Publications by authors named "Yukiko Komeno"

33 Publications

Prolonged Myelosuppression due to Progressive Bone Marrow Fibrosis in a Patient with Acute Promyelocytic Leukemia.

Case Rep Hematol 2019 27;2019:1616237. Epub 2019 Nov 27.

Department of Hematology, Japan Community Healthcare Organization (JCHO) Tokyo Yamate Medical Center, Tokyo, Japan.

A 34-year-old woman was diagnosed with acute promyelocytic leukemia. Chemotherapy was administered following the JALSG APL204 protocol. Induction therapy with all-trans retinoic acid resulted in complete remission on day 49. She developed coccygeal pain from day 18, which spread to the spine and cheekbones and lasted 5 weeks. She had similar bone pain on days 7-10 of the first consolidation therapy and on days 4-12 of the second consolidation therapy. Oral loxoprofen was prescribed for pain relief. On day 33 of the third consolidation, white blood cell and neutrophil counts were 320/L and 20/L, respectively. After she developed epigastralgia and hematemesis, she developed septic shock. Gastroendoscopy revealed markedly thickened folds and diffusely damaged mucosa with blood oozing. Computed tomography revealed thickened walls of the antrum and the pylorus. Despite emergency treatments, she died. Bacterial culture of the gastric fluid yielded and enterococci growth. Collectively, she was diagnosed with phlegmonous gastritis. Retrospective examination of serial bone marrow biopsy specimens demonstrated progressive bone marrow fibrosis, which may have caused prolonged myelosuppression. Thus, evaluation of bone marrow fibrosis by bone marrow biopsy after each treatment cycle might serve as a predictor of persistent myelosuppression induced by chemotherapy.
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http://dx.doi.org/10.1155/2019/1616237DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6900957PMC
November 2019

Hemophagocytic Syndrome-Associated Variant of Methotrexate-Associated Intravascular Large B-Cell Lymphoma in a Rheumatoid Arthritis Patient.

Case Rep Hematol 2019 11;2019:8947616. Epub 2019 Sep 11.

Department of Hematology, Japan Community Healthcare Organization (JCHO) Tokyo Yamate Medical Center, Hyakunin-cho, Shinjuku, Tokyo 169-0073, Japan.

A 59-year-old man was treated for rheumatoid arthritis (RA) for 12 years with methotrexate (MTX) and prednisolone. After MTX-associated interstitial pneumonia developed, he was treated with cyclophosphamide and prednisolone for 7 months. Arthritis worsened, and tacrolimus was added to the treatment regimen. One month later, he had fever, loss of appetite, and dyspnea on exertion. Blood tests showed pancytopenia with large, atypical lymphocytes. Computed tomography showed mild splenomegaly. Bone marrow examination demonstrated CD20-positive, EBER-positive atypical lymphocytes, and hemophagocytosis. Random skin biopsy led to the diagnosis of intravascular large B-cell lymphoma (IVLBCL). The final diagnosis was a hemophagocytic syndrome-associated variant of IVLBCL. Complete remission was achieved after seven courses of R-CHOP. However, within a month, he complained of dizziness. Magnetic resonance imaging revealed focal infarctions in the cerebellum and around the left lateral ventricle. Central nervous system relapse was suspected. Although salvage chemotherapy (CHASER), whole brain irradiation, and intrathecal injection of cytarabine and prednisolone were temporarily effective, he died. Autopsy revealed infiltration of lymphoma cells in the brain and adrenal glands. To the best of our knowledge, this is the sixth case of IVLBCL and the first case of the hemophagocytic syndrome-associated variant of IVLBCL in RA patients in the literature.
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http://dx.doi.org/10.1155/2019/8947616DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6755279PMC
September 2019

Secondary Syphilis with Tonsillar and Cervical Lymphadenopathy and a Pulmonary Lesion Mimicking Malignant Lymphoma.

Am J Case Rep 2018 Mar 4;19:238-243. Epub 2018 Mar 4.

Department of Hematology, Japan Community Healthcare Organization (JCHO), Tokyo Yamate Medical Center, Tokyo, Japan.

BACKGROUND Syphilis is a sexually transmitted disease caused by the pathogen Treponema pallidum. Prevalence continues to rise, especially among men who have sex with men (MSM). Due to changes in patterns of sexual activity, manifestations of the disease are highly variable. CASE REPORT A 27-year-old male visited the hospital for a low-grade fever and tender 5-cm mass in the right side of his neck. His right tonsil was swollen and covered with a white coating. Levofloxacin was prescribed, but ineffective. The patient's levels of liver function enzymes increased gradually. Systemic magnetic resonance imaging (MRI) revealed bilateral cervical lymphadenopathy with right predominance, a right pulmonary nodule, and a periportal lymph node, suggestive of malignant lymphoma. However, a biopsy of the right cervical lymph node showed nonspecific inflammation. Preoperative rapid plasma reagin (RPR) and T. pallidum latex agglutination (TPLA) tests were positive. The patient was MSM and reported oral sex with many sexual partners. A diagnosis of secondary syphilis was made. Oral amoxicillin was effective, and all symptoms other than periportal lymph node resolved. CONCLUSIONS Tonsillitis, cervical lymphadenopathy, and lung lesions can be manifestations of secondary syphilis. A detailed history, pathology, and serology are crucial for diagnosis.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5846205PMC
http://dx.doi.org/10.12659/ajcr.907127DOI Listing
March 2018

Bosutinib as a fourth-line therapy for a patient with T315I-positive lymphoid blastic phase chronic myeloid leukemia: A case report.

