, Hilger N, Müller AM, Bill M, Schwind S, Tenen DG, Niederwieser D, Alberich-Jorda M, Behre G. Disruption of the C/EBPα-miR-182 balance impairs granulocytic differentiation. Nat Commun 2017; 8:46. [PMID: 28663557 PMCID: PMC5491528 DOI: 10.1038/s41467-017-00032-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 04/30/2017] [Indexed: 02/04/2023] Open
Abstract
Transcription factor C/EBPα is a master regulator of myelopoiesis and its inactivation is associated with acute myeloid leukemia. Deregulation of C/EBPα by microRNAs during granulopoiesis or acute myeloid leukemia development has not been studied. Here we show that oncogenic miR-182 is a strong regulator of C/EBPα. Moreover, we identify a regulatory loop between C/EBPα and miR-182. While C/EBPα blocks miR-182 expression by direct promoter binding during myeloid differentiation, enforced expression of miR-182 reduces C/EBPα protein level and impairs granulopoiesis in vitro and in vivo. In addition, miR-182 expression is highly elevated particularly in acute myeloid leukemia patients with C-terminal CEBPA mutations, thereby depicting a mechanism by which C/EBPα blocks miR-182 expression. Furthermore, we present miR-182 expression as a prognostic marker in cytogenetically high-risk acute myeloid leukemia patients. Our data demonstrate the importance of a controlled balance between C/EBPα and miR-182 for the maintenance of healthy granulopoiesis. C/EBPα is a critical transcription factor involved in myelopoiesis and its inactivation is associated with acute myeloid leukemia (AML). Here the authors show a negative feedback loop between C/EBPα and miR-182 and identify this miRNA as a marker of high-risk AML.
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Affiliation(s)
- Alexander Arthur Wurm
- Division of Hematology and Oncology, Leipzig University Hospital, Johannisallee 32a, Leipzig, 04103, Germany
| | - Polina Zjablovskaja
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Miroslava Kardosova
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Dennis Gerloff
- Division of Hematology and Oncology, Leipzig University Hospital, Johannisallee 32a, Leipzig, 04103, Germany
| | - Daniela Bräuer-Hartmann
- Division of Hematology and Oncology, Leipzig University Hospital, Johannisallee 32a, Leipzig, 04103, Germany
| | - Christiane Katzerke
- Division of Hematology and Oncology, Leipzig University Hospital, Johannisallee 32a, Leipzig, 04103, Germany
| | - Jens-Uwe Hartmann
- Division of Hematology and Oncology, Leipzig University Hospital, Johannisallee 32a, Leipzig, 04103, Germany
| | - Touati Benoukraf
- Cancer Science Institute, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore
| | - Stephan Fricke
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraße 1, Leipzig, 04103, Germany
| | - Nadja Hilger
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraße 1, Leipzig, 04103, Germany
| | - Anne-Marie Müller
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstraße 1, Leipzig, 04103, Germany
| | - Marius Bill
- Division of Hematology and Oncology, Leipzig University Hospital, Johannisallee 32a, Leipzig, 04103, Germany
| | - Sebastian Schwind
- Division of Hematology and Oncology, Leipzig University Hospital, Johannisallee 32a, Leipzig, 04103, Germany
| | - Daniel G Tenen
- Cancer Science Institute, National University of Singapore, 14 Medical Drive, Singapore, 117599, Singapore.,Harvard Stem Cell Institute, Harvard Medical School, 3 Blackfan Circle, Boston, MA, 02115, USA
| | - Dietger Niederwieser
- Division of Hematology and Oncology, Leipzig University Hospital, Johannisallee 32a, Leipzig, 04103, Germany
| | - Meritxell Alberich-Jorda
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Gerhard Behre
- Division of Hematology and Oncology, Leipzig University Hospital, Johannisallee 32a, Leipzig, 04103, Germany.
