Publications by authors named "Hisamaru Hirai"

98 Publications

Gain-of-function of mutated C-CBL tumour suppressor in myeloid neoplasms.

Nature 2009 Aug 20;460(7257):904-8. Epub 2009 Jul 20.

Cancer Genomics Project, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.

Acquired uniparental disomy (aUPD) is a common feature of cancer genomes, leading to loss of heterozygosity. aUPD is associated not only with loss-of-function mutations of tumour suppressor genes, but also with gain-of-function mutations of proto-oncogenes. Here we show unique gain-of-function mutations of the C-CBL (also known as CBL) tumour suppressor that are tightly associated with aUPD of the 11q arm in myeloid neoplasms showing myeloproliferative features. The C-CBL proto-oncogene, a cellular homologue of v-Cbl, encodes an E3 ubiquitin ligase and negatively regulates signal transduction of tyrosine kinases. Homozygous C-CBL mutations were found in most 11q-aUPD-positive myeloid malignancies. Although the C-CBL mutations were oncogenic in NIH3T3 cells, c-Cbl was shown to functionally and genetically act as a tumour suppressor. C-CBL mutants did not have E3 ubiquitin ligase activity, but inhibited that of wild-type C-CBL and CBL-B (also known as CBLB), leading to prolonged activation of tyrosine kinases after cytokine stimulation. c-Cbl(-/-) haematopoietic stem/progenitor cells (HSPCs) showed enhanced sensitivity to a variety of cytokines compared to c-Cbl(+/+) HSPCs, and transduction of C-CBL mutants into c-Cbl(-/-) HSPCs further augmented their sensitivities to a broader spectrum of cytokines, including stem-cell factor (SCF, also known as KITLG), thrombopoietin (TPO, also known as THPO), IL3 and FLT3 ligand (FLT3LG), indicating the presence of a gain-of-function that could not be attributed to a simple loss-of-function. The gain-of-function effects of C-CBL mutants on cytokine sensitivity of HSPCs largely disappeared in a c-Cbl(+/+) background or by co-transduction of wild-type C-CBL, which suggests the pathogenic importance of loss of wild-type C-CBL alleles found in most cases of C-CBL-mutated myeloid neoplasms. Our findings provide a new insight into a role of gain-of-function mutations of a tumour suppressor associated with aUPD in the pathogenesis of some myeloid cancer subsets.
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http://dx.doi.org/10.1038/nature08240DOI Listing
August 2009

Phase II study of tacrolimus and methotrexate for prophylaxis of acute graft-versus-host disease after HLA-A, B, and DRB1 genotypically mismatched unrelated bone marrow transplantation among Japanese patients.

Int J Hematol 2009 Jan 4;89(1):98-105. Epub 2008 Dec 4.

Department of Internal Medicine, Japanese Red Cross Nagoya First Hospital, Nagoya, Japan.

Bone marrow transplantation from unrelated donors (UR-BMT) has been considered to be effective for patients with hematological malignancies who have no suitable related donor. However, disparities of HLA between a recipient and a donor increase the risk of severe acute graft-versus-host disease (GVHD). We evaluated GVHD prophylaxis using tacrolimus and methotrexate for HLA-A, B, or DRB1 genotypically mismatched UR-BMT. Fifty-five patients were enrolled in this study. The incidence of grade III to IV acute GVHD was 23.6% for all patients. No significant difference in the incidence of grade III to IV acute GVHD was observed between HLA-A or B 1 locus mismatch transplantation (18.8%) and HLA-DRB1 1 locus mismatch transplantation (16.7%) (P = 0.96). The incidence of chronic GVHD was 71.7%. Disease-free survival at 5 years was 53.2% for patients with standard risk disease and 24.5% for patients with high-risk disease. Patients with chronic GVHD exhibited better disease-free survival than those without chronic GVHD (53.2 vs. 30.9%, P = 0.011). Twenty patients (36.4%) had a relapse of leukemia and 14 of them died of recurrent leukemia. This study indicates tacrolimus and methotrexate can lower the risk of severe acute GVHD after HLA-A, B, or DRB1 genotypically 1 locus mismatched UR-BMT.
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http://dx.doi.org/10.1007/s12185-008-0219-8DOI Listing
January 2009

Long-term sustained mixed chimerism after allogeneic stem cell transplantation in a patient with severe aplastic anemia.

Intern Med 2007 3;46(23):1923-6. Epub 2007 Dec 3.

Department of Hematology/Oncology, Graduate School of Medicine and Department of Cell Therapy/Transplantation Medicine, University of Tokyo Hospital, University of Tokyo, Tokyo.

Mixed chimerism in a post-transplant patient with severe aplastic anemia (SAA) is generally considered to be a status preceding donor-cell rejection and bone marrow failure. Here, we report on a rare, prolonged mixed chimerism in a patient with SAA who showed a full recovery in hematological and immunological status after transplantation. The analysis in this patient showed about 20% and 80% recipient-type cells of total blood cells and T cells, respectively, at two years post-transplantation, and 14% and 25% of total blood cells and T cells, respectively, at four years post-transplantation. This report describes the most comprehensive case study known to date.
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http://dx.doi.org/10.2169/internalmedicine.46.0249DOI Listing
January 2008

CD1d expression level in tumor cells is an important determinant for anti-tumor immunity by natural killer T cells.

Leuk Lymphoma 2006 Oct;47(10):2218-23

Department of Hematology/Oncology, University of Tokyo Graduate School of Medicine and Hospital, Hongo, Tokyo, Japan.

