Down-Regulation of Microrna 223 and 148a Mediates Resistance of Human Acute Myeloid Leukemia Cells to Pan-Histone Deacetylase (HDAC) Inhibitors.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2401-2401
Author(s):  
Jianguang Chen ◽  
Veena Kandaswamy ◽  
Warren Fiskus ◽  
Yongchao Wang ◽  
Rekha Rao ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Histone Deacetylase ◽  
Myeloid Leukemia ◽  
Hdac Inhibitors ◽  
Ectopic Expression ◽  
K562 Cells ◽  
Methyl Transferase ◽  
Human Acute Myeloid Leukemia ◽  
Acute Myeloid

Abstract Abstract 2401 Poster Board II-378 MicroRNA (miR) alterations are highly involved in the pathogenesis of leukemia. However, the role of miRs in de novo or acquired resistance of cancer cells to therapeutic agents has not been fully elucidated. Recently, we reported the isolation and characterization of HL-60/LR cells, derived from human acute myeloid leukemia HL-60 cells, that are resistant to pan-histone deacetylase (HDAC) inhibitors (HDIs), including vorinostat and panobinostat (Blood. 2008; 112: 2896). To explore the role of miRs in acquiring resistance to HDIs, we performed a miR microarray analysis of the parental HL-60 and HL-60/LR cells. Compared to HL-60 cells, expression of thirteen microRNAs were discovered to be significantly increased (> 4-fold) and fourteen miRs were markedly down-regulated (> 4-fold) in HL-60/LR cells. Alterations in the expression of three of the most promising upregulated (miR-21, miR-126 and miR-146a) and down-regulated (miR-223, miR-148a and miR-342) miRs were confirmed by Q-PCR in HL-60/LR cells. The expression of miR-223, miR-148a and miR-342 was also significant lower in the relatively HDI-resistant K562 cells as compared to HDI-sensitive U937 and HL-60 cells. Conversely, miR-126 and miR-146a expressions were higher in K562 cells compared to U937 and HL-60 cells. Short term (24 hours) treatment with panobinostat (10 to 50 nM) did not alter the expression of miR-223 or miR-148a expression in HL-60 cells. As compared to treatment with either agent alone, co-treatment with the histone methyl transferase EZH2 antagonist 3-deazaneplanocin (DZnep, 1.0 uM) and DNA methyl transferase inhibitor decitabine (2.0 uM) induced miR-223 and miR-148a levels and mediated apoptosis of HL-60/LR cells, suggesting that an epigenetic silencing mechanism(s) may be involved in the down-modulation of miR-223 and miR-148a in HL-60/LR cells. To determine whether the alterations in the miR levels were mechanistically involved in conferring resistance to HDIs, we engineered through retroviral transduction stable ectopic expressions of miR-223, miR-148a and miR-342 into HL-60/LR cells and miR-21 and miR-146a into HL-60 cells. Ectopic expression of miR-223 and miR-148a significantly increased the sensitivity of HL-60/LR cells to panobinostat and vorinostat. In contrast, re-expression of miR-342 had an insignificant effect on HDI sensitivity. Increased expression of miR-21 and miR-146a did not confer resistance to the HDIs in HL-60 and U937 cells. Next, by Western analyses, we compared the expression levels of several of the predicted target proteins of miR-223 and miR-148a, (as predicted by the computer programs TargetScan and picTAR), in HL-60 versus HL-60/LR cells, as well as in the HL-60/LR cells with stable ectopic expression of miR-223 and miR-148a. Several candidate proteins including GRP94, Ribosomal protein S6 kinase MSK1, MEF2C and DNMT1 showed higher level of expression in HL-60/LR versus HL-60 and were down-regulated in miR-223 or miR-148a transduced HL-60/LR cells, suggesting that these proteins may confer resistance against HDI. Parenthetically, miR-223 was shown to be a myeloid-specific miR which negatively regulates progenitor proliferation and granulocyte differentiation and activation. miR-223 mutant mice have an expanded granulocytic compartment resulting from an increase in the number of granulocyte progenitors. In summary, our observations indicate that high miR-223 and miR-148a levels may be predictive biomarkers for sensitivity to HDIs in human AML cells. Additionally, induction of miR-223 and miR-148a by EZH2 antagonist may increase sensitivity and overcome resistance to HDIs in human AML cells. Targeting the levels and/or activity of the miR-223 and miR-148a target proteins may also be an effective strategy in enhancing the activity of HDI based combination therapy against AML. Disclosures: Atajada: Novartis: Employment. Bhalla:Merck: Honoraria; Novartis: Honoraria, Research Funding.

