Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s12185-024-03751-x

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Other Link： https://link.springer.com/article/10.1007/s12185-024-03751-x/fulltext.html

Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Abstract

Despite recent advances in the treatment of acute myeloid leukemia (AML), there has been limited success in targeting surface antigens in AML, in part due to shared expression across malignant and normal cells. Here, high-density immunophenotyping of AML coupled with proteogenomics identified unique expression of a variety of antigens, including the RNA helicase U5 snRNP200, on the surface of AML cells but not on normal hematopoietic precursors and skewed Fc receptor distribution in the AML immune microenvironment. Cell membrane localization of U5 snRNP200 was linked to surface expression of the Fcγ receptor IIIA (FcγIIIA, also known as CD32A) and correlated with expression of interferon-regulated immune response genes. Anti-U5 snRNP200 antibodies engaging activating Fcγ receptors were efficacious across immunocompetent AML models and were augmented by combination with azacitidine. These data provide a roadmap of AML-associated antigens with Fc receptor distribution in AML and highlight the potential for targeting the AML cell surface using Fc-optimized therapeutics.

DOI： 10.1038/s43018-023-00656-2

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Other Link： https://www.nature.com/articles/s43018-023-00656-2

Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

Abstract

O-linked N-acetylglucosamine transferase (OGT) critically regulates wide variety of biological processes such as gene expression, metabolism, stress response, signaling and proteostasis. In adult hematopoiesis, OGT is crucial for differentiation of B and T cells and the maintenance of hematopoietic stem cells (HSCs). However, a role for OGT in fetal liver (FL) hematopoiesis remains unknown. To investigate a role for OGT in FL hematopoiesis, we conditionally disrupted OGT in hematopoietic cells in developing FLs. Hematopoietic specific disruption of OGT resulted in embryonic lethality in late stage of gestation due to severe anemia and growth retardation. OGT loss led to profound reduction of differentiating erythroid cells and erythroid progenitors in FLs due to massive apoptosis. In addition, clonogenic capacity of FL cells was severely impaired by OGT loss. Interestingly, expression of BCL-XL, a well-known inhibitor of apoptosis in FL cells, dramatically decreased, and the levels of reactive oxygen species (ROS) were increased in OGT-deficient FL cells. Overexpression of Bcl-xL and reduction of ROS significantly restored the colony formation of OGT-deficient FL cells. This study revealed a novel role for OGT during embryogenesis, which ensures survival of FL hematopoietic cells partly by regulating Bcl-xL and oxidative phosphorylation.

DOI： 10.1093/stmcls/sxad076

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a new disease entity with autoinflammatory disorders (AID) driven by somatic variants in UBA1 that frequently co-exists with myelodysplastic syndromes (MDS). Clinicopathological and molecular features of Japanese cases with VEXAS-associated MDS remain elusive. We previously reported high prevalence of UBA1 variants in Japanese patients with relapsing polychondritis, in which 5 cases co-occurred with MDS. Here, we report clinicopathological and variant profiles of these 5 cases and 2 additional cases of MDS associated with VEXAS syndrome. Clinical characteristics of these cases included high prevalence of macrocytic anemia with marked cytoplasmic vacuoles in myeloid/erythroid precursors and low bone marrow (BM) blast percentages. All cases were classified as low or very low risk by the revised international prognostic scoring system (IPSS-R). Notably, 4 out of 7 cases showed significant improvement of anemia by treatment with prednisolone (PSL) or cyclosporin A (CsA), suggesting that an underlying inflammatory milieu induced by VEXAS syndrome may aggravate macrocytic anemia in VEXAS-associated MDS. Targeted deep sequencing of blood samples suggested that MDS associated with VEXAS syndrome tends to involve a smaller number of genes and lower risk genetic lesions than classical MDS.

