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1.
Cell ; 173(2): 470-484.e18, 2018 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-29551267

RESUMO

B cell activation during normal immune responses and oncogenic transformation impose increased metabolic demands on B cells and their ability to retain redox homeostasis. While the serine/threonine-protein phosphatase 2A (PP2A) was identified as a tumor suppressor in multiple types of cancer, our genetic studies revealed an essential role of PP2A in B cell tumors. Thereby, PP2A redirects glucose carbon utilization from glycolysis to the pentose phosphate pathway (PPP) to salvage oxidative stress. This unique vulnerability reflects constitutively low PPP activity in B cells and transcriptional repression of G6PD and other key PPP enzymes by the B cell transcription factors PAX5 and IKZF1. Reflecting B-cell-specific transcriptional PPP-repression, glucose carbon utilization in B cells is heavily skewed in favor of glycolysis resulting in lack of PPP-dependent antioxidant protection. These findings reveal a gatekeeper function of the PPP in a broad range of B cell malignancies that can be efficiently targeted by small molecule inhibition of PP2A and G6PD.


Assuntos
Carbono/metabolismo , Glucose/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Animais , Linfócitos B/citologia , Linfócitos B/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Glicólise , Humanos , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Estresse Oxidativo , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/metabolismo , Via de Pentose Fosfato , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Proteína Fosfatase 2/deficiência , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transcrição Gênica
2.
Mol Cell ; 81(10): 2094-2111.e9, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-33878293

RESUMO

Even though SYK and ZAP70 kinases share high sequence homology and serve analogous functions, their expression in B and T cells is strictly segregated throughout evolution. Here, we identified aberrant ZAP70 expression as a common feature in a broad range of B cell malignancies. We validated SYK as the kinase that sets the thresholds for negative selection of autoreactive and premalignant clones. When aberrantly expressed in B cells, ZAP70 competes with SYK at the BCR signalosome and redirects SYK from negative selection to tonic PI3K signaling, thereby promoting B cell survival. In genetic mouse models for B-ALL and B-CLL, conditional expression of Zap70 accelerated disease onset, while genetic deletion impaired malignant transformation. Inducible activation of Zap70 during B cell development compromised negative selection of autoreactive B cells, resulting in pervasive autoantibody production. Strict segregation of the two kinases is critical for normal B cell selection and represents a central safeguard against the development of autoimmune disease and B cell malignancies.


Assuntos
Autoimunidade , Neoplasias/enzimologia , Neoplasias/prevenção & controle , Quinase Syk/metabolismo , Proteína-Tirosina Quinase ZAP-70/metabolismo , Animais , Antígenos CD19/metabolismo , Linfócitos B , Cálcio/metabolismo , Diferenciação Celular , Transformação Celular Neoplásica , Ativação Enzimática , Humanos , Tolerância Imunológica , Linfoma de Células B/enzimologia , Linfoma de Células B/patologia , Camundongos , Modelos Genéticos , Fatores de Transcrição NFATC/metabolismo , Proteínas de Neoplasias , Fosfatidilinositol 3-Quinases/metabolismo , Ligação Proteica , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais
3.
Nature ; 583(7818): 845-851, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32699415

RESUMO

Malignant transformation of cells typically involves several genetic lesions, whose combined activity gives rise to cancer1. Here we analyse 1,148 patient-derived B-cell leukaemia (B-ALL) samples, and find that individual mutations do not promote leukaemogenesis unless they converge on one single oncogenic pathway that is characteristic of the differentiation stage of transformed B cells. Mutations that are not aligned with this central oncogenic driver activate divergent pathways and subvert transformation. Oncogenic lesions in B-ALL frequently mimic signalling through cytokine receptors at the pro-B-cell stage (via activation of the signal-transduction protein STAT5)2-4 or pre-B-cell receptors in more mature cells (via activation of the protein kinase ERK)5-8. STAT5- and ERK-activating lesions are found frequently, but occur together in only around 3% of cases (P = 2.2 × 10-16). Single-cell mutation and phospho-protein analyses reveal the segregation of oncogenic STAT5 and ERK activation to competing clones. STAT5 and ERK engage opposing biochemical and transcriptional programs that are orchestrated by the transcription factors MYC and BCL6, respectively. Genetic reactivation of the divergent (suppressed) pathway comes at the expense of the principal oncogenic driver and reverses transformation. Conversely, deletion of divergent pathway components accelerates leukaemogenesis. Thus, persistence of divergent signalling pathways represents a powerful barrier to transformation, while convergence on one principal driver defines a central event in leukaemia initiation. Pharmacological reactivation of suppressed divergent circuits synergizes strongly with inhibition of the principal oncogenic driver. Hence, reactivation of divergent pathways can be leveraged as a previously unrecognized strategy to enhance treatment responses.