Invariant natural killer T (iNKT) cells are thought to regulate anti-tumor immunity. Human iNKT (i.e. Valpha24+ NKT) cells have been reported to recognize CD1d on target cells and show cytotoxicity directly on the target cells in vitro. However, the anti-tumor effect of mouse iNKT (i.e. Valpha14+ NKT) cells has been repeatedly reported to be dependent on the activity of natural killer (NK) cells via interferon-gamma, with no evidence of direct cytotoxicity. In the present study, we report that in vitro cytolysis of EL-4 mouse lymphoblastic lymphoma cells by Valpha24+ NKT cells and in vivo eradication of these cells are both dependent on the level of CD1d expression on the tumor cell surface. These observations possibly suggest that direct cytotoxicity of tumor cells by iNKT cells is common to both humans and mice, and that the high expression level of CD1d may be a predictor whether the tumor is a good target of iNKT cells.
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http://dx.doi.org/10.1080/10428190600682688DOI Listing
October 2006

Antineoplastic effect of a single oral dose of the novel Flt3 inhibitor KRN383 on xenografted human leukemic cells harboring Flt3-activating mutations.

Leuk Res 2006 Dec 17;30(12):1541-6. Epub 2006 Apr 17.

Pharmaceutical Development Laboratories, Kirin Brewery Co. Ltd., Gunma, Japan.

Activating mutations of Fms-like tyrosine kinase 3 (Flt3) are the most common genetic abnormalities found in acute myeloid leukemia (AML) and represent potential therapeutic targets. The novel Flt3 inhibitor KRN383 inhibited the autophosphorylation of Flt3 bearing internal tandem duplications (ITDs) and the Asp835Tyr (D835Y) point mutation with half-maximal inhibitory concentration (IC(50)) values of < or =5.9 and 43 nM, respectively. KRN383 also inhibited the proliferation of the ITD-positive cell lines with IC(50) values of < or =2.9 nM. A single oral administration of 80 mg/kg of KRN383 eradicated ITD-positive xenograft tumors in nude mice and prolonged the survival of SCID mice carrying ITD-positive AML cells. The effectiveness of a single oral dose of KRN383 suggests that it has the potential to be used in a wide variety of clinical regimens, including multicycle and combination therapies.
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http://dx.doi.org/10.1016/j.leukres.2006.02.028DOI Listing
December 2006

A randomized controlled trial to compare once- versus twice-daily filgrastim for mobilization of peripheral blood stem cells from healthy donors.

Biol Blood Marrow Transplant 2006 Apr;12(4):408-13

Department of Hematology and Oncology, University of Tokyo Graduate School of Medicine and Hospital, Japan.

Although the mobilization of peripheral blood stem cells from normal donors using granulocyte colony-stimulating factor is widely used, the ideal method for the administration of filgrastim has not been determined. Therefore, we compared the efficacy of peripheral blood stem cell mobilization on day 4 of filgrastim between once-daily (group O) and twice-daily (group T) administration of filgrastim at 400 microg/m(2)/d. In all, 38 and 34 donors were randomly assigned to groups O and T, respectively. The number of CD34(+) cells collected on day 4 was not significantly different (1.74 x 10(6) cells/kg in group O and 2.08 x 10(6) cells/kg in group T, P = .37). The incidence and severity of adverse events were similar in the two groups. The baseline white blood cell count was the strongest predictor of poor mobilization. Donor age, sex, and serum concentrations of several cytokines did not significantly affect the CD34(+) cell yield. In conclusion, once-daily administration of filgrastim at 400 microg/m(2)/d appeared to be appropriate for the mobilization of CD34(+) cells in normal donors when apheresis is planned on day 4 of filgrastim. Selection of a donor with a steady-state white blood cell count of 5.0 x 10(9)/L or more may lead to a lower incidence of poor mobilization.
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http://dx.doi.org/10.1016/j.bbmt.2005.11.007DOI Listing
April 2006

Hematopoietic stem cells expanded by fibroblast growth factor-1 are excellent targets for retrovirus-mediated gene delivery.

Exp Hematol 2005 Dec;33(12):1459-69

Department of Hematology/Oncology, University of Tokyo, Japan.

Objective: For the study of the function of genes of interest in hematopoietic stem cells (HSCs) and for successful gene therapy, it is fundamental to develop a method of efficient gene transfer into HSCs. In mice experiments, efforts have been made to raise the transduction efficiency by modifying the vectors, administrating 5-fluorouracil (5-FU) to donor mice, selecting cytokine cocktails to better sustain the long-term repopulating potential of the stem cells, and so on. The objective of this study is to examine whether the use of fibroblast growth factor-1 (FGF-1)-expanded bone marrow cells provide an improved source for retroviral gene delivery to HSCs.

Materials And Methods: Unfractionated bone marrow cells from one mouse were cultured in serum-free medium containing FGF-1. Both floating and attached cells were transferred to retronectin precoated dishes and infected with virus supernatant from MP34 cells stably transduced with pMY/GFP retrovirus. After 3-day infection, the green fluorescence protein-positive fraction was sorted and the cells were transplanted to lethally irradiated mice.

Results: The experiments illustrated that the number of bone marrow-derived competitive repopulation units (CRUs) was increased from 600 to 9300 per mouse after a 3-week culture period with FGF-1. Following retroviral transduction of the expanded cells, the absolute number of sorted retrovirus-transduced CRUs was 4200. Using these retrovirus-transduced cells in noncompetitive reconstitution assay, we achieved radiation protection and long-term bone marrow reconstitution in 100% of the recipients with average myeloid and lymphoid chimerisms of 70% and 50%, respectively, even if we transplanted 150 recipients with cells derived from a single donor mouse.

Conclusion: In conclusion, FGF-1-expanded bone marrow cells constitute an excellent source of stem cells that could be used in a range of gene delivery protocols.
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http://dx.doi.org/10.1016/j.exphem.2005.09.001DOI Listing
December 2005

Assessment of the international prognostic scoring system for determining chemotherapeutic indications in myelodysplastic syndrome: Japanese retrospective multicenter study.

