bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclin-Dependent Kinases Phosphorylate AML1 (RUNX1) and Regulate AML1 Transactivation.
Authors: Biggs Joseph R. , Peterson Luke F. , Zhang Youhong , Kraft Andrew S. , Zhang Dong-Er 
Published: April 2020

Abstract
The transcription factor AML1 (RUNX1) plays a critical role in normal hematopoiesis and in the development of leukemia. The phenotype generated by knockout of the AML1 gene demonstrates that AML1 is necessary for normal development of fetal hematopoietic cells. Conditional knockout of AML1 expression in adult bone marrow leads to lineage-specific effects on B- and T-cell maturation and pronounced inhibition of common lymphocyte progenitor production. In addition, the AML1-deficient adult mice exhibited inefficient platelet production and a mild myeloproliferative phenotype characterized by an increase in peripheral blood neutrophils, an increase in myeloid progenitor populations, and extramedullary hematopoiesis composed of maturing myeloid and erythroid elements. Previous studies have shown that phosphorylation of AML1, particularly at serines 276 and 303, can affect transcriptional activation. We have now shown that phosphorylation of AML1 serines 276 and 303 can be blocked in vivo by inhibitors of the cyclin-dependent kinases (Cdks) Cdk1 and Cdk2. In addition, these two sites can be phosphorylated in vitro by purified, active Cdk1/cyclin B and Cdk2/cyclin A, but not by Cdk4/cyclin D. Mutation of AML1 serines 276 and 303 reduces AML1 activity during most phases of the cell cycle. In addition, mutation of serines 276 and 303 prevents phosphorylation from occurring at two nearby sites (serine 293 and threonine 300). Mutation of serine 293 and threonine 300 causes an increase of AML1 activity, especially in cells arrested in G2/M by treatment with nocodazole. Since Cdk phosphorylation can be stimulatory (serines 276 and 303) or inhibitory (serine 293, threonine 300), the interplay of Cdk phosphorylation at different sites might confer a very fine level of regulation of AML1 activity.
Gfi-1 Represses PU.1 Activity To Promote Granulocyte over Macrophage Differentiation.
Authors: Dahl Richard E. , Iyer Sangeeta R. , Cuylear Dorothy D. , Simon M. Celeste 
Published: April 2020

Abstract
Mice lacking the zinc finger transcriptional repressor protein Gfi-1 are neutropenic. These mice generate abnormal immature myeloid cells exhibiting characteristics of both macrophages and granulocytes. Interestingly these immature Gfi-1−/− myeloid cells overexpress target genes of the PU.1 transcription factor: M-CSF receptor (M-CSFR) and PU.1 itself. Because of this we sought to determine if Gfi-1 modulates the transcriptional activity of PU.1. Here we demonstrate that Gfi-1 physically associates with PU.1 and represses PU.1- dependent transcription from the M-CSFR promoter. This interaction is functionally relevant as Gfi-1 blocks PU.1- dependent macrophage differentiation, but not granulocyte differentiation of a multipotential hematopoietic progenitor cell line. Additionally infection of primary bone marrow progenitors with a Gfi-1 retrovirus promotes granulocyte differentiation at the expense of macrophage differentiation. In contrast, a Gfi-1 mutant lacking repressor activity strongly promotes macrophage differentiation of hematopoietic progenitors. In transient transfections this Gfi-1 mutant not only blocks Gfi-1 repression of PU.1 transcriptional activity but C/EBP alpha mediated repression as well. From this data we hypothesize that Gfi-1 along with other transcriptional regulators target PU.1 for repression in the granulocyte-macrophage progenitor (GMP) in order to direct granulocyte differentiation. If true decreasing the concentration of PU.1 may decrease the need for Gfi-1 in directing granulocyte development. We are currently testing this in vivo by examining myeloid development in PU.1+/−Gfi-1−/− mice.
Transcriptional Regulation of the LMO2 T-Cell Leukaemia Oncogene.
Authors: Landry Josette-Renée , Kinston Sarah , Knezevic Kathy , Green Anthony R. , Göttgens Berthold 
Published: April 2020

