51
|
Varney ME, Choi K, Bolanos L, Christie S, Fang J, Grimes HL, Maciejewski JP, Inoue JI, Starczynowski DT. Epistasis between TIFAB and miR-146a: neighboring genes in del(5q) myelodysplastic syndrome. Leukemia 2016; 31:491-495. [PMID: 27733775 DOI: 10.1038/leu.2016.276] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
52
|
Cancelas J, Zhang C, D'Alessandro A, Wellendorf A, Mohmoud F, Dasgupta B, Whitsett J, Grimes HL. KLF5 deficiency is required for B-cell lymphoid progenitor leukemogenesis to promote glutathione biosynthesis and prevent oxidative stress. Exp Hematol 2016. [DOI: 10.1016/j.exphem.2016.06.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
53
|
Fang J, Liu X, Bolanos L, Barker B, Rigolino C, Cortelezzi A, Oliva EN, Cuzzola M, Grimes HL, Fontanillo C, Komurov K, MacBeth K, Starczynowski DT. A calcium- and calpain-dependent pathway determines the response to lenalidomide in myelodysplastic syndromes. Nat Med 2016; 22:727-34. [PMID: 27294874 DOI: 10.1038/nm.4127] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 05/13/2016] [Indexed: 12/15/2022]
Abstract
Despite the high response rates of individuals with myelodysplastic syndrome (MDS) with deletion of chromosome 5q (del(5q)) to treatment with lenalidomide (LEN) and the recent identification of cereblon (CRBN) as the molecular target of LEN, the cellular mechanism by which LEN eliminates MDS clones remains elusive. Here we performed an RNA interference screen to delineate gene regulatory networks that mediate LEN responsiveness in an MDS cell line, MDSL. We identified GPR68, which encodes a G-protein-coupled receptor that has been implicated in calcium metabolism, as the top candidate gene for modulating sensitivity to LEN. LEN induced GPR68 expression via IKAROS family zinc finger 1 (IKZF1), resulting in increased cytosolic calcium levels and activation of a calcium-dependent calpain, CAPN1, which were requisite steps for induction of apoptosis in MDS cells and in acute myeloid leukemia (AML) cells. In contrast, deletion of GPR68 or inhibition of calcium and calpain activation suppressed LEN-induced cytotoxicity. Moreover, expression of calpastatin (CAST), an endogenous CAPN1 inhibitor that is encoded by a gene (CAST) deleted in del(5q) MDS, correlated with LEN responsiveness in patients with del(5q) MDS. Depletion of CAST restored responsiveness of LEN-resistant non-del(5q) MDS cells and AML cells, providing an explanation for the superior responses of patients with del(5q) MDS to LEN treatment. Our study describes a cellular mechanism by which LEN, acting through CRBN and IKZF1, has cytotoxic effects in MDS and AML that depend on a calcium- and calpain-dependent pathway.
Collapse
|
54
|
Li KP, Fähnrich A, Roy E, Cuda C, Grimes HL, Perlman H, Kalies K, Hildeman DA. Temporal expression of Bim limits the development and repertoire of TCR+ double negative thymocytes and CD8αα intestinal intraepithelial lymphocytes. THE JOURNAL OF IMMUNOLOGY 2016. [DOI: 10.4049/jimmunol.196.supp.121.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
DN T cells (CD4−CD8α−TCRαβ+) and CD8αα T cells compose a major lymphocyte population in the intestine and promote gut homeostasis. Their thymic development, i.e. agonist selection, has been shown to be controlled by the pro-apoptotic factor Bim. In addition to its role in the thymus, Bim also controls peripheral T cell survival. However, the role of Bim in thymic and peripheral homeostasis of DN T and CD8αα T cells remain unclear. Here, we found that T cell-specific expression of Bim during early, but not late, thymic development limits the levels of DN T and CD8αα T cells in the spleen and iIEL compartments. The loss of Bim altered the TCR repertoire of DN T cells, but not conventional CD4 or CD8 T cells. As IL-15 controls CD8αα cell homeostasis, and antagonizes Bim in other T cells, we examined whether the additional loss of Bim would restore CD8αα T cells in IL-15−/− mice. Strikingly, the additional loss of Bim restored splenic, but not intestinal, DN T and CD8αα T cells in IL-15−/− mice. Instead, IL-15 signaling via Stat5 synergized with TCR signaling in peripheral DN T cells to increase expression of CD8α. Furthermore, adoptive transfer of splenic DN T cells gave rise to CD8αα cells in immune intact recipients. Combined, these data show that Bim functions temporally to limit the development and TCR repertoire of CD8αα precursors in the thymus. Moreover, Bim limits IL-15-driven homeostasis of CD8αα cells in the secondary lymphoid organs; but does not restrict their IL-15-driven maturation that is critical for intestinal homeostasis.