Int J Hematol 2005 Oct;82(3):236-42

First Department of Internal Medicine, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo, Japan.

To standardize a rational therapeutic strategy of chemotherapy using the International Prognostic Scoring System (IPSS), we retrospectively analyzed 292 high-risk myelodysplastic syndrome (MDS) patients in 20 hospitals in Japan. Results of multivariate analysis of the data on patients who received all types of chemotherapy indicated that poor cytogenetics as shown by the IPSS was the only significant risk factor (P = .047). We then focused on the IPSS composition of each patient. The intermediate 2 (Int-2) category consisted of a heterogeneous group. We attempted to subdivide the category into Int-2A and Int-2B. Patients with good or intermediate cytogenetics had > or = 5% bone marrow (BM) blasts (Int-2A), and most of the other patients had poor cytogenetics and < or = 10% BM blasts (Int-2B). In the Int-2B category, overall survival for patients who received chemotherapy was significantly worse than for those who did not receive chemotherapy (P = .005). Most patients in the High category who had the diagnosis of MDS according to the World Health Organization classification had poor overall survival with or without chemotherapy. We propose the Int-2B and High categories may be considered possible high risk, whereas all patients in the Int-2A category and patients with more than 5% BM blasts in the Int-1 category may be categorized as being at possible intermediate risk. Our proposition may be useful for developing a chemotherapeutic strategy for patients with MDS in Japan.
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http://dx.doi.org/10.1532/IJH97.04191DOI Listing
October 2005

Mycosis fungoides associated with intestinal mucosa-associated lymphoid tissue lymphoma.

Int J Dermatol 2005 Oct;44(10):878-80

Department of Dermatology, Faculty of Medicine, University of Tokyo, Tokyo, Japan.

Coexistence of cutaneous T-cell lymphoma (CTCL) and a B-cell malignancy is rare. We report a case of mycosis fungoides (MF) associated with intestinal mucosa-associated lymphoid tissue (MALT) lymphoma, which is a low-grade B-cell lymphoma of marginal cell origin. To the best of our knowledge, there have been only two cases of coexistent CTCL and MALT lymphoma, and this is the first case with typical MF and intestinal MALT lymphoma. The coexistence in our case might be coincidental, but genetic predisposition and the immunoregulatory capacity of neoplastic T lymphocytes may be factors contributing to this association.
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http://dx.doi.org/10.1111/j.1365-4632.2005.02247.xDOI Listing
October 2005

Crk-associated substrate lymphocyte type is required for lymphocyte trafficking and marginal zone B cell maintenance.

J Immunol 2005 Sep;175(6):3492-501

Department of Hematology and Oncology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.

The lymphocyte-specific Cas family protein Cas-L (Crk-associated substrate lymphocyte type) has been implicated to function in lymphocyte movement, mediated mainly by integrin signaling. However, its physiological role is poorly understood. In this study we analyzed the function of Cas-L in lymphocytes using gene-targeted mice. The mutant mice showed a deficit of marginal zone B (MZB) cells and a decrease of cell number in secondary lymphoid organs. An insufficient chemotactic response and perturbed cell adhesion were observed in Cas-L-deficient lymphocytes, suggesting that the aberrant localization was responsible for the deficit of MZB cells. Moreover, we found that lymphocyte trafficking was altered in Cas-L-deficient mice, which gave a potential reason for contraction of secondary lymphoid tissues. Thus, Cas-L affects homeostasis of MZB cells and peripheral lymphoid organs, which is considered to be relevant to impaired lymphocyte migration and adhesion.
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http://dx.doi.org/10.4049/jimmunol.175.6.3492DOI Listing
September 2005

Host-residual invariant NK T cells attenuate graft-versus-host immunity.

J Immunol 2005 Jul;175(2):1320-8

Departments of Hematology/Oncology, Cell Therapy/Transplantation Medicine, University of Tokyo Graduate School of Medicine and Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.

Invariant NK T (iNKT) cells have an invariant TCR-alpha chain and are activated in a CD1d-restricted manner. They are thought to regulate immune responses and play important roles in autoimmunity, allergy, infection, and tumor immunity. They also appear to influence immunity after hemopoietic stem cell transplantation. In this study, we examined the role of iNKT cells in graft-vs-host disease (GVHD) and graft rejection in a mouse model of MHC-mismatched bone marrow transplantation, using materials including alpha-galactosylceramide, NKT cells expanded in vitro, and Jalpha18 knockout mice that lack iNKT cells. We found that host-residual iNKT cells constitute effector cells which play a crucial role in reducing the severity of GVHD, and that this reduction is associated with a delayed increase in serum Th2 cytokine levels. Interestingly, we also found that host-residual iNKT cause a delay in engraftment and, under certain conditions, graft rejection. These results indicate that host-residual iNKT cells attenuate graft-vs-host immunity rather than host-vs-graft immunity.
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http://dx.doi.org/10.4049/jimmunol.175.2.1320DOI Listing
July 2005

Chest computed tomography of late invasive aspergillosis after allogeneic hematopoietic stem cell transplantation.

Biol Blood Marrow Transplant 2005 Jul;11(7):506-11

Hematopoietic Stem Cell Transplantation Unit, The National Cancer Center Hospital, Tokyo, Japan.