scholarly journals Disruption of SIRPα signaling in macrophages eliminates human acute myeloid leukemia stem cells in xenografts

2012 ◽  
Vol 209 (10) ◽  
pp. 1883-1899 ◽  
Author(s):  
Alexandre P.A. Theocharides ◽  
Liqing Jin ◽  
Po-Yan Cheng ◽  
Tatiana K. Prasolava ◽  
Andrei V. Malko ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Cell Function ◽  
Leukemia Stem Cell ◽  
Tumor Surveillance ◽  
Human Acute Myeloid Leukemia ◽  
Differential Ability ◽  
Acute Myeloid

Although tumor surveillance by T and B lymphocytes is well studied, the role of innate immune cells, in particular macrophages, is less clear. Moreover, the existence of subclonal genetic and functional diversity in some human cancers such as leukemia underscores the importance of defining tumor surveillance mechanisms that effectively target the disease-sustaining cancer stem cells in addition to bulk cells. In this study, we report that leukemia stem cell function in xenotransplant models of acute myeloid leukemia (AML) depends on SIRPα-mediated inhibition of macrophages through engagement with its ligand CD47. We generated mice expressing SIRPα variants with differential ability to bind human CD47 and demonstrated that macrophage-mediated phagocytosis and clearance of AML stem cells depend on absent SIRPα signaling. We obtained independent confirmation of the genetic restriction observed in our mouse models by using SIRPα-Fc fusion protein to disrupt SIRPα–CD47 engagement. Treatment with SIRPα-Fc enhanced phagocytosis of AML cells by both mouse and human macrophages and impaired leukemic engraftment in mice. Importantly, SIRPα-Fc treatment did not significantly enhance phagocytosis of normal hematopoietic targets. These findings support the development of therapeutics that antagonize SIRPα signaling to enhance macrophage-mediated elimination of AML.

scholarly journals A New Entity of Acute Myeloid Leukemia Driven By Epigenetic and Somatic Dis-Regulation of Uncx, a Novel Homeobox Transcription Factor Gene

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1356-1356
Author(s):  
Giulia Daniele ◽  
Clelia Tiziana Storlazzi ◽  
Cristina Papayannidis ◽  
Ilaria Iacobucci ◽  
Angelo Lonoce ◽  
...  
Keyword(s):  
Stem Cells ◽  
Acute Myeloid Leukemia ◽  
Transcription Factor ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Ectopic Expression ◽  
Response To Therapy ◽  
Hematopoietic Stem ◽  
Acute Myeloid

Abstract We describe a new AML entity, occurring in 30% of de novo acute myeloid leukemia, due to structural and epigenetic deregulation of the UNCX homeobox (HB) gene. By molecular approaches, we identified a M5 AML patient with a t(7;10)(p22;p14) translocation as the sole cytogenetic anomaly and showing ectopic expression of UNCX (7p22.3), which encode for a transcription factor involved in somitogenesis and neurogenesis. Since UNCX was never reported in association with cancer but only with common myeloid cell proliferation and regulation of cell differentiation, we decided to investigate its contribution to leukemogenesis. We observed UNCX ectopic expression in 32.3% (20/62) and in 8% (6/75) of acute myeloid leukemia (AML) patients and cell lines, respectively. Notably, retroviral-mediated UNCX transfer in CD34+ HSCs induced a slow-down in their proliferation and differentiation and transduced cells showed a lower growth rate but a higher percentage of CD34+ stem cells in liquid culture than controls. Additionally, UNCX infected cells displayed a decrease of MAP2K1 proliferation marker but increase of KLF4, HOXA10, and CCNA1, associated with impaired differentiation and pluripotency. Similarly, UNCX-positive patients revealed alteration of gene pathways involved in proliferation, cell cycle control and hematopoiesis. Since HB genes encode for transcription factors showing a crucial role in normal hematopoiesis and in leukemogenesis, we focused our attention on the role of altered UNCX expression level. Of note, its murine ortholog, (Uncx) was previously described as embedded within a low-methylated regions (≤ 10%) called "canyon" and dysregulated in murine hematopoietic stem cells (HSCs) as a consequence of altered methylation at canyons edges (borders) due to Dnmt3a inactivation. In our hands, UNCX activation was accompanied by methylation changes at both its canyon borders, clearly indicating an epigenetic regulation of this gene, although not induced by DNMT3A mutations. Clinical parameters and correlation with response to therapy will be presented. Taken together, our results indicate that more than 30% of de novo AML have a novel entity with a putative leukemogenic role of UNCX, whose activation may be ascribed to epigenetic regulators. Acknowledgments: MG, CP, GS, and AP(2) and this work was supported by ELN, AIL, AIRC, progetto Regione-Università 2010-12 (L. Bolondi), Fondazione del Monte di Bologna e Ravenna, FP7 NGS-PTL project. CTS, GD and AL are supported by Associazione Italiana Ricerca sul Cancro (AIRC) funding. Disclosures Nadarajah: MLL Munich Leukemia Laboratory: Employment. Martinelli:MSD: Consultancy; Novartis: Consultancy, Speakers Bureau; Ariad: Consultancy; BMS: Consultancy, Speakers Bureau; Pfizer: Consultancy; AMGEN: Consultancy; ROCHE: Consultancy.