Oncol Lett 2017 Jun 5;13(6):4285-4289. Epub 2017 Apr 5.

Department of Hematology, Japan Community Healthcare Organization (JCHO) Tokyo Yamate Medical Center, Hyakunin-cho, Shinjuku, Tokyo 169-0073, Japan.

A 35-year-old male was diagnosed with chronic myeloid leukemia in the chronic phase and was prescribed 100 mg daily dasatinib. However, dasatinib was discontinued due to thrombocytopenia, and within six months, the disease progressed to the lymphoid blastic phase. Hyper-cyclophosphamide, vincristine, adriamycin and dexamethasone chemotherapy combined with 140 mg dasatinib or 600 mg imatinib was prescribed. The two inhibitors were soon discontinued due to severe thrombocytopenia and jaundice, respectively. Myelosuppression persisted subsequent to the nadir. Bone marrow (BM) aspiration and biopsy revealed hypercellular marrow filled with blasts. Sequencing of the leukemia cells revealed overlapping peaks for the wild-type sequence and the T315I mutant sequence. The patient was treated with 500 mg bosutinib (which was later reduced to 300 mg) for pretransplant cytoreduction. After 5 months, the patient's spleen exhibited a reduction in volume and the percentage of blasts in the BM decreased from 96.1 to 17.5%. The patient successfully underwent cord blood transplantation. The patient has been disease-free for 5 months subsequent to transplantation. This case suggests that bosutinib may be effective for cytoreduction prior to stem cell transplantation, unless the leukemia cells consistently harbor the T315I mutation.
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http://dx.doi.org/10.3892/ol.2017.5989DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5452986PMC
June 2017

Splenic Marginal Zone Lymphoma with Acquired von Willebrand Syndrome Diagnosed via Splenic Bleeding.

Intern Med 2017 1;56(5):557-562. Epub 2017 Mar 1.

Department of Hematology, Japan Community Healthcare Organization (JCHO) Tokyo Yamate Medical Center, Japan.

An 85-year-old woman underwent emergent splenectomy due to left abdominal pain and active bleeding in a massively enlarged spleen. The histological diagnosis was splenic marginal zone lymphoma (SMZL). A prolonged activated partial thromboplastin time (APTT) was noted, and additional tests led to the diagnosis of type 2A-like acquired von Willebrand syndrome (AVWS). An APTT cross mixing test ruled out the presence of inhibitors. She received eight courses of rituximab monotherapy. The coagulation data showed no improvement, possibly because the lymphoma showed a poor response to the treatment. AVWS rarely causes bleeding in solid organs. This is the first case of SMZL with AVWS diagnosed via splenic bleeding.
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http://dx.doi.org/10.2169/internalmedicine.56.7258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5399210PMC
April 2017

Intestinal Intravascular Large B-cell Lymphoma Mimicking Ulcerative Colitis with Secondary Membranoproliferative Glomerulonephritis.

Intern Med 2016 1;55(17):2475-81. Epub 2016 Sep 1.

Department of Hematology, Japan Community Healthcare Organization (JCHO) Tokyo Yamate Medical Center, Japan.

A 47-year-old woman with ulcerative colitis (UC) was admitted to our hospital for renal dysfunction and progressive anemia. Colonoscopy revealed intestinal lesions and pathological findings showed intravascular large B-cell lymphoma (IVLBCL). According to the polymerase chain reaction analysis of sequential rectal specimens, we concluded that she suffered from intestinal BCL, not UC. After chemotherapy, her renal function progressed to nephrotic syndrome. The pathological findings of renal biopsy specimens indicated membranoproliferative glomerulonephritis (MPGN). Chemotherapy was continued and led to the remission of BCL and MPGN. We herein describe the first case of intestinal IVLBCL mimicking UC with secondary MPGN.
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http://dx.doi.org/10.2169/internalmedicine.55.6737DOI Listing
March 2017

Esophageal Candidiasis as the Initial Manifestation of Acute Myeloid Leukemia.

Intern Med 2015 1;54(23):3087-92. Epub 2015 Dec 1.

Department of Hematology, Japan Community Healthcare Organization (JCHO) Tokyo Yamate Medical Center, Japan.

A 47-year-old woman presented with persistent dysphagia. A gastroendoscopy revealed massive esophageal candidiasis, and oral miconazole was prescribed. Three weeks later, she returned to our hospital without symptomatic improvement. She was febrile, and blood tests showed leukocytosis (137,150 /μL, blast 85%), anemia and thrombocytopenia. She was diagnosed with acute myeloid leukemia (AML). She received chemotherapy and antimicrobial agents. During the recovery from the nadir, bilateral ocular candidiasis was detected, suggesting the presence of preceding candidemia. Thus, esophageal candidiasis can be an initial manifestation of AML. Thorough examination to detect systemic candidiasis is strongly recommended when neutropenic patients exhibit local candidiasis prior to chemotherapy.
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http://dx.doi.org/10.2169/internalmedicine.54.4613DOI Listing
August 2016

Novel working hypothesis for pathogenesis of hematological malignancies: combination of mutations-induced cellular phenotypes determines the disease (cMIP-DD).