DOI： 10.1007/s12185-023-03598-8

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Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Immune checkpoint inhibitors (ICIs) have been a breakthrough in cancer therapy. ICI therapy is generally better tolerated than cytotoxic chemotherapy; however, hematological adverse events (AEs) have not been fully analyzed. Hence, we performed a meta-analysis to evaluate the incidence and risk of ICI-related hematological AEs. METHODS: A systematic literature search was performed using PubMed, EMBASE, Cochrane Library, and the Web of Science Core Collection. Phase III randomized controlled trials (RCTs) involving ICI combination regimens were selected. The experimental group received ICIs with systemic treatment, and the control group received only the same systemic treatment. Odds ratios (ORs) for anemia, neutropenia, and thrombocytopenia were calculated using a random-model meta-analysis. RESULTS: We identified 29 RCTs with 20,033 patients. The estimated incidence rates for anemia of all grades and grades III-V were 36.5% (95% confidence interval (CI) 30.23 - 42.75) and 4.1% (95% CI 3.85 - 4.42), respectively. The incidence of neutropenia (all grades 29.7%, grades III-V 5.3%) and thrombocytopenia (all grades 18.0%, grades III-V 1.6%) was also calculated. CONCLUSION: Treatment with ICIs seemed unlikely to increase the incidence of anemia, neutropenia, and thrombocytopenia in all grades. However, programmed cell death-1 receptor ligand inhibitors significantly increased the risk of grades III-V thrombocytopenia (OR 1.53; 95% CI 1.11 - 2.11). Further research is needed to examine the potential risk factors.

DOI： 10.14740/jh1090

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Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

DOI： 10.1080/16078454.2022.2052601

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Society of Hematology  

Detailed genomic and epigenomic analyses of MECOM (the MDS1 and EVI1 complex locus) have revealed that inversion or translocation of chromosome 3 drive inv(3)/t(3;3) myeloid leukemias via structural rearrangement of an enhancer which upregulates transcription of EVI1. Here we identify a novel, previously unannotated oncogenic RNA-splicing derived isoform of EVI1 which is frequently present in inv(3)/t(3;3) AML and directly contributes to leukemic transformation. This EVI1 isoform is generated by oncogenic mutations in the core RNA splicing factor SF3B1, which is mutated in >30% of inv(3)/t(3;3) myeloid neoplasm patients and thereby represents the single most commonly co-occurring genomic alteration in inv(3)/t(3;3) patients. SF3B1 mutations are statistically uniquely enriched in inv(3)/t(3;3) myeloid neoplasm patients and patient-derived cell lines compared with other forms of AML and promote mis-splicing of EVI1 generating an in-frame insertion of six amino acids at the 3' end of the second Zinc finger domain of EVI1. Expression of this EVI1 splice variant enhanced the self-renewal of hematopoietic stem cells and introduction of mutant SF3B1 in mice bearing the humanized inv(3)(q21q26) allele resulted in generation of this novel EVI1 isoform in mice and hastened leukemogenesis in vivo. The mutant SF3B1 spliceosome depends upon an exonic splicing enhancer within EVI1 exon 13 to promote usage of a cryptic branch point and aberrant 3' splice site within intron 12 resulting in the generation of this isoform. These data provide a mechanistic basis for the frequent co-occurrence of SF3B1 mutations as well as new insights into the pathogenesis of myeloid leukemias harboring inv(3)/t(3;3).

DOI： 10.1182/blood.2021015325

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Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

We conducted population pharmacokinetic (PPK) analysis and Monte Carlo simulations to determine the appropriate prophylactic dose of fluconazole to prevent invasive candidiasis in patients with hematological malignancies. Patients receiving chemotherapy or hematopoietic stem cell transplantation at Yokohama City University Hospital between November 2018 and March 2020 were included. Additionally, patients receiving oral fluconazole for prophylaxis were recruited. We set the free area under the curve/minimum inhibitory concentration (MIC) = 50 as the target and determined the largest MIC (breakpoint MIC) that could achieve more than 90% probability of target attainment. The blood fluconazole concentration of 54 patients (119 points) was used for PPK analysis. The optimal model was the one-compartment model with first-order administration and first-order elimination incorporating creatinine clearance (CLcr) as a covariate of clearance and body weight as a covariate of distribution volume. We conducted Monte Carlo simulation with fluconazole at 200 mg/day or 400 mg/day dosing schedules and patient body weight and CLcr ranging from 40 to 70 kg and 40–140 mL/min, respectively. The breakpoint MICs on the first dosing day and at steady state were 0.5–1.0 μg/mL and 1.0–2.0 μg/mL for 200 mg/day and 1.0–2.0 μg/mL and 2.0–4.0 μg/mL for 400 mg/day, respectively. The recommended dose was 400–700 mg/day for the loading dose and 200–400 mg/day for the maintenance dose. Our findings suggest that the optimal prophylactic dose of fluconazole in hematological malignancy patients depends on CLcr and body weight, and a sufficient loading and maintenance dose may be needed to completely prevent invasive candidiasis.

