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1.
Transplant Cell Ther ; 29(10): 622-631, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37536453

RESUMEN

In Japan, only single-unit cord blood transplantations (CBTs) are typically performed, and their number has increased over the last 23 years, with ongoing improvement in results. In most cases, CBTs with multiple HLA mismatches are used, owing to a low HLA barrier, and lower engraftment rate is a problem that must be overcome. Here, as part of an effort to improve guidelines for the selection and processing of CB units for transplantation, we sought to assess the present status of CBT in Japan and to elucidate factors contributing to the favorable outcomes, focusing in particular on selection by cell components of CB unit and HLA allele matching. We conducted a nationwide study analyzing 13,443 patients who underwent first CBT between in Japan between December 1997 and December 2019 using multivariate regression analysis. Both patient- and transplantation-related variables, such as age and Hematopoietic Cell Transplantation Comorbidity Index, as well as selected CB unit characteristics, were included in the analysis. The interaction analysis elucidated that CB unit selection favoring higher counts of CD34+ cells and granulocyte macrophage colony-forming units (GM-CFU)/kg, but not of total nucleated cells, contributed to improved engraftment after transplantation. Moreover, a higher CD34+ cell dose was associated with improved overall survival (OS). Distinctive HLA allele matching was observed. A 0 or 1 HLA allele mismatch between patient and donor had favorable engraftment and carried significantly lower risks of acute GVHD and chronic GVHD but had a significantly higher leukemia relapse rate, compared with a 3-HLA allele mismatch. HLA-DRB1 mismatches were associated with reduced risk of leukemia relapse. Notably, the number of HLA allele mismatches had no incremental effect on engraftment, acute and chronic GVHD, or relapse incidence. As a result, 5-year overall survival did not differ significantly among patients receiving CB units with 0 to 7 HLA allele mismatches. The main points of CB unit selection are as follows. First, selection according to a higher number of CD34+ cells/kg and then of CFU-GM/kg is recommended to obtain favorable engraftment. A unit with .5 × 105 CD34+ cells/kg is minimally acceptable. For units with a CD34+ cell dose of .5 to 1.0 × 105 cells/kg, applying the parameter of ≥20 to 50 × 103 GM-CFU/kg (66.5% of transplanted CB units in this cohort) is associated with a neutrophil engraftment rate of approximately 90%. A unit with ≥1.0 × 105 CD34+ cells/kg can achieve a ≥90% mean neutrophil engraftment rate. Subsequently, HLA allele matching of HLA-A, -B, -C, and -DRB1 at the 2-field level should be searched for units with 0 or 1 HLA allele mismatch in the host-versus-graft direction for favorable engraftment. Units with 2 to 6 HLA allele mismatches are acceptable in patients age ≥15 years and units with 2 to 4 HLA allele mismatches are acceptable in patients age ≤14 years. Units with HLA-DRB1 and/or -B allele mismatch(es) might not be preferable owing to an increased GVHD risk. Our analysis demonstrates that single-unit CBT with the selection of adequate CD34+/kg and GM-CFU/kg and HLA allele matching showed favorable outcomes in both pediatric and adult patients.

2.
Vox Sang ; 117(1): 128-132, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34125957

RESUMEN

BACKGROUND: CD36 is a glycoprotein expressed on platelets and monocytes of the blood. There are two types of CD36 deficiency, type I and type II. Individuals with type I-deficiency do not express CD36 in any cell type and can produce the CD36 antibody, which causes pathological conditions, such as fetal/neonatal alloimmune thrombocytopenia (FNAIT) and platelet transfusion refractory (PTR), through antigenic exposure via transfusion or pregnancy. CASE PRESENTATION: We experienced a case of Philadelphia-positive acute lymphoblastic leukaemia with PTR. In addition to the CD36 antibody, multiple-specificity HLA antibodies were present in the patient's plasma, requiring transfusion of HLA-compatible and CD36-negative platelets (PC-HLA). Since the number of donors was limited, it was necessary to set-up a blood transfusion schedule so that hyper-fractionated cyclophosphamide, vincristine and doxorubicin therapy (hyper-CVAD) and ponatinib combination chemotherapy could be safely administered to achieve molecular remission. Rituximab administration resulted in reduced levels of both CD36 antibody and HLA antibody. Given the expression of CD36 on haematopoietic stem cells and the limited availability of CD36-negative PC-HLA, haematopoietic stem cell transplantation (HSCT) was not considered to be an option. CONCLUSION: If CD36-negative, allogeneic haematopoietic stem cell donors are unable to be found, the indications for HSCT in patients with type I CD36-deficiency should be carefully weighed. In the present case, molecular remission has been able to be maintained to the present day after completion of a two-year maintenance regimen.


Asunto(s)
Trastornos de las Plaquetas Sanguíneas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Trombocitopenia Neonatal Aloinmune , Femenino , Enfermedades Genéticas Congénitas , Humanos , Cromosoma Filadelfia , Embarazo
3.
Leuk Lymphoma ; 62(11): 2737-2746, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34128753

RESUMEN

The combined effects of HLA-allele matching at six-loci (HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1) and CD34+ cell dose on clinical outcomes were analyzed in 1,226 adult cases with single-unit unrelated cord blood transplantation. In the six-loci analysis, low HLA-allele matches did not significantly increase the overall mortality compared to higher matches, whereas in the five-loci analysis excluding HLA-DPB1, they caused a higher overall mortality (HR 1.42, p = .002), possibly due to the graft-versus-leukemia effect of HLA-DPB1 mismatches. A lower CD34+ cell dose (<.50 × 105/kg) resulted in higher mortality and lower engraftment; these inferior outcomes were offset by high HLA-allele matches (7-10/10 match), while the inferior outcomes of low HLA-allele matches were improved by increasing the CD34+ cell dose. Consideration of the combined effects of the CD34+ cell dose and HLA matching may expand the options for transplantable units when HLA matching or the CD34+ cell dose is inadequate.


Asunto(s)
Trasplante de Células Madre de Sangre del Cordón Umbilical , Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Adulto , Alelos , Prueba de Histocompatibilidad , Humanos
5.
Vox Sang ; 115(7): 579-585, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32314425

RESUMEN

BACKGROUND AND OBJECTIVES: MNS is a highly polymorphic blood group comprising 49 antigens recognized by International Society of Blood Transfusion, some of which may have been generated by genomic recombination among the closely linked genes GYPA, GYPB and GYPE. The GYPE gene has an almost identical sequence to GYPA*01 allele in exon 2 (99% homology), which accounts for M antigen. We investigated an unusual glycophorin molecule with protease-resistant M antigen. METHODS: Blood samples were screened by an automated blood typing system (PK7300) using bromelain-treated red blood cells (RBCs) and murine monoclonal anti-M. The M-positive RBC samples were analysed by immunoblotting using anti-M as the primary antibody. GYPA, GYPB and GYPE genes were analysed by polymerase chain reaction (PCR), cloning and sequencing using reticulocyte mRNA and genomic DNA. RESULTS: Serological tests and immunoblotting revealed that 103 of the 193 009 individuals (0·0534%) expressed protease-resistant M-active glycophorin having a molecular weight of 20 kDa. All the 103 individuals were S+ s- or S- s+. When reticulocyte mRNA from the individuals with M-active glycophorin (20 kDa) was examined by PCR and cloning followed by sequencing, a novel GYPE-B hybrid transcript was identified. Long-range PCR and sequencing using genomic DNA revealed that the individuals had a GYPB-E(2-4)-B hybrid gene. This hybrid gene was predicted to encode a 59-amino-acid mature glycoprotein that expresses no S or s antigens CONCLUSIONS: The prevalence of the M-active glycophorin (20 kDa) in the Japanese population is 0·0534%. This glycophorin is predicted to be a 59 amino acids polypeptide encoded by the novel GYPB-E(2-4)-B hybrid gene.


Asunto(s)
Alelos , Glicoforinas/genética , Células Cultivadas , Glicoforinas/química , Glicoforinas/metabolismo , Humanos , Péptido Hidrolasas/metabolismo , Polimorfismo Genético , Dominios Proteicos , Proteolisis , ARN Mensajero/genética , ARN Mensajero/metabolismo
6.
Pediatr Blood Cancer ; 66(3): e27555, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30488611

RESUMEN

Maternal antibodies against human platelet antigen (HPA) and/or human leukocyte antigen (HLA) cause fetal and neonatal alloimmune thrombocytopenia (FNAIT) in 0.09-0.15% of live births. Severe cases account for 5-31% and the frequency of multiple kinds of alloantibodies is 6.9-9% of FNAIT. We present a case of severe FNAIT associated with anti-HPA-5b, anti-HLA-A31, and anti-HLA-B55 antibodies, successfully treated with immunoglobulin and platelet transfusion. The anti-HLA-B55 antibody was detected in the newborn's serum, but disappeared on the 20th day, which was followed by an increase of the platelet count. These findings suggested the potential involvement of an anti-HLA antibody in the pathogenesis of FNAIT.


Asunto(s)
Antígenos de Plaqueta Humana/inmunología , Antígenos HLA-A/inmunología , Antígenos HLA-B/inmunología , Inmunidad Materno-Adquirida/inmunología , Isoanticuerpos/inmunología , Trombocitopenia Neonatal Aloinmune/inmunología , Adulto , Femenino , Humanos , Inmunoglobulinas/administración & dosificación , Recién Nacido , Masculino , Transfusión de Plaquetas/métodos , Pronóstico , Trombocitopenia Neonatal Aloinmune/patología , Trombocitopenia Neonatal Aloinmune/terapia
7.
J Biochem ; 159(1): 17-25, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26590301

RESUMEN

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.


Asunto(s)
Carcinogénesis/genética , Neoplasias Hematológicas/genética , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicos/genética , Translocación Genética , Animales , Proliferación Celular , Transformación Celular Neoplásica/genética , Epigénesis Genética , Células Madre Hematopoyéticas/metabolismo , Humanos , Ratones , Ratones Transgénicos , Mutación , Proteínas de Fusión Oncogénica/genética , Fenotipo
8.
Transfus Apher Sci ; 52(1): 112-21, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25467707

RESUMEN

BACKGROUND: Multiple platelet exposure induces anti-HLA and/or anti-HPA antibody production, which may cause platelet transfusion refractoriness (PTR). In Japan, the universal pre-storage leukocyte reduction (ULR) was fully implemented since 2006, but prior to ULR, in our institution, leukocyte reduction filters were routinely used at the bedside (bedside leukoreduction, BSLR) for all onco-hematological patients receiving multiple platelet transfusions. OBJECTIVE: We retrospectively compared patients receiving platelet transfusions in the era of ULR with those of BSLR era. MATERIALS AND METHODS: Patients of the BSLR group (409 cases) and the ULR group (586 cases) were compared in terms of alloimmunization and immunological PTR. The clinico-pathological features, including gender, history of pregnancy, number of exposed transfusion donors, periods of transfusion, and prior stem cell transplantation were compared, and the risk factors of alloimmunization were determined. RESULTS: The antibody detection rate was significantly higher in the ULR compared to BSLR group (8.7% vs. 5.4%), as well as the immunological PTR rate (7.3% vs. 3.2%). By the multivariate analysis, female gender and the number of platelet donor exposure, but not universal leukoreduction or transfusion period, were found to be the risk factors strongly associated with alloantibody formation. CONCLUSION: Although ULR may be superior to BSLR in terms of preventing non-hemolytic transfusion reactions, BSLR was found to be as effective as ULR in terms of preventing platelet alloimmunization and refractoriness. Thus, BSLR should be actively indicated as a realistic alternative in developing countries, before the universal leukoreduction is fully implemented.


Asunto(s)
Incompatibilidad de Grupos Sanguíneos/sangre , Neoplasias Hematológicas/sangre , Neoplasias Hematológicas/terapia , Isoanticuerpos/sangre , Leucaféresis , Transfusión de Plaquetas/efectos adversos , Sistemas de Atención de Punto , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Incompatibilidad de Grupos Sanguíneos/epidemiología , Incompatibilidad de Grupos Sanguíneos/etiología , Femenino , Neoplasias Hematológicas/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Embarazo , Estudios Retrospectivos , Factores Sexuales , Factores de Tiempo
9.
Blood ; 124(24): 3587-96, 2014 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-25298035

RESUMEN

Ecotropic viral integration site 1 (Evi1) is a transcription factor that is highly expressed in hematopoietic stem cells and is crucial for their self-renewal capacity. Aberrant expression of Evi1 is observed in 5% to 10% of de novo acute myeloid leukemia (AML) patients and predicts poor prognosis, reflecting multiple leukemogenic properties of Evi1. Here, we show that thrombopoietin (THPO) signaling is implicated in growth and survival of Evi1-expressing cells using a mouse model of Evi1 leukemia. We first identified that the expression of megakaryocytic surface molecules such as ITGA2B (CD41) and the THPO receptor, MPL, positively correlates with EVI1 expression in AML patients. In agreement with this finding, a subpopulation of bone marrow and spleen cells derived from Evi1 leukemia mice expressed both CD41 and Mpl. CD41(+) Evi1 leukemia cells induced secondary leukemia more efficiently than CD41(-) cells in a serial bone marrow transplantation assay. Importantly, the CD41(+) cells predominantly expressing Mpl effectively proliferated and survived on OP9 stromal cells in the presence of THPO via upregulating BCL-xL expression, suggesting an essential role of the THPO/MPL/BCL-xL cascade in enhancing the progression of Evi1 leukemia. These observations provide a novel aspect of the diverse functions of Evi1 in leukemogenesis.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Leucemia/metabolismo , Neoplasias Experimentales/metabolismo , Proteínas Oncogénicas/metabolismo , Glicoproteína IIb de Membrana Plaquetaria/metabolismo , Receptores de Trombopoyetina/metabolismo , Transducción de Señal , Trombopoyetina/metabolismo , Factores de Transcripción/metabolismo , Animales , Supervivencia Celular , Proteínas de Unión al ADN/genética , Regulación Leucémica de la Expresión Génica/genética , Leucemia/genética , Leucemia/patología , Proteína del Locus del Complejo MDS1 y EV11 , Ratones , Trasplante de Neoplasias , Neoplasias Experimentales/genética , Neoplasias Experimentales/patología , Proteínas Oncogénicas/genética , Glicoproteína IIb de Membrana Plaquetaria/genética , Proto-Oncogenes/genética , Receptores de Trombopoyetina/genética , Trombopoyetina/genética , Factores de Transcripción/genética , Células Tumorales Cultivadas , Proteína bcl-X/biosíntesis , Proteína bcl-X/genética
11.
Genome Res ; 24(4): 580-91, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24414704

RESUMEN

The myelodysplastic syndrome (MDS) is a clonal hematologic disorder that frequently evolves to acute myeloid leukemia (AML). Its pathogenesis remains unclear, but mutations in epigenetic modifiers are common and the disease often responds to DNA methylation inhibitors. We analyzed DNA methylation in the bone marrow and spleen in two mouse models of MDS/AML, the NUP98-HOXD13 (NHD13) mouse and the RUNX1 mutant mouse model. Methylation array analysis showed an average of 512/3445 (14.9%) genes hypermethylated in NHD13 MDS, and 331 (9.6%) genes hypermethylated in RUNX1 MDS. Thirty-two percent of genes in common between the two models (2/3 NHD13 mice and 2/3 RUNX1 mice) were also hypermethylated in at least two of 19 human MDS samples. Detailed analysis of 41 genes in mice showed progressive drift in DNA methylation from young to old normal bone marrow and spleen; to MDS, where we detected accelerated age-related methylation; and finally to AML, which markedly extends DNA methylation abnormalities. Most of these genes showed similar patterns in human MDS and AML. Repeat element hypomethylation was rare in MDS but marked the transition to AML in some cases. Our data show consistency in patterns of aberrant DNA methylation in human and mouse MDS and suggest that epigenetically, MDS displays an accelerated aging phenotype.


Asunto(s)
Metilación de ADN/genética , Epigénesis Genética/genética , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicos/genética , Animales , Células de la Médula Ósea , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Modelos Animales de Enfermedad , Humanos , Leucemia Mieloide Aguda/patología , Ratones , Síndromes Mielodisplásicos/patología , Proteínas de Complejo Poro Nuclear/genética
12.
Transfusion ; 54(4): 1093-9, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24147542

RESUMEN

BACKGROUND: Several studies have documented the role of antibodies against human platelet (PLT) antigen (HPA)-15 in alloimmune-mediated thrombocytopenia including neonatal alloimmune thrombocytopenia, PLT transfusion refractoriness (PTR), and posttransfusion purpura in Caucasian persons. However, the relevance of anti-HPA-15 in PTR among the Japanese population is still unclear. STUDY DESIGN AND METHODS: The sera of 305 multiply PLT transfused (MPT) patients, previously investigated for the presence of human leukocyte antigen (HLA) and HPA antibodies by mixed passive hemagglutination, were reexamined for the presence of HPA-15 alloantibodies, using the monoclonal antibody-specific immobilization of PLT antigens (MAIPA) technique. RESULTS: Among the 305 MPT samples, antibodies against HPA-15 alloantigen was detected in seven (2.3%), two (0.66%) being anti-HPA-15a and five (1.64%) being anti-HPA-15b. Additionally, one case of CD109 panreactive antibody was found (0.33%). Among them, one aplastic anemia patient with blood group O developed multispecific anti-HLA and anti-HPA-15b alloantibody after MPTs. However, transfusion with HLA-matched PLTs of blood group AB did not result in adequate PLT count increment. Analysis of the possible influence of immune anti-A and anti-B by the MAIPA assay resulted negative, indicating that anti-HPA-15b is responsible for the refractory state in this patient. CONCLUSION: In this study, we found alloimmunization against HPA-15a and -15b in Japanese populations and demonstrated the relevance of these antibodies in a patient with PTR.


Asunto(s)
Antígenos CD/inmunología , Plaquetas/inmunología , Isoanticuerpos/inmunología , Proteínas de Neoplasias/inmunología , Transfusión de Plaquetas , Adulto , Antígenos de Plaqueta Humana/inmunología , Pueblo Asiatico , Línea Celular , Estudios de Cohortes , Femenino , Proteínas Ligadas a GPI/inmunología , Humanos , Transfusión de Plaquetas/efectos adversos , Embarazo , Complicaciones Hematológicas del Embarazo/inmunología , Recurrencia , Trombocitopenia/inmunología
14.
Int J Hematol ; 98(1): 56-65, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23695795

RESUMEN

Allogeneic peripheral blood stem cell transplantation (PBSCT) is an indispensable treatment option for hematological malignancy. The optimal collection day after granulocyte colony-stimulating factor (G-CSF) administration should be determined by peripheral blood pre-apheresis CD34 positive (CD34⁺) cell percentage. However, pre-apheresis CD34⁺ cell analysis is not available for most institutions in Japan. Prediction of the optimal collection day based on objective parameters, other than direct CD34⁺ cell count, is thus an important matter for investigation. To identify potential predictive factors, clinical parameters in 79 related donors who received allogeneic peripheral blood stem cell (PBSC) collection were analyzed. Eight factors were significantly correlated with the number of CD34⁺ cells per donor body weight on the fourth day (day 4) after G-CSF administration in univariate analysis. Using multi-regression analysis, we made a simple scoring system comprising age, sex, LDH on day 4 and RBC count at the baseline, which significantly predicted CD34⁺ cell yield (P = 0.048). This system allows us to determine the optimal PBSC collection day. When the score is 0 or 1 on day 4, starting apheresis on day 5 potentially helps avoiding the need for multiple harvests. Score 3 or 4 on day 4 is indicative of better performance if apheresis is started on day 4.


Asunto(s)
Antígenos CD34/sangre , Donantes de Sangre , Factor Estimulante de Colonias de Granulocitos/farmacología , Inmunomodulación , Linfopoyesis/efectos de los fármacos , Modelos Biológicos , Células Madre/efectos de los fármacos , Adolescente , Adulto , Antígenos CD34/metabolismo , Niño , Femenino , Humanos , Lactato Deshidrogenasas/sangre , Masculino , Persona de Mediana Edad , Trasplante de Células Madre de Sangre Periférica , Estudios Retrospectivos , Células Madre/metabolismo , Factores de Tiempo , Trasplante Homólogo , Adulto Joven
15.
Int J Hematol ; 97(6): 726-34, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23613270

RESUMEN

Since its discovery from a translocation in leukemias, the runt-related transcription factor 1/acute myelogenous leukemia-1 (RUNX1/AML1), which is widely expressed in hematopoietic cells, has been extensively studied. Many lines of evidence have shown that RUNX1 plays a critical role in regulating the development and precise maintenance of mammalian hematopoiesis. Studies using knockout mice have shown the importance of RUNX1 in a wide variety of hematopoietic cells, including hematopoietic stem cells and megakaryocytes. Recently, target molecular processes of RUNX1 in normal and malignant hematopoiesis have been revealed. Although RUNX1 is not required for the maintenance of hematopoietic stem cells, it is required for the homeostasis of hematopoietic stem and progenitor cells, and expansion of hematopoietic stem and progenitor cells due to RUNX1 deletion may be an important cause of human leukemias. Molecular abnormalities cooperating with loss of RUNX1 have also been identified. These findings may lead to a further understanding of human leukemias, and suggest novel molecular targeted therapies in the near future.


Asunto(s)
Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Hematopoyesis/genética , Leucemia Mieloide/genética , Leucemia Mieloide/metabolismo , Animales , Plaquetas/metabolismo , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Regulación Leucémica de la Expresión Génica , Humanos , Megacariocitos/metabolismo , Unión Proteica
16.
Blood ; 121(20): 4142-55, 2013 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-23547050

RESUMEN

Ecotropic viral integration site 1 (Evi1) is one of the master regulators in the development of acute myeloid leukemia (AML) and myelodysplastic syndrome. High expression of Evi1 is found in 10% of patients with AML and indicates a poor outcome. Several recent studies have indicated that Evi1 requires collaborative factors to induce AML. Therefore, the search for candidate factors that collaborate with Evi1 in leukemogenesis is one of the key issues in uncovering the mechanism of Evi1-related leukemia. Previously, we succeeded in making a mouse model of Evi1-related leukemia using a bone marrow transplantation (BMT) system. In the Evi1-induced leukemic cells, we identified frequent retroviral integrations near the CCAAT/enhancer-binding protein ß (C/EBPß) gene and overexpression of its protein. These findings imply that C/EBPß is a candidate gene that collaborates with Evi1 in leukemogenesis. Cotransduction of Evi1 and the shortest isoform of C/EBPß, liver inhibitory protein (LIP), induced AML with short latencies in a mouse BMT model. Overexpression of LIP alone also induced AML with longer latencies. However, excision of all 3 isoforms of C/EBPß (LAP*/LAP/LIP) did not inhibit the development of Evi1-induced leukemia. Therefore, isoform-specific intervention that targets LIP is required when we consider C/EBPß as a therapeutic target.


Asunto(s)
Trasplante de Médula Ósea , Proteína beta Potenciadora de Unión a CCAAT/fisiología , Transformación Celular Neoplásica/genética , Proteínas de Unión al ADN/fisiología , Leucemia Mieloide Aguda/genética , Proto-Oncogenes/fisiología , Factores de Transcripción/fisiología , Animales , Trasplante de Médula Ósea/efectos adversos , Trasplante de Médula Ósea/patología , Proteína beta Potenciadora de Unión a CCAAT/genética , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Células Cultivadas , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Regulación Leucémica de la Expresión Génica , Humanos , Leucemia Mieloide Aguda/etiología , Leucemia Mieloide Aguda/patología , Proteína del Locus del Complejo MDS1 y EV11 , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Biológicos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/fisiología , Proto-Oncogenes/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
18.
Blood ; 118(25): 6626-37, 2011 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-22021368

RESUMEN

Functional deregulation of transcription factors has been found in many types of tumors. Transcription factor AML1/RUNX1 is one of the most frequent targets of chromosomal abnormalities in human leukemia and altered function of AML1 is closely associated with malignant transformation of hematopoietic cells. However, the molecular basis and therapeutic targets of AML1-related leukemia are still elusive. Here, we explored immediate target pathways of AML1 by in vitro synchronous inactivation in hematopoietic cells. We found that AML1 inhibits NF-κB signaling through interaction with IκB kinase complex in the cytoplasm. Remarkably, AML1 mutants found in myeloid tumors lack the ability to inhibit NF-κB signaling, and human cases with AML1-related leukemia exhibits distinctly activated NF-κB signaling. Furthermore, inhibition of NF-κB signaling in leukemic cells with mutated AML1 efficiently blocks their growth and development of leukemia. These findings reveal a novel role for AML1 as a cytoplasmic attenuator of NF-κB signaling and indicate that NF-κB signaling is one of the promising therapeutic targets of hematologic malignancies with AML1 abnormality.


Asunto(s)
Subunidad alfa 2 del Factor de Unión al Sitio Principal/fisiología , Leucemia Mieloide/metabolismo , FN-kappa B/metabolismo , Transducción de Señal/fisiología , Enfermedad Aguda , Animales , Antineoplásicos/farmacología , Western Blotting , Ácidos Borónicos/farmacología , Bortezomib , Línea Celular Tumoral , Transformación Celular Neoplásica/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Citoplasma/metabolismo , Femenino , Regulación Leucémica de la Expresión Génica , Células HEK293 , Humanos , Quinasa I-kappa B/genética , Quinasa I-kappa B/metabolismo , Leucemia Mieloide/tratamiento farmacológico , Leucemia Mieloide/patología , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Mutación , FN-kappa B/genética , Unión Proteica , Pirazinas/farmacología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Ensayos Antitumor por Modelo de Xenoinjerto
19.
Blood ; 117(13): 3617-28, 2011 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-21289308

RESUMEN

Evi1 (ecotropic viral integration site 1) is essential for proliferation of hematopoietic stem cells and implicated in the development of myeloid disorders. Particularly, high Evi1 expression defines one of the largest clusters in acute myeloid leukemia and is significantly associated with extremely poor prognosis. However, mechanistic basis of Evi1-mediated leukemogenesis has not been fully elucidated. Here, we show that Evi1 directly represses phosphatase and tensin homologue deleted on chromosome 10 (PTEN) transcription in the murine bone marrow, which leads to activation of AKT/mammalian target of rapamycin (mTOR) signaling. In a murine bone marrow transplantation model, Evi1 leukemia showed modestly increased sensitivity to an mTOR inhibitor rapamycin. Furthermore, we found that Evi1 binds to several polycomb group proteins and recruits polycomb repressive complexes for PTEN down-regulation, which shows a novel epigenetic mechanism of AKT/mTOR activation in leukemia. Expression analyses and ChIPassays with human samples indicate that our findings in mice models are recapitulated in human leukemic cells. Dependence of Evi1-expressing leukemic cells on AKT/mTOR signaling provides the first example of targeted therapeutic modalities that suppress the leukemogenic activity of Evi1. The PTEN/AKT/mTOR signaling pathway and the Evi1-polycomb interaction can be promising therapeutic targets for leukemia with activated Evi1.


Asunto(s)
Proteínas de Unión al ADN/fisiología , Fosfohidrolasa PTEN/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proto-Oncogenes/fisiología , Proteínas Represoras/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Factores de Transcripción/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Células Cultivadas , Proteínas de Unión al ADN/metabolismo , Regulación hacia Abajo/genética , Femenino , Regulación Leucémica de la Expresión Génica , Humanos , Leucemia/genética , Leucemia/metabolismo , Leucemia/patología , Proteína del Locus del Complejo MDS1 y EV11 , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Persona de Mediana Edad , Modelos Biológicos , Fosfohidrolasa PTEN/metabolismo , Proteínas del Grupo Polycomb , Unión Proteica , Transducción de Señal/genética , Factores de Transcripción/metabolismo , Adulto Joven
20.
Blood ; 117(1): 221-33, 2011 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-20884804

RESUMEN

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.


Asunto(s)
Proteína alfa Potenciadora de Unión a CCAAT/genética , Modelos Animales de Enfermedad , Leucemia Mieloide Aguda/etiología , Leucemia Mieloide Aguda/patología , Mutación/genética , Síndromes Mielodisplásicos/etiología , Síndromes Mielodisplásicos/patología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Apoptosis , Western Blotting , Trasplante de Médula Ósea , Proteína alfa Potenciadora de Unión a CCAAT/metabolismo , Diferenciación Celular , Proliferación Celular , Ensayo de Cambio de Movilidad Electroforética , Femenino , Citometría de Flujo , Humanos , Leucemia Mieloide Aguda/terapia , Luciferasas/metabolismo , Masculino , Ratones , Persona de Mediana Edad , Síndromes Mielodisplásicos/terapia , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple , ARN Mensajero/genética , Tasa de Supervivencia , Activación Transcripcional
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