scholarly journals Efficacy of a New Small-Molecule Inhibitor of Histone Deacetylase 6 (HDAC6) in Preclinical Models of B-Cell Lymphoma and Acute Myeloid Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5383-5383
Author(s):  
Montserrat Perez-Salvia ◽  
Aldaba Eneko ◽  
Vara Yosu ◽  
Fabre Myriam ◽  
Ferrer Cristina ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
B Cell ◽  
Histone Deacetylase ◽  
Myeloid Leukemia ◽  
Cell Lymphoma ◽  
Hdac Inhibitors ◽  
Histone Deacetylase 6 ◽  
Preclinical Models ◽  
Hdac6 Inhibitor ◽  
Acute Myeloid

Abstract Histone deacetylase 6 (HDAC6) is a protein modifier that is an increasingly attractive pharmacological target. Interestingly, the observation that the HDAC6 knock-out mouse is not lethal, in contrast to those undergoing complete loss of class I, II and III HDACs, suggests that specific HDAC6 inhibitors may be better tolerated than pan-HDAC inhibitors or drugs that target the other HDAC classes. In this regard, the compound ACY-1215 (Rocilinostat), the described selective HDAC6 inhibitors, is undergoing clinical trials for the treatment of multiple myeloma. Taking into account the previous information about HDAC6 inhibitor structures, the structural differences between HDAC6 and other HDAC isoforms and also the structural information of other developed HDAC inhibitors, we have previously designed and synthesized a new potential HDAC6 selective inhibitor, QTX125 with growth inhibitory effects in mantle cell lymphoma (MCL) cell lines, mouse models and ex vivo treatment of primary samples obtained from patients with MCL. Herein, we have extended these findings to show that the newly identified HDAC6 inhibitor QTX125 is also able to inhibit the growth of preclinical models of other B-cell lymphomas such as follicular lymphoma and Burkitt's cell lymphoma, but also of acute acute myeloid leukemia. In addition beyond a-tubulin, a well known HDAC6 target, we have developed a pharmacological and proteomic screening to identify other proteins modified by HDAC6 that can contribute to the described lymphoma and leukemia phenotypes. Disclosures Eneko: Quimatryx: Employment. Yosu:Quimatryx: Employment. Myriam:Oncomatryx: Employment. Cristina:Oncomatryx: Employment. González-Barca:Roche: Speakers Bureau; Celtrion: Consultancy; Gilead: Consultancy; janssen: Consultancy, Speakers Bureau. Fernando:Quimatryx: Consultancy.

Molecular and biologic characterization and drug sensitivity of pan-histone deacetylase inhibitor–resistant acute myeloid leukemia cells

Blood ◽  
2008 ◽  
Vol 112 (7) ◽  
pp. 2896-2905 ◽  
Author(s):  
Warren Fiskus ◽  
Rekha Rao ◽  
Pravina Fernandez ◽  
Bryan Herger ◽  
Yonghua Yang ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Histone Deacetylase ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Acquired Resistance ◽  
Hdac Inhibitors ◽  
Hsp90 Inhibitor ◽  
Growth Fraction ◽  
Clinical Activity ◽  
Acute Myeloid

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.