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Jentzsch M, Bill M, Nicolet D, Leiblein S, Schubert K, Pless M, Bergmann U, Wildenberger K, Schuhmann L, Cross M, Pönisch W, Franke GN, Vucinic V, Lange T, Behre G, Mrózek K, Bloomfield CD, Niederwieser D, Schwind S. Prognostic impact of the CD34+/CD38- cell burden in patients with acute myeloid leukemia receiving allogeneic stem cell transplantation. Am J Hematol 2017; 92:388-396. [PMID: 28133783 DOI: 10.1002/ajh.24663] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/18/2017] [Accepted: 01/23/2017] [Indexed: 01/09/2023]
Abstract
In acute myeloid leukemia (AML), leukemia-initiating cells exist within the CD34+/CD38- cell compartment. They are assumed to be more resistant to chemotherapy, enriched in minimal residual disease cell populations, and responsible for relapse. Here we evaluated clinical and biological associations and the prognostic impact of a high diagnostic CD34+/CD38- cell burden in 169 AML patients receiving an allogeneic stem cell transplantation in complete remission. Here, the therapeutic approach is mainly based on immunological graft-versus-leukemia effects. Percentage of bone marrow CD34+/CD38- cell burden at diagnosis was measured using flow cytometry and was highly variable (median 0.5%, range 0%-89% of all mononuclear cells). A high CD34+/CD38- cell burden at diagnosis associated with worse genetic risk and secondary AML. Patients with a high CD34+/CD38- cell burden had shorter relapse-free and overall survival which may be mediated by residual leukemia-initiating cells in the CD34+/CD38- cell population, escaping the graft-versus-leukemia effect after allogeneic transplantation. Evaluating the CD34+/CD38- cell burden at diagnosis may help to identify patients at high risk of relapse after allogeneic transplantation. Further studies to understand leukemia-initiating cell biology and develop targeting therapies to improve outcomes of AML patients are needed.
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Affiliation(s)
- Madlen Jentzsch
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Marius Bill
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Deedra Nicolet
- The Ohio State University Comprehensive Cancer Center; Columbus Ohio USA
| | - Sabine Leiblein
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Karoline Schubert
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Martina Pless
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Ulrike Bergmann
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Kathrin Wildenberger
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Luba Schuhmann
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Michael Cross
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Wolfram Pönisch
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Georg-Nikolaus Franke
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Vladan Vucinic
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Thoralf Lange
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Gerhard Behre
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Krzysztof Mrózek
- The Ohio State University Comprehensive Cancer Center; Columbus Ohio USA
| | | | - Dietger Niederwieser
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
| | - Sebastian Schwind
- Department of Hematology; Oncology and Hemostaseology, University of Leipzig; Leipzig Germany
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Rázga F, Dvořáková D, Jurřček T, Ježíšková I, Křístková Z, Mayer J. CEBPA Gene Mutational Status. Mol Diagn Ther 2012. [DOI: 10.1007/bf03256325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Lu Y, Chen W, Chen W, Stein A, Weiss LM, Huang Q. C/EBPA gene mutation and C/EBPA promoter hypermethylation in acute myeloid leukemia with normal cytogenetics. Am J Hematol 2010; 85:426-30. [PMID: 20513120 DOI: 10.1002/ajh.21706] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In the current study, we investigated C/EBPA gene mutations and promoter hypermethylation in a series of 53 patients with CN-AML. In addition, we also analyzed two other frequent mutations (FLT3/ITD and NPM1) in these patients and correlated them with C/EBPA gene alterations. 13/53 patients were FLT3/ITD+/NPM1-, 11/53 patients were FLT3/ITD+/NPM1+, 9/53 patients were FLT3/ITD-/NPM1+, and 20/53 patients were FLT3/ITD-/NPM1-. Four of 53 cases displayed C/EBPA mutations, whereas 49 cases had only C/EBPA wild-type alleles. Of the four positive cases, three patients had N-terminal mutations only, whereas one patient had mutations in both the N- and C-terminal region. Two of the four positive cases also harbored both FLT3/ITD and NPM1 mutation simultaneously, whereas the other two patients had neither FLT3/ITD nor NPM1 mutations. Furthermore, 7/53 cases displayed C/EBPA promoter hypermethylation. Interestingly, they were all in CN-AML cases without FLT3/ITD or NPM1 mutations. None of the seven patients with C/EBPA promoter hypermethylation showed C/EBPA mutation. In conclusion, C/EBPA mutation and promoter hypermethylation can be detected at a relatively low frequency in de novo CN-AML patients, suggesting they may contribute to leukemogenesis. C/EBPA mutation appears to be seen in "high-risk" AML (FLT3/ITD+/NPM1+; FLT3/ITD+/NPM1- or FLT3/ITD-/NPM1-), while C/EBPA hypermethylation appears to be more common in AML with FLT3/ITD- /NPM1- and is not associated with C/EBPA mutation.
