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1.
Blood Cancer J ; 14(1): 99, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890297

RESUMO

Current therapies for high-grade TP53-mutated myeloid neoplasms (≥10% blasts) do not offer a meaningful survival benefit except allogeneic stem cell transplantation in the minority who achieve a complete response to first line therapy (CR1). To identify reliable pre-therapy predictors of complete response to first-line therapy (CR1) and outcomes, we assembled a cohort of 242 individuals with TP53-mutated myeloid neoplasms and ≥10% blasts with well-annotated clinical, molecular and pathology data. Key outcomes examined were CR1 & 24-month survival (OS24). In this elderly cohort (median age 68.2 years) with 74.0% receiving frontline non-intensive regimens (hypomethylating agents +/- venetoclax), the overall cohort CR1 rate was 25.6% (50/195). We additionally identified several pre-therapy factors predictive of inferior CR1 including male gender (P = 0.026), ≥2 autosomal monosomies (P < 0.001), -17/17p (P = 0.011), multi-hit TP53 allelic state (P < 0.001) and CUX1 co-alterations (P = 0.010). In univariable analysis of the entire cohort, inferior OS24 was predicated by ≥2 monosomies (P = 0.004), TP53 VAF > 25% (P = 0.002), TP53 splice junction mutations (P = 0.007) and antecedent treated myeloid neoplasm (P = 0.001). In addition, mutations/deletions in CUX1, U2AF1, EZH2, TET2, CBL, or KRAS ('EPI6' signature) predicted inferior OS24 (HR = 2.0 [1.5-2.8]; P < 0.0001). In a subgroup analysis of HMA +/-Ven treated individuals (N = 144), TP53 VAF and monosomies did not impact OS24. A risk score for HMA +/-Ven treated individuals incorporating three pre-therapy predictors including TP53 splice junction mutations, EPI6 and antecedent treated myeloid neoplasm stratified 3 prognostic distinct groups: intermediate, intermediate-poor, and poor with significantly different median (12.8, 6.0, 4.3 months) and 24-month (20.9%, 5.7%, 0.5%) survival (P < 0.0001). For the first time, in a seemingly monolithic high-risk cohort, our data identifies several baseline factors that predict response and 24-month survival.


Assuntos
Mutação , Proteína Supressora de Tumor p53 , Humanos , Masculino , Feminino , Idoso , Proteína Supressora de Tumor p53/genética , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Adulto , Prognóstico , Resultado do Tratamento
4.
Mod Pathol ; 33(5): 834-845, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31822802

RESUMO

Although the distinction of classical Hodgkin lymphoma from nodular lymphocyte predominant Hodgkin lymphoma using morphology and immunostains is straightforward in most instances, occasional cases pose diagnostic challenge. We sought to determine the utility of the novel YE361 STAT6 rabbit monoclonal antibody in Hodgkin lymphoma and diagnostically challenging B- and T-cell non-Hodgkin lymphoma entities with Hodgkin-like features. Cases from seven institutions included: 57 classical Hodgkin lymphomas (31% EBV+), 34 nodular lymphocyte predominant Hodgkin lymphomas, 34 mimicking B- and T-cell non-Hodgkin lymphomas, and 7 reactive lymphoproliferations. After review of histology, STAT6YE361 immunostaining was performed. The intensity and spatial localization of immunopositivity was assessed in neoplastic cells. Additional FISH for programmed death ligand-1 (PD-L1) was performed in one patient in paired treatment-naive and relapse biopsy tissues. Two STAT6YE361 immunopositive cases were examined by whole-exome sequencing after flow sorting to assess mutations in STAT6 pathway genes. Most classical Hodgkin lymphomas showed nuclear staining for STAT6YE361 [46/57 cases (80%)] on Hodgkin cells. Staining was exclusively nuclear in a minority [12/46 (26%)], while dual nuclear and cytoplasmic localization was more common [34/46 (74%)]. In contrast, all nodular lymphocyte predominant Hodgkin lymphomas [0/34 (0%)] were negative for nuclear STAT6YE361 staining on the lymphocyte predominant cells. Within B- and T-cell non-Hodgkin lymphomas, nuclear STAT6YE361 was seen in: B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma, and in primary mediastinal large B-cell lymphoma. Strong PD-L1 gene amplification was noted in the paired cHL and relapse B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma, although STAT6YE361 was negative in both biopsies. Whole-exome sequencing identified mutations in B2M, XPO1, and ITPKB as well CISHP213L (in the STAT pathway) in one classical Hodgkin lymphoma patient positive for nuclear STAT6YE361 although no underlying STAT6 mutations were observed in either sample examined. STAT6YE361 nuclear staining has 100% positive predictive value and 85.7% negative predictive value in confirming or excluding classical Hodgkin lymphoma diagnosis in the distinction from nodular lymphocyte predominant Hodgkin lymphoma and other benign and malignant entities.