Assuntos
Linfócitos B/citologia , Linfócitos B/metabolismo , Transformação Celular Neoplásica , Leucemia de Células B/metabolismo , Leucemia de Células B/patologia , Transdução de Sinais , Animais , Linfócitos B/patologia , Linhagem Celular Tumoral , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Humanos , Camundongos , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Fator de Transcrição STAT5/metabolismo
4.
Int J Gynecol Pathol ; 43(2): 182-189, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37406452

RESUMO

Leiomyosarcoma (LMS) with osteoclast-like giant cells (OLGCs) is a rare entity with only 18 reported cases thus far. It is not known whether these OLGCs are a reactive or malignant component of LMS. Herein we describe the clinical, histologic, and molecular characteristics of 2 cases of LMS with OLGCs and perform a brief literature review. In 2 of our cases, the OLGCs, marked with CD68, had a low proliferation index with Ki67 and did not show diffuse positivity for smooth muscle markers by immunohistochemistry. By next-generation sequencing, one case harbored a clinically significant TP53 mutation, which has been reported in a significant subset of conventional LMSs. In this case, based on immunohistochemistry, OLGCs showed different molecular alterations as compared with LMS. Although we did not show a distinct immunophenotype or molecular profile for LMS with OLGCs, this study provides additional data on this rare entity.


Assuntos
Leiomiossarcoma , Neoplasias Pélvicas , Neoplasias Uterinas , Feminino , Humanos , Leiomiossarcoma/diagnóstico , Leiomiossarcoma/genética , Osteoclastos/patologia , Neoplasias Uterinas/diagnóstico , Neoplasias Uterinas/genética , Neoplasias Uterinas/patologia , Neoplasias Pélvicas/patologia , Células Gigantes/patologia
5.
Nature ; 558(7711): E5, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29849140

RESUMO

In Fig. 3c of this Letter, the the effects of CRISPR-Cas9-mediated deletion of NR3C1, TXNIP and CNR2 in patient-derived B-lineage leukaemia cells were shown. For curves depicting NR3C1 (left graph), data s for TXNIP (middle graph) were inadvertently plotted. This figure has been corrected online, and the original Fig. 3c is shown as Supplementary Information to this Amendment for transparency. The error does not affect the conclusions of the Letter. In addition, Source Data files have been added for the Figs. 1-4 and Extended Data Figs. 1-10 of the original Letter.