Collapse
|
55
|
Meyer SE, Qin T, Muench DE, Masuda K, Venkatasubramanian M, Orr E, Suarez L, Gore SD, Delwel R, Paietta E, Tallman MS, Fernandez H, Melnick A, Le Beau MM, Kogan S, Salomonis N, Figueroa ME, Grimes HL. DNMT3A Haploinsufficiency Transforms FLT3ITD Myeloproliferative Disease into a Rapid, Spontaneous, and Fully Penetrant Acute Myeloid Leukemia. Cancer Discov 2016; 6:501-15. [PMID: 27016502 DOI: 10.1158/2159-8290.cd-16-0008] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/24/2016] [Indexed: 11/16/2022]
Abstract
UNLABELLED Cytogenetically normal acute myeloid leukemia (CN-AML) represents nearly 50% of human AML. Co-occurring mutations in the de novo DNA methyltransferase DNMT3A and the FMS related tyrosine kinase 3 (FLT3) are common in CN-AML and confer a poorer prognosis. We demonstrate that mice with Flt3-internal tandem duplication (Flt3(ITD)) and inducible deletion of Dnmt3a spontaneously develop a rapidly lethal, completely penetrant, and transplantable AML of normal karyotype. AML cells retain a single Dnmt3a floxed allele, revealing the oncogenic potential of Dnmt3a haploinsufficiency. FLT3(ITD)/DNMT3A-mutant primary human and murine AML exhibit a similar pattern of global DNA methylation associated with changes in the expression of nearby genes. In the murine model, rescuing Dnmt3a expression was accompanied by DNA remethylation and loss of clonogenic potential, suggesting that Dnmt3a-mutant oncogenic effects are reversible. Dissection of the cellular architecture of the AML model using single-cell assays, including single-cell RNA sequencing, identified clonogenic subpopulations that express genes sensitive to the methylation of nearby genomic loci and responsive to DNMT3A levels. Thus, Dnmt3a haploinsufficiency transforms Flt3(ITD) myeloproliferative disease by modulating methylation-sensitive gene expression within a clonogenic AML subpopulation. SIGNIFICANCE DNMT3A haploinsufficiency results in reversible epigenetic alterations that transform FLT3(ITD)-mutant myeloproliferative neoplasm into AML. Cancer Discov; 6(5); 501-15. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 461.
Collapse
|
56
|
Nayak RC, Trump LR, Aronow BJ, Myers K, Mehta P, Kalfa T, Wellendorf AM, Valencia CA, Paddison PJ, Horwitz MS, Grimes HL, Lutzko C, Cancelas JA. Pathogenesis of ELANE-mutant severe neutropenia revealed by induced pluripotent stem cells. J Clin Invest 2015; 125:3103-16. [PMID: 26193632 DOI: 10.1172/jci80924] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 06/05/2015] [Indexed: 12/27/2022] Open
Abstract
Severe congenital neutropenia (SCN) is often associated with inherited heterozygous point mutations in ELANE, which encodes neutrophil elastase (NE). However, a lack of appropriate models to recapitulate SCN has substantially hampered the understanding of the genetic etiology and pathobiology of this disease. To this end, we generated both normal and SCN patient-derived induced pluripotent stem cells (iPSCs), and performed genome editing and differentiation protocols that recapitulate the major features of granulopoiesis. Pathogenesis of ELANE point mutations was the result of promyelocyte death and differentiation arrest, and was associated with NE mislocalization and activation of the unfolded protein response/ER stress (UPR/ER stress). Similarly, high-dose G-CSF (or downstream signaling through AKT/BCL2) rescues the dysgranulopoietic defect in SCN patient-derived iPSCs through C/EBPβ-dependent emergency granulopoiesis. In contrast, sivelestat, an NE-specific small-molecule inhibitor, corrected dysgranulopoiesis by restoring normal intracellular NE localization in primary granules; ameliorating UPR/ER stress; increasing expression of CEBPA, but not CEBPB; and promoting promyelocyte survival and differentiation. Together, these data suggest that SCN disease pathogenesis includes NE mislocalization, which in turn triggers dysfunctional survival signaling and UPR/ER stress. This paradigm has the potential to be clinically exploited to achieve therapeutic responses using lower doses of G-CSF combined with targeting to correct NE mislocalization.
Collapse
|
57
|
Abstract
Hematopoiesis is characterized by a lifelong balance between hematopoietic stem cell (HSC) self-renewal and differentiation into mature blood populations. Proper instruction of cell fate decisions requires tight homeostatic regulation of transcriptional programs through a combination of epigenetic modifications, management of cis-regulatory elements, and transcription factor activity. Recent work has focused on integrating biochemical, genetic, and evolutionary data sets to gain further insight into these regulatory components. Long noncoding RNA (lncRNA), post-translational modifications of transcription factors, and circadian rhythm add additional layers of complexity. These analyses have provided a wealth of information, much of which has been made available through public databases. Elucidating the regulatory processes that govern hematopoietic transcriptional programs is expected to provide useful insights into hematopoiesis that may be applied broadly across tissue types while enabling the discovery and implementation of therapeutics to treat human disease.