DOI： 10.3390/jof7110975

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Language：English   Publishing type：Research paper (scientific journal)  

O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) is a unique enzyme introducing O-GlcNAc moiety on target proteins, and it critically regulates various cellular processes in diverse cell types. However, its roles in hematopoietic stem and progenitor cells (HSPCs) remain elusive. Here, using Ogt conditional knockout mice, we show that OGT is essential for HSPCs. Ogt is highly expressed in HSPCs, and its disruption induces rapid loss of HSPCs with increased reactive oxygen species and apoptosis. In particular, Ogt-deficient hematopoietic stem cells (HSCs) lose quiescence, cannot be maintained in vivo, and become vulnerable to regenerative and competitive stress. Interestingly, Ogt-deficient HSCs accumulate defective mitochondria due to impaired mitophagy with decreased key mitophagy regulator, Pink1, through dysregulation of H3K4me3. Furthermore, overexpression of PINK1 restores mitophagy and the number of Ogt-deficient HSCs. Collectively, our results reveal that OGT critically regulates maintenance and stress response of HSCs by ensuring mitochondrial quality through PINK1-dependent mitophagy.

DOI： 10.1016/j.celrep.2020.108579

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

Recent genomics studies have revealed that clonal hematopoietic expansion due to recurrent somatic mutations in hematopoietic cells are common in older people without evidence of hematological malignancies. This phenomenon, termed clonal hematopoiesis of indeterminate potential (CHIP), is associated with greater risk for hematological malignancy and cardiovascular diseases, leading to decreased overall survival of the affected individuals. The most frequently mutated genes in CHIP cases include genes associated with epigenetic modification, cell signaling, DNA damage response and RNA splicing, which are all recurrently mutated in myeloid malignancies. Recent findings suggest that these genetic alleles exert pleiotropic effects on hematopoietic stem cell (HSC) functions, transcriptional regulations, DNA damage responses and resistance to cellular stresses. Recent studies have uncovered the clinical relevance of CHIP in various settings during the management of hematological malignancies. Elucidating overall picture of clonal evolution based on CHIP will help developing preventive measures and novel treatments for hematological malignancies.

DOI： 10.1016/j.leukres.2020.106457

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Regulation of genome-wide DNA methylation is fundamental for a variety of biological processes such as mammalian development, stem cell function, cellular proliferation/differentiation, and oncogenesis. Among the regulators of DNA methylation, ten-eleven translocation 2 (TET2) is one of the most frequently mutated genes in clonal hematopoiesis of indeterminate potential and in various hematological malignancies, underscoring a pivotal role for TET2 in blood homeostasis and hematopoietic transformation. TET2 oxidizes methylated cytosines to further modify cytosines, which behave as intermediates in active/passive DNA demethylation processes. TET2 itself associates with histone modifiers, thereby regulating histone modifications and expression of target genes. A number of studies have reported pleiotropic effects of TET2 on hematopoietic stem cell self-renewal, hematopoietic differentiation, genome instability and inflammatory response. Recent single-cell genomics studies have identified gene promoters as well as transcription factor binding sites as TET2-targeted genetic loci in which disruption of DNA methylation can fundamentally modify hematopoietic differentiation and promote leukemogenesis. TET2 mutations show convergent cooperativity with other disease alleles in signaling molecules, epigenetic modifiers, and spliceosome factors in hematopoietic transformation. Future studies focusing on the molecular basis of stem cell and immune regulation by TET2 loss will further deepen our understanding of the entire landscape of pathophysiology and molecular vulnerabilities of TET2-mutated hematological malignancies.