6.
Nature ; 542(7642): 479-483, 2017 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-28192788

RESUMO

B-lymphoid transcription factors, such as PAX5 and IKZF1, are critical for early B-cell development, yet lesions of the genes encoding these transcription factors occur in over 80% of cases of pre-B-cell acute lymphoblastic leukaemia (ALL). The importance of these lesions in ALL has, until now, remained unclear. Here, by combining studies using chromatin immunoprecipitation with sequencing and RNA sequencing, we identify a novel B-lymphoid program for transcriptional repression of glucose and energy supply. Our metabolic analyses revealed that PAX5 and IKZF1 enforce a state of chronic energy deprivation, resulting in constitutive activation of the energy-stress sensor AMPK. Dominant-negative mutants of PAX5 and IKZF1, however, relieved this glucose and energy restriction. In a transgenic pre-B ALL mouse model, the heterozygous deletion of Pax5 increased glucose uptake and ATP levels by more than 25-fold. Reconstitution of PAX5 and IKZF1 in samples from patients with pre-B ALL restored a non-permissive state and induced energy crisis and cell death. A CRISPR/Cas9-based screen of PAX5 and IKZF1 transcriptional targets identified the products of NR3C1 (encoding the glucocorticoid receptor), TXNIP (encoding a glucose-feedback sensor) and CNR2 (encoding a cannabinoid receptor) as central effectors of B-lymphoid restriction of glucose and energy supply. Notably, transport-independent lipophilic methyl-conjugates of pyruvate and tricarboxylic acid cycle metabolites bypassed the gatekeeper function of PAX5 and IKZF1 and readily enabled leukaemic transformation. Conversely, pharmacological TXNIP and CNR2 agonists and a small-molecule AMPK inhibitor strongly synergized with glucocorticoids, identifying TXNIP, CNR2 and AMPK as potential therapeutic targets. Furthermore, our results provide a mechanistic explanation for the empirical finding that glucocorticoids are effective in the treatment of B-lymphoid but not myeloid malignancies. Thus, B-lymphoid transcription factors function as metabolic gatekeepers by limiting the amount of cellular ATP to levels that are insufficient for malignant transformation.


Assuntos
Linfócitos B/metabolismo , Metabolismo Energético/genética , Regulação Neoplásica da Expressão Gênica , Glucose/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Fatores de Transcrição/metabolismo , Quinases Proteína-Quinases Ativadas por AMP , Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Trifosfato de Adenosina/metabolismo , Animais , Linfócitos B/efeitos dos fármacos , Carcinogênese/genética , Proteínas de Transporte/agonistas , Proteínas de Transporte/metabolismo , Morte Celular , Imunoprecipitação da Cromatina , Ciclo do Ácido Cítrico , Modelos Animais de Doenças , Feminino , Glucocorticoides/farmacologia , Glucocorticoides/uso terapêutico , Humanos , Fator de Transcrição Ikaros/metabolismo , Camundongos , Camundongos Transgênicos , Fator de Transcrição PAX5/deficiência , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Ácido Pirúvico/metabolismo , Receptor CB2 de Canabinoide/agonistas , Receptor CB2 de Canabinoide/metabolismo , Receptores de Glucocorticoides/metabolismo , Análise de Sequência de RNA
7.
Cytopathology ; 33(6): 707-715, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35869577

RESUMO

BACKGROUND: The clinical performance of the Yokohama reporting system for breast cytology remains uncertain. METHODS: In this study, we retrospectively evaluated 318 breast fine needle aspirations (FNABs) from Los Angeles County Hospital over a five-year period, analysing data for breast cytology, histology, and radiology. RESULTS: Among 318 breast FNAB cases, 78.3% (249/318) were benign and 5.3% (17/318) malignant. Of 83 cases with follow-up histology, 14.5% (12/83) were insufficient, 66.3% (55/83) were benign, and 16.9% (17/83) were malignant. Of 55 benign cases, 61.8% (34/55) were fibroadenoma and 9 (9/55, 16.4%) were fibrocystic changes. Two cases were diagnosed as "atypical" but confirmed "benign" on core needle biopsy (CNB). No "suspicious" cases were found. Seventeen malignant cases were confirmed by CNB, including 70.6% (12/17) invasive ductal carcinoma, 11.8% (2/17) invasive lobular carcinoma, and one malignant phyllodes tumour. Receptor studies on cell blocks of three malignant cases showed concordant results with CNB results. In addition, 82.2% (148/180) of lesions with Breast Imaging-Reporting and Data System (BI-RADS) scores of 2 or 3 were benign and 92.3% (12/13) BI-RADS score 5 lesions were malignant on FNAB. Finally, 90% (67/74) of BI-RADS 4a lesions were benign, and 97% (36/37) of fibroadenomas were BI-RADS score 4a. CONCLUSION: This, by far the largest U.S. breast cytology study, showed 93.3% sensitivity, 100% specificity, 100% positive predictive value, and 98.2% negative predictive value for breast FNAB. Women with breast lesions of BI-RADS score 3 or less have a low risk of malignancy; FNAB would contribute to the reduction of excisional biopsies. FNAB can be considered as an initial diagnostic tool for BI-RADS 4 mass/lesions and satellite lesions, as well as for triaging patients.