Collapse
|
58
|
Cumaraswamy AA, Lewis AM, Geletu M, Todic A, Diaz DB, Cheng XR, Brown CE, Laister RC, Muench D, Kerman K, Grimes HL, Minden MD, Gunning PT. Nanomolar-Potency Small Molecule Inhibitor of STAT5 Protein. ACS Med Chem Lett 2014; 5:1202-1206. [PMID: 25419444 PMCID: PMC4234445 DOI: 10.1021/ml500165r] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 09/19/2014] [Indexed: 02/04/2023] Open
Abstract
![]()
We herein report the design and synthesis
of the first nanomolar
binding inhibitor of STAT5 protein. Lead compound 13a, possessing a phosphotyrosyl-mimicking salicylic acid group, potently
and selectively binds to STAT5 over STAT3, inhibits STAT5–SH2
domain complexation events in vitro, silences activated
STAT5 in leukemic cells, as well as STAT5′s downstream transcriptional
targets, including MYC and MCL1,
and, as a result, leads to apoptosis. We believe 13a represents
a useful probe for interrogating STAT5 function in cells as well as
being a potential candidate for advanced preclinical trials.
Collapse
|
59
|
Velu CS, Chaubey A, Phelan JD, Meyer S, Horman SR, Wunderlich M, Guzman ML, Jegga AG, Zeleznik-Le NJ, Chen J, Mulloy JC, Cancelas JA, Jordan CT, Aronow BJ, Marcucci G, Bhat B, Gebelein B, Grimes HL. Abstract 979: microRNA-mediated leukemia-initiating cell activity. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The HoxA9 transcription activator and the Gfi1 transcriptional repressor compete for the regulation of common target genes. We exploited HoxA9 versus Gfi1 antagonism to identify the genes encoding microRNA-21 and microRNA-196b as transcriptional targets of Hox-based leukemia oncoproteins. Therapeutic inhibition of microRNA-21 and microRNA-196b significantly inhibits in vitro colony forming activity, and quantitatively depletes in vivo leukemia-initiating-cell activity of Hox-based leukemias leading to leukemia-free survival of murine AML and significant delay in disease onset in xenograft models. A novel microRNA target identification platform both validates therapeutic intervention and reveals biological impact of disrupting microRNA function. These data establish microRNA as functional effectors of endogenous HoxA9 and Hox-based leukemia oncoproteins, provide a concise in vivo platform to test RNA therapeutics, and suggest therapeutic value for microRNA antagonists in AML.
Citation Format: Chinavenmeni S. Velu, Aditya Chaubey, James D. Phelan, Sara Meyer, Shane R. Horman, Mark Wunderlich, Monica L. Guzman, Anil G. Jegga, Nancy J. Zeleznik-Le, Jianjun Chen, James C. Mulloy, Jose A. Cancelas, Craig T. Jordan, Bruce J. Aronow, Guido Marcucci, Balkrishen Bhat, Brian Gebelein, H. Leighton Grimes. microRNA-mediated leukemia-initiating cell activity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 979. doi:10.1158/1538-7445.AM2014-979
Collapse
|
60
|
Fang J, Barker B, Bolanos L, Liu X, Jerez A, Makishima H, Christie S, Chen X, Rao DS, Grimes HL, Komurov K, Weirauch MT, Cancelas JA, Maciejewski JP, Starczynowski DT. Myeloid malignancies with chromosome 5q deletions acquire a dependency on an intrachromosomal NF-κB gene network. Cell Rep 2014; 8:1328-38. [PMID: 25199827 DOI: 10.1016/j.celrep.2014.07.062] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 06/05/2014] [Accepted: 07/31/2014] [Indexed: 01/09/2023] Open
Abstract
Chromosome 5q deletions (del[5q]) are common in high-risk (HR) myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML); however, the gene regulatory networks that sustain these aggressive diseases are unknown. Reduced miR-146a expression in del(5q) HR MDS/AML and miR-146a(-/-) hematopoietic stem/progenitor cells (HSPCs) results in TRAF6/NF-κB activation. Increased survival and proliferation of HSPCs from miR-146a(low) HR MDS/AML is sustained by a neighboring haploid gene, SQSTM1 (p62), expressed from the intact 5q allele. Overexpression of p62 from the intact allele occurs through NF-κB-dependent feedforward signaling mediated by miR-146a deficiency. p62 is necessary for TRAF6-mediated NF-κB signaling, as disrupting the p62-TRAF6 signaling complex results in cell-cycle arrest and apoptosis of MDS/AML cells. Thus, del(5q) HR MDS/AML employs an intrachromosomal gene network involving loss of miR-146a and haploid overexpression of p62 via NF-κB to sustain TRAF6/NF-κB signaling for cell survival and proliferation. Interfering with the p62-TRAF6 signaling complex represents a therapeutic option in miR-146a-deficient and aggressive del(5q) MDS/AML.
Collapse
|
61
|
Grimes HL, Olsson A, Aronow B, Chaudhri V, Dexheimer P, Singh H. Single cell transcriptome-based dissection of lineage fate decisions in myelopoiesis. Exp Hematol 2014. [DOI: 10.1016/j.exphem.2014.07.073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
62
|
Northcott PA, Lee C, Zichner T, Stütz AM, Erkek S, Kawauchi D, Shih DJH, Hovestadt V, Zapatka M, Sturm D, Jones DTW, Kool M, Remke M, Cavalli FMG, Zuyderduyn S, Bader GD, VandenBerg S, Esparza LA, Ryzhova M, Wang W, Wittmann A, Stark S, Sieber L, Seker-Cin H, Linke L, Kratochwil F, Jäger N, Buchhalter I, Imbusch CD, Zipprich G, Raeder B, Schmidt S, Diessl N, Wolf S, Wiemann S, Brors B, Lawerenz C, Eils J, Warnatz HJ, Risch T, Yaspo ML, Weber UD, Bartholomae CC, von Kalle C, Turányi E, Hauser P, Sanden E, Darabi A, Siesjö P, Sterba J, Zitterbart K, Sumerauer D, van Sluis P, Versteeg R, Volckmann R, Koster J, Schuhmann MU, Ebinger M, Grimes HL, Robinson GW, Gajjar A, Mynarek M, von Hoff K, Rutkowski S, Pietsch T, Scheurlen W, Felsberg J, Reifenberger G, Kulozik AE, von Deimling A, Witt O, Eils R, Gilbertson RJ, Korshunov A, Taylor MD, Lichter P, Korbel JO, Wechsler-Reya RJ, Pfister SM. Enhancer hijacking activates GFI1 family oncogenes in medulloblastoma. Nature 2014; 511:428-34. [PMID: 25043047 DOI: 10.1038/nature13379] [Citation(s) in RCA: 431] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 04/15/2014] [Indexed: 02/08/2023]
Abstract
Medulloblastoma is a highly malignant paediatric brain tumour currently treated with a combination of surgery, radiation and chemotherapy, posing a considerable burden of toxicity to the developing child. Genomics has illuminated the extensive intertumoral heterogeneity of medulloblastoma, identifying four distinct molecular subgroups. Group 3 and group 4 subgroup medulloblastomas account for most paediatric cases; yet, oncogenic drivers for these subtypes remain largely unidentified. Here we describe a series of prevalent, highly disparate genomic structural variants, restricted to groups 3 and 4, resulting in specific and mutually exclusive activation of the growth factor independent 1 family proto-oncogenes, GFI1 and GFI1B. Somatic structural variants juxtapose GFI1 or GFI1B coding sequences proximal to active enhancer elements, including super-enhancers, instigating oncogenic activity. Our results, supported by evidence from mouse models, identify GFI1 and GFI1B as prominent medulloblastoma oncogenes and implicate 'enhancer hijacking' as an efficient mechanism driving oncogene activation in a childhood cancer.
Collapse
|
63
|
Velu CS, Chaubey A, Phelan JD, Horman SR, Wunderlich M, Guzman ML, Jegga AG, Zeleznik-Le NJ, Chen J, Mulloy JC, Cancelas JA, Jordan CT, Aronow BJ, Marcucci G, Bhat B, Gebelein B, Grimes HL. Therapeutic antagonists of microRNAs deplete leukemia-initiating cell activity. J Clin Invest 2014; 124:222-36. [PMID: 24334453 PMCID: PMC3871218 DOI: 10.1172/jci66005] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 10/10/2013] [Indexed: 12/14/2022] Open
Abstract
Acute myelogenous leukemia (AML) subtypes that result from oncogenic activation of homeobox (HOX) transcription factors are associated with poor prognosis. The HOXA9 transcription activator and growth factor independent 1 (GFI1) transcriptional repressor compete for occupancy at DNA-binding sites for the regulation of common target genes. We exploited this HOXA9 versus GFI1 antagonism to identify the genes encoding microRNA-21 and microRNA-196b as transcriptional targets of HOX-based leukemia oncoproteins. Therapeutic inhibition of microRNA-21 and microRNA-196b inhibited in vitro leukemic colony forming activity and depleted in vivo leukemia-initiating cell activity of HOX-based leukemias, which led to leukemia-free survival in a murine AML model and delayed disease onset in xenograft models. These data establish microRNA as functional effectors of endogenous HOXA9 and HOX-based leukemia oncoproteins, provide a concise in vivo platform to test RNA therapeutics, and suggest therapeutic value for microRNA antagonists in AML.
Collapse
MESH Headings
- Animals
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Base Sequence
- Binding Sites
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Combined Modality Therapy
- Cytarabine/administration & dosage
- DNA-Binding Proteins/metabolism
- Doxorubicin/administration & dosage
- Gene Expression Regulation, Leukemic
- Homeodomain Proteins/metabolism
- Humans
- Induction Chemotherapy
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Leukemia, Myeloid, Acute/therapy
- Mice
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, SCID
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Myeloid Ecotropic Viral Integration Site 1 Protein
- Neoplasm Proteins/metabolism
- Neoplastic Stem Cells/physiology
- Phosphorothioate Oligonucleotides/genetics
- Pre-B-Cell Leukemia Transcription Factor 1
- Protein Binding
- Proto-Oncogene Proteins/metabolism
- Regulatory Sequences, Nucleic Acid
- Transcription Factors/metabolism
- Transcriptome
- Xenograft Model Antitumor Assays
Collapse
|
64
|
Taniguchi Ishikawa E, Chang KH, Nayak R, Olsson HA, Ficker AM, Dunn SK, Madhu MN, Sengupta A, Whitsett JA, Grimes HL, Cancelas JA. Klf5 controls bone marrow homing of stem cells and progenitors through Rab5-mediated β1/β2-integrin trafficking. Nat Commun 2013; 4:1660. [PMID: 23552075 PMCID: PMC3627399 DOI: 10.1038/ncomms2645] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 02/22/2013] [Indexed: 01/05/2023] Open
Abstract
Kruppel-like factor 5 (Klf5) regulates pluripotent stem cell self-renewal but its role in somatic stem cells is unknown. Here we show that Klf5 deficient haematopoietic stem cells and progenitors (HSC/P) fail to engraft after transplantation. This HSC/P defect is associated with impaired bone marrow homing and lodging and decreased retention in bone marrow, and with decreased adhesion to fibronectin and expression of membrane-bound β1/β2-integrins. In vivo inducible gain-of-function of Klf5 in HSCs increases HSC/P adhesion. The expression of Rab5 family members, mediators of β1/β2-integrin recycling in the early endosome, is decreased in Klf5Δ/Δ HSC/Ps. Klf5 binds directly to the promoter of Rab5a/b and overexpression of Rab5b rescues the expression of activated β1/β2-integrins, adhesion and bone marrow homing of Klf5Δ/Δ HSC/Ps. Altogether, these data indicate that Klf5 is indispensable for adhesion, homing, lodging and retention of HSC/Ps in the bone marrow through Rab5-dependent post-translational regulation of β1/β2 integrins.
Collapse
|
65
|
Phelan JD, Saba I, Zeng H, Kosan C, Messer MS, Olsson HA, Fraszczak J, Hildeman DA, Aronow BJ, Möröy T, Grimes HL. Growth factor independent-1 maintains Notch1-dependent transcriptional programming of lymphoid precursors. PLoS Genet 2013; 9:e1003713. [PMID: 24068942 PMCID: PMC3772063 DOI: 10.1371/journal.pgen.1003713] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 06/25/2013] [Indexed: 11/19/2022] Open
Abstract
Growth factor independent 1 (Gfi1) is a transcriptional repressor originally identified as a gene activated in T-cell leukemias induced by Moloney-murine-leukemia virus infection. Notch1 is a transmembrane receptor that is frequently mutated in human T-cell acute lymphoblastic leukemia (T-ALL). Gfi1 is an important factor in the initiation and maintenance of lymphoid leukemias and its deficiency significantly impedes Notch dependent initiation of T-ALL in animal models. Here, we show that immature hematopoietic cells require Gfi1 to competently integrate Notch-activated signaling. Notch1 activation coupled with Gfi1 deficiency early in T-lineage specification leads to a dramatic loss of T-cells, whereas activation in later stages leaves development unaffected. In Gfi1 deficient multipotent precursors, Notch activation induces lethality and is cell autonomous. Further, without Gfi1, multipotent progenitors do not maintain Notch1-activated global expression profiles typical for T-lineage precursors. In agreement with this, we find that both lymphoid-primed multipotent progenitors (LMPP) and early T lineage progenitors (ETP) do not properly form or function in Gfi1−/− mice. These defects correlate with an inability of Gfi1−/− progenitors to activate lymphoid genes, including IL7R, Rag1, Flt3 and Notch1. Our data indicate that Gfi1 is required for hematopoietic precursors to withstand Notch1 activation and to maintain Notch1 dependent transcriptional programming to determine early T-lymphoid lineage identity. Understanding the mechanisms that protect lymphoid cells from transformation is a critical first step in developing therapies against blood cancers. Recently, we demonstrated that the Growth factor independent-1 transcriptional repressor protein is required for cancer development driven by activation of Notch1 signaling. Here, we investigated the mechanisms by which Gfi1 protects lymphoid transformation. Using complex genetic mouse models to delete Gfi1 and activate Notch1, we demonstrate that Gfi1 is required to maintain both the homeostatic levels of Notch1 target genes in normal lymphoid precursors in the bone marrow, as well as to maintain the supraphysiologic levels of Notch1 signaling present in pre-malignant lymphoid progenitors. Consequently, without Gfi1 the pool of premalignant cells available for transformation is depleted. Our data provide additional insight into the multiple mechanisms by which developmental networks may have evolved to protect lymphoid cells from transformation.
Collapse
|
66
|
Goyama S, Schibler J, Cunningham L, Zhang Y, Rao Y, Nishimoto N, Nakagawa M, Olsson A, Wunderlich M, Link KA, Mizukawa B, Grimes HL, Kurokawa M, Liu PP, Huang G, Mulloy JC. Transcription factor RUNX1 promotes survival of acute myeloid leukemia cells. J Clin Invest 2013; 123:3876-88. [PMID: 23979164 DOI: 10.1172/jci68557] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 06/20/2013] [Indexed: 12/12/2022] Open
Abstract
RUNX1 is generally considered a tumor suppressor in myeloid neoplasms. Inactivating RUNX1 mutations have frequently been found in patients with myelodysplastic syndrome (MDS) and cytogenetically normal acute myeloid leukemia (AML). However, no somatic RUNX1 alteration was found in AMLs with leukemogenic fusion proteins, such as core-binding factor (CBF) leukemia and MLL fusion leukemia, raising the possibility that RUNX1 could actually promote the growth of these leukemia cells. Using normal human cord blood cells and those expressing leukemogenic fusion proteins, we discovered a dual role of RUNX1 in myeloid leukemogenesis. RUNX1 overexpression inhibited the growth of normal cord blood cells by inducing myeloid differentiation, whereas a certain level of RUNX1 activity was required for the growth of AML1-ETO and MLL-AF9 cells. Using a mouse genetic model, we also showed that the combined loss of Runx1/Cbfb inhibited leukemia development induced by MLL-AF9. RUNX2 could compensate for the loss of RUNX1. The survival effect of RUNX1 was mediated by BCL2 in MLL fusion leukemia. Our study unveiled an unexpected prosurvival role for RUNX1 in myeloid leukemogenesis. Inhibiting RUNX1 activity rather than enhancing it could be a promising therapeutic strategy for AMLs with leukemogenic fusion proteins.
Collapse
|
67
|
Guo F, Li J, Zhang S, Du W, Amarachintha S, Sipple J, Phelan J, Grimes HL, Zheng Y, Pang Q. mTOR kinase inhibitor sensitizes T-cell lymphoblastic leukemia for chemotherapy-induced DNA damage via suppressing FANCD2 expression. Leukemia 2013; 28:203-6. [PMID: 23852546 DOI: 10.1038/leu.2013.215] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
68
|
Raines AM, Adam M, Magella B, Meyer SE, Grimes HL, Dey SK, Potter SS. Recombineering-based dissection of flanking and paralogous Hox gene functions in mouse reproductive tracts. Development 2013; 140:2942-52. [PMID: 23760953 DOI: 10.1242/dev.092569] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hox genes are key regulators of development. In mammals, the study of these genes is greatly confounded by their large number, overlapping functions and interspersed shared enhancers. Here, we describe the use of a novel recombineering strategy to introduce simultaneous frameshift mutations into the flanking Hoxa9, Hoxa10 and Hoxa11 genes, as well as their paralogs on the HoxD cluster. The resulting Hoxa9,10,11 mutant mice displayed dramatic synergistic homeotic transformations of the reproductive tracts, with the uterus anteriorized towards oviduct and the vas deferens anteriorized towards epididymis. The Hoxa9,10,11 mutant mice also provided a genetic setting that allowed the discovery of Hoxd9,10,11 redundant reproductive tract patterning function. Both shared and distinct Hox functions were defined. Hoxd9,10,11 play a crucial role in the regulation of uterine immune function. Non-coding non-polyadenylated RNAs were among the key Hox targets, with dramatic downregulation in mutants. We observed Hox cross-regulation of transcription and splicing. In addition, we observed a surprising anti-dogmatic apparent posteriorization of the uterine epithelium. In caudal regions of the uterus, the normal simple columnar epithelium flanking the lumen was replaced by a pseudostratified transitional epithelium, normally found near the more posterior cervix. These results identify novel molecular functions of Hox genes in the development of the male and female reproductive tracts.