Computed tomography (CT) is a powerful diagnostic tool for invasive aspergillosis (IA) after allogeneic stem cell transplantation (allo-SCT); however, little information is available concerning CT findings of late IA after allo-SCT. To characterize CT findings of late IA, we retrospectively examined medical records and high-resolution CT findings of 27 allo-SCT recipients with late IA. Either acute or chronic GVHD was diagnosed in 24 patients. All 27 patients were given corticosteroids at IA diagnosis. High-resolution CT findings included halo (n=12), centrilobular nodules (n=12), ill-defined consolidation (n=13), ground-glass attenuation (n=8), pleural effusion (n=7), pleural-based consolidation (n=4), and cavitation (n=4). CT findings showing centrilobular nodules and either halo or cavitation were classified into bronchopneumonia type and angioinvasive type, respectively. Angioinvasive-type, bronchopneumonia-type, and combination-type IA were diagnosed in 11, 8, and 4 patients, respectively. CT findings were nonspecific in the other 4 patients. One bronchopneumonia-type case and 2 angioinvasive-type IA cases were subsequently diagnosed as combination type. Although there were no significant differences in patient characteristics between the 2 types of IA, bronchopneumonia-type IA had a poorer prognosis than angioinvasive IA ( P=.022). Halo is a useful diagnostic marker in late IA as well as early IA, and late IA frequently manifests as bronchopneumonia.
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http://dx.doi.org/10.1016/j.bbmt.2005.03.005DOI Listing
July 2005

Dysplastic definitive hematopoiesis in AML1/EVI1 knock-in embryos.

Blood 2005 Sep 24;106(6):2147-55. Epub 2005 May 24.

Department of Hematology, Dokkyo University School of Medicine, 880 Kitakobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan.

The AML1/EVI1 chimeric gene is created by the t(3;21)(q26;q22) chromosomal translocation seen in patients with leukemic transformation of myelodysplastic syndrome or blastic crisis of chronic myelogenous leukemia. We knocked-in the AML1/EVI1 chimeric gene into mouse Aml1 genomic locus to explore its effect in developmental hematopoiesis in vivo. AML1/EVI1/+ embryo showed defective hematopoiesis in the fetal liver and died around embryonic day 13.5 (E13.5) as a result of hemorrhage in the central nervous system. The peripheral blood had yolk-sac-derived nucleated erythroblasts but lacked erythrocytes of the definitive origin. Although E12.5 fetal liver contained progenitors for macrophage only, E13.5 fetal liver contained multilineage progenitors capable of differentiating into dysplastic myelocyte and megakaryocyte. No erythroid progenitor was detected in E12.5 or E13.5 fetal liver. Hematopoietic progenitors from E13.5 AML1/EVI1/+ fetal liver were highly capable of self-renewal compared with those from wild-type liver. Maintained expression of PU.1 gene and decreased expression of LMO2 and SCL genes may explain the aberrant hematopoiesis in AML1/EVI1/+ fetal liver.
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http://dx.doi.org/10.1182/blood-2004-11-4330DOI Listing
September 2005

In vivo alemtuzumab enables haploidentical human leukocyte antigen-mismatched hematopoietic stem-cell transplantation without ex vivo graft manipulation.

Transplantation 2005 May;79(10):1351-7

Department of Cell Therapy and Transplantation Medicine, University of Tokyo Hospital, Hongo, Tokyo, Japan.

Background: Alemtuzumab, a humanized monoclonal antibody directed against human CD52, has a strong lympholytic effect. This study evaluates the safety of unmanipulated peripheral blood stem-cell transplantation from two or three loci-mismatched related donors using alemtuzumab in vivo.

Methods: A total body irradiation-based regimen was used in young patients, whereas those 50 years or older received fludarabine-based conditioning. Alemtuzumab was added to these regimens by intravenous infusion at 0.2 mg/kg per day for 6 days (days -8 to -3).

Results: We treated 12 patients with a median age of 49.5 years. Eight patients demonstrated active disease, and four patients demonstrated acute leukemia in high-risk remission. All achieved neutrophil engraftment a median of 17.5 days after transplantation with complete donor-type chimerism. The cumulative incidence of grades III to IV acute graft-versus-host disease was only 9%. Infection-related deaths were not observed. CD3+/CD4+ and CD3+/CD8+ T cells were strongly suppressed within 2 months after transplantation, but recovered on day 90. Relapse was observed in five of eight patients who underwent transplantation for active disease, whereas none of the three patients who underwent transplantation in first remission had a relapse.

Conclusions: We conclude that in vivo alemtuzumab enables haploidentical hematopoietic stem-cell transplantation without ex vivo graft manipulation.
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http://dx.doi.org/10.1097/01.tp.0000158718.49286.14DOI Listing
May 2005

Notch1 oncoprotein antagonizes TGF-beta/Smad-mediated cell growth suppression via sequestration of coactivator p300.

Cancer Sci 2005 May;96(5):274-82

Department of Hematology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan.

The Notch proteins constitute a family of transmembrane receptors that play a pivotal role in cellular differentiation, proliferation and apoptosis. Although it has been recognized that excess Notch signaling is potentially tumorigenic, little is known about precise mechanisms through which dysregulated Notch signaling induces neoplastic transformation. Here we demonstrate that Notch signaling has a transcriptional cross-talk with transforming growth factor-beta (TGF-beta) signaling, which is well characterized by its antiproliferative effects. TGF-beta-mediated transcriptional responses are suppressed by constitutively active Notch1, and this inhibitory effect is canceled by introduction of transcriptional coactivator p300. We further show that this blockade of TGF-beta signaling is executed by the sequestration of p300 from Smad3. Moreover, in a human cervical carcinoma cell line, CaSki, in which Notch1 is spontaneously activated, suppression of Notch1 expression with small interfering RNA significantly restores the responsiveness to TGF-beta. Taken together, we propose that Notch oncoproteins promote cell growth and cancer development partly by suppressing the growth inhibitory effects of TGF-beta through sequestrating p300 from Smad3.
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http://dx.doi.org/10.1111/j.1349-7006.2005.00048.xDOI Listing
May 2005

Oligomerization of Evi-1 regulated by the PR domain contributes to recruitment of corepressor CtBP.