Abstract
Transcriptional control has long been identified as a key mechanism regulating the formation and subsequent behaviour of haematopoietic stem cells. We have used a comparative genomics approach to identify transcriptional regulatory elements of the LMO2 gene, a transcriptional cofactor originally identified through its involvement in T-cell leukaemia and subsequently shown to be critical for the formation of haematopoietic stem cells and endothelial development. An initial stringent search for homology between evolutionary distant species demonstrated that, apart from the coding exons, high level of identity between mammalian, amphibian and fish sequences was restricted to the proximal promoter region of LMO2. Real-time RT-PCR expression analysis identified this promoter as the predominant source of transcription in haematopoietic tissue. Transient and stable transfections indicated that the proximal promoter was active in haematopoietic progenitor and endothelial cell lines and this activity was shown to depend on three conserved Ets sites which were bound in vivo by Elf1, Fli1 and Ets1. Transgenic analysis demonstrated that the LMO2 proximal promoter was sufficient for expression in endothelial cells in vivo. However, no haematopoietic expression was observed indicating that additional enhancers are required to mediate transcription from the proximal promoter in haematopoietic cells.
To identify additional elements involved in haematopoietic expression of LMO2, we have performed a less restrictive search for conserved sequences by comparing the human, dog, rat and mouse LMO2 loci to the marsupial opossum LMO2 locus. The addition of the opossum locus, and removal of the more distant fish and amphibian sequences from the alignment, resulted in the discovery of eleven conserved regions. These sequences represent candidate haematopoietic regulatory regions as they contain conserved transcription factor binding sites (E boxes, Ets and Gata sites) previously shown to regulate several other haematopoietic genes. We will present results from a systematic analysis of these regions for enhancer activity in both haematopoietic cell lines and transgenic mice, which suggest that several of these elements indeed act as enhancers. Taken together, our experiments will provide a framework for the transcriptional hierarchies within which LMO2 exerts its function in normal haematopoietic cells. Moreover, the current studies will serve as a platform to examine potential molecular mechanisms that can cause ectopic expression of LMO2 in T-cell progenitors with the ultimate consequence of developing T-ALL.
Increased Incidence of Metabolic Syndrome after Hematopoietic Stem Cell Transplantation.
Authors: Deliliers Giorgio Lambertenghi , Airaghi Lorena , Usardi Patrizia , Orsatti Alessandra , Baldini Marina , Giunta Valeria , Vener Claudia , Annaloro Claudio 
Published: April 2020

Abstract
Metabolic syndrome (MS), formerly known as X-syndrome, is a clinical and laboratory entity involving obesity, hypertension, and borderline fasting glucose, high triglyceride and low HDL cholesterol levels, that is considered to be a counterpart of insulin resistance with overweight playing a key role; increased insulin, leptin, adiponectin and resistin levels link its various features and some common flanking findings such as hypercholesterolemia, hyperuricemia and hyperferritinemia. Clinical and laboratory data reminiscent of metabolic syndrome are commonly observed after hematopoietic stem cell transplantation (HSCT). We evaluated the body mass index (BMI), routine lipid and glucidic markers, and common endocrinologic parameters in 37 HSCT recipients (19 males; median age 45 years, range 26–60; 22 autologous, 15 allogeneic) whose continuous CR lasted at least five years; insulin (baseline and after an oral glucose test), leptin, resistin, TNF-alpha and adiponectin levels were also detemined. Diabetic HSCT recipients were excluded. The control group consisted of 23 healthy volunteers of comparable age and sex without a family history of diabetes. In comparison with the controls, the HSCT recipients had significantly increased levels of TNF (median 10.05 vs 9.3 pg/mL, p=0.034), insulin (13.6 vs 10.1 mIU/mL, p=0.029) and leptin (13.71 vs 3.69 ng/mL, p= 0.02); there were no significant differences in adiponectin and resistin levels, BMI or the other considered parameters. In comparison with the other HSCT recipients, the 16 patients with higher baseline insulin levels (&gt;15 mIU/mL) had significantly higher leptin levels (median 23.665 vs 8.3, p&lt;0.001), and also different total cholesterol (231 vs 202 mg/dL, p&lt;0.01), HDL-cholesterol (58 vs 68 mg/dL, p&lt;0.01), triglyceride (150 vs 92 mg/dL, p&lt;0.01) and ferritin levels (635 vs 491 ng/mL, p&lt;0.01). This preliminary investigation show an increased prevalence of MS findings in HSCT recipients, and a relationship between baseline insulin levels and some common laboratory features of MS. Unlike in spontaneously occurring cases, obesity does not seem to play a primary role; furthermore, BMI and adiponectin were not significantly increased. However, the significant increase in TNF (another inducer of insulin resistance) suggests a possible pathogenetic sequence of post-HSCT MS linking TNF, insulin and leptin. The association between MS and the development of cardiovascular diseases is well known, but HSCT may, in alternative ways, induce a long-term metabolic derangement that affects the life expectancy of patients already cured of their baseline neoplastic disease.
Differences in Histone Acetylation Levels in CD34+ Cells between Acute Myeloid Leukemia (AML) and Myelodysplastic Syndrome (MDS): Correlation between Higher Levels of Histone 2B Acetylation and Survival in AML.
Authors: Gorre M. , Jilani I. , Chang R. , Bareng J. , Chan H. , Keating M. , Kantarjian H. , Estey E. , O’Brien S. , Giles F. , Albitar M. 
Published: April 2020