Assuntos
Biomarcadores Tumorais/análise , Doença de Hodgkin/diagnóstico , Linfoma não Hodgkin/diagnóstico , Fator de Transcrição STAT6/biossíntese , Diagnóstico Diferencial , Humanos , Valor Preditivo dos Testes , Fator de Transcrição STAT6/análise
5.
Clin Case Rep ; 7(5): 1053-1056, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31110744

RESUMO

Transformation of lymphoma is an infrequent phenomenon, and involvement of the eye as such is even uncommon. Histological transformation in patients with follicular lymphoma who were previously treated with immune-chemotherapy carry a poor outcome. Here, we illustrate such a case with aggressive histological transformation from a low-grade lymphoma.

6.
Appl Immunohistochem Mol Morphol ; 27(3): 180-184, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-28877074

RESUMO

BACKGROUND: Classic Hodgkin lymphoma (CHL) and nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) are clinically distinct entities, with different prognostic and treatment implications. In addition, several large B-cell lymphomas and some T-cell lymphomas can mimic CHL. Differentiating these entities from CHL is crucial for ensuring appropriate therapy. GATA3 is a T-cell transcription factor involved in T-cell maturation and has been previously shown to be overexpressed in CHL cells via gene expression profiling. We investigated the utility of GATA3 immunostain in differentiating CHL from NLPHL and other mimicking entities. MATERIALS AND METHODS: We accrued 17 NLPHLs, 49 CHLs [23 nodular sclerosis (NS), 3 syncytial variants, 3 lymphocyte rich and 13 mixed cellularity types], 4 primary mediastinal large B-cell lymphomas (PMBLs), 2 Epstein-Barr virus (EBV) positive diffuse large B-cell lymphomas (DLBCLs) (EBV+LBCLs), 2 T-cell/histiocyte-rich large B-cell lymphomas (TCHRBCLs), 1 gray zone lymphoma, and 2 tissue microarrays consisting of 72 DLBCLs. One slide from each was stained with GATA3 and percent positive tumor cells and intensity of nuclear expression was semiquantitatively graded independently by 2 board certified hematopathologists. RESULTS: GATA3 was positive in 80% of CHLs. Both percent positivity and intensity of staining varied greatly. Syncytial variant of NS subtype showed the highest positivity rate (3/3; 100%), followed by NS (20/23; 87%), mixed cellularity (9/13; 70%), and lymphocyte rich (2/3; 67%). GATA3 was negative in all NLPHLs, EBV+LBCLs, TCRBCLs, and DLBCLs stained. The single gray zone lymphoma and 3/4 PMBLs were positive. CONCLUSIONS: Nuclear expression of GATA3 can be used to delineate CHL from NLPHL. GATA3 positivity effectively excludes NLPHL with 100% negative predictive value. However, as 20% of CHL can be negative for GATA3, CHL cannot be ruled out with negative GATA3. Additional findings include GATA3 positivity among PMBLs, whereas all 72 DLBCLs were negative for GATA3. This finding further highlights similarities between CHL and PMBL.