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Affiliation(s)
- Ying Lu
- Department of Pathology, City of Hope National Medical Center, Duarte, California 91010, USA
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Elevated PIN1 expression by C/EBPalpha-p30 blocks C/EBPalpha-induced granulocytic differentiation through c-Jun in AML. Leukemia 2010; 24:914-23. [PMID: 20376080 DOI: 10.1038/leu.2010.37] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The transcription factor CCAAT enhancer-binding protein alpha (C/EBPalpha) has an important role in granulopoiesis. The tumor suppressor function of C/EBPalpha is shown by the findings that loss of expression or function of C/EBPalpha in leukemic blasts contributes to a block in myeloid cell differentiation and to leukemia. C/EBPalpha mutations are found in around 9% of acute myeloid leukemia (AML) patients. The mechanism by which the mutant form of C/EBPalpha (C/EBPalpha-p30) exerts a differentiation block is not well understood. By using a proteomic screen, we have recently reported PIN1 as a target of C/EBPalpha-p30 in AML. In the present study, we show that C/EBPalpha-p30 induces PIN1 expression. We observed elevated PIN1 expression in leukemic patient samples. Induction of C/EBPalpha-p30 results in recruitment of E2F1 in the PIN1 promoter. We show that the inhibition of PIN1 leads to myeloid differentiation in primary AML blasts with C/EBPalpha mutations. Overexpression of PIN1 in myeloid cells leads to block of granulocyte differentiation. We also show that PIN1 increases the stability of the c-Jun protein by inhibiting c-Jun ubiquitination, and c-Jun blocks granulocyte differentiation mediated by C/EBPalpha. Our data suggest that the inhibition of PIN1 could be a potential strategy of treating AML patients with C/EBPalpha mutation.
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Rázga F, Dvoráková D, Jurcek T, Jezísková I, Krístková Z, Mayer J. CEBPA gene mutational status: a complete screening using high-resolution melt curve analysis. Mol Diagn Ther 2009; 13:195-200. [PMID: 19650672 DOI: 10.2165/01250444-200913030-00004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In recent years, several independent prognostic factors in cytogenetically normal acute myeloid leukemia (CN-AML) have been reported. Mutations or the expression levels of certain genes have been often used as molecular markers for prediction of a patient's outcome or for evaluation of treatment outcome. One of them, the gene encoding CCAAT/enhanced binding protein alpha (CEBPA), plays an important role in myeloid differentiation and, when mutated, confers a favorable prognosis for patients with CN-AML. Complete mutation screening of the CEBPA gene is therefore beneficial and requires fast, precise, and sensitive diagnostic tools. Thus, for routine diagnostics, we developed a screening method using high-resolution melt curve analysis prior to direct sequencing, where only positive samples (according to reference) are further sequenced. With this approach, all positive and negative patients were successfully distinguished, and the results obtained were in absolute concordance with the direct sequence analysis.
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Affiliation(s)
- Filip Rázga
- Center of Molecular Biology and Gene Therapy, Department of Internal Medicine-Hemato-Oncology, University Hospital Brno and Masaryk University, Brno, Czech Republic.
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Downregulation of RUNX1 by RUNX3 requires the RUNX3 VWRPY sequence and is essential for Epstein-Barr virus-driven B-cell proliferation. J Virol 2009; 83:6909-16. [PMID: 19403666 DOI: 10.1128/jvi.00216-09] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Cross-regulation of RUNX1 expression by RUNX3 plays a critical role in regulating proliferation of human B cells infected with Epstein-Barr virus (EBV). When EBV infection induces RUNX3, the consequent reduction in RUNX1 levels is required for the ensuing cell proliferation because forced expression of RUNX1 in an EBV lymphoblastoid cell line prevented cell proliferation. The TEL-RUNX1 fusion gene from acute B-lymphocytic leukemia retains almost all of the RUNX1 sequence but does not prevent B-cell proliferation in the same assay. B-cell maturation antigen (BCMA) was found to be induced by conditionally expressed RUNX3 in a lymphoma cell line. Chromatin immunoprecipitation assays confirmed that RUNX3 binds to the RUNX1 promoter in a lymphoblastoid cell line and a Burkitt's lymphoma cell line. The TLE binding VWRPY sequence from the C terminus of RUNX3 was found to be required for repression of the RUNX1 P1 promoter in a B-lymphoma cell line. The mechanism of repression in B-cell lines most likely involves recruitment of corepressor TLE3 or TLE4 to the RUNX1 promoter. The results demonstrate the importance of RUNX3-mediated repression of RUNX1 for EBV-driven B-cell proliferation and identify functional differences between human RUNX family proteins.
