bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myc Induces Acute Myeloid Leukemia by Conferring Self-Renewal Activity to Committed Myeloid Progenitor Cells That Resist Apoptosis Via Endogenous Mcl-1.
Authors: Luo Hui , Cain Jennifer A. , Molitoris AnnaLynn , Opferman Joseph , Tomasson Michael H. 
Published: April 2020

Abstract
Ectopic expression of Myc in most primary cell types induces apoptosis, and cancer development typically requires additional, anti-apoptotic mutations. We reported previously that ectopic expression of Myc in unfractionated murine bone marrow cells induced rapid onset acute myeloid leukemia (AML) without detectable anti-apoptotic mutations. We hypothesized that AML developed in our model because a subset of normal primary bone marrow cells were inherently resistant to Myc-induced apoptosis. Consistent with this model, seven days of Myc activation in the bone marrow of mice caused the reduction of B-lineage cells while at the same time inducing the expansion of myeloid lineage cells. We sought to determine the mechanism by which myeloid progenitor cells evaded Myc-induced apoptosis, and found that Myc-induced AML cells exhibited a distinct profile of pro- and anti-apoptotic proteins, including high levels of the anti-apoptotic Bcl-2 family member Mcl-1. To prioritize apoptosis genes, we examined AML patient microarray data and found MCL1 to be uniformly expressed at high levels in human AML (94/94, 100%). We used Mcl1 heterozygous mice (Mcl1F/null) as bone marrow donors for transduction-transplantation experiments and found that, compared with Mcl1 wild-type (median survival=60 days), haploinsufficiency for Mcl1 completely protected mice from Myc-induced AML (median survival not reached). Mice transplanted with Mcl1F/null cells co-expressing Myc and Bcl2 succumbed rapidly to disease (median survival 25 days). In wild-type mice, defined hematopoietic stem and myeloid progenitor cell populations were not significantly increased by Myc activation. However, Myc transduction conferred serial replating ability to sorted hematopoietic stem and progenitor cells including lineage-committed (Lin+Kit+) progenitors cells. These data demonstrate a critical role for Mcl1 in our AML model and suggest that dysregulation of MYC in MCL1-expressing progenitor cells may mediate AML pathogenesis in humans.
HOX Genes - Candidate Tumor Suppressor Genes in Adult and Childhood Leukemia.
Authors: Strathdee Gordon R. , Holyoake Tessa L. , Sim Alyson , Parker Anton , Oscier David G. , Melo Junia V. , Meyer Stefan , Eden Tim , Dickinson Anne M. , Mountford Joanne , Jorgensen Heather G. , Soutar Richard , Brown Robert 
Published: April 2020

Abstract
The role of the HOX gene family in leukemia development has been extensively studied. However, these studies have focused almost exclusively on the potential oncogenic role of HOX gene family members. In contrast to the oncogenic function often attributed to HOX genes, our studies have identified several HOX gene family members as candidate tumor suppressor genes and shown that inactivation of HOX genes, particularly HOXA4, is associated with poor prognosis. We have used multiple quantitative methylation assays to search for epigenetic inactivation of HOX genes in adult and childhood leukemia. In both adult myeloid and lymphoid leukemia two members of the HOXA cluster (HOXA4 and A5) were found to be frequently inactivated by promoter hypermethylation (26–64% of cases were hypermethylated). In contrast, a further 12 HOXA, B and C cluster genes were found to be essentially devoid of hypermethylation (except HOXA6 in CLL, where 34% of samples exhibited hypermethylation). HOXA4 and HOXA5 were also frequently inactivated in childhood ALL and AML (39–79% of samples). However, in contrast to the adult leukemias, all but one of the additional HOX genes analyzed were also found to be targets for hypermethylation in both ALL and AML (4–26% of samples), suggesting that HOX genes are differentially regulated in childhood versus adult leukemia. Hypermethylation of HOX genes (HOXA4, HOXA5 and HOXA6) was associated with loss of expression of the corresponding gene. Expression analysis also suggests that interaction between different HOX genes may be crucial. In normal karyotype AML samples, those expressing of high levels of HOXA9, but not those with low HOXA9 expression, were associated with invariable HOXA4 hypermethylation (p=0.01). Interestingly HOXA4 hypermethylation also correlates with poor prognosis in all types of leukemia tested. Hypermethylation of HOXA4 correlates with progression to blast crisis (p=0.007) and poor response to imatinib in CML (p=0.04), with cytogenetic status in AML (33%, 72% and 100% in good, intermediate and poor prognostic groups respectively, p=0.0004) and with IgVh mutational status (p=0.003) and poor survival in CLL (median survival 159 versus 199 months in hypermethylated and non hypermethylated patients, respectively). Furthermore transfection of a HOXA4 expressing construct into a CML blast crisis cell line results in re-expression of markers of myeloid differentiation, suggesting that loss of HOXA4 is functionally relevant in leukemic cells. These results indicate that aberrant epigenetic regulation of HOXA4, and indeed other frequently inactivated HOX genes such as HOXA5 and HOXA6, may play a key role in the development of multiple types of leukemia. Thus co-ordinated up and down regulation of expression of HOX gene family members may be crucial in the leukemogenic process.
CDC4 and NOTCH1 Mutations in Childhood T-Cell Acute Lymphoblastic Leukemia and T Cell Non-Hodgkin’s Lymphoma; a Japan Association of Childhood Leukemia Study Group.
Authors: Park Myoung-ja , Taki Tomohiko , Suzuki Nobuhiro , Oda Megumi , Yagi Keiko , Kobayashi Ryoji , Hara Juniti , Horize Keizo , Hayashi Yasuhide 
Published: April 2020