Abstract
Histone acetylation, along with DNA methylation, is a major epigenetic silencing mechanism believed to play a role in oncogenesis. Agents counteracting histone acetylation, such as the histone deacetylase (HDAC) inhibitors sodium phenylbutyrate and valproic acid, have shown promise in some types of leukemia and MDS. Despite the interest in HDAC inhibitors as therapeutic agents, little is known about the levels of histone acetylation and its clinical relevance in leukemia. In this study we used flow cytometry to quantify the levels of histone 2B acetylation (H2B-ac) and H3-ac in CD34+ and CD3+ cells in AML and MDS patients. Quantification using QuantiBRITE and PE (phycoerythrin)-labeled antibodies with a 1:1 ratio allowed us to specifically measure the antibody binding capacity in 100 CD34+ or CD3+ cells (molecules/100 CD34+ or CD3+ cells). While there was no significant difference in H2B-ac in CD3+ cells between previously untreated AML (50 patients) and previously untreated MDS (11 patients), a significantly higher percentage of CD34+ cells in MDS patients were positive for H2B-ac (P=0.03). In contrast, H3-ac levels were significantly higher in CD34+ and CD3+ cells in MDS than in AML (P=0.02 and P=0.03, respectively). This supports the concept that MDS is not simply a preleukemic disease and the blast population in MDS has characteristics different from those of blasts in AML. In patients with AML, higher levels of H2B-ac in CD34+ cells were associated with longer survival (P=0.03; Figure); multivariate analysis showed that this association was independent of cytogenetic abnormalities. This data confirms that epigenetic changes play a role in clinical behavior in patients with AML and that these patients may benefit from therapy that modifies histone deacetylation.
Figure Figure
Array CGH Discovers Novel Genomic Signatures in De Novo Acute Myeloid Leukemia (AML): Results of Children’s Oncology Group (COG) Study POG #9421.
Authors: Kuo Dennis J. , Lacayo Norman J. , Hoang Don , Juric Dejan , Raimondi Susana C. , Chen David , Chang Myron N. , Ravindranath Yaddanapudi , Weinstein Howard J. , Sikic Branimir I. , Dahl Gary Van Houten 
Published: April 2020

Abstract
Acute myeloid leukemia (AML) is a heterogeneous disease. Risk factors such as karyotype, FAB subtype, FLT3 status and response to induction therapy are determinants of outcome with current therapies. We hypothesize that array comparative genomic hybridization (CGH) will identify gene copy number changes that are determinants of outcome. Array CGH was performed on diagnostic bone marrow samples from patients on the COG study POG #9421. In order to determine regions of altered gene copy number, labeled genomic DNA samples were hybridized together with sex-matching normal human reference DNA to cDNA microarrays with 41,751 features (corresponding to 24,473 unique Unigene cluster IDs), arrays were obtained from the Stanford University Microarray Core Facility. Control hybridizations were performed to assess intra- and inter-experimental variability. We studied 70 samples with adequate high-quality DNA. Circular binary segmentation was used to distinguish discrete gene copy number transition points from chance noise events and to transform primary clone-by-clone data into genomic regions of equal copy number. Using gain/loss threshold, based on two-standard deviation range of control self-to-self distribution, novel gene amplifications and deletions were found in profiled samples. The highest alteration recurrence was observed for gains of chromosome 8 (21%) and losses of chromosome 6 (29%). The area of chromosome 8 which was found to be gained is notable for the presence of potential oncogenes such as ERK8. The deleted area of chromosome 6 is notable for the presence of potential regulators of oncogenesis: MDC1, DDR1, NFKBIL1, TNF, and BRD2. In summary, array CGH has identified novel areas of gene copy number gain and loss in this population of pediatric de novo AML patients. Further studies are needed to assess whether these genes are associated with outcome, known risk factors and whether they will provide insight into the heterogeneity of de novo AML.
Is Consolidation and/or Maintenance Treatment a Standard Therapy in Elderly AML in First Complete Remission?.
Authors: Corre Elise , Marie Jean-Pierre , Legrand Ollivier 
Published: April 2020

Abstract
The treatment of elderly patients with acute myeloid leukemia (AML) is very disappointing. Studies have established that if half of the intensivity treated patients achieve complete remission (CR), the high rate of relapse within the first year jeopardize the long term survival. No clearly effective postremission therapy had been established. Therefore we retrospective analyzed 141 elderly patients (&gt;60 yo) in first CR, to evaluate the effectiveness of postremission therapy, consolidation (3+7or 2+5) and/or maintenance (low dose AraC). All patiens received a 3+7 induction therapy. In these 141 patients DFS and OS at 4 years are respectively 14%, and 19%.
According to the clinical status of the patient after induction, 20 (14%) patients did not receive therapy after induction, 30 (21%) patients received only maintenance therapy, 53 (38%) patients received only consolidation therapy, and 38 patients (27%) received both consolidation and maintenance therapy. These 4 groups were stratified according to age (&lt; &gt;70 yo) and WBC (&lt; or &gt; 30 x 109/l) (See Tables). The outcome of these patients receiving or not post induction therapy is shown in these Tables.
Patients DFS at 4 years OS at 4 years Consolidation No consolidation P value consolidation No consolidation P value Outcome of patients receiving or not consolidation therapy in 4 groups stratified according to age and WBC count &lt; 70yo and WBC&lt; 30x109/l 19% 13% p=0.01 27% 13% p=0.0074 &lt;70yo and WBC&gt;30x109/l 26% 0% p=0.08 38% 0% p=0.05 &gt;70 yo and WBC &lt; 30x109/l 0% 30% p=0.001 6% 30% p=0.01 &gt;70 yo and WBC&gt; 30x109/l 2% 0% NS 4% 0% NS
In patients &gt; 70 yo and WBC &lt; 30 x 109/l patients who received consolidation have a poorer prognosis than patients who did not because the mortality in first complete remission (mortality during consolidation) was high (25% versus 0% respectively, P=0.01).
Patients DFS at 4 years OS at 4 years Maintenance No Maintenance p value Maintenance No Maintenance P value Outcome of patients receiving or not maintenance therapy in 4 groups stratified according to age and WBC count &lt;70yo and WBC&lt;30x109/ 17% 20% NS 22% 25% NS &lt;70 yo and WBC&gt;30x109/l 23% 14% p=0.05 32% 23% NS &gt;70 yo and WBC&lt;30x109/l 25% 5% p=0.01 25% 5% p=0.008 &gt;70 yo and WBC &gt;30x109/l 2% 0% NS 4% 0% NS
In conclusion, in patients &lt; 70 yo consolidation ± maintenance therapy (for DFS in patients with &gt; 30 x109/l) improves the outcome of these patients (DFS and OS). In patients &gt; 70 yo and with WBC &lt; 30 x109/l maintenance therapy without consolidation, improves outcome. In these later patients (&gt; 70 yo and with WBC &lt; 30 x 109/l) consolidation therapy decrease outcome. In patients &gt; 70yo and with WBC &gt; 30 x 109/l, both consolidation and/or maintenance therapy does not improve outcome.
Circulating Endothelial Cells Are an Indicator of Response to Treatment in Acute Myeloid Leukemia Patients.
Authors: Wierzbowska Agnieszka , Robak Tadeusz , Krawczynska Anna , Wrzesien-Kus Agata , Pluta Agnieszka , Cebula Barbara , Smolewski Piotr 
Published: April 2020

Abstract
Introduction. The circulating endothelial cells (CEC) are proposed to be a noninvasive marker of angiogenesis. The number of CEC in peripheral blood of patients (pts) with acute myeloid leukemia (AML) has not been investigated so far.
Patients and Methods. We evaluated the count of resting (rCEC) and activated (aCEC) CEC and circulating endothelial progenitor cells (CEPC) as well as apoptotic CEC (CECAnnV+) in 62 AML pts at the time of diagnosis and 30 healthy controls. Additionally in 26 pts measurements were performed at the time of response evaluation and in 15 pts also 24 h after the first and last dose of chemotherapy. The levels of CEC were correlated with known prognostic factors and response to treatment. CEC were evaluated by the four colour flow cytometry using a panel of previously described monoclonal antibodies and an appropriate analysis gate. CEPC were defined as negative for hematopoietic marker CD45 and positive for endothelial cells markers CD34, CD31 and the endothelial progenitor marker CD133. Resting CEC were defined as CD45−, CD133−, CD31+, CD34+, CD146+ and negative for activation markers (CD105, CD106). CD105 or CD106 positive mature endothelial cells were classified as activated CEC. Apoptotic CEC were CD146 and Annexin V positive.
Results. In untreated AML pts we observed 10-fold higher CEC level (median 29,3/μL) than in the control group (2,95/μL) p&lt;0,0001. The numbers of aCEC (12,7/μL), rCEC (12,3/μL) and CEPC (1,7/μL) were significantly higher in AML pts at diagnosis when compared to healthy controls (aCEC 0,9/μL, rCEC 1,6/μL and 0,1/μL; p&lt;0,0001). CECAnnV+ count was also 10-fold higher in AML (1,5/μL) than in controls (0,15/μL; p&lt;0,0001). Both CEC and CECAnnV+ counts did not correlate with WBC, hemoglobin and platelets count as well as percentage of blasts in bone marrow and absolute blast count. The positive correlations between CEC number and CEPC count (r=0,435; p&lt;0,001), CECAnnV+ count (r=0,502; p&lt;0,01) as well as LDH activity (r=0,328; p&lt;0,02) were found. The significant decrease of aCEC and rCEC numbers 24 hours after the first dose of chemotherapy was noted in patients who achieved complete remission (CR)(p&lt;0,04) but not in pts refractory to treatment. Moreover aCEC, rCEC, CEPC and CECAnnV+ counts determined at the time of response’s evaluation were significantly lower then at the time of diagnosis in pts who achieved CR (p&lt;0,01) and did not differ in refractory AML. There was no difference between levels of both viable and apoptotic CEC in AML pts in CR and in the control group (p&gt;0,05).
Conclusions. The CEC and CECAnnV+ levels are significantly higher in AML patients than in healthy subjects and correlate with response to treatment. Further investigation should be undertaken to better determine their prognostic and therapeutic value.
Tandem Duplications of the FLT3 and MLL Are Independent Poor Prognostic Factors in Pediatric Acute Myeloid Leukemia. AML99 Study in Japan.
Authors: Shimada Akira , Taki Tomohiko , Tabuchi Ken , Taketani Takeshi , Hanada Ryoji , Tawa Akio , Tsuchida Masahiro , Horibe Keizo , Tsukimoto Ichiro , Hayashi Yasuhide 
Published: April 2020

Abstract
To find poor prognostic factors other than karyotypes is desired to improve the treatment outcome in pediatric acute myeloid leukemia (AML). Total three hundread and eighteen patients were enrolled in Japanese Childhood AML Cooperative Treatment Protocol, AML99, from January 2000 to December 2002. We performed the mutation analysis of FLT3 and MLL in 158 patients (13 of 29 with FAB-M3, 10 of 49 with Down syndrome, 135 of 240 with other type of AML) Patients with FAB-M3 and patients with Down syndrome were treated on different protocol. Seventeen (12.6%) of 135 patients had FLT3-internal tandem duplication (ITD). The differences between AML patients with or without FLT3-ITD were significant in 4-year overall survival (OS) (35.3% vs. 86.1%, p&lt;0.00001), disease free survival (DFS) (38.5% vs. 68.1%, p=0.0013), and relapse rate (RR) (53.8% vs. 28.5%, p=0.0029). Furthermore, MLL-partial tandem duplication (PTD) was found in 21 (15.6%) of 135 patients. The differences between patients with or without MLL-PTD were significant in 4y-OS (56.3% vs. 81.4%, p=0.013), DFS (41.7% vs. 68.3%, p=0.017), and RR (53.9% vs. 27.5%, p=0.0078). Out of 18 patients with MLL-PTD who received allo-SCT, 9 patients survived (6 of 8 in 1st CR, 3 of 4 in 2nd CR, 0 of 6 in non CR). Out of 12 patients with FLT3-ITD who received allo-SCT, 4 patients survived (4 of 6 in 1st CR, 0 of 6 in non CR). Allo-SCT is considered to be effective for the patients with TD of both genes. Coduplication of both genes was observed in 3 patients. FLT3 kinase domain mutation was found in 7.0% and MLL translocations were found in 11.4% of the patients, but both aberrations did not show poor outcome in this study. FLT3-ITD and MLL-PTD were found in 9 (25.7%) and 8 (22.9%) of 35 patients with normal karyotype. FLT3-ITD and MLL-PTD are considered to be independent poor prognostic factors of pediatric AML patients, especially in patients with normal karyotype. The different therapeutic approach including allo-SCT will be needed for these patients.