The Role of Monocytes in Phagocytosis and Mixed Leukocyte Reactivity in Human Acute Myeloid Leukemia

1979 ◽  
Vol 8 (3) ◽  
pp. 279-301 ◽  
Author(s):  
Thomas D. Miale ◽  
Leif Å. L. Stenke ◽  
Marta Penchansky ◽  
Toini Lehtinen ◽  
Peter G. Reizenstein
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Human Acute Myeloid Leukemia ◽  
Acute Myeloid

scholarly journals The ubiquitin ligase RNF5 determines acute myeloid leukemia growth and susceptibility to histone deacetylase inhibitors

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ali Khateb ◽  
Anagha Deshpande ◽  
Yongmei Feng ◽  
Darren Finlay ◽  
Joo Sang Lee ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Histone Deacetylase ◽  
Ubiquitin Ligase ◽  
Myeloid Leukemia ◽  
Histone Deacetylase Inhibitors ◽  
Hdac Inhibitors ◽  
Favorable Prognosis ◽  
Transcriptional Changes ◽  
Acute Myeloid

AbstractAcute myeloid leukemia (AML) remains incurable, largely due to its resistance to conventional treatments. Here, we find that increased abundance of the ubiquitin ligase RNF5 contributes to AML development and survival. High RNF5 expression in AML patient specimens correlates with poor prognosis. RNF5 inhibition decreases AML cell growth in culture, in patient-derived xenograft (PDX) samples and in vivo, and delays development of MLL-AF9–driven leukemogenesis in mice, prolonging their survival. RNF5 inhibition causes transcriptional changes that overlap with those seen upon histone deacetylase (HDAC)1 inhibition. RNF5 induces the formation of K29 ubiquitin chains on the histone-binding protein RBBP4, promoting its recruitment to and subsequent epigenetic regulation of genes involved in AML maintenance. Correspondingly, RNF5 or RBBP4 knockdown enhances AML cell sensitivity to HDAC inhibitors. Notably, low expression of both RNF5 and HDAC coincides with a favorable prognosis. Our studies identify an ERAD-independent role for RNF5, demonstrating that its control of RBBP4 constitutes an epigenetic pathway that drives AML, and highlight RNF5/RBBP4 as markers useful to stratify patients for treatment with HDAC inhibitors.

scholarly journals RNF5 Defines Acute Myeloid Leukemia Growth and Susceptibility to Histone Deacetylase Inhibitors

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 31-32
Author(s):  
Ali Khateb ◽  
Anagha Deshpande ◽  
Yongmei Feng ◽  
Ikrame Lazar ◽  
Joo Sang Lee ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Board Of Directors ◽  
Histone Deacetylase ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Histone Deacetylase Inhibitors ◽  
Hdac Inhibitors ◽  
Therapeutic Modality ◽  
Advisory Committees ◽  
Acute Myeloid

Acute myeloid leukemia (AML) remains an incurable blood cancer largely due to rapid emergence of resistance to conventional treatments. Thus, new therapeutic modalities are greatly needed to halt AML development. Here, using genetic and xenograft mouse models, we reveal that inhibition of the ubiquitin ligase RNF5 in human AML cell lines and in MLL-AF9-driven AML severely decreased the leukemogenic potential of those cells and prolonged survival of model leukemic mice. These findings suggest the possibility that targeting a single gene, namely RNF5, could effectively inhibit different AML subtypes. We initially focused on RNF5 as its expression is upregulated in AML patient cohorts as well as in AML-derived cell lines compared with normal hematopoietic cells. Furthermore, high RNF5 expression in AML patient specimens correlated with poor prognosis, relapse and short overall patient survival. By contrast, specimens from AML patients who responded to therapy exhibited low RNF5 levels. In vitro, RNF5 loss impaired the clonogenic potential of MLL-AF9-transduced bone marrow cells and markedly attenuated growth and survival of AML but not CML or T-ALL cell lines, in which RNF5 is also highly expressed. High-throughput screen and bioinformatics analysis identified RNF5 and ER-associated degradation (ERAD) components, as augmenting AML cell sensitivity to histone deacetylase (HDAC) inhibition. Indeed, inhibition of RNF5 sensitized AML cells to HDAC inhibitors. Correspondingly, a favorable prognosis was observed in AML patients exhibiting low expression of RNF5 and HDAC. Collectivity, our studies identify a potential new therapeutic modality based on targeting RNF5 to inhibit AML and suggest that RNF5 expression could serve as a prognostic marker and means to stratify patients for treatment with HDAC inhibitors. Disclosures Ofran: AbbVie: Membership on an entity's Board of Directors or advisory committees. Vuori:Bionano Genomics: Membership on an entity's Board of Directors or advisory committees.

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