Abstract
Risk-adapted therapy has resulted in a improvement of outcome in childhood acute lymphoblastic leukemia (ALL), however, T-cell ALL (T-ALL) have still relatively poor outcome compared to B-precursor ALL. Although activating mutations of the NOTCH1 gene have been reported in more than half of T-ALL, the prognostic significance of this finding has yet to be determined. CDC4 gene was isolated as a negative regulator of NOTCH1 and mutations were detected in T-ALL cell line and other cancers. We performed mutation analysis of the NOTCH1 and CDC4 gene in 14 T-ALL cell lines, 52 T-ALL and 17 T cell non-Hodgkin’s lymphoma (T-NHL) fresh samples. All children with T-ALL and T-NHL were treated on Japan Association of Childhood Leukemia Study (JACLS) ALL-97 and NHL-98 protocol after obtaining informed consent. Mutation detection was performed via PCR based denaturing HPLC followed by direct sequence.Mutations of the NOTCH1 were identified in 10 (71.4%) of 14 T-ALL cell lines, 16 (30.8%) of 52 T-ALL and 6 (35.3%) of 17 T-NHL fresh samples. Twelve mutations in heterodimerization domain (HD) and 12 mutations in PEST domain (PD) were found in 69 fresh samples. The incidence of the NOTCH1 mutation is less frequent than that of previous reports. We found CDC4 mutations in 12 (35.3%) of 52 T-ALL and 2 (11.8%) of 17 T-NHL fresh samples. One insertion mutation in exon 3 and 11 missense mutations were detected in CDC4 gene. Both NOTCH1 and CDC4 mutations were found in 7 patients. Interestingly, the NOTCH1 mutations were only observed in T-ALL and T-NHL patients without relapse, suggesting to be associated with favorable prognosis. However, CDC4 gene was found not to be associated with prognosis.
Use of Chromosome Engineering To Model a Leukemia-Associated 7q22 Deletion in the Mouse.
Authors: Wong Jasmine C. , Zhang Yan , Tran Marie T. , Lieuw Kenneth H. , Wolff Linda , Killeen Nigel , Shannon Kevin 
Published: April 2020