Assuntos
Fator de Transcrição GATA3/metabolismo , Doença de Hodgkin , Linfoma Difuso de Grandes Células B , Neoplasias do Mediastino , Proteínas de Neoplasias/metabolismo , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Doença de Hodgkin/diagnóstico , Doença de Hodgkin/metabolismo , Doença de Hodgkin/patologia , Humanos , Imuno-Histoquímica , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Masculino , Neoplasias do Mediastino/diagnóstico , Neoplasias do Mediastino/metabolismo , Neoplasias do Mediastino/patologia , Pessoa de Meia-Idade , Coloração e Rotulagem
7.
Mod Pathol ; 29(10): 1173-82, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27312067

RESUMO

Nodal follicular helper T-cell-derived lymphoproliferations (specifically the less common peripheral T-cell lymphomas of follicular type) exhibit a spectrum of histologic features that may mimic reactive hyperplasia or Hodgkin lymphoma. Even though angioimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma of follicular type share a common biologic origin from follicular helper T-cells and their morphology has been well characterized, flow cytometry of peripheral T-cell lymphomas of follicular type has not been widely discussed as a tool for identifying this reactive hyperplasia/Hodgkin lymphoma mimic. We identified 10 peripheral T-cell lymphomas of follicular type with available flow cytometry data from five different institutions, including two cases with peripheral blood evaluation. For comparison, we examined flow cytometry data for 8 classical Hodgkin lymphomas (including 1 lymphocyte-rich classical Hodgkin lymphoma), 15 nodular lymphocyte predominant Hodgkin lymphomas, 15 angioimmunoblastic T-cell lymphomas, and 26 reactive nodes. Lymph node histology and flow cytometry data were reviewed, specifically for the presence of a CD3(-/dim)CD4(+) aberrant T-cell population (described in angioimmunoblastic T-cell lymphomas), besides other T-cell aberrancies. Nine of 10 (90%) peripheral T-cell lymphomas of follicular type showed a CD3(-/dim)CD4(+) T-cell population constituting 29.3% (range 7.9-62%) of all lymphocytes. Five of 10 (50%) had nodular lymphocyte predominant Hodgkin lymphoma or lymphocyte-rich classical Hodgkin lymphoma-like morphology with scattered Hodgkin-like cells that expressed CD20, CD30, CD15, and MUM1. Three cases had a nodular growth pattern and three others exhibited a perifollicular growth pattern without Hodgkin-like cells. Epstein-Barr virus was positive in 1 of 10 cases (10%). PCR analysis showed clonal T-cell receptor gamma gene rearrangement in all 10 peripheral T-cell lymphomas of follicular type. By flow cytometry, 11 of 15 (73.3%) angioimmunoblastic T-cell lymphomas showed the CD3(-/dim)CD4(+) population (mean: 19.5%, range: 3-71.8%). Using a threshold of 3% for CD3(-/dim)CD4(+) T cells, all 15 nodular lymphocyte predominant Hodgkin lymphoma controls and 8 classical Hodgkin lymphomas were negative (Mann-Whitney P=0.01, F-PTCL vs Hodgkin lymphomas), as were 25 of 26 reactive lymph nodes. The high frequency of CD3(-/dim)CD4(+) aberrant T cells is similar in angioimmunoblastic T-cell lymphomas and peripheral T-cell lymphomas of follicular type, and is a useful feature in distinguishing peripheral T-cell lymphomas of follicular type from morphologic mimics such as reactive hyperplasia or Hodgkin lymphoma.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Doença de Hodgkin/diagnóstico , Linfoma de Células T Periférico/diagnóstico , Subpopulações de Linfócitos T/imunologia , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Citometria de Fluxo , Doença de Hodgkin/imunologia , Humanos , Linfoma de Células T Periférico/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
8.
Am J Surg Pathol ; 39(12): 1719-1729, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26379152