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Huang AC, Hu L, Kauffman SA, Zhang W, Shmulevich I. Using cell fate attractors to uncover transcriptional regulation of HL60 neutrophil differentiation. BMC SYSTEMS BIOLOGY 2009; 3:20. [PMID: 19222862 PMCID: PMC2652435 DOI: 10.1186/1752-0509-3-20] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Accepted: 02/18/2009] [Indexed: 12/16/2022]
Abstract
BACKGROUND The process of cellular differentiation is governed by complex dynamical biomolecular networks consisting of a multitude of genes and their products acting in concert to determine a particular cell fate. Thus, a systems level view is necessary for understanding how a cell coordinates this process and for developing effective therapeutic strategies to treat diseases, such as cancer, in which differentiation plays a significant role. Theoretical considerations and recent experimental evidence support the view that cell fates are high dimensional attractor states of the underlying molecular networks. The temporal behavior of the network states progressing toward different cell fate attractors has the potential to elucidate the underlying molecular mechanisms governing differentiation. RESULTS Using the HL60 multipotent promyelocytic leukemia cell line, we performed experiments that ultimately led to two different cell fate attractors by two treatments of varying dosage and duration of the differentiation agent all-trans-retinoic acid (ATRA). The dosage and duration combinations of the two treatments were chosen by means of flow cytometric measurements of CD11b, a well-known early differentiation marker, such that they generated two intermediate populations that were poised at the apparently same stage of differentiation. However, the population of one treatment proceeded toward the terminally differentiated neutrophil attractor while that of the other treatment reverted back toward the undifferentiated promyelocytic attractor. We monitored the gene expression changes in the two populations after their respective treatments over a period of five days and identified a set of genes that diverged in their expression, a subset of which promotes neutrophil differentiation while the other represses cell cycle progression. By employing promoter based transcription factor binding site analysis, we found enrichment in the set of divergent genes, of transcription factors functionally linked to tumor progression, cell cycle, and development. CONCLUSION Since many of the transcription factors identified by this approach are also known to be implicated in hematopoietic differentiation and leukemia, this study points to the utility of incorporating a dynamical systems level view into a computational analysis framework for elucidating transcriptional mechanisms regulating differentiation.
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Molecular and biologic characterization and drug sensitivity of pan-histone deacetylase inhibitor-resistant acute myeloid leukemia cells. Blood 2008; 112:2896-905. [PMID: 18660379 DOI: 10.1182/blood-2007-10-116319] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hydroxamic acid analog pan-histone deacetylase (HDAC) inhibitors (HA-HDIs) have shown preclinical and clinical activity against human acute leukemia. Here we describe HA-HDI-resistant human acute myeloid leukemia (AML) HL-60 (HL-60/LR) cells that are resistant to LAQ824, vorinostat, LBH589, and sodium butyrate. HL-60/LR cells show increased expression of HDACs 1, 2, and 4 but lack HDAC6 expression, with concomitant hyperacetylation of heat shock protein 90 (hsp90). Treatment with HA-HDI failed to further augment hsp90 acetylation, or increase the levels of p21 or reactive oxygen species (ROSs), in HL-60/LR versus HL-60 cells. Although cross-resistant to antileukemia agents (eg, cytarabine, etoposide, and TRAIL), HL-60/LR cells are collaterally sensitive to the hsp90 inhibitor 17-AAG. Treatment with 17-AAG did not induce hsp70 or deplete the hsp90 client proteins AKT and c-Raf. HL-60/LR versus HL-60 cells display a higher growth fraction and shorter doubling time, along with a shorter interval to generation of leukemia and survival in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice. Thus, resistance of AML cells to HA-HDIs is associated with loss of HDAC6, hyperacetylation of hsp90, aggressive leukemia phenotype, and collateral sensitivity to 17-AAG. These findings suggest that an hsp90 inhibitor-based antileukemia therapy may override de novo or acquired resistance of AML cells to HA-HDIs.
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