J Biochem 2016 Jan 20;159(1):17-25. Epub 2015 Nov 20.

Division of Cellular Therapy/Division of Stem Cell Signaling, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.

Recent progress in high-speed sequencing technology has revealed that tumors harbor novel mutations in a variety of genes including those for molecules involved in epigenetics and splicing, some of which were not categorized to previously thought malignancy-related genes. However, despite thorough identification of mutations in solid tumors and hematological malignancies, how these mutations induce cell transformation still remains elusive. In addition, each tumor usually contains multiple mutations or sometimes consists of multiple clones, which makes functional analysis difficult. Fifteen years ago, it was proposed that combination of two types of mutations induce acute leukemia; Class I mutations induce cell growth or inhibit apoptosis while class II mutations block differentiation, co-operating in inducing acute leukemia. This notion has been proven using a variety of mouse models, however most of recently found mutations are not typical class I/II mutations. Although some novel mutations have been found to functionally work as class I or II mutation in leukemogenesis, the classical class I/II theory seems to be too simple to explain the whole story. We here overview the molecular basis of hematological malignancies based on clinical and experimental results, and propose a new working hypothesis for leukemogenesis.
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http://dx.doi.org/10.1093/jb/mvv114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4882650PMC
January 2016

SRSF2 Is Essential for Hematopoiesis, and Its Myelodysplastic Syndrome-Related Mutations Dysregulate Alternative Pre-mRNA Splicing.

Mol Cell Biol 2015 Sep 29;35(17):3071-82. Epub 2015 Jun 29.

Moores UCSD Cancer Center, University of California, San Diego, La Jolla, California, USA Division of Biological Sciences, University of California, San Diego, La Jolla, California, USA Department of Pathology, University of California, San Diego, La Jolla, California, USA

Myelodysplastic syndromes (MDS) are a group of neoplasms characterized by ineffective myeloid hematopoiesis and various risks for leukemia. SRSF2, a member of the serine/arginine-rich (SR) family of splicing factors, is one of the mutation targets associated with poor survival in patients suffering from myelodysplastic syndromes. Here we report the biological function of SRSF2 in hematopoiesis by using conditional knockout mouse models. Ablation of SRSF2 in the hematopoietic lineage caused embryonic lethality, and Srsf2-deficient fetal liver cells showed significantly enhanced apoptosis and decreased levels of hematopoietic stem/progenitor cells. Induced ablation of SRSF2 in adult Mx1-Cre Srsf2(flox/flox) mice upon poly(I):poly(C) injection demonstrated a significant decrease in lineage(-) Sca(+) c-Kit(+) cells in bone marrow. To reveal the functional impact of myelodysplastic syndromes-associated mutations in SRSF2, we analyzed splicing responses on the MSD-L cell line and found that the missense mutation of proline 95 to histidine (P95H) and a P95-to-R102 in-frame 8-amino-acid deletion caused significant changes in alternative splicing. The affected genes were enriched in cancer development and apoptosis. These findings suggest that intact SRSF2 is essential for the functional integrity of the hematopoietic system and that its mutations likely contribute to development of myelodysplastic syndromes.
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http://dx.doi.org/10.1128/MCB.00202-15DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4525309PMC
September 2015

The molecular basis of myeloid malignancies.

Proc Jpn Acad Ser B Phys Biol Sci 2014 ;90(10):389-404

Division of Cellular Therapy/Division of Stem Cell Signaling, The Institute of Medical Science, The University of Tokyo.

Myeloid malignancies consist of acute myeloid leukemia (AML), myelodysplastic syndromes (MDS) and myeloproliferative neoplasm (MPN). The latter two diseases have preleukemic features and frequently evolve to AML. As with solid tumors, multiple mutations are required for leukemogenesis. A decade ago, these gene alterations were subdivided into two categories: class I mutations stimulating cell growth or inhibiting apoptosis; and class II mutations that hamper differentiation of hematopoietic cells. In mouse models, class I mutations such as the Bcr-Abl fusion kinase induce MPN by themselves and some class II mutations such as Runx1 mutations induce MDS. Combinations of class I and class II mutations induce AML in a variety of mouse models. Thus, it was postulated that hematopoietic cells whose differentiation is blocked by class II mutations would autonomously proliferate with class I mutations leading to the development of leukemia. Recent progress in high-speed sequencing has enabled efficient identification of novel mutations in a variety of molecules including epigenetic factors, splicing factors, signaling molecules and proteins in the cohesin complex; most of these are not categorized as either class I or class II mutations. The functional consequences of these mutations are now being extensively investigated. In this article, we will review the molecular basis of hematological malignancies, focusing on mouse models and the interfaces between these models and clinical findings, and revisit the classical class I/II hypothesis.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4335136PMC
http://dx.doi.org/10.2183/pjab.90.389DOI Listing
August 2015

Hes1 promotes blast crisis in chronic myelogenous leukemia through MMP-9 upregulation in leukemic cells.

Blood 2014 Jun 13;123(25):3932-42. Epub 2014 May 13.