Abstract
Identifying tumor suppressor genes from intervals that are deleted in human hematologic malignancies such as 5q, 7q, 9q, and 20q has proven extremely challenging, and several laboratories have implicated haploinsufficiency as a likely mechanism. Chromosome engineering, which involves performing sequential rounds of gene targeting to insert loxP sites at flanking loci in mouse embryonic stem (ES) cells and using Cre recombination to delete the intervening sequences, was recently used to successfully interrogate the 1p36 interval in human solid tumors (Cell128(3):459–75, 2007). Monosomy 7 and deletion 7q [del(7q)] are among the most common cytogenetic alterations found in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Cytogenetic analysis of patients who developed myeloid disorders with del(7q) uncovered a 2.5 Mb commonly deleted segment (CDS) within 7q22 (Blood88(6):1930–5, 1996), suggesting that this region plays an important role in leukemogenesis. To investigate the in vivo consequences of somatic loss of this interval, we generated a 5A3flox mouse model that harbor loxP sites flanking a ∼2 Mb interval on mouse chromosome 5A3 that is syntenic to the human 7q22 CDS. We intercrossed these mice with the interferon inducible Mx1-Cre transgenic strain, and injected these mice with polyinosinic-polycytidylic acid (pIpC) to delete the region in the hematopoietic compartment. The desired recombination is relatively inefficient; however, hematopoietic cells with loss of this region persist in the stem/progenitor compartment for over 1 year and are transplantable. We neither observed a block in differentiation nor clonal outgrowth of mutant hematopoietic cells, suggesting that additional mutations are necessary to initiate leukemia. We initiated AML in these mice by introducing additional genetic lesions using retroviral insertional mutagenesis, and we are characterizing these leukemias to study the effects of the 5A3 deletion on leukemogenesis and to clone cooperating genes. Chromosome engineering is a robust strategy for modeling leukemia-associated deletions in vivo, and for interrogating how loss of a specific interval alters hematopoietic growth. We are using the 5A3 strain to analyze candidate myeloid tumor suppressor genes from chromosome 7q and to uncover genes and pathways that cooperate in leukemogenesis.
Transcriptional Regulation of Hepcidin by Iron.
Authors: Lee Pauline , Jaroslav Truksa , Peng Hongfan , Beutler Ernest 
Published: April 2020

Abstract
Transcriptional regulation by iron in mammalian systems is poorly understood. Hepcidin, a 25 amino acid peptide that plays a central role in iron homeostasis, is transcriptionally regulated by iron. A region of the murine hepcidin promoter 1.6 to 1.8 kb upstream from the start of translation was recently identified to be important in transcriptional regulation by iron (Truksa J, et al. The distal location of the iron responsive region of the hepcidin promoter. Blood DOI 10.1182/blood-2007-05-091108, 2007). In order to identify transcription factors that might be important in regulation by iron, transcription factor microarray analyses (Panomics TranSignal Protein/DNA Array) were performed with nuclear extracts from livers of mice made iron deficient or iron loaded for 4 weeks. The analyses revealed 43 transcription factors that were upregulated in iron loaded liver nuclear extracts and 39 transcription factors that were upregulated in iron deficient nuclear extracts. In the region of the promoter we had found essential for transcriptional regulation by iron, −1.6 to −1.8 kb, consensus motifs were identified by Genomatix MatInspector for 10 transcription factors that corresponded to transcription factors upregulated in high iron nuclear extracts by array analyses. Similarly, the consensus sequences for 5 transcription factors corresponded to transcription factors identified in iron deficient nuclear extracts. Electrophoretic mobility shift assays were performed with probes across this region of the murine hepcidin promoter. Several probes exhibited differential binding between deficient and high iron nuclear extracts. These include the probe encompassing the CCAAT box and MEL1 motif, a probe containing a HLH motif, and a probe containing a bZIP and COUP motif. The probe containing the CCAAT motif was supershifted with antibodies against CBF, but was not supershifted with antibodies against SMAD4, CEBPα, and COUP. The probe containing a bZIP and COUP motif can be supershifted with antibodies against COUP-Tf and HNF4α, but not with antibodies against SMAD4, CEBPα, and COUP. Our data suggest that CBFA, COUP, and HNF4α are involved in transcriptional regulation of hepcidin by iron.
Liver Iron Measurement by SQUID Biosusceptometry Compared to Liver Biopsy: A More Accurate Definition of Optimal Iron Range.
Authors: Pakbaz Zahra , Fischer Roland , Vichinsky Elliott , Fagaly Robert L. , Paulson Douglas , Pratt Kevin , Butz 5 John , Foote Drucilla , Quirolo Keith , Harmatz Paul 
Published: April 2020