Oncogene 2005 Sep;24(40):6165-73

Department of Hematology and Oncology, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655, Japan.

Evi-1 is a transcription factor that is implicated in leukemic transformation of hematopoietic cells. Two distinct alternative forms, Evi-1a and Evi-1c, are generated from the EVI-1 gene. Whereas Evi-1a is widely recognized as an oncoprotein, a role for Evi-1c, which has an additional PR domain in the amino-terminus of Evi-1a, in leukemogenesis, has not been elucidated thus far. Aberrant oligomerization of transcription factors has recently emerged as a prevalent mechanism for activating their oncogenic potential in hematopoietic malignancies. Here, to study the mechanisms that underlie Evi-1-mediated oncogenesis, we investigated formation of oligomeric complexes by the Evi-1 proteins. We show that Evi-1a forms homo-oligomers, whereas Evi-1c exclusively exists as a monomer in mammalian cells. Remarkably, Evi-1c has lost the ability to interact with CtBP, a transcriptional corepressor that associates with Evi-1a. As a consequence, the ability of Evi-1c to repress transforming growth factor-beta (TGF-beta) signaling is significantly abrogated. These results identify a novel function of a PR domain to regulate oligomerization of transcription factors and suggest that homo-oligomerization may play a critical role in corepressor recruitment by the Evi-1 proteins. In addition, we found that the chimeric oncoprotein acute myelocytic leukemia (AML)1-Evi-1, generated in t(3;21) leukemia, also forms homo-oligomers and hetero-oligomers with Evi-1a, while it did not interact with Evi-1c. Consistent with the results, repression of TGF-beta by AML1-Evi-1 was significantly enhanced by Evi-1a, whereas it was hardly affected by the presence of Evi-1c. These results suggest that oligomerization may contribute to the oncogenic potential of Evi-1-containing proteins.
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http://dx.doi.org/10.1038/sj.onc.1208754DOI Listing
September 2005

Graft-versus-tumor effect against advanced pancreatic cancer after allogeneic reduced-intensity stem cell transplantation.

Transplantation 2005 Apr;79(7):821-7

Department of Cell Therapy & Transplantation Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.

Background: The prognosis of advanced pancreatic cancer is extremely poor and therefore a novel treatment strategy is desired. The authors thus started a prospective study of allogeneic reduced-intensity hematopoietic stem cell transplantation (RIST) for patients with advanced pancreatic cancer to evaluate the feasibility and efficacy of this approach for such patients.

Methods: Only patients with pathologically proven pancreatic cancer that was locally advanced or metastatic and not amenable to curative resection were included. The conditioning regimen consisted of gemcitabine, fludarabine, and busulfan.

Results: In the first stage of this study, the authors treated seven patients. Treatment-related mortality before day 100 was observed in one patient. The median survival after RIST was 229 days. An objective response on computed tomographic scan was observed in two patients and another had a tumor marker response. Marked tumor shrinkage was observed in one of the remaining patients after donor lymphocyte infusion. These antitumor effects appeared after the effect of the conditioning regimen had disappeared. In addition, some of these responses were associated with an increase in the serum anticarcinoembryonic antigen antibody level.

Conclusions: Pancreatic cancer appeared to be sensitive to a graft-versus-tumor effect; therefore, a larger clinical study with a refined strategy is warranted.
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http://dx.doi.org/10.1097/01.tp.0000153507.94980.a5DOI Listing
April 2005

The nucleocytoplasmic shuttling protein CIZ reduces adult bone mass by inhibiting bone morphogenetic protein-induced bone formation.

J Exp Med 2005 Mar;201(6):961-70

Department of Molecular Pharmacology, Tokyo Medical and Dental University, Tokyo, Japan.

Osteoporosis is a major health problem; however, the mechanisms regulating adult bone mass are poorly understood. Cas-interacting zinc finger protein (CIZ) is a nucleocytoplasmic shuttling protein that localizes at cell adhesion plaques that form where osteoblasts attach to substrate. To investigate the potential role of CIZ in regulating adult bone mass, we examined the bones in CIZ-deficient mice. Bone volume was increased and the rates of bone formation were increased in CIZ-deficient mice, whereas bone resorption was not altered. CIZ deficiency enhanced the levels of mRNA expression of genes encoding proteins related to osteoblastic phenotypes, such as alkaline phosphatase (ALP) as well as osterix mRNA expression in whole long bones. Bone marrow cells obtained from the femora of CIZ-deficient mice revealed higher ALP activity in culture and formed more mineralized nodules than wild-type cells. CIZ deficiency enhanced bone morphogenetic protein (BMP)-induced osteoblastic differentiation in bone marrow cells in cultures, indicating that BMP is the target of CIZ action. CIZ deficiency increased newly formed bone mass after femoral bone marrow ablation in vivo. Finally, BMP-2-induced bone formation on adult mouse calvariae in vivo was enhanced by CIZ deficiency. These results establish that CIZ suppresses the levels of adult bone mass through inhibition of BMP-induced activation of osteoblasts.
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http://dx.doi.org/10.1084/jem.20041097DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2213105PMC
March 2005

Functional domains of Runx1 are differentially required for CD4 repression, TCRbeta expression, and CD4/8 double-negative to CD4/8 double-positive transition in thymocyte development.

J Immunol 2005 Mar;174(6):3526-33

Department of Hematology and Oncology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.