Division of Cellular Therapy, Advanced Clinical Research Center, Division of Stem Cell Signaling, Center for Stem Cell Therapy, Institute of Medical Science, The University of Tokyo, Tokyo, Japan;

High levels of HES1 expression are frequently found in BCR-ABL(+) chronic myelogenous leukemia in blast crisis (CML-BC). In mouse bone marrow transplantation (BMT) models, co-expression of BCR-ABL and Hes1 induces CML-BC-like disease; however, the underlying mechanism remained elusive. Here, based on gene expression analysis, we show that MMP-9 is upregulated by Hes1 in common myeloid progenitors (CMPs). Analysis of promoter activity demonstrated that Hes1 upregulated MMP-9 by activating NF-κB. Analysis of 20 samples from CML-BC patients showed that MMP-9 was highly expressed in three, with two exhibiting high levels of HES1 expression. Interestingly, MMP-9 deficiency impaired the cobblestone area-forming ability of CMPs expressing BCR-ABL and Hes1 that were in conjunction with a stromal cell layer. In addition, CMPs expressing BCR-ABL and Hes1 secreted MMP-9, promoting the release of soluble Kit-ligand (sKitL) from stromal cells, thereby enhancing proliferation of the leukemic cells. In accordance, mice transplanted with CMPs expressing BCR-ABL and Hes1 exhibited high levels of sKitL as well as MMP-9 in the serum. Importantly, MMP-9 deficiency impaired the development of CML-BC-like disease induced by BCR-ABL and Hes1 in mouse BMT models. The present results suggest that Hes1 promotes the development of CML-BC, partly through MMP-9 upregulation in leukemic cells.
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http://dx.doi.org/10.1182/blood-2013-01-476747DOI Listing
June 2014

Runx1 exon 6-related alternative splicing isoforms differentially regulate hematopoiesis in mice.

Blood 2014 Jun 25;123(24):3760-9. Epub 2014 Apr 25.

Moores University California San Diego Cancer Center, Biomedical Science Graduate Program, and Division of Biological Sciences, University of California San Diego, La Jolla, CA; Department of Pathology, University of California San Diego, La Jolla, CA.

RUNX1 is an important transcription factor for hematopoiesis. There are multiple alternatively spliced isoforms of RUNX1. The best known isoforms are RUNX1a from use of exon 7A and RUNX1b and c from use of exon 7B. RUNX1a has unique functions due to its lack of C-terminal regions common to RUNX1b and c. Here, we report that the ortholog of human RUNX1a was only found in primates. Furthermore, we characterized 3 Runx1 isoforms generated by exon 6 alternative splicing. Runx1bEx6(-) (Runx1b without exon 6) and a unique mouse Runx1bEx6e showed higher colony-forming activity than the full-length Runx1b (Runx1bEx6(+)). They also facilitated the transactivation of Runx1bEx6(+). To gain insight into in vivo functions, we analyzed a knock-in (KI) mouse model that lacks isoforms Runx1b/cEx6(-) and Runx1bEx6e. KI mice had significantly fewer lineage-Sca1(+)c-Kit(+) cells, short-term hematopoietic stem cells (HSCs) and multipotent progenitors than controls. In vivo competitive repopulation assays demonstrated a sevenfold difference of functional HSCs between wild-type and KI mice. Together, our results show that Runx1 isoforms involving exon 6 support high self-renewal capacity in vitro, and their loss results in reduction of the HSC pool in vivo, which underscore the importance of fine-tuning RNA splicing in hematopoiesis.
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http://dx.doi.org/10.1182/blood-2013-08-521252DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4055923PMC
June 2014

Cooperation between RUNX1-ETO9a and novel transcriptional partner KLF6 in upregulation of Alox5 in acute myeloid leukemia.

PLoS Genet 2013 10;9(10):e1003765. Epub 2013 Oct 10.

Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America.

Fusion protein RUNX1-ETO (AML1-ETO, RUNX1-RUNX1T1) is expressed as the result of the 8q22;21q22 translocation [t(8;21)], which is one of the most common chromosomal abnormalities found in acute myeloid leukemia. RUNX1-ETO is thought to promote leukemia development through the aberrant regulation of RUNX1 (AML1) target genes. Repression of these genes occurs via the recruitment of the corepressors N-COR and SMRT due to their interaction with ETO. Mechanisms of RUNX1-ETO target gene upregulation remain less well understood. Here we show that RUNX1-ETO9a, the leukemogenic alternatively spliced transcript expressed from t(8;21), upregulates target gene Alox5, which is a gene critically required for the promotion of chronic myeloid leukemia development by BCR-ABL. Loss of Alox5 expression reduces activity of RUNX1-ETO9a, MLL-AF9 and PML-RARα in vitro. However, Alox5 is not essential for the induction of leukemia by RUNX1-ETO9a in vivo. Finally, we demonstrate that the upregulation of Alox5 by RUNX1-ETO9a occurs via the C₂H₂ zinc finger transcription factor KLF6, a protein required for early hematopoiesis and yolk sac development. Furthermore, KLF6 is specifically upregulated by RUNX1-ETO in human leukemia cells. This identifies KLF6 as a novel mediator of t(8;21) target gene regulation, providing a new mechanism for RUNX1-ETO transcriptional control.
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http://dx.doi.org/10.1371/journal.pgen.1003765DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3794898PMC
March 2014

Upregulation of CD200R1 in lineage-negative leukemic cells is characteristic of AML1-ETO-positive leukemia in mice.

Int J Hematol 2012 Nov 25;96(5):638-48. Epub 2012 Oct 25.

Division of Cellular Therapy, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.