RESUMO

Primary central nervous system (CNS) lymphomas are relatively rare with the most common subtype being diffuse large B-cell lymphoma. Primary CNS T-cell lymphomas (PCNSTL) account for <5% of CNS lymphomas. We report the clinical, morphologic, immunophenotypic, and molecular characteristics of 18 PCNSTLs. Fifteen cases were classified as peripheral T-cell lymphoma, not otherwise specified, 2 of which were of γδ T-cell derivation and 1 was TCR silent; there was 1 anaplastic large cell lymphoma, ALK-positive and 2 anaplastic large cell lymphoma, ALK-negative. Median age was 58.5 years (range, 21 to 81 y), with an M:F ratio of 11:7. Imaging results showed that 15 patients had supratentorial lesions. Regardless of subtype, necrosis and perivascular cuffing of tumor cells were frequently observed (11/18 cases). CD3 was positive in all cases but 1; 10/17 were CD8-positive, and 5/17 were CD4-positive. Most cases studied had a cytotoxic phenotype with expression of TIA1 (13/15) and granzyme-B (9/13). Polymerase chain reaction analysis of T-cell receptor γ rearrangement confirmed a T-cell clone in 14 cases with adequate DNA quality. Next-generation sequencing showed somatic mutations in 36% of cases studied; 2 had >1 mutation, and none showed overlapping mutations. These included mutations in DNMT3A, KRAS, JAK3, STAT3, STAT5B, GNB1, and TET2 genes, genes implicated previously in other T-cell neoplasms. The outcome was heterogenous; 2 patients are alive without disease, 4 are alive with disease, and 6 died of disease. In conclusion, PCNSTLs are histologically and genomically heterogenous with frequent phenotypic aberrancy and a cytotoxic phenotype in most cases.


Assuntos
Biomarcadores Tumorais , Neoplasias do Sistema Nervoso Central/diagnóstico , Imunofenotipagem , Linfoma de Células T/diagnóstico , Técnicas de Diagnóstico Molecular , Linfócitos T , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Biópsia , Neoplasias do Sistema Nervoso Central/química , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/imunologia , Neoplasias do Sistema Nervoso Central/mortalidade , Neoplasias do Sistema Nervoso Central/patologia , Análise Mutacional de DNA , Feminino , Rearranjo Gênico da Cadeia delta dos Receptores de Antígenos dos Linfócitos T , Rearranjo Gênico da Cadeia gama dos Receptores de Antígenos dos Linfócitos T , Predisposição Genética para Doença , Humanos , Imuno-Histoquímica , Hibridização In Situ , Linfoma de Células T/química , Linfoma de Células T/genética , Linfoma de Células T/imunologia , Linfoma de Células T/mortalidade , Linfoma de Células T/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Fenótipo , Reação em Cadeia da Polimerase , Valor Preditivo dos Testes , Prognóstico , Receptores de Antígenos de Linfócitos T gama-delta/genética , Linfócitos T/química , Linfócitos T/imunologia , Linfócitos T/patologia , Fatores de Tempo , Adulto Jovem
11.
Case Rep Pathol ; 2015: 380451, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26819793

RESUMO

Blast phase in chronic myelogenous leukemia (CML) has rarely been reported to involve extramedullary sites like skin, lymph nodes, and central nervous system. Clinical history, characteristic hematologic findings (elevated leukocyte counts, myelocytic predominance, and basophilia), and Philadelphia chromosome are of high diagnostic significance especially in isolated extramedullary presentations. We describe a unique case of CML relapse with blast phase involving the eye. A 66-year-old man with a known diagnosis of CML on imatinib and in molecular remission for 3 years presented with a painful blind eye. Histologic examination revealed diffuse involvement of choroid, iris, vitreous humor, and the optic nerve by blast cells. The blasts expressed CD34, aberrant TdT, and a myeloid phenotype (CD13, CD33, and CD117). Fluorescence in situ hybridization (FISH) of vitreous fluid detected BCR-ABL1 gene rearrangement. Additionally, trisomy 8 and gains of 9 and 22 were seen which were not present in the initial diagnostic marrow study 3 years ago. At relapse, the bone marrow, peripheral blood, and the cerebrospinal fluid were not involved by CML. Patient received induction chemotherapy and single dose prophylactic intrathecal methotrexate and was maintained on antityrosine kinase therapy and eventually underwent allogenic stem cell transplantation.