Abstract
The “Optimal Liver Iron” range in iron overloaded patients with thalassemia has been established by Olivieri and Brittenham (Blood, 1997) as 1–2.2 mg/g wet weight liver using direct measurement or calculated as 3.2 to 7 mg/g dry liver weight based on a 3.33 correction factor for body water. This report describes the relationship between liver iron concentration (LIC) measured by SQUID biosusceptometry (BLS, wet weight) compared to liver biopsy (dry weight), in patients with thalassemia (THAL) or sickle cell disease (SCD). A total of 38 chronically transfused patients (THAL n=19, SCD n=19) were prospectively assessed for LIC measured by BLS and liver biopsy within 2 month of each other. Most BLS results were submitted to data repository before receiving iron concentration from liver biopsy. LIC was measured by a low temperature SQUID biosusceptometer system (Ferritometer®) under the standardized Hamburg-Torino-Oakland protocol. Iron in fresh tissue and paraffin embedded liver biopsy samples was measured at Mayo clinics by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Subjects ranged in age from 5 to 40 years (median: 18 y). Median LIC (n=38) measured by SQUID was 1777 (365–4883) [mg/g wet weight], median LIC by biopsy (fresh tissue) was 10861(1854–32864) [mg/g dry weight]. After excluding the subjects with BMI&gt;30 kg/m2 (n=5), the Spearman rank correlation between wet weight LIC assessed by BLS and dry weight LIC from fresh tissue sample measured by ICP-MS was highly significant (RS=0.90, p&lt;0.0001). No significant difference between fresh tissue and paraffin embedded LIC values was observed. The agreement between BLS and fresh tissue biopsy was tested by Bland-Altman plots. After normalization, no significant proportional or zero bias was visible. The 95% limits of agreement between SQUID-BLS and biopsy LIC values were found between −56% (or –6733 μg/g) and 48% (or 7027 μg/g). This kind of agreement is similar to the results achieved with MRI-R2 by St. Pierre et al (Blood, 2005)(–56% and 50%), however, BLS is a totally independent method relying only on the specific magnetic susceptibility of the hemosiderin-ferritin iron complex. The conversion factor between the two methods (LIC by fresh tissue biopsy vs. LIC by BLS) obtained from a weighted linear regression with zero intercept (Marquardt algorithm) was 6.1 ± 0.3 (R2 = 0.86–0.88, cn2 = 2.3–2.6). Using this conversion factor, the recommended “optimal range” for liver iron in patients with thalassemia major should be considered as 6–13.2 mg/g dry weight liver rather than the generally accepted 3.2–7 mg/g dry weight liver.
Identification of a Protein S-Interactive Site on the Factor VIII A2 Domain.
Authors: Takeyama Masahiro , Nogami Keiji , Soeda Tetsuhiro , Yoshioka Akira , Shima Midori 
Published: April 2020

Abstract
Protein S functions as a cofactor of activated protein C that inactivates factor VIII(a) and factor V(a). We recently have reported a new regulatory mechanism that protein S interacted with both the A2 and A3 domains in factor VIII, and consequently this cofactor directly impaired the factor Xase complex by competing the interaction of factor IXa to factor VIIIa (Blood2006; 108, 487a). Since factor IXa blocked the binding of A2 subunit to protein S, we attempted several approaches to localize the protein S-interactive site(s) on the factor VIII A2 domain. An anti-A2 monoclonal antibody (mAb413) with the 484–509 epitope, recognizing a factor IXa-interactive site on the A2, inhibited the A2 binding to immobilized protein S up to approximately 90% in a dose-dependent manner in a surface plasmon resonance-based assay. Furthermore, ELISA-based assay showed that a synthetic peptide corresponding to residues 484–509 directly bound to protein S dose-dependently. Covalent cross-linking was observed between the 484–509 peptide and protein S following reaction with EDC (1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide) using SDS-PAGE. The cross-linked product formed with EDC was consistent with 1:1 stoichiometry of reactants, suggesting specificity in the 484–509 peptide and protein S interaction. This cross-linking formation was blocked by the addition of the 484–497 peptide, whilst not by the 498–509 peptide, supporting the presence of protein S-interactive site within residues 484–497. Furthermore, N-terminal sequence analysis of the 484–509 peptide-protein S product showed that three sequential basic residues (S488, R489 and R490) could not be detected, supporting that three residues participate in cross-link formation. To confirm the significance of these residues in A2 domain for protein S-binding, the mutant forms of the A2 domain, converted to alanine, were expressed in baculovirus system and purified. Compared with wild type A2 (Kd: ∼9 nM), each binding affinity of S488A, R489A, or R490A A2 mutant for protein S was decreased by 4∼5-fold (32, 40 and 40 nM, respectively). These results indicate that the 484–509 region in the factor VIII A2 domain, and in particular a cluster of basic amino acids at residues 488–490, contributes to a unique protein S-interactive site.
Immunogenicity of Factor VIII: Is Clotting the “Danger” Signal?.
Authors: Skupsky Jonathan , Scott David W. 
Published: April 2020

Abstract
It is well established that mice lacking factor VIII (E16 or fVIII−/−) respond to intravenous (i.v.) or intraperitoneal (i.p.) injections of therapeutic doses of human fVIII in PBS. This leads to both T-cell priming for cytokine production and inhibitor formation against fVIII with specificity similar to that of hemophilia A patients (Pratt et al., 2004). The lack of tolerance to murine fVIII may be important in the ability of fVIII−/− mice to respond to human fVIII. Nonetheless, the ability to respond effectively in the absence of extrinsic adjuvant begs the question of what is the “danger signal” required for immune responsiveness to fVIII. Even more surprising is the fact that mice with normal hemostasis respond to therapeutic doses of human fVIII given intravenously (i.v.), a normally tolerogenic route (Lin, Soukhareva, and Scott, ASH 2004). We proposed to investigate whether fVIII has any intrinsic adjuvanticity. Preliminary experiments failed to support the notion that fVIII was a polyclonal B cell activator or could stimulate up regulation of MHC class II or co-stimulatory molecules in vitro or in vivo. We hypothesized that the immunogenicity of fVIII is due to its ability to initiate clotting and that this cascade leads to local co-stimulatory events. To test this, fVIII−/− (C57Bl/6 background) or normal Balb/c mice were injected with either native (N) fVIII or heat inactivated (HI) fVIII (56o, 30′). This heat inactivation method was verified to destroy biologic activity of fVIII in chromogenic assays. After five injections, the antibody response elicited by NfVIII was three- to fourfold higher than that elicited by HIfVIII. ELISA assays with monoclonal antibodies against different fVIII domains (a gift of Dr. Pete Lollar) indicated a partial loss of binding to conformational B cell epitopes in HIfVIII. T cell proliferation to both preparations of fVIII demonstrated conservation of T cell epitopes. Importantly, the T cell response to fVIII was dramatically reduced in the group immunized with HIfVIII. These results suggest that the ability of fVIII to initiate a localized clotting event plays a critical role in the immunogenicity of fVIII.
(Supported by NIH grants R01 HL061883 and T32 HL07698).
Dasatinib Inhibits the Growth of Neoplastic Human Eosinophils (EOL-1) through Targeting of FIP1L1-PDGFRα.
Authors: Baumgartner Christian , Gleixner Karoline V. , Gruze Alexander , Samorapoompichit Puchit , Esterbauer Harald , Pickl Winfried F. , Sillaber Christian , Valent Peter 
Published: April 2020

Abstract
Chronic eosinophilic leukemia (CEL) is a myeloproliferative disorder characterized by molecular and/or cytogenetic evidence of monoclonality of eosinophils, sustained marked eosinophilia, and consecutive organ damage. In a majority of patients with CEL with or without associated mastocytosis, the transforming mutation FIP1L1-PDGFRα and the related CHIC2 deletion is found. The respective oncoprotein, FIP1L1-PDGFRα, is considered to play a major role in malignant cell growth in CEL. The tyrosine kinase (TK) inhibitor imatinib (STI571) has been described to counteract the TK activity of FIP1L1-PDGFRα in most patients, and has been introduced as a novel effective therapy in CEL. However, not all patients with CEL show a response to imatinib. Therefore, several attempts have been made to identify other TK inhibitors that counteract growth of neoplastic eosinophils in CEL. We provide evidence that dasatinib, a multi-targeted kinase inhibitor, blocks the growth and survival of EOL-1, an eosinophil leukemia cell line carrying FIP1L1-PDGFRα. The effects of dasatinib on proliferation of EOL-1 cells were dose-dependent, with an IC50 of 0.5–1 nM, that was found to be in the same range compared to IC50 values produced by imatinib. Dasatinib was also found to induce apoptosis in EOL-1 cells in a dose-dependent manner (IC-50: 1–10 nM). The apoptosis-inducing effects of dasatinib on EOL-1 cells were demonstrable by light microscopy, flow cytometry, and by a Tunel assay. To further examine the mechanism of growth inhibition induced by dasatinib in neoplastic eosinophils, Western blot experiments were performed using antibodies directed against phosphorylated or total PDGFRα. In these experiments, we were able to show that dasatinib at 1 μM completely blocks the phosphorylation of FIP1L1-PDGFRα in EOL-1 cells. In summary, our data show that dasatinib inhibits the growth of leukemic eosinophils through targeting of the TK activity of the disease-related oncoprotein FIP1L1-PDGFRα. Based on this observation, dasatinib may be considered as a new interesting treatment option for patients with CEL. As dasatinib is also known to block various KIT mutants as well as wild type KIT, such therapy may also be of interest for patients who have systemic mastocytosis (SM) with an associated CEL (SM-CEL).