Runx1 (AML1) has multiple functions in thymocyte development, including CD4 repression in immature thymocytes, expression of TCRbeta, and efficient beta-selection. To determine the functional domains of Runx1 important for thymocyte development, we cultured Runx1-deficient murine fetal liver (FL) cells on OP9-Delta-like 1 murine stromal cells, which express Delta-like 1 and support thymocyte development in vitro, and introduced Runx1 or C-terminal-deletion mutants of Runx1 into the FL cells by retrovirus infection. In this system, Runx1-deficient FL cells failed to follow normal thymocyte development, whereas the introduction of Runx1 into the cells was sufficient to produce thymocyte development that was indistinguishable from that in wild-type FL cells. In contrast, Runx1 mutants that lacked the activation domain necessary for initiating gene transcription did not fully restore thymocyte differentiation, in that it neither repressed CD4 expression nor promoted the CD4/8 double-negative to CD4/8 double-positive transition. Although the C-terminal VWRPY motif-deficient mutant of Runx1, which cannot interact with the transcriptional corepressor Transducin-like enhancer of split (TLE), promoted the double-negative to double-positive transition, it did not efficiently repress CD4 expression. These results suggest that the activation domain is essential for Runx1 to establish thymocyte development and that Runx1 has both TLE-dependent and TLE-independent functions in thymocyte development.
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http://dx.doi.org/10.4049/jimmunol.174.6.3526DOI Listing
March 2005

A prospective trial to evaluate the safety and efficacy of pravastatin for the treatment of refractory chronic graft-versus-host disease.

Transplantation 2005 Feb;79(3):372-4

Hematopoietic Stem Cell Transplant Unit, National Cancer Center Hospital, Tokyo, Japan.

This prospective study evaluates the safety and efficacy of pravastatin for the treatment of chronic graft-versus-host disease (GVHD). We included 18 patients with refractory chronic GVHD. Oral pravastatin was started at 10 mg/day, and the dose was increased up to 40 mg/day in 4 weeks. This maximum dose was administered over 8 weeks. There were no severe adverse events caused by pravastatin. A clinical response was observed in the skin score in two patients, mouth score in five patients, eye score in two patients, liver score in three patients, platelet count score in one patient, and weight loss in two patients. The overall response rate was 28%. Immunophenotypic analyses showed that T-helper (Th)1 cells were dominant in all but one patient before treatment and that the Th1/Th2 ratio tended to be lower in the responders than in the nonresponders. A randomized controlled trial is warranted to evaluate the efficacy of pravastatin against chronic GVHD.
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http://dx.doi.org/10.1097/01.tp.0000151001.64189.1dDOI Listing
February 2005

Clinical significance of peripheral blood erythroblastosis after hematopoietic stem cell transplantation.

Leuk Lymphoma 2004 Dec;45(12):2439-43

Department of Cell Therapy and Transplantation Medicine, University of Tokyo, Japan.

Erythroblasts (EBL) are normally not observed in peripheral blood, but may be found in patients suffering from a variety of severe diseases. The detection of EBL in peripheral blood has been shown to be associated with a poor prognosis. However, the clinical significance of peripheral erythroblastosis after hematopoietic stem cell transplantation (HSCT) has not been evaluated. We retrospectively analyzed the records of 161 patients who underwent HSCT at our hospital from June 1995 to October 2001. EBL at any level were detected in 94% of the patients. Forty-four and 11 patients experienced erythroblastosis exceeding 200 and 1,000/ul, respectively. The erythroblast count was higher in patients who died than in the survivors (geometric mean value 184 vs. 100/ul, P=0.01). High-level erythroblastosis ( >1,000/ul) within 180 days after HSCT was associated with an extremely poor prognosis (median survival 22.5 days). Among the possible confounding factors, the use of total body irradiation (RR 2.35, 95% CI 1.22 - 4.54, P=0.011) and the disease status before transplantation (RR 2.51, 95% CI 1.15 - 5.49, P=0.021) were independent significant factors for erythroblastosis after HSCT. As for post-transplant events, a high EBL concentration was frequently preceded by graft-vs.-host disease, thrombotic microangiopathy, hypoxia, and hematological relapse.
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http://dx.doi.org/10.1080/10428190310001609915DOI Listing
December 2004

CYP3A4*18: it is not rare allele in Japanese population.

Drug Metab Pharmacokinet 2003 ;18(4):267-8

Department of Pharmacy, University of Tokyo Hospital, Japan.

We sequenced all 13 exons of the CYP3A4 gene derived from 48 Japanese subjects. One subject possess the 20070 T>C mutation in the exon 10 (result in leu293Pro substitution, namely CYP3A4(*)18), as heterozygote. Thus, we investigated the frequency of CYP3A4(*)18 in 118 Japanese population using polymerase chain reaction-restriction fragment length polymorphism with Msp I and determined that the frequency of the CYP3A4(*)18 allele was 1.3%.
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http://dx.doi.org/10.2133/dmpk.18.267DOI Listing
March 2005

Identification of a SRC-like tyrosine kinase gene, FRK, fused with ETV6 in a patient with acute myelogenous leukemia carrying a t(6;12)(q21;p13) translocation.

Genes Chromosomes Cancer 2005 Mar;42(3):269-79

Department of Hematology and Oncology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.

The SRC family of kinases is rarely mutated in primary human tumors. We report the identification of a SRC-like tyrosine kinase gene, FRK (Fyn-related kinase), fused with ETV6 in a patient with acute myelogenous leukemia carrying t(6;12)(q21;p13). Both reciprocal fusion transcripts, ETV6/FRK and FRK/ETV6, were expressed. In ETV6/FRK, exon 4 of ETV6 was fused in-frame to exon 3 of FRK, producing a chimeric protein consisting of the entire oligomerization domain of ETV6 and the kinase domain of FRK. The ETV6/FRK protein was shown to be constitutively autophosphorylated on its tyrosine residues. ETV6/FRK phosphorylated histones H2B and H4 in vitro to a greater extent than did FRK, suggesting it had elevated kinase activity. ETV6/FRK could transform both Ba/F3 cells and NIH3T3 cells, which depended on its kinase activity. Moreover, ETV6/FRK inhibited ETV6-mediated transcriptional repression in a dominant-negative manner. This report provides the first evidence that a SRC-like kinase gene, FRK fused with ETV6, could directly contribute to leukemogenesis by producing an oncoprotein, ETV6/FRK, with dual functions: constitutive activation of the ETV6/FRK tyrosine kinase and dominant-negative modulation of ETV6-mediated transcriptional repression.
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http://dx.doi.org/10.1002/gcc.20147DOI Listing
March 2005

Role of Dok-1 and Dok-2 in leukemia suppression.