Assuntos
Neoplasias da Mama , Fibroadenoma , Biópsia por Agulha Fina , Mama/anormalidades , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Feminino , Fibroadenoma/diagnóstico , Hospitais , Humanos , Hipertrofia , Estudos Retrospectivos , Sensibilidade e Especificidade
8.
Nature ; 521(7552): 357-61, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25799995

RESUMO

B cells are selected for an intermediate level of B-cell antigen receptor (BCR) signalling strength: attenuation below minimum (for example, non-functional BCR) or hyperactivation above maximum (for example, self-reactive BCR) thresholds of signalling strength causes negative selection. In ∼25% of cases, acute lymphoblastic leukaemia (ALL) cells carry the oncogenic BCR-ABL1 tyrosine kinase (Philadelphia chromosome positive), which mimics constitutively active pre-BCR signalling. Current therapeutic approaches are largely focused on the development of more potent tyrosine kinase inhibitors to suppress oncogenic signalling below a minimum threshold for survival. We tested the hypothesis that targeted hyperactivation--above a maximum threshold--will engage a deletional checkpoint for removal of self-reactive B cells and selectively kill ALL cells. Here we find, by testing various components of proximal pre-BCR signalling in mouse BCR-ABL1 cells, that an incremental increase of Syk tyrosine kinase activity was required and sufficient to induce cell death. Hyperactive Syk was functionally equivalent to acute activation of a self-reactive BCR on ALL cells. Despite oncogenic transformation, this basic mechanism of negative selection was still functional in ALL cells. Unlike normal pre-B cells, patient-derived ALL cells express the inhibitory receptors PECAM1, CD300A and LAIR1 at high levels. Genetic studies revealed that Pecam1, Cd300a and Lair1 are critical to calibrate oncogenic signalling strength through recruitment of the inhibitory phosphatases Ptpn6 (ref. 7) and Inpp5d (ref. 8). Using a novel small-molecule inhibitor of INPP5D (also known as SHIP1), we demonstrated that pharmacological hyperactivation of SYK and engagement of negative B-cell selection represents a promising new strategy to overcome drug resistance in human ALL.


Assuntos
Linfócitos B/metabolismo , Linfócitos B/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Transdução de Sinais , Motivos de Aminoácidos/genética , Animais , Antígenos CD/metabolismo , Linfócitos B/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Feminino , Proteínas de Fusão bcr-abl/genética , Deleção de Genes , Humanos , Inositol Polifosfato 5-Fosfatases , Peptídeos e Proteínas de Sinalização Intracelular/agonistas , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Monoéster Fosfórico Hidrolases/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Células Precursoras de Linfócitos B/efeitos dos fármacos , Células Precursoras de Linfócitos B/metabolismo , Células Precursoras de Linfócitos B/patologia , Proteína Tirosina Fosfatase não Receptora Tipo 6/deficiência , Proteína Tirosina Fosfatase não Receptora Tipo 6/genética , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Proteínas Tirosina Quinases/metabolismo , Receptores de Antígenos de Linfócitos B/deficiência , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/metabolismo , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Quinase Syk , Tirosina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Mediators Inflamm ; 2021: 9979032, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33967626

RESUMO

Coronaviruses (CoVs) are enveloped and harbor an unusually large (30-32 kb) positive-strand linear RNA genome. Highly pathogenic coronaviruses cause severe acute respiratory syndrome (SARS) (SARS-CoV and SARS-CoV-2) and Middle East respiratory syndrome (MERS) (MERS-CoV) in humans. The coronavirus mouse hepatitis virus (MHV) infