Cdx4 Upregulates Hox Gene Expression and Generates Acute Myeloid Leukemia Alone and in Cooperation with Meis1a in a Murine Model.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 10-10
Author(s):  
Dimple Bansal ◽  
Claudia Scholl ◽  
Stefan Frohling ◽  
Elizabeth Mcdowell ◽  
Benjamin H. Lee ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Acute Leukemia ◽  
Myeloid Leukemia ◽  
Hox Genes ◽  
Function Analysis ◽  
Marrow Transplant ◽  
Hox Gene ◽  
Acute Myeloid

Abstract HOX genes have emerged as critical effectors of leukemogenesis, but the mechanisms that regulate their expression in leukemia are not well understood. Recent data suggest that the caudal homeobox transcription factors CDX1, 2 and 4, developmental regulators of HOX gene expression, may contribute to HOX gene dysregulation in leukemia. We report here that CDX4 is normally expressed in early hematopoietic progenitors, and is aberrantly expressed in~25% of AML patient samples. Cdx4 regulates Hox gene expression in the adult murine hematopoietic system, and upregulates Hox genes that are implicated in leukemogenesis. Furthermore, bone marrow progenitors that are retrovirally engineered to express Cdx4 serially replate in methylcellulose cultures, grow in liquid culture and generate a partially penetrant, long-latency acute myeloid leukemia (AML) in bone marrow transplant recipients. Co-expression of the Hox co-factor Meis1a accelerates the Cdx4 AML phenotype and renders it fully penetrant. Structure -function analysis demonstrates that leukemic transformation requires intact Cdx4 transactivation and DNA-binding domains, but not the Pbx co-factor interaction motif. Taken together, these data indicate that Cdx4 regulates Hox gene expression in adult hematopoiesis and may serve as an upstream regulator of Hox gene expression in the induction of acute leukemia. Inasmuch as many human leukemias show dysregulated expression of a spectrum of HOX family members, these collective findings also suggest a central role for CDX4 expression in the genesis of acute leukemia.

scholarly journals PROGNOSTIC VALUE OF BRAIN AND ACUTE LEUKEMIA CYTOPLASMIC GENE EXPRESSION IN EGYPTIAN CHILDREN WITH ACUTE MYELOID LEUKEMIA

2015 ◽  
Vol 7 ◽  
pp. e2015033 ◽  
Author(s):  
Adel Abd elhaleim Hagag
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Complete Remission ◽  
Acute Leukemia ◽  
Myeloid Leukemia ◽  
Egyptian Children ◽  
Significant Difference ◽  
The Impact ◽  
Acute Myeloid

Abstract      Background: Acute myeloid leukemia (AML) accounts for 25%-35% of the acute leukemia in children. BAALC (Brain and Acute Leukemia, Cytoplasmic gene) is a recently identified gene on chromosome 8q22.3 that has prognostic significance in AML.  The aim of this work was to study the impact of BAALC gene expression on prognosis of AML in Egyptian children. Patients and methods: This study was conducted on 40 patients of newly diagnosed AML who were subjected to the following: Full history taking, clinical examination, laboratory investigations including: complete blood count, LDH, bone marrow aspiration, cytochemistry and immunophenotyping, assessment of BAALC Gene by real time PCR in bone marrow aspirate mononuclear cells before the start of chemotherapy. Results: BAALC gene expression showed positive expression in 24 cases (60%) and negative expression in 16 cases (40%). Patients who showed positive BAALC gene expression included 10 patients achieved complete remission, 8 patients died and 6 relapsed patients, while patients who showed negative expression include 12 patients achieved complete remission, 1 relapsed patient and 3 patients died. There was significant association between BAALC gene expression and FAB classification of patients of AML patientsas positive BAALC expression is predominantly seen in FAB subtypes M1 and M2 compared with negative BAALC gene expression that was found more in M3 and M4 (8 cases with M1, 12 cases with M2, 1 case with M3 and 3 cases with M4 in positive BAALC expression versus 2 cases with M1, 3 cases with M2, 4 cases with M3 and 7 cases with M4 in BAALC gene negative expression group with significant difference regarding FAB subtypes). As regard age, sex, splenomegaly, lymphadenopathy, pallor, purpura, platelets count, WBCs count, and percentage of blast cells in BM, the present study showed no significant association with BAALC. Conclusion: BAALC expression is an important prognostic factor in AML patients and its incorporation into novel risk-adapted therapeutic strategies will improve the currently disappointing cure rate of this group of patients.

Overexpression of CDX2 perturbs HOX gene expression in murine progenitors depending on its N-terminal domain and is closely correlated with deregulated HOX gene expression in human acute myeloid leukemia

Blood ◽  
2008 ◽  
Vol 111 (1) ◽  
pp. 309-319 ◽  
Author(s):  
Vijay P. S. Rawat ◽  
Silvia Thoene ◽  
Vegi M. Naidu ◽  
Natalia Arseni ◽  
Bernhard Heilmeier ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Hox Genes ◽  
Constitutive Expression ◽  
Normal Karyotype ◽  
Parahox Gene ◽  
Hox Gene ◽  
Terminal Domain ◽  
Acute Myeloid

The mechanisms underlying deregulation of HOX gene expression in AML are poorly understood. The ParaHox gene CDX2 was shown to act as positive upstream regulator of several HOX genes. In this study, constitutive expression of Cdx2 caused perturbation of leukemogenic Hox genes such as Hoxa10 and Hoxb8 in murine hematopoietic progenitors. Deletion of the N-terminal domain of Cdx2 abrogated its ability to perturb Hox gene expression and to cause acute myeloid leukemia (AML) in mice. In contrast inactivation of the putative Pbx interacting site of Cdx2 did not change the leukemogenic potential of the gene. In an analysis of 115 patients with AML, expression levels of CDX2 were closely correlated with deregulated HOX gene expression. Patients with normal karyotype showed a 14-fold higher expression of CDX2 and deregulated HOX gene expression compared with patients with chromosomal translocations such as t(8:21) or t(15;17). All patients with AML with normal karyotype tested were negative for CDX1 and CDX4 expression. These data link the leukemogenic potential of Cdx2 to its ability to dysregulate Hox genes. They furthermore correlate the level of CDX2 expression with HOX gene expression in human AML and support a potential role of CDX2 in the development of human AML with aberrant Hox gene expression.

scholarly journals Cdx4 dysregulates Hox gene expression and generates acute myeloid leukemia alone and in cooperation with Meis1a in a murine model

2006 ◽  
Vol 103 (45) ◽  
pp. 16924-16929 ◽  
Author(s):  
D. Bansal ◽  
C. Scholl ◽  
S. Frohling ◽  
E. McDowell ◽  
B. H. Lee ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Murine Model ◽  
Myeloid Leukemia ◽  
Hox Gene ◽  
Acute Myeloid

Long-Term Expansion and Self Renewal Is Contained in the CD34+, but Not the CD34- Subfraction of Nucleophosmin Mutated Acute Myeloid Leukemia Cells.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1349-1349
Author(s):  
Carolien Woolthuis ◽  
Lina Han ◽  
Djoke van Gosliga ◽  
Philip Kluin ◽  
Edo Vellenga ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Hox Genes ◽  
Mutant Protein ◽  
Self Renewal ◽  
Cd34 Cells ◽  
Stromal Layer ◽  
Acute Myeloid

Abstract Mutations in the nucleophosmin (NPM) gene are found in about 30% of cases of acute myeloid leukemia (AML) and lead to a dislocation of the nucleophosmin protein from the nucleus to the cytoplasm (NPMc+ AML). NPMc+ AML shows distinctive biological and clinical features, including a unique gene expression profile, a distinct microRNA signature, low percentage of CD34+ cells, increased incidence of Flt3-ITD (about 40% of cases), good response to induction chemotherapy and (in the absence of Flt3-ITD) a favourable prognosis. Despite significant progress in the characterization of the NPMc+ AML subgroup, questions remain about the leukemia-initiating cell. Distinct features of NPMc+ AML, including multilineage involvement and overexpression of HOX-genes, may point to an early progenitor as the leukemia-initiating cell, but the characteristic low percentage of CD34+ cells may point to a more differentiated leukemic stem cell in NPMc+ AML. To gain more insight in the leukemia-initiating cell in AML with mutated NPM, NPMc+ AML cells were sorted based on the expression of CD34 (n=8, the percentage of CD34+ in the total AML fraction varied between 0.06 and 37%). Western blotting, using an antibody that specifically recognizes the nucleophosmin mutant protein revealed that the NPM mutant protein is expressed in both CD34+ and CD34− cells, proving that the CD34+ NPMc+ AML cells belong to the leukemic clone. This was verified by sequencing the NPM gene in CD34+ and CD34− AML cells. Importantly, culture of sorted CD34+ and CD34− NPMc+ AML cells on a stromal layer revealed that the CD34+ but not the CD34− cells of NPMc+ AML were capable of expanding and initiating long-term growth. In the first 5 weeks of culture an at least 16 fold (range 16–208) expansion of CD34+ AML cells was seen in 5 out of 6 NPMc+ AML cases. This expansion was associated with the formation of cobblestone areas (CAs) under the stromal layer within 3 weeks after plating. The NPMc+ AML cells which expanded in culture were able to expand further after replating in 4 out of 5 investigated cases (fold expansion range 1.6–2.5), indicative of the self renewal capacity of these CD34+ NPMc+ AML cells. Gene expression analysis of CD34+ and CD34− NPMc+ AML cells of 4 cases analyzed thus far revealed the presence of the characteristic HOX-overexpression profile in both CD34+ and CD34− NPMc+ AML cells. In summary, this study shows that the NPM mutation is not only present in CD34−, but also in CD34+ cells of NPMc+ AML and that the properties of long-term expansion and self renewal belong exclusively to the CD34+ subfraction of NPMc+ AML.

Constitutive Activation of SHP2 Protein Tyrosine Phosphatase Cooperates with HoxA10 Overexpression for Progression to Acute Myeloid Leukemia in a Murine Model

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 752-752
Author(s):  
Hao Wang ◽  
Stephan Lindsey ◽  
Iwona Konieczna ◽  
Elizabeth Horvath ◽  
Ling Bei ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Protein Tyrosine Phosphatase ◽  
Myeloid Leukemia ◽  
Tyrosine Phosphatase ◽  
Post Translational Modification ◽  
Protein Tyrosine ◽  
Acute Myeloid ◽  
Myeloid Progenitors

Abstract HOX genes encode highly conserved homeodomain (HD) transcription factors and are arranged in four groups (A–D). During definitive hematopoiesis, HOX gene expression is activated 3′ to 5′ through each group. Therefore, HOX1-4 are actively transcribed in hematopoietic stem cells and HOX7-11 in committed progenitors. Under normal conditions, HoxA7-11 expression decreases during CD34+ to CD34− maturation. Abnormal Hox expression is characteristic of several poor prognosis subtypes of Acute Myeloid Leukemia (AML) including AML with translocations or duplications of the MLL gene. In such leukemias, expression of HoxB3, B4 and A7-11 is sustained in CD34−CD38+ cells. In murine bone marrow transplantation experiments, expression of MLL fusion proteins, HoxA9 or HoxA10 induces a myeloproliferative disorder (MPD) characterized by increased neutrophils (PMN). Over time, the mice progress to AML with circulating myeloid blasts. These results suggest overexpression of HoxA9 or HoxA10 is adequate for MPD, but differentiation block (AML) requires additional lesions. We found that HoxA9 and HoxA10 proteins not only decrease in expression during the CD34+ to CD34− transition, but also are tyrosine phosphorylated. In additional studies, we found that HoxA10 tyrosine phosphorylation state is relevant for differentiation stage-specific target gene expression during myelopoiesis. HoxA10 represses genes encoding phagocyte effector proteins in undifferentiated myeloid cells. During myelopoiesis, phosphorylation of conserved HD-HoxA10 tyrosines decreases binding to these genes, permitting phenotypic and functional differentiation. HoxA10 activates transcription of the gene encoding Mkp2 (Dusp4) in myeloid progenitors. Decrease in HoxA10-binding to this gene as differentiation proceeds decreases transcription and renders the cells susceptible to Jnk induced apoptosis. Therefore, we hypothesized that genetic lesions which influence post translational modification might cooperate with HoxA10 overexpression to lead from MPD to AML. In myeloid progenitors, HoxA10 is maintained in a non-phosphorylated state by SHP2 protein tyrosine phosphatase. SHP2 activity decreases as differentiation proceeds. Activating mutations in SHP2 have been described in AML. We found that such activated SHP2 mutants dephosphorylate HoxA10 through out ex vivo myelopoiesis. Therefore, we investigated cooperation between these two leukemia associated abnormalities in vivo. Mice were transplanted with bone marrow overexpressing HoxA10 (or empty vector control) with or without activated SHP2 (E76K). To control for SHP2 overexpression, other mice were transplanted with bone marrow overexpressing HoxA10 and wild type SHP2. Mice transplanted with bone marrow overexpressing HoxA10 (±SHP2) developed MPD which evolved to AML over 4 mos, consistent with previous observations. However, mice transplanted with bone marrow overexpressing HoxA10 and E76K SHP2 developed AML within 4 wks. This rapid development of AML correlated with abnormalities in expression of myeloid specific HoxA10 target genes. These studies indicate the importance of HoxA10 post translational modification for physiologically relevant function and identify cooperating lesions which may be significant for disease progression in human AML.

Inhibition Of LSD1 As a Therapeutic Strategy For The Treatment Of Acute Myeloid Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3964-3964 ◽  
Author(s):  
Ryan G. Kruger ◽  
Helai Mohammad ◽  
Kimberly Smitheman ◽  
Monica Cusan ◽  
Yan Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Cell Surface ◽  
Growth Inhibition ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Stem Cell Differentiation ◽  
Ethical Review Process ◽  
Acute Myeloid

Abstract Lysine specific demethylase 1 (LSD1) is a histone H3K4me1/2 demethylase found in various transcriptional co-repressor complexes. These complexes include Histone Deacetylases (HDAC1/2) and Co-Repressor for Element-1-Silencing Transcription factor (CoREST). LSD1 mediated H3K4 demethylation can result in a repressive chromatin environment that silences gene expression. LSD1 has been shown to play a role in development in various contexts. LSD1 can interact with pluripotency factors in human embryonic stem cells and is important for decommissioning enhancers in stem cell differentiation. Beyond embryonic settings, LSD1 is also critical for hematopoietic differentiation. LSD1 is overexpressed in multiple cancer types and recent studies suggest inhibition of LSD1 reactivates the all-trans retinoic acid receptor pathway in acute myeloid leukemia (AML). These studies implicate LSD1 as a key regulator of the epigenome that modulates gene expression through post-translational modification of histones and through its presence in transcriptional complexes. The current study describes the anti-tumor effects of a novel LSD1 inhibitor (GSK2879552) in AML. GSK2879552 is a potent, selective, mechanism-based, irreversible inhibitor of LSD1. Screening of over 150 cancer cell lines revealed that AML cells have a unique requirement for LSD1. While LSD1 inhibition did not affect the global levels of H3K4me1 or H3K4me2, local changes in these histone marks were observed near transcriptional start sites of putative LSD1 target genes. This increase in the transcriptionally activating histone modification correlated with a dose dependent increase in gene expression. Treatment with GSK2879552 promoted the expression of cell surface markers, including CD11b and CD86, associated with a differentiated immunophenotype in 12 of 13 AML cell lines. For example, in SKM-1 cells, increases in cell surface expression of CD86 and CD11b occurred after as early as one day of treatment with EC50 values of 13 and 7 nM respectively. In a separate study using an MV-4-11 engraftment model, increases in CD86 and CD11b were observed as early as 8 hours post dosing. GSK2879552 treatment resulted in a potent anti-proliferative growth effect in 19 of 25 AML cell lines (average EC50 = 38 nM), representing a range of AML subtypes. Potent growth inhibition was also observed on AML blast colony forming ability in 4 out of 5 bone marrow samples derived from primary AML patient samples (average EC50 = 205 nM). The effects of LSD1 inhibition were further characterized in an in vivo mouse model of AML induced by transduction of mouse hematopoietic progenitor cells with a retrovirus encoding MLL-AF9 and GFP. Primary AML cells were transplanted into a cohort of secondary recipient mice and upon engraftment, the mice were treated for 17 days. After 17 days of treatment, control treated mice had 80% GFP+ cells in the bone marrow whereas treated mice possessed 2.8% GFP positive cells (p<0.012). The percentage of GFP+ cells continued to decrease to 1.8% by 1-week post therapy. Remarkably, in a preliminary assessment for survival, control-treated mice succumbed to AML by 28 days post transplant, while treated mice showed prolonged survival. Together, these data demonstrate that pharmacological inhibition of LSD1 may provide a promising treatment for AML by promoting differentiation and subsequent growth inhibition of AML blasts. GSK2879552 is currently in late preclinical development and clinical trials are anticipated to start in 2014. All studies were conducted in accordance with the GSK Policy on the Care, Welfare and Treatment of Laboratory Animals and were reviewed the Institutional Animal Care and Use Committee either at GSK or by the ethical review process at the institution where the work was performed. Disclosures: Kruger: GlaxoSmithKline Pharmaceuticals: Employment. Mohammad:GlaxoSmithKline Pharmaceuticals: Employment. Smitheman:GlaxoSmithKline Pharmaceuticals: Employment. Liu:GlaxoSmithKline Pharmaceuticals: Employment. Pappalardi:GlaxoSmithKline Pharmaceuticals: Employment. Federowicz:GlaxoSmithKline Pharmaceuticals: Employment. Van Aller:GlaxoSmithKline Pharmaceuticals: Employment. Kasparec:GlaxoSmithKline Pharmaceuticals: Employment. Tian:GlaxoSmithKline Pharmaceuticals: Employment. Suarez:GlaxoSmithKline Pharmaceuticals: Employment. Rouse:GlaxoSmithKline Pharmaceuticals: Employment. Schneck:GlaxoSmithKline Pharmaceuticals: Employment. Carson:GlaxoSmithKline Pharmaceuticals: Employment. McDevitt:GlaxoSmithKline Pharmaceuticals: Employment. Ho:GlaxoSmithKline Pharmaceuticals: Employment. McHugh:GlaxoSmithKline Pharmaceuticals: Employment. Miller:GlaxoSmithKline Pharmaceuticals: Employment. Johnson:GlaxoSmithKline Pharmaceuticals: Employment. Armstrong:Epizyme Inc.: Has consulted for Epizyme Inc. Other. Tummino:GlaxoSmithKline Pharmaceuticals: Employment.

The Role of TWIST1 Gene Expression and Hypoxic Microenvironment in Acute Myeloid Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3839-3839
Author(s):  
Emilia Carolina Malafaia ◽  
A. Mario Marcondes ◽  
Ekapun Karoopongse ◽  
Daniele Serehi ◽  
Maria de Lourdes L. F. Chauffaille ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Leukemia Cells ◽  
Twist1 Expression ◽  
Disease Biology ◽  
Acute Myeloid

Abstract TWIST1, a basic helix-loop-helix (bHLH) transcription factor, plays a critical role in mesodermal development and organogenesis. Overexpressed TWIST1 has been thoroughly related to epithelial-mesenchymal transition (EMT) in solid tumors (QIN Q et al., 2012) and has been described as an emerging risk factor in hematological neoplasms (MERINDOL et al., 2014). . Many questions remain to be addressed concerning to the role of TWIST1 in acute myeloid leukemia (AML). The understanding of TWIST1 in leukemia cells and its interaction with microenvironment can offer new insights in regards to disease biology and therapeutic targets for patients with AML. Objectives: 1) to evaluate the role of stroma contact and hypoxia in TWIST1 expression in myeloid cell lines. 2) To evaluate the functional impact of overexpressing TWIST1 on KG1a and PL21 cells. 3) To evaluate TWIST1 expression in primary cells of AML patients. Methods: In order to mimic bone marrow microenvironment, myeloid cells were co-cultured with mesenchymal HS5 cell line and PO2 1% was established with Smart -Trak¨ 2 (Sierra Instruments, Inc.) equipment. Quantitative mRNA was determined using TaqMan¨ Universal Master Mix (Applied Biosystems, Foster City, CA) and 3-step standard cycling conditions with sequence-specific primer TWIST1 normalized to the expression of β-actin. KG1a and PL21 cells were transduced with lentivirus vector carrying e-GFP ("enhanced green fluorescence protein") for stable expression of TWIST1. Transduced cells were sorted by FITC fluorochrome and then verified through western blot analysis with TWIST1 antibody. For quantification of apoptosis, cells were labeled with PE-conjugated antibody using annexin V-phycoerythrin and propidium iodide (BD Biosciences, USA). DAPI (4',6- diamidino-2-phenylindole dihydrochloride) was used to stain DNA and determine cell cycle information . Apoptosis and cell cycle were analyzed by FACS -Becton Dickinson Canto II (BD Biosciences). Statistical analysis was assessed with unpaired t test. Results: Hypoxia induced TWIST1 mRNA expression in OCIAML3, PL21, KG1a and ML1 cell lines (fold-increased 46.3, 29.8, 12.9 and 2.3 respectively). Cells expressing endogenous TWIST1 protein (OCIAML3 and ML1) showed resistance to apoptosis in a hypoxic microenvironment (normoxia versus hypoxia: OCI/AML3, 22.6 % vs 11.7% and ML1, 29.8% vs. 7.5%) in contrast, cells not expressing endogenous TWIST1 protein (KG1a and PL21) went to apoptosis in the same conditions. Thus, overexpressing TWIST1 in KG1a and PL21 induced apoptosis protection in hypoxia (KG1a unmodified vs. modified: 17.6 ± 6.3 vs. 2.8 ± 6.3, p=0.04; PL21 unmodified vs. modified: 26.9 ± 10.9 vs. 3.2 ± 0.6, p=0.04) (fig 1). We found increased TWIST1 mRNA levels in bone marrow samples of 23 AML patients (3.88 ± 1.59) compared with 5 healthy controls (0.54 ±0.25) (p= 0.02) (fig 2). Patients in the highest tertile of TWIST1 expression did not show differences in percentage of blasts in bone marrow and complete remission after treatment compared with patients in low and middle tertile. Conclusion: Our data suggest TWIST1 gene expression protects acute myeloid leukemia cells from apoptosis in a hypoxic microenvironment. Moreover, our results showed increased expression of TWIST1 in AML patients. Thus, TWIST1 is a potential gene involved in leukemogenesis and should be further explored to understand disease biology and potential therapeutic targets. Disclosures No relevant conflicts of interest to declare.

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