12.
Nano Lett ; 13(6): 2423-30, 2013 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-23668724

RESUMO

We report the phase transformation of hematite (α-Fe2O3) single crystal nanowires to crystalline FeS nanotubes using sulfurization with H2S gas at relatively low temperatures. Characterization indicates that phase pure hexagonal FeS nanotubes were formed. Time-series sulfurization experiments suggest epitaxial growth of FeS as a shell layer on hematite. This is the first report of hollow, crystalline FeS nanotubes with NiAs structure and also on the Kirkendall effect in solid-gas reactions with nanowires involving sulfurization.

14.
Cancer J ; 18(5): 411-20, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23006945

RESUMO

Diffuse large B-cell lymphomas (DLBCLs) are aggressive B-cell lymphomas that are clinically, pathologically, and genetically diverse, in part reflecting the functional diversity of the B-cell system. The focus in recent years has been toward incorporation of clinical features, morphology, immunohistochemistry, and ever evolving genetic data into the classification scheme. The 2008 World Health Organization classification reflects this complexity with the addition of several new entities and variants. The discovery of distinct subtypes by gene expression profiling heralded a new era with a focus on pathways of transformation as well as a promise of more targeted therapies, directed at specific pathways. Some DLBCLs exhibit unique clinical characteristics with a predilection for specific anatomic sites; the anatomic site often reflects underlying biological distinctions. Recently, the spectrum of Epstein-Barr virus (EBV)-driven B-cell proliferations in patients without iatrogenic or congenital immunosuppression has been better characterized; most of these occur in patients of advanced age and include Epstein-Barr virus (EBV)-positive large B-cell lymphoma of the elderly. Human herpesvirus 8 is involved in the pathogenesis of primary effusion lymphoma, which can present as a "solid variant." Two borderline categories were created; one deals with tumors at the interface between classic Hodgkin lymphoma and DLBCL. The second confronts the interface between Burkitt lymphoma and DLBCL, so-called "B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma" in the 2008 classification. Most cases harbor both MYC and BCL2 translocations and are highly aggressive. Another interesting entity is anaplastic lymphoma kinase-positive DLBCL, which renders itself potentially targetable by anaplastic lymphoma kinase inhibitors. Ongoing investigations at the genomic level, with both exome and whole-genome sequencing, are sure to reveal new pathways of transformation in the future.


Assuntos
Linfócitos B , Linfoma de Burkitt , Doença de Hodgkin , Linfoma Difuso de Grandes Células B , Fatores Etários , Linfócitos B/metabolismo , Linfócitos B/patologia , Linfócitos B/virologia , Linfoma de Burkitt/classificação , Linfoma de Burkitt/metabolismo , Linfoma de Burkitt/patologia , Perfilação da Expressão Gênica , Herpesvirus Humano 4/patogenicidade , Herpesvirus Humano 8/patogenicidade , Doença de Hodgkin/classificação , Doença de Hodgkin/metabolismo , Doença de Hodgkin/patologia , Humanos , Imunofenotipagem , Linfoma Difuso de Grandes Células B/classificação , Linfoma Difuso de Grandes Células B/patologia , Linfoma Difuso de Grandes Células B/virologia , Organização Mundial da Saúde
15.
Leuk Res ; 35(6): 766-70, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21367453

RESUMO

Expression of CD34 on mature-appearing megakaryocytes can be seen in various intrinsic bone marrow (BM) disorders as well as reactive bone marrows. In this study we investigate the clinical significance of CD34+ megakaryocytes in myelodysplastic syndromes (MDSs). Expression of CD34 on megakaryocytes was assessed on BM biopsies obtained from 202 patients with MDS. High-level (≥20%) CD34 expression on megakaryocytes was found in BM of 29 patients (14%). The expression of CD34 on megakaryocytes is correlated with severe cytopenia, higher numbers of myeloblasts, more frequent and higher risk cytogenetic abnormalities, and a shorter overall survival. Multivariate analysis indicated that the expression of CD34 on megakaryocytes could be a strong and an independent poor prognostic factor in MDS, with a hazard ratio of 2.53.


Assuntos
Antígenos CD34/biossíntese , Megacariócitos/metabolismo , Síndromes Mielodisplásicas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Medula Óssea/metabolismo , Medula Óssea/patologia , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Megacariócitos/patologia , Pessoa de Meia-Idade , Análise Multivariada , Síndromes Mielodisplásicas/patologia , Avaliação de Resultados em Cuidados de Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais
16.
J Biol Chem ; 283(52): 36665-75, 2008 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-18854306

RESUMO

During anemia erythropoiesis is bolstered by several factors including KIT ligand, oncostatin-M, glucocorticoids, and erythropoietin. Less is understood concerning factors that limit this process. Experiments performed using dual-specificity tyrosine-regulated kinase-3 (DYRK3) knock-out and transgenic mice reveal that erythropoiesis is attenuated selectively during anemia. DYRK3 is restricted to erythroid progenitor cells and testes. DYRK3-/- mice exhibited essentially normal hematological profiles at steady state and reproduced normally. In response to hemolytic anemia, however, reticulocyte production increased severalfold due to DYRK3 deficiency. During 5-fluorouracil-induced anemia, both reticulocyte and red cell formation in DYRK3-/- mice were elevated. In short term transplant experiments, DYRK3-/- progenitors also supported enhanced erythroblast formation, and erythropoietic advantages due to DYRK3-deficiency also were observed in 5-fluorouracil-treated mice expressing a compromised erythropoietin receptor EPOR-HM allele. As analyzed ex vivo, DYRK3-/- erythroblasts exhibited enhanced CD71posTer119pos cell formation and 3HdT incorporation. Transgenic pA2gata1-DYRK3 mice, in contrast, produced fewer reticulocytes during hemolytic anemia, and pA2gata1-DYRK3 progenitors were compromised in late pro-erythroblast formation ex vivo. Finally, as studied in erythroid K562 cells, DYRK3 proved to effectively inhibit NFAT (nuclear factor of activated T cells) transcriptional response pathways and to co-immunoprecipitate with NFATc3. Findings indicate that DYRK3 attenuates (and possibly apportions) red cell production selectively during anemia.


Assuntos
Eritropoese , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Tirosina Quinases/fisiologia , Alelos , Anemia/metabolismo , Animais , Antígenos CD/metabolismo , Transplante de Medula Óssea , Linhagem Celular , Fluoruracila/farmacologia , Humanos , Células K562 , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Receptores da Transferrina/metabolismo , Transgenes
17.
Blood ; 112(3): 886-90, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18535204