Collapse
|
69
|
Khandanpour C, Phelan JD, Vassen L, Schütte J, Chen R, Horman SR, Gaudreau MC, Krongold J, Zhu J, Paul WE, Dührsen U, Göttgens B, Grimes HL, Möröy T. Growth factor independence 1 antagonizes a p53-induced DNA damage response pathway in lymphoblastic leukemia. Cancer Cell 2013; 23:200-14. [PMID: 23410974 PMCID: PMC3597385 DOI: 10.1016/j.ccr.2013.01.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 09/11/2012] [Accepted: 01/18/2013] [Indexed: 12/14/2022]
Abstract
Most patients with acute lymphoblastic leukemia (ALL) fail current treatments highlighting the need for better therapies. Because oncogenic signaling activates a p53-dependent DNA damage response and apoptosis, leukemic cells must devise appropriate countermeasures. We show here that growth factor independence 1 (Gfi1) can serve such a function because Gfi1 ablation exacerbates p53 responses and lowers the threshold for p53-induced cell death. Specifically, Gfi1 restricts p53 activity and expression of proapoptotic p53 targets such as Bax, Noxa (Pmaip1), and Puma (Bbc3). Subsequently, Gfi1 ablation cures mice from leukemia and limits the expansion of primary human T-ALL xenografts in mice. This suggests that targeting Gfi1 could improve the prognosis of patients with T-ALL or other lymphoid leukemias.
Collapse
|
70
|
Horwitz MS, Corey SJ, Grimes HL, Tidwell T. ELANE mutations in cyclic and severe congenital neutropenia: genetics and pathophysiology. Hematol Oncol Clin North Am 2013; 27:19-41, vii. [PMID: 23351986 PMCID: PMC3559001 DOI: 10.1016/j.hoc.2012.10.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The 2 main forms of hereditary neutropenia are cyclic (CN) and severe congenital (SCN) neutropenia. CN is an autosomal dominant disorder in which neutrophil counts fluctuate with 21-day periodicity. SCN consists of static neutropenia, with promyelocytic maturation arrest in the bone marrow. Unlike CN, SCN displays frequent acquisition of somatic mutations in the gene CSF3R. CN is caused by heterozygous mutations in the gene ELANE, encoding neutrophil elastase. SCN is genetically heterogeneous but is most frequently associated with ELANE mutations. We discuss how the mutations provide clues into the pathogenesis of neutropenia and describe current hypotheses for its molecular mechanisms.
Collapse
|
71
|
Velu CS, Grimes HL. Utilizing antagomiR (antisense microRNA) to knock down microRNA in murine bone marrow cells. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2012; 928:185-95. [PMID: 22956143 DOI: 10.1007/978-1-62703-008-3_15] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
MicroRNAs (miRNAs) are highly conserved small RNAs which regulate gene expression primarily through base pairing to the 3' untranslated region of target messenger RNA (mRNA), leading to mRNA degradation or translation inhibition depending on the complementarity between the miRNA and target mRNA. Single miRNA regulates multiple target mRNA. miRNAs have been shown to regulate gene expression in the hematopoietic stem cells, as well as at key decision points for various lineages. However, aberrant expression of miRNAs has been documented in cancer and disease models. Rigorous dissection of miRNA pathways and biology requires facile loss of function modeling. This chapter describes detailed protocol for knockdown miRNA-21 which is involved in myelopoiesis using antagomiRs in primary murine bone marrow stem/progenitor cells.
Collapse
|
72
|
McClendon AK, Dean JL, Ertel A, Fu Z, Rivadeneira DB, Reed CA, Bourgo RJ, Witkiewicz A, Addya S, Mayhew CN, Grimes HL, Fortina P, Knudsen ES. RB and p53 cooperate to prevent liver tumorigenesis in response to tissue damage. Gastroenterology 2011; 141:1439-50. [PMID: 21704587 PMCID: PMC4562673 DOI: 10.1053/j.gastro.2011.06.046] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 06/01/2011] [Accepted: 06/13/2011] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS The tumor suppressors retinoblastoma (RB) and p53 are important regulators of the cell cycle. Although human cancer cells inactivate RB and p53 by many mechanisms, the cooperative roles of these proteins in tumorigenesis are complex and tissue specific. We analyzed the cooperation of RB and p53 in liver development and pathogenesis of hepatocellular carcinoma. METHODS Spontaneous and carcinogen-induced (diethylnitrosamine) tumorigenesis were studied in mice with liver-specific deletions of Rb and/or p53 (Rbf/f;albcre+, p53f/f;albcre+ and Rbf/f; p53f/f;albcre+ mice). Genotype, histologic, immunohistochemical, microarray, quantitative polymerase chain reaction, immunoblot, and comparative genomic hybridization analyses were performed using normal and tumor samples. Comparative microarray analyses were performed against publicly available human microarray data sets. RESULTS Deletion of RB and p53 from livers of mice deregulated the transcriptional programs associated with human disease. These changes were not sufficient for spontaneous tumorigenesis; potent quiescence mechanisms compensated for loss of these tumor suppressors. In response to hepatocarcinogen-induced damage, distinct and cooperative roles of RB and p53 were revealed; their loss affected cell cycle control, checkpoint response, and genome stability. In damaged tissue, combined loss of RB and p53 resulted in early lesion formation, aggressive tumor progression, and gene expression signatures and histologic characteristics of advanced human hepatocellular carcinoma. CONCLUSIONS The effects RB and p53 loss are determined by the tissue environment; cell stresses that promote aggressive disease reveal the functions of these tumor suppressors.
Collapse
|
73
|
Stoffers SL, Meyer SE, Grimes HL. MicroRNAs in the midst of myeloid signal transduction. J Cell Physiol 2011; 227:525-33. [PMID: 21567394 DOI: 10.1002/jcp.22823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
MicroRNA (miRNA) play important roles in the development and physiological function of hematopoietic stem/progenitor and mature cell lineages. In addition, deregulated miRNA expression and subsequent gene expression changes are associated with hematologic diseases including myelodysplastic syndromes and acute myeloid leukemia. This review focuses on myelopoiesis as a model to highlight the involvement of miRNA in the regulation of normal and malignant cellular signaling pathways. By incorporating miRNA regulation into well-established myeloid signal transduction pathways, we hope to shed light on targetable factors both upstream and downstream of miRNA signaling. These pathway-specific miRNA functions suggest scenarios wherein miRNA-based therapeutics may be beneficial either alone or in combination with current therapies.
Collapse
|
74
|
Kurtulus S, Tripathi P, Moreno-Fernandez ME, Sholl A, Katz JD, Grimes HL, Hildeman DA. Bcl-2 allows effector and memory CD8+ T cells to tolerate higher expression of Bim. THE JOURNAL OF IMMUNOLOGY 2011; 186:5729-37. [PMID: 21451108 DOI: 10.4049/jimmunol.1100102] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
As acute infections resolve, most effector CD8(+) T cells die, whereas some persist and become memory T cells. Recent work showed that subsets of effector CD8(+) T cells, identified by reciprocal expression of killer cell lectin-like receptor G1 (KLRG1) and CD127, have different lifespans. Similar to previous reports, we found that effector CD8(+) T cells reported to have a longer lifespan (i.e., KLRG1(low)CD127(high)) have increased levels of Bcl-2 compared with their shorter-lived KLRG1(high)CD127(low) counterparts. Surprisingly, we found that these effector KLRG1(low)CD127(high) CD8(+) T cells also had increased levels of Bim compared with KLRG1(high)CD127(low) cells. Similar effects were observed in memory cells, in which CD8(+) central memory T cells expressed higher levels of Bim and Bcl-2 than did CD8(+) effector memory T cells. Using both pharmacologic and genetic approaches, we found that survival of both subsets of effector and memory CD8(+) T cells required Bcl-2 to combat the proapoptotic activity of Bim. Interestingly, inhibition or absence of Bcl-2 led to significantly decreased expression of Bim in surviving effector and memory T cells. In addition, manipulation of Bcl-2 levels by IL-7 or IL-15 also affected expression of Bim in effector CD8(+) T cells. Finally, we found that Bim levels were significantly increased in effector CD8(+) T cells lacking Bax and Bak. Together, these data indicate that cells having the highest levels of Bim are selected against during contraction of the response and that Bcl-2 determines the level of Bim that effector and memory T cells can tolerate.
Collapse
|
75
|
Guo F, Zhang S, Tripathi P, Mattner J, Phelan J, Sproles A, Mo J, Wills-Karp M, Grimes HL, Hildeman D, Zheng Y. Distinct roles of Cdc42 in thymopoiesis and effector and memory T cell differentiation. PLoS One 2011; 6:e18002. [PMID: 21455314 PMCID: PMC3063799 DOI: 10.1371/journal.pone.0018002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 02/17/2011] [Indexed: 12/14/2022] Open
Abstract
Cdc42 of the Rho GTPase family has been implicated in cell actin organization, proliferation, survival, and migration but its physiological role is likely cell-type specific. By a T cell-specific deletion of Cdc42 in mouse, we have recently shown that Cdc42 maintains naïve T cell homeostasis through promoting cell survival and suppressing T cell activation. Here we have further investigated the involvement of Cdc42 in multiple stages of T cell differentiation. We found that in Cdc42−/− thymus, positive selection of CD4+CD8+ double-positive thymocytes was defective, CD4+ and CD8+ single-positive thymocytes were impaired in migration and showed an increase in cell apoptosis triggered by anti-CD3/-CD28 antibodies, and thymocytes were hyporesponsive to anti-CD3/-CD28-induced cell proliferation and hyperresponsive to anti-CD3/-CD28-stimulated MAP kinase activation. At the periphery, Cdc42-deficient naive T cells displayed an impaired actin polymerization and TCR clustering during the formation of mature immunological synapse, and showed an enhanced differentiation to Th1 and CD8+ effector and memory cells in vitro and in vivo. Finally, Cdc42−/− mice exhibited exacerbated liver damage in an induced autoimmune disease model. Collectively, these data establish that Cdc42 is critically involved in thymopoiesis and plays a restrictive role in effector and memory T cell differentiation and autoimmunity.
Collapse
|