DOI： 10.1111/cas.14688

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Ovid Technologies (Wolters Kluwer Health)  

Acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) with both inv(3)(q21q26.2)/t(3;3)(q21;q26.2) and monosomy 7 defines an extremely aggressive myeloid cancer whose molecular pathogenesis and optimal therapeutic strategy still remain unclear. We established a new MDS/AML cell line, YCU-AML1, and its patient-derived xenograft (PDX) model from a high-risk MDS patient who later transformed into AML harboring both t(3;3)(q21;q26.2) and monosomy 7. YCU-AML1 cells propagated in co-culture system with stromal cells in granulocyte macrophage colony-stimulating factor (GM-CSF)-dependent manner. CD34+ bone marrow cells derived from our PDX model showed high EVI1 and low GATA2 expression. Moreover, mutational profile of our MDS/AML model was consistent with recently published mutational spectrum of myeloid malignancies with inv(3)/t(3;3). These data suggest that YCU-AML1 cells and its MDS/AML model strongly mimics a high-risk human myeloid cancer with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) and monosomy 7 in terms of both clinical phenotype and molecular basis. We believe our model can be used as a feasible tool to further explore molecular pathogenesis and novel treatment strategy of high-risk MDS/AML with t(3;3)(q21;q26.2) and monosomy 7.

DOI： 10.1097/hs9.0000000000000469

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.ccell.2017.11.012

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Publishing type：Research paper (scientific journal)   Publisher：American Association for Cancer Research (AACR)  

DOI： 10.1158/2159-8290.cd-16-1032

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Recent genetic analyses have revealed that premalignant somatic mutations in hematopoietic cells are common in older people without an evidence of hematologic malignancies, leading to clonal hematopoietic expansion. This phenomenon has been termed clonal hematopoiesis of indeterminate potential (CHIP). Frequency of such clonal somatic mutations increases with age: in 5-10% of people older than 70 years and around 20% of people older than 90 years. The most commonly mutated genes found in individuals with CHIP were epigenetic regulators, including DNA methyltransferase 3A (DNMT3A), Ten-eleven-translocation 2 (TET2), and Additional sex combs-like 1 (ASXL1), which are also recurrently mutated in myeloid malignancies. Recent functional studies have uncovered pleiotropic effect of mutations in DNMT3A, TET2, and ASXL1 in hematopoietic stem cell regulation and leukemic transformation. Of note, CHIP is associated with an increased risk of hematologic malignancy and all-cause mortality, albeit the annual risk of leukemic transformation was relatively low (0.5-1%). These findings suggest that clonal hematopoiesis per se may not be sufficient to engender preleukemic state. Further studies are required to decipher the exact mechanism by which preleukemic stem cells originate and transform into a full-blown leukemic state.

DOI： 10.1007/s12185-017-2257-6

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Other Link： http://link.springer.com/content/pdf/10.1007/s12185-017-2257-6.pdf

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：American Society of Hematology  

<title>Key Points</title>
Aid loss leads to altered differentiation, transcription, and methylation in specific genetic loci in hematopoietic stem/progenitor cells. Aid loss does not contribute to enhanced HSC self-renewal or cooperate with Flt3-ITD in myeloid leukemogenesis.

DOI： 10.1182/blood-2016-06-721977

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1038/bcj.2015.81

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Other Link： http://www.nature.com/articles/bcj201581

Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Somatic mutation of RUNX1 is implicated in various hematological malignancies, including myelodysplastic syndrome and acute myeloid leukemia (AML), and previous studies using mouse models disclosed its critical roles in hematopoiesis. However, the role of RUNX1 in human hematopoiesis has never been tested in experimental settings. Familial platelet disorder (FPD)/AML is an autosomal dominant disorder caused by germline mutation of RUNX1, marked by thrombocytopenia and propensity to acute leukemia. To investigate the physiological function of RUNX1 in human hematopoiesis and pathophysiology of FPD/AML, we derived induced pluripotent stem cells (iPSCs) from three distinct FPD/AML pedigrees (FPD-iPSCs) and examined their defects in hematopoietic differentiation. By in vitro differentiation assays, FPD-iPSCs were clearly defective in the emergence of hematopoietic progenitors and differentiation of megakaryocytes, and overexpression of wild-type (WT)-RUNX1 reversed most of these phenotypes. We further demonstrated that overexpression of mutant-RUNX1 in WT-iPSCs did not recapitulate the phenotype of FPD-iPSCs, showing that the mutations were of loss-of-function type. Taken together, this study demonstrated that haploinsufficient RUNX1 allele imposed cell-intrinsic defects on hematopoietic differentiation in human experimental settings and revealed differential impacts of RUNX1 dosage on human and murine megakaryopoiesis. FPD-iPSCs will be a useful tool to investigate mutant RUNX1-mediated molecular processes in hematopoiesis and leukemogenesis.