RESUMO

The adult erythron is maintained via dynamic modulation of erythroblast survival potentials. Toward identifying novel regulators of this process, murine splenic erythroblasts at 3 developmental stages were prepared, purified and profiled. Stage-to-stage modulated genes were then functionally categorized, with a focus on apoptotic factors. In parallel with BCL-X and NIX, death-associated protein kinase-2 (DAPK2) was substantially up-modulated during late erythropoiesis. Among hematopoietic lineages, DAPK2 was expressed predominantly in erythroid cells. In a Gata1-IE3.9int-DAPK2 transgenic mouse model, effects on steady-state reticulocyte and red blood cell (RBC) levels were limited. During hemolytic anemia, however, erythropoiesis was markedly deficient. Ex vivo ana-lyses revealed heightened apoptosis due to DAPK2 at a Kit(-)CD71(high)Ter119(-) stage, together with a subsequent multifold defect in late-stage Kit(-)CD71(high)Ter119(+) cell formation. In UT7epo cells, siRNA knock-down of DAPK2 enhanced survival due to cytokine withdrawal, and DAPK2's phosphorylation and kinase activity also were erythropoietin (EPO)-modulated. DAPK2 therefore comprises a new candidate attenuator of stress erythropoiesis.


Assuntos
Proteínas Reguladoras de Apoptose/fisiologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/fisiologia , Eritroblastos/citologia , Eritropoese/genética , Eritropoetina/farmacologia , Anemia Hemolítica , Animais , Proteínas Reguladoras de Apoptose/análise , Proteínas Reguladoras de Apoptose/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/análise , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Linhagem da Célula , Proteínas Quinases Associadas com Morte Celular , Hemostasia , Camundongos , Camundongos Transgênicos , Fosforilação/efeitos dos fármacos , Baço/citologia , Regulação para Cima/genética
18.
Blood ; 110(7): 2361-70, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17548578

RESUMO

Erythropoietin (EPO's) actions on erythroblasts are ascribed largely to survival effects. Certain studies, however, point to EPO-regulated proliferation. To investigate this problem in a primary system, Kit(pos)CD71(high) erythroblasts were prepared from murine bone marrow, and were first used in the array-based discovery of EPO-modulated cell-cycle regulators. Five cell-cycle progression factors were rapidly up-modulated: nuclear protein 1 (Nupr1), G1 to S phase transition 1 (Gspt1), early growth response 1 (Egr1), Ngfi-A binding protein 2 (Nab2), and cyclin D2. In contrast, inhibitory cyclin G2, p27/Cdkn1b, and B-cell leukemia/lymphoma 6 (Bcl6) were sharply down-modulated. For CYCLIN G2, ectopic expression also proved to selectively attenuate EPO-dependent UT7epo cell-cycle progression at S-phase. As analyzed in primary erythroblasts expressing minimal EPO receptor alleles, EPO repression of cyclin G2 and Bcl6, and induction of cyclin D2, were determined to depend on PY343 (and Stat5) signals. Furthermore, erythroblasts expressing a on PY-null EPOR-HM allele were abnormally distributed in G0/G1. During differentiation divisions, EPOR-HM Ter119(pos) erythroblasts conversely accumulated in S-phase and faltered in an apparent EPO-directed transition to G0/G1. EPO/EPOR signals therefore control the expression of select cell-cycle regulatory genes that are proposed to modulate stage-specific decisions for erythroblast cell-cycle progression.


Assuntos
Medula Óssea/metabolismo , Proteínas de Ciclo Celular/metabolismo , Divisão Celular , Eritroblastos/citologia , Eritroblastos/metabolismo , Eritropoetina/farmacologia , Alelos , Animais , Proteínas de Ciclo Celular/genética , Células Cultivadas , Regulação da Expressão Gênica , Camundongos , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos , Receptores da Eritropoetina/genética , Receptores da Eritropoetina/metabolismo
19.
Blood ; 110(2): 509-18, 2007 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-17403918

RESUMO

Epo's erythropoietic capacity is ascribed largely to its antiapoptotic actions. In part via gene profiling of bone marrow erythroblasts, Epo is now shown to selectively down-modulate the adhesion/migration factors chemokine receptor-4 (Cxcr4) and integrin alpha-4 (Itga4) and to up-modulate growth differentiation factor-3 (Gdf3), oncostatin-M (OncoM), and podocalyxin like-1 (PODXL). For PODXL, Epo dose-dependent expression of this CD34-related sialomucin was discovered in Kit(+)CD71(high) proerythroblasts and was sustained at subsequent Kit(-)CD71(high) and Ter119(+) stages. In vivo, Epo markedly induced PODXL expression in these progenitors and in marrow-resident reticulocytes. This was further associated with a rapid release of PODXL(+) reticulocytes to blood. As studied in erythroblasts expressing minimal Epo receptor (EpoR) alleles, efficient PODXL induction proved dependence on an EpoR-PY343 Stat5 binding site. Moreover, in mice expressing an EpoR-HM F343 allele, compromised Epo-induced PODXL expression correlated with abnormal anucleated red cell representation in marrow. By modulating this select set of cell-surface adhesion molecules and chemokines, Epo is proposed to mobilize erythroblasts from a hypothesized stromal niche and possibly promote reticulocyte egress to blood.


Assuntos
Eritroblastos/fisiologia , Eritropoetina/farmacologia , Receptores da Eritropoetina/genética , Sialoglicoproteínas/genética , Animais , Apoptose/efeitos dos fármacos , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/fisiologia , Núcleo Celular/fisiologia , Eritroblastos/efeitos dos fármacos , Citometria de Fluxo , Perfilação da Expressão Gênica , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sialoglicoproteínas/efeitos dos fármacos , Sialomucinas/efeitos dos fármacos , Sialomucinas/genética
20.
J Clin Invest ; 116(3): 683-94, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16511603

RESUMO

Anemia due to chronic disease or chemotherapy often is ameliorated by erythropoietin (Epo). Present studies reveal that, unlike steady-state erythropoiesis, erythropoiesis during anemia depends sharply on an Epo receptor-phosphotyrosine-343-Stat5 signaling axis. In mice expressing a phosphotyrosine-null (PY-null) Epo receptor allele (EpoR-HM), severe and persistent anemia was induced by hemolysis or 5-fluorouracil. In short-term transplantation experiments, donor EpoR-HM bone marrow cells also failed to efficiently repopulate the erythroid compartment. In each context, stress erythropoiesis was rescued to WT levels upon the selective restoration of an EpoR PY343 Stat5-binding site (EpoR-H allele). As studied using a unique primary culture system, EpoR-HM erythroblasts exhibited marked stage-specific losses in Epo-dependent growth and survival. EpoR-H PY343 signals restored efficient erythroblast expansion, and the selective Epo induction of the Stat5 target genes proviral integration site-1 (Pim-1) and oncostatin-M. Bcl2-like 1 (Bcl-x), in contrast, was not significantly induced via WT-EpoR, EpoR-HM, or EpoR-H alleles. In Kit+ CD71+ erythroblasts, EpoR-PY343 signals furthermore enhanced SCF growth effects, and SCF modulation of Pim-1 kinase and oncostatin-M expression. In maturing Kit- CD71+ erythroblasts, oncostatin-M exerted antiapoptotic effects that likewise depended on EpoR PY343-mediated events. Stress erythropoiesis, therefore, requires stage-specific EpoR-PY343-Stat5 signals, some of which selectively bolster SCF and oncostatin-M action.


Assuntos
Diferenciação Celular/fisiologia , Eritropoese/fisiologia , Fosfotirosina/metabolismo , Receptores da Eritropoetina/fisiologia , Fator de Transcrição STAT5/fisiologia , Transdução de Sinais/fisiologia , Anemia/sangue , Anemia/induzido quimicamente , Anemia/genética , Animais , Sítios de Ligação/genética , Células da Medula Óssea/citologia , Diferenciação Celular/genética , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Células Cultivadas , Eritroblastos/citologia , Eritropoese/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Fenil-Hidrazinas/administração & dosagem , Fosfotirosina/genética , Fosfotirosina/fisiologia , Proteínas Proto-Oncogênicas c-kit/metabolismo , Receptores da Eritropoetina/biossíntese , Receptores da Eritropoetina/genética , Transdução de Sinais/genética
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