Activating mutations of c-Kit are frequently found in acute myeloid leukemia (AML) patients harboring t(8;21) chromosomal translocation generating a fusion protein AML1-ETO. Here we show that an active mutant of c-Kit cooperates with AML1-ETO to induce AML in mouse bone marrow transplantation models. Leukemic cells expressing AML1-ETO with c-Kit(D814V) were serially transplantable. Transplantation experiments indicated that lineage(-)c-Kit(+)Sca-1(+) (KSL) leukemic cells, but not lineage(+) leukemic cells, were enriched for leukemia stem cells (LSCs). Comparison of gene expression profiles between KSL leukemic and normal cells delineated that CD200R1 was highly expressed in KSL leukemic cells as compared with KSL normal cells. Upregulation of CD200R1 was verified in lineage(-) leukemic cells, but not in lineage(+) leukemic cells. CD200R1 expression in the lineage(-) leukemic cells was not correlated with the frequency of LSCs, indicating that CD200R1 is not a useful marker for LSCs in these models. Interestingly, CD200R1 was upregulated in KSL cells transduced with AML1-ETO, but not with other leukemogenic mutants, including c-Kit(D814V), AML1(D171N), and AML1(S291fsX300). Consistently, upregulation of CD200R1 in lineage(-) leukemic cells was observed only in the BM of mice suffering from AML1-ETO-positive leukemia. In conclusion, AML1-ETO upregulated CD200R1 in lineage(-) cells, which was characteristic of AML1-ETO-positive leukemia in mice.
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http://dx.doi.org/10.1007/s12185-012-1207-6DOI Listing
November 2012

Expression of the runt homology domain of RUNX1 disrupts homeostasis of hematopoietic stem cells and induces progression to myelodysplastic syndrome.

Blood 2012 Nov 23;120(19):4028-37. Epub 2012 Aug 23.

Moores UCSD Cancer Center, University of California San Diego, La Jolla, CA 92093, USA.

Mutations of RUNX1 are detected in patients with myelodysplastic syndrome (MDS). In particular, C-terminal truncation mutations lack a transcription regulatory domain and have increased DNA binding through the runt homology domain. The expression of the runt homology domain, RUNX1(41-214), in mouse hematopoietic cells induced progression to MDS and acute myeloid leukemia. Analysis of premyelodysplastic animals found expansion of c-Kit(+)Sca-1(+)Lin(-) cells and skewed differentiation to myeloid at the expense of the lymphoid lineage. These abnormalities correlate with the phenotype of Runx1-deficient animals, as expected given the reported dominant-negative role of C-terminal mutations over the full-length RUNX1. However, MDS is not observed in Runx1-deficient animals. Gene expression profiling found that RUNX1(41-214) c-Kit(+)Sca-1(+)Lin(-) cells have an overlapping yet distinct gene expression profile from Runx1-deficient animals. Moreover, an unexpected parallel was observed between the hematopoietic phenotype of RUNX1(41-214) and aged animals. Genes deregulated in RUNX1(41-214), but not in Runx1-deficient animals, were inversely correlated with the aging gene signature of HSCs, suggesting that disruption of the expression of genes related to normal aging by RUNX1 mutations contributes to development of MDS. The data presented here provide insights into the mechanisms of development of MDS in HSCs by C-terminal mutations of RUNX1.
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http://dx.doi.org/10.1182/blood-2012-01-404533DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3496957PMC
November 2012

Combined gene expression and DNA occupancy profiling identifies potential therapeutic targets of t(8;21) AML.

Blood 2012 Aug 26;120(7):1473-84. Epub 2012 Jun 26.

Moores Cancer Center, University of California-San Diego, La Jolla, CA 92093, USA.

Chromosome translocation 8q22;21q22 [t(8;21)] is commonly associated with acute myeloid leukemia (AML), and the resulting AML1-ETO fusion proteins are involved in the pathogenesis of AML. To identify novel molecular and therapeutic targets, we performed combined gene expression microarray and promoter occupancy (ChIP-chip) profiling using Lin(-)/Sca1(-)/cKit(+) cells, the major leukemia cell population, from an AML mouse model induced by AML1-ETO9a (AE9a). Approximately 30% of the identified common targets of microarray and ChIP-chip assays overlap with the human t(8;21)-gene expression molecular signature. CD45, a protein tyrosine phosphatase and a negative regulator of cytokine/growth factor receptor and JAK/STAT signaling, is among those targets. Its expression is substantially down-regulated in leukemia cells. Consequently, JAK/STAT signaling is enhanced. Re-expression of CD45 suppresses JAK/STAT activation, delays leukemia development, and promotes apoptosis of t(8;21)-positive cells. This study demonstrates the benefit of combining gene expression and promoter occupancy profiling assays to identify molecular and potential therapeutic targets in human cancers and describes a previously unappreciated signaling pathway involving t(8;21) fusion proteins, CD45, and JAK/STAT, which could be a potential novel target for treating t(8;21) AML.
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http://dx.doi.org/10.1182/blood-2011-12-395335DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3423785PMC
August 2012

PRMT1 interacts with AML1-ETO to promote its transcriptional activation and progenitor cell proliferative potential.

Blood 2012 May 12;119(21):4953-62. Epub 2012 Apr 12.

Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093, USA.