J Exp Med 2004 Dec;200(12):1689-95

Cancer Biology and Genetics Program and Dept. of Pathology, Box 110, Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New York, NY 10021, USA.

Chronic myelogenous leukemia (CML) is characterized by the presence of the chimeric p210bcr/abl oncoprotein that shows elevated and constitutive protein tyrosine kinase activity relative to the normal c-abl tyrosine kinase. Although several p210bcr/abl substrates have been identified, their relevance in the pathogenesis of the disease is unclear. We have identified a family of proteins, Dok (downstream of tyrosine kinase), coexpressed in hematopoietic progenitor cells. Members of this family such as p62dok (Dok-1) and p56dok-2 (Dok-2) associate with the p120 rasGTPase-activating protein (rasGAP) upon phosphorylation by p210bcr/abl as well as receptor and nonreceptor tyrosine kinases. Here, we report the generation and characterization of single and double Dok-1 or Dok-2 knockout (KO) mutants. Single KO mice displayed normal steady-state hematopoiesis. By contrast, concomitant Dok-1 and Dok-2 inactivation resulted in aberrant hemopoiesis and Ras/MAP kinase activation. Strikingly, all Dok-1/Dok-2 double KO mutants spontaneously developed transplantable CML-like myeloproliferative disease due to increased cellular proliferation and reduced apoptosis. Furthermore, Dok-1 or Dok-2 inactivation markedly accelerated leukemia and blastic crisis onset in Tec-p210bcr/abl transgenic mice known to develop, after long latency, a myeloproliferative disorder resembling human CML. These findings unravel the critical and unexpected role of Dok-1 and Dok-2 in tumor suppression and control of the hematopoietic compartment homeostasis.
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http://dx.doi.org/10.1084/jem.20041306DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2211998PMC
December 2004

Role of Dok-1 and Dok-2 in myeloid homeostasis and suppression of leukemia.

J Exp Med 2004 Dec;200(12):1681-7

Dept. of Cell Regulation, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.

Dok-1 and Dok-2 are closely related rasGAP-associated docking proteins expressed preferentially in hematopoietic cells. Although they are phosphorylated upon activation of many protein tyrosine kinases (PTKs), including those coupled with cytokine receptors and oncogenic PTKs like Bcr-Abl, their physiological roles are largely unidentified. Here, we generated mice lacking Dok-1 and/or Dok-2, which included the double-deficient mice succumbed to myeloproliferative disease resembling human chronic myelogenous leukemia (CML) and chronic myelomonocytic leukemia. The double-deficient mice displayed medullary and extramedullary hyperplasia of granulocyte/macrophage progenitors with leukemic potential, and their myeloid cells showed hyperproliferation and hypo-apoptosis upon treatment and deprivation of cytokines, respectively. Consistently, the mutant myeloid cells showed enhanced Erk and Akt activation upon cytokine stimulation. Moreover, loss of Dok-1 and/or Dok-2 induced blastic transformation of chronic phase CML-like disease in mice carrying the bcr-abl gene, a cause of CML. These findings demonstrate that Dok-1 and Dok-2 are key negative regulators of cytokine responses and are essential for myeloid homeostasis and suppression of leukemia.
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http://dx.doi.org/10.1084/jem.20041247DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2211997PMC
December 2004

Efficacy and safety of imatinib mesylate for patients in the first chronic phase of chronic myeloid leukemia: results of a Japanese phase II clinical study.

Int J Hematol 2004 Oct;80(3):261-6

Department of Hematology and Cell Therapy, Aichi Cancer Center Hospital, Nagoya, Japan.

Imatinib mesylate is a relatively new drug that targets the BCR-ABL chimeric protein, the molecular basis of chronic myeloid leukemia (CML). A phase II clinical trial in 39 Japanese patients in the first chronic phase of CML was conducted with imatinib mesylate at a dose of 400 mg/day. Hematologic complete response was obtained in 92.3% of the patients, complete cytogenetic response (CR) was obtained in 43.6%, and major partial CR was obtained in 20.5% of the patients. Although 29 of 39 patients required an adjustment of dosing because of grade 3 or 4 adverse events, most of the events were reversible, and 25 of the 29 patients were able to resume therapy. Between day 15 and day 35, grade 3 or 4 neutropenia and/or leukocytopenia occurred in 13 patients, and grade 3 thrombocytopenia occurred in 5 patients. Overall, nonhematologic grade 3 adverse events occurred in 28.2% of the patients. These data support the use of imatinib mesylate as the treatment of choice for chronic-phase CML patients.
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http://dx.doi.org/10.1532/ijh97.04074DOI Listing
October 2004

Immature granulocyte fraction in the peripheral blood is a practical indicator for mobilization of CD34(+) cells.

Am J Hematol 2004 Nov;77(3):223-8

Departments of Cell Therapy/Transplantation Medicine and Hematology/Oncology, University of Tokyo Hospital and Graduate School of Medicine, Tokyo, Japan.