DOI： 10.1038/leu.2014.136

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Other Link： http://www.nature.com/articles/leu2014136

Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DNA methylation is one of the critical epigenetic modifications regulating various cellular processes such as differentiation or proliferation, and its dysregulation leads to disordered stem cell function or cellular transformation. The ten-eleven translocation (TET) gene family, initially found as a chromosomal translocation partner in leukemia, turned out to be a key enzyme for DNA demethylation. TET genes hydroxylate 5-methylcytosine to 5-hydroxymethylcytosine, which is then converted to unmodified cytosine through multiple mechanisms. Somatic mutations of the TET2 gene were reported in a variety of human hematological malignancies such as leukemia, myelodysplastic syndrome, and malignant lymphoma, suggesting a critical role for TET2 in hematopoiesis. The importance of the TET-mediated cytosine demethylation pathway is also underscored by a recurrent mutation of isocitrate dehydrogenase 1 (IDH1) and IDH2 in hematological malignancies, whose mutation inhibits TET function through a novel oncometabolite, 2-hydroxyglutarate. Studies using mouse models revealed that TET2 is critical for the function of hematopoietic stem cells, and disruption of TET2 results in the expansion of multipotent as well as myeloid progenitors, leading to the accumulation of premalignant clones. In addition to cytosine demethylation, TET proteins are involved in chromatin modifications and other cellular processes through the interaction with O-linked β-N-acetylglucosamine transferase. In summary, TET2 is a critical regulator for hematopoietic stem cell homeostasis whose functional impairment leads to hematological malignancies. Future studies will uncover the whole picture of epigenetic and signaling networks wired with TET2, which will help to develop ways to intervene in cellular pathways dysregulated by TET2 mutations.

DOI： 10.1111/cas.12484

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/cas.12484

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Society of Hematology  

DOI： 10.1182/blood-2014-01-552471

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Internal Medicine  

The classification of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has limitations because the condition includes disorders with similar general clinical features, similar characteristics of lung and renal involvement and a positive ANCA serology. A 40-year-old woman was admitted to our hospital for hemoptysis and dyspnea. She had no history of bronchial asthma. Laboratory examinations revealed hypereosinophilia, positive anti-myeloperoxidase antibodies, hematuria and proteinuria. The patient was ultimately diagnosed with AAV associated with diffuse alveolar hemorrhage, rapidly progressive glomerulonephritis and hypereosinophilia without bronchial asthma. Obtaining a definitive diagnosis of ANCA vasculitis can be very difficult, and the characteristics of this case were not compatible with the findings of typical AVV. We herein report a rare case of AVV.<br>

DOI： 10.2169/internalmedicine.52.0481

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Somatic mutation of ten-eleven translocation 2 (TET2) gene is frequently found in human myeloid malignancies. Recent reports showed that loss of Tet2 led to pleiotropic hematopoietic abnormalities including increased competitive repopulating capacity of bone marrow (BM) HSCs and myeloid transformation. However, precise impact of Tet2 loss on the function of fetal liver (FL) HSCs has not been examined. Here we show that disruption of Tet2 results in the expansion of Lin(-)Sca-1(+)c-Kit(+) (LSK) cells in FL. Furthermore, Tet2 loss led to enhanced self-renewal and long-term repopulating capacity of FL-HSCs in in vivo serial transplantation assay. Disruption of Tet2 in FL also led to altered differentiation of mature blood cells, expansion of common myeloid progenitors and increased resistance for hematopoietic progenitor cells (HPCs) to differentiation stimuli in vitro. These results demonstrate that Tet2 plays a critical role in homeostasis of HSCs and HPCs not only in the BM, but also in FL.

DOI： 10.1038/srep00273

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Other Link： http://www.nature.com/articles/srep00273.pdf

Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1111/j.1365-2516.2011.02650.x

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.bbmt.2011.06.008

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s00535-008-2165-x

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Other Link： http://link.springer.com/article/10.1007/s00535-008-2165-x/fulltext.html

Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER SOC HEMATOLOGY  

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：AMER SOC HEMATOLOGY  

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Language：Japanese  

CiNii Books

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Other Link： http://search.jamas.or.jp/link/ui/2011073629

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