Fusion protein AML1-ETO, resulting from t(8;21) translocation, is highly related to leukemia development. It has been reported that full-length AML1-ETO blocks AML1 function and requires additional mutagenic events to promote leukemia. We have previously shown that the expression of AE9a, a splice isoform of AML1-ETO, can rapidly cause leukemia in mice. To understand how AML1-ETO is involved in leukemia development, we took advantage of our AE9a leukemia model and sought to identify its interacting proteins from primary leukemic cells. Here, we report the discovery of a novel AE9a binding partner PRMT1 (protein arginine methyltransferase 1). PRMT1 not only interacts with but also weakly methylates arginine 142 of AE9a. Knockdown of PRMT1 affects expression of a specific group of AE9a-activated genes. We also show that AE9a recruits PRMT1 to promoters of AE9a-activated genes, resulting in enrichment of H4 arginine 3 methylation, H3 Lys9/14 acetylation, and transcription activation. More importantly, knockdown of PRMT1 suppresses the self-renewal capability of AE9a, suggesting a potential role of PRMT1 in regulating leukemia development.
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http://dx.doi.org/10.1182/blood-2011-04-347476DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3367897PMC
May 2012

Transforming growth factor-β-stimulated clone-22 is a negative-feedback regulator of Ras / Raf signaling: Implications for tumorigenesis.

Cancer Sci 2012 Jan 1;103(1):26-33. Epub 2011 Nov 1.

Division of Cellular Therapy, Institute of Medical Science, University of Tokyo, Tokyo, Japan.

Transforming growth factor-β (TGF-β)-stimulated clone-22 (TSC-22), also called TSC22D1-2, is a putative tumor suppressor. We previously identified TSC-22 downstream of an active mutant of fms-like tyrosine kinase-3 (Flt3). Here, we show that TSC-22 works as a tumor suppressor through inhibiting Ras/Raf signaling. Notably, TSC-22 was upregulated by Ras/Raf activation, whereas its upregulation was inhibited by concurrent STAT5 activation. Although TSC-22 was normally retained in the cytoplasm by its nuclear export signal (NES), Ras/Raf activation caused nuclear translocation of TSC-22, but not TSC22D1-1. Unlike glucocorticoid-induced leucine zipper (GILZ/TSC22D3-2) previously characterized as a negative regulator of Ras/Raf signaling, TSC-22 failed to interact physically with Ras/Raf. Importantly, transduction with TSC-22, but not TSC22D1-1, suppressed the growth, transformation and tumorigenesis of NIH3T3 cells expressing oncogenic H-Ras: this suppression was enhanced by transduction with a TSC-22 mutant lacking NES that had accumulated in the nucleus. Collectively, upregulation and nuclear translocation of TSC-22 played an important role in the feedback suppression of Ras/Raf signaling. Consistently, TSC22D1-deficient mice were susceptible to tumorigenesis in a mouse model of chemically-induced liver tumors bearing active mutations of Ras/Raf. Thus, TSC-22 negatively regulated Ras/Raf signaling through a mechanism different from GILZ, implicating TSC-22 as a novel suppressor of oncogenic Ras/Raf-induced tumors.
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http://dx.doi.org/10.1111/j.1349-7006.2011.02108.xDOI Listing
January 2012

Two types of C/EBPα mutations play distinct but collaborative roles in leukemogenesis: lessons from clinical data and BMT models.

Blood 2011 Jan 30;117(1):221-33. Epub 2010 Sep 30.

Division of Cellular Therapy, Institute of Medical Science, University of Tokyo, Tokyo, Japan.

Two types of mutations of a transcription factor CCAAT-enhancer binding protein α (C/EBPα) are found in leukemic cells of 5%-14% of acute myeloid leukemia (AML) patients: N-terminal mutations expressing dominant negative p30 and C-terminal mutations in the basic leucine zipper domain. Our results showed that a mutation of C/EBPα in one allele was observed in AML after myelodysplastic syndrome, while the 2 alleles are mutated in de novo AML. Unlike an N-terminal frame-shift mutant (C/EBPα-N(m))-transduced cells, a C-terminal mutant (C/EBPα-C(m))-transduced cells alone induced AML with leukopenia in mice 4-12 months after bone marrow transplantation. Coexpression of both mutants induced AML with marked leukocytosis with shorter latencies. Interestingly, C/EBPα-C(m) collaborated with an Flt3-activating mutant Flt3-ITD in inducing AML. Moreover, C/EBPα-C(m) strongly blocked myeloid differentiation of 32Dcl3 cells, suggesting its class II mutation-like role in leukemogenesis. Although C/EBPα-C(m) failed to inhibit transcriptional activity of wild-type C/EBPα, it suppressed the synergistic effect between C/EBPα and PU.1. On the other hand, C/EBPα-N(m) inhibited C/EBPα activation in the absence of PU.1, despite low expression levels of p30 protein generated by C/EBPα-N(m). Thus, 2 types of C/EBPα mutations are implicated in leukemo-genesis, involving different and cooperating molecular mechanisms.
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http://dx.doi.org/10.1182/blood-2010-02-270181DOI Listing
January 2011

TIM1 is an endogenous ligand for LMIR5/CD300b: LMIR5 deficiency ameliorates mouse kidney ischemia/reperfusion injury.

J Exp Med 2010 Jul 21;207(7):1501-11. Epub 2010 Jun 21.

Division of Cellular Therapy, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan.

Leukocyte mono-immunoglobulin (Ig)-like receptor 5 (LMIR5)/CD300b is a DAP12-coupled activating receptor predominantly expressed in myeloid cells. The ligands for LMIR have not been reported. We have identified T cell Ig mucin 1 (TIM1) as a possible ligand for LMIR5 by retrovirus-mediated expression cloning. TIM1 interacted only with LMIR5 among the LMIR family, whereas LMIR5 interacted with TIM4 as well as TIM1. The Ig-like domain of LMIR5 bound to TIM1 in the vicinity of the phosphatidylserine (PS)-binding site within the Ig-like domain of TIM1. Unlike its binding to TIM1 or TIM4, LMIR5 failed to bind to PS. LMIR5 binding did not affect TIM1- or TIM4-mediated phagocytosis of apoptotic cells, and stimulation with TIM1 or TIM4 induced LMIR5-mediated activation of mast cells. Notably, LMIR5 deficiency suppressed TIM1-Fc-induced recruitment of neutrophils in the dorsal air pouch, and LMIR5 deficiency attenuated neutrophil accumulation in a model of ischemia/reperfusion injury in the kidneys in which TIM1 expression is up-regulated. In that model, LMIR5 deficiency resulted in ameliorated tubular necrosis and cast formation in the acute phase. Collectively, our results indicate that TIM1 is an endogenous ligand for LMIR5 and that the TIM1-LMIR5 interaction plays a physiological role in immune regulation by myeloid cells.
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http://dx.doi.org/10.1084/jem.20090581DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2901072PMC
July 2010

Hes1 immortalizes committed progenitors and plays a role in blast crisis transition in chronic myelogenous leukemia.

Blood 2010 Apr 27;115(14):2872-81. Epub 2009 Oct 27.

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

Hairy enhancer of split 1 (Hes1) is a basic helix-loop-helix transcriptional repressor that affects differentiation and often helps maintain cells in an immature state in various tissues. Here we show that retroviral expression of Hes1 immortalizes common myeloid progenitors (CMPs) and granulocyte-macrophage progenitors (GMPs) in the presence of interleukin-3, conferring permanent replating capability on these cells. Whereas these cells did not develop myeloproliferative neoplasms when intravenously administered to irradiated mice, the combination of Hes1 and BCR-ABL in CMPs and GMPs caused acute leukemia resembling blast crisis of chronic myelogenous leukemia (CML), resulting in rapid death of the recipient mice. On the other hand, BCR-ABL alone caused CML-like disease when expressed in c-Kit-positive, Sca-1-positive, and lineage-negative hematopoietic stem cells (KSLs), but not committed progenitors CMPs or GMPs, as previously reported. Leukemic cells derived from Hes1 and BCR-ABL-expressing CMPs and GMPs were more immature than those derived from BCR-ABL-expressing KSLs. Intriguingly, Hes1 was highly expressed in 8 of 20 patients with CML in blast crisis, but not in the chronic phase, and dominant negative Hes1 retarded the growth of some CML cell lines expressing Hes1. These results suggest that Hes1 is a key molecule in blast crisis transition in CML.
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http://dx.doi.org/10.1182/blood-2009-05-222836DOI Listing
April 2010

Possible involvement of RasGRP4 in leukemogenesis.

Int J Hematol 2009 May 7;89(4):470-481. Epub 2009 Apr 7.

Division of Cellular Therapy, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan.

It is now conceivable that leukemogenesis requires two types of mutations, class I and class II mutations. We previously established a mouse bone marrow-derived HF6, an IL-3-dependent cell line, that was immortalized by a class II mutation MLL/SEPT6 and can be fully transformed by class I mutations such as FLT3 mutants. To understand the molecular mechanism of leukemogenesis, particularly progression of myelodysplastic syndrome (MDS) to acute leukemia, we made cDNA libraries from the samples of patients and screened them by expression-cloning to detect class I mutations that render HF6 cells factor-independent. We identified RasGRP4, an activator of Ras, as a candidate for class I mutation from three of six patients (MDS/MPD = 1, MDS-RA = 1, MDS/AML = 2, CMMoL/AML = 1 and AML-M2 = 1). To investigate the potential roles of RasGRP4 in leukemogenesis, we tested its in vivo effect in a mouse bone marrow transplantation (BMT) model. C57BL/6J mice transplanted with RasGRP4-transduced primary bone marrow cells died of T cell leukemia, myeloid leukemia, or myeloid leukemia with T cell leukemia. To further examine if the combination of class I and class II mutations accelerated leukemic transformation, we performed a mouse BMT model in which both AML1 mutant (S291fsX300) and RasGRP4 were transduced into bone marrow cells. The double transduction led to early onset of T cell leukemia but not of AML in the transplanted mice when compared to transduction of RasGRP4 alone. Thus, we have identified RasGRP4 as a gene potentially involved in leukemogenesis and suggest that RasGRP4 cooperates with AML1 mutations in T cell leukemogenesis as a class I mutation.
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http://dx.doi.org/10.1007/s12185-009-0299-0DOI Listing
May 2009

Molecular bases of myelodysplastic syndromes: lessons from animal models.

J Cell Physiol 2009 Jun;219(3):529-34

Division of Cellular Therapy, Institute of Medical Science, the University of Tokyo, Tokyo, Japan.

Myelodysplastic syndrome (MDS) is a clonal disorder of hematopietic stem cells characterized by ineffective hematopoiesis, peripheral blood cytopenia, morphologic dysplasia, and susceptibility to acute myeloid leukemia. Several mechanisms have been suggested as causes of MDS: unbalanced chromosomal abnormalities reflecting a gain or loss of chromosomal material, point mutations of transcription factors, and inactivation of p53. However, appropriate animal models that mimic MDS have long been lacking. We recently reported a novel murine model of MDS that recapitulates trilineage dysplasia and transformation to AML. In this review, we summarize the animal models of MDS and discuss the molecular bases of MDS as well as those of leukemia and myeloproliferative disorders (MPD). J. Cell. Physiol. 219: 529-534, 2009. (c) 2009 Wiley-Liss, Inc.
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http://dx.doi.org/10.1002/jcp.21739DOI Listing
June 2009

Enhanced expression of p210BCR/ABL and aberrant expression of Zfp423/ZNF423 induce blast crisis of chronic myelogenous leukemia.

Blood 2009 May 20;113(19):4702-10. Epub 2009 Feb 20.

Department of Developmental Biology, Research Institute of Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.

Chronic myelogenous leukemia (CML) is a hematopoietic disorder originating from p210BCR/ABL-transformed stem cells, which begins as indolent chronic phase (CP) but progresses into fatal blast crisis (BC). To investigate molecular mechanism(s) underlying disease evolution, CML-exhibiting p210BCR/ABL transgenic mice were crossed with BXH2 mice that transmit a replication-competent retrovirus. Whereas nontransgenic mice in the BXH2 background exclusively developed acute myeloid leukemia, p210BCR/ABL transgenic littermates developed nonmyeloid leukemias, in which inverse polymerase chain reaction detected 2 common viral integration sites (CISs). Interestingly, one CIS was transgene's own promoter, which up-regulated p210BCR/ABL expression. The other was the 5' noncoding region of a transcription factor, Zfp423, which induced aberrant Zfp423 expression. The cooperative activities of Zfp423 and p210BCR/ABL were demonstrated as follows: (1) introduction of Zfp423 in p210BCR/ABL transgenic bone marrow (BM) cells increased colony-forming ability, (2) suppression of ZNF423 (human homologue of Zfp423) in ZNF423-expressing, p210BCR/ABL-positive hematopoietic cells retarded cell growth, (3) mice that received a transplant of BM cells transduced with Zfp423 and p210BCR/ABL developed acute leukemia, and (4) expression of ZNF423 was found in human BCR/ABL-positive cell lines and CML BC samples. These results demonstrate that enhanced expression of p210BCR/ABL and deregulated expression of Zfp423/ZNF423 contribute to CML BC.
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http://dx.doi.org/10.1182/blood-2007-05-088724DOI Listing
May 2009

AML1 mutations induced MDS and MDS/AML in a mouse BMT model.

Blood 2008 Apr 11;111(8):4297-308. Epub 2008 Jan 11.

Division of Cellular Therapy, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo, USA.

Myelodysplastic syndrome (MDS) is a hematopoietic stem-cell disorder characterized by trilineage dysplasia and susceptibility to acute myelogenous leukemia (AML). Analysis of molecular basis of MDS has been hampered by the heterogeneity of the disease. Recently, mutations of the transcription factor AML1/RUNX1 have been identified in 15% to 40% of MDS-refractory anemia with excess of blasts (RAEB) and MDS/AML. We performed mouse bone marrow transplantation (BMT) using bone marrow cells transduced with the AML1 mutants. Most mice developed MDS and MDS/AML-like symptoms within 4 to 13 months after BMT. Interestingly, among integration sites identified, Evi1 seemed to collaborate with an AML1 mutant harboring a point mutation in the Runt homology domain (D171N) to induce MDS/AML with an identical phenotype characterized by marked hepatosplenomegaly, myeloid dysplasia, leukocytosis, and biphenotypic surface markers. Collaboration between AML1-D171N and Evi1 was confirmed by a BMT model where coexpression of AML1-D171N and Evi1 induced acute leukemia of the same phenotype with much shorter latencies. On the other hand, a C-terminal truncated AML1 mutant (S291fsX300) induced pancytopenia with erythroid dysplasia in transplanted mice, followed by progression to MDS-RAEB or MDS/AML. Thus, we have developed a useful mouse model of MDS/AML that should help in the understanding of the molecular basis of MDS and the progression of MDS to overt leukemia.
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http://dx.doi.org/10.1182/blood-2007-01-068346DOI Listing
April 2008

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

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

Ischemic colitis as a manifestation of thrombotic microangiopathy following bone marrow transplantation.

Intern Med 2003 Dec;42(12):1228-32

Department of Cell Therapy & Transplantation Medicine, University of Tokyo Hospital, Tokyo.

Thrombotic microangiopathy (TMA) is a microvascular disorder characterized by platelet aggregation and hemolytic anemia. In the setting of bone marrow transplantation (BMT), ischemic colitis due to TMA is difficult to differentiate from acute graft-versus-host disease. We report a 32-year-old man who presented ischemic colitis due to TMA after unrelated BMT for myelodysplastic syndrome. He suffered from treatment-resistant bloody diarrhea, and died of renal failure and Aspergillus pleuritis on day 253 post-BMT. Autopsy revealed endothelial injuries of arterioles and ischemic changes in the intestines and kidneys. Clinical and pathological characteristics of ischemic colitis due to BMT-associated TMA are described.
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http://dx.doi.org/10.2169/internalmedicine.42.1228DOI Listing
December 2003