We propose a simple parameter that improves prediction of the number of CD34(+) cells in blood cells collected by apheresis for autologous peripheral blood stem cell (PBSC) transplantation following administration of granulocyte colony-stimulating factor. The percentage of immature granulocytes including myeloblasts, promyelocytes, myelocytes, and metamyelocytes (LSI for left-shift index) immediately prior to the start of each apheresis correlated with the number of CD34(+) cells in PBSC collections (r = 0.79, P < 0.0001, Y = 0.227X - 0.99, R(2) = 0.623) much better than did the white blood cell count (r = 0.07), currently the most commonly used predictor in deciding the initiation of apheresis. We then used receiver operating characteristic (ROC) curves to determine a cutoff point for LSI to prevent unnecessary apheresis. At LSI > 7.5, sensitivity and specificity of cutoff points in the probability of obtaining >1.0 x 10(6) CD34(+) cells/kg BW were 93.3% and 94.3% (95% CI, 91.4-100.0%), respectively. When LSI reaches 15.25, nearly 100% of apheresis will attain the target CD34(+) cell dose. These findings indicate that LSI is a useful and simple method for predicting the yield of CD34(+) cells before the start of PBSC collection and avoiding unnecessary apheresis.
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http://dx.doi.org/10.1002/ajh.20193DOI Listing
November 2004

Incidence of invasive aspergillosis after allogeneic hematopoietic stem cell transplantation with a reduced-intensity regimen compared with transplantation with a conventional regimen.

Biol Blood Marrow Transplant 2004 Sep;10(9):645-52

Hematopoietic Stem Cell Transplantation Unit, National Cancer Center Hospital, Tokyo, Japan.

To evaluate the clinical characteristics of invasive aspergillosis (IA) after reduced-intensity stem cell transplantation (RIST) compared with those after conventional stem cell transplantation (CST), we examined the medical records of 486 CST and 178 RIST recipients. The overall incidence of IA after allogeneic transplantation was 35 (5.3%) of 664, which gave a 3-year cumulative incidence of 5.6%. The estimated 3-year incidence of IA in CST and RIST was 4.5% and 8.2% (P = .045), respectively, but the mortality rates were similar (76% and 86%). The median onset of IA after RIST (day 127) occurred significantly later than that after CST (day 97). A multivariate analysis revealed that IA was associated with age older than 50 years (relative risk, 2.12; 95% confidence interval, 1.08-4.17; P = .03) and the presence of acute and/or chronic GVHD (relative risk, 6.2; 95% confidence interval, 2.4-16.4; P = .0002). IA remains an important complication after allogeneic transplantation, regardless of the type of conditioning regimen.
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http://dx.doi.org/10.1016/j.bbmt.2004.06.003DOI Listing
September 2004

The transcriptionally active form of AML1 is required for hematopoietic rescue of the AML1-deficient embryonic para-aortic splanchnopleural (P-Sp) region.

Blood 2004 Dec 22;104(12):3558-64. Epub 2004 Jul 22.

Department of Hematology & Oncology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.

Acute myelogenous leukemia 1 (AML1; runt-related transcription factor 1 [Runx1]) is a member of Runx transcription factors and is essential for definitive hematopoiesis. Although AML1 possesses several subdomains of defined biochemical functions, the physiologic relevance of each subdomain to hematopoietic development has been poorly understood. Recently, the consequence of carboxy-terminal truncation in AML1 was analyzed by the hematopoietic rescue assay of AML1-deficient mouse embryonic stem cells using the gene knock-in approach. Nonetheless, a role for specific internal domains, as well as for mutations found in a human disease, of AML1 remains to be elucidated. In this study, we established an experimental system to efficiently evaluate the hematopoietic potential of AML1 using a coculture system of the murine embryonic para-aortic splanchnopleural (P-Sp) region with a stromal cell line, OP9. In this system, the hematopoietic defect of AML1-deficient P-Sp can be rescued by expressing AML1 with retroviral infection. By analysis of AML1 mutants, we demonstrated that the hematopoietic potential of AML1 was closely related to its transcriptional activity. Furthermore, we showed that other Runx transcription factors, Runx2/AML3 or Runx3/AML2, could rescue the hematopoietic defect of AML1-deficient P-Sp. Thus, this experimental system will become a valuable tool to analyze the physiologic function and domain contribution of Runx proteins in hematopoiesis.
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http://dx.doi.org/10.1182/blood-2004-04-1535DOI Listing
December 2004

Roles of Bim in apoptosis of normal and Bcr-Abl-expressing hematopoietic progenitors.

Mol Cell Biol 2004 Jul;24(14):6172-83

Department of Hematology, Jichi Medical School, Tochigi, Japan.

Bcr-Abl kinase is known to reverse apoptosis of cytokine-dependent cells due to cytokine deprivation, although it has been controversial whether chronic myeloid leukemia (CML) progenitors have the potential to survive under conditions in which there are limited amounts of cytokines. Here we demonstrate that early hematopoietic progenitors (Sca-1(+) c-Kit(+) Lin(-)) isolated from normal mice rapidly undergo apoptosis in the absence of cytokines. In these cells, the expression of Bim, a proapoptotic relative of Bcl-2 which plays a key role in the cytokine-mediated survival system, is induced. In contrast, those cells isolated from our previously established CML model mice resist apoptosis in cytokine-free medium without the induction of Bim expression, and these effects are reversed by the Abl-specific kinase inhibitor imatinib mesylate. In addition, the expression levels of Bim are uniformly low in cell lines established from patients in the blast crisis phase of CML, and imatinib induced Bim in these cells. Moreover, small interfering RNA that reduces the expression level of Bim effectively rescues CML cells from apoptosis caused by imatinib. These findings suggest that Bim plays an important role in the apoptosis of early hematopoietic progenitors and that Bcr-Abl supports cell survival in part through downregulation of this cell death activator.
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http://dx.doi.org/10.1128/MCB.24.14.6172-6183.2004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC434248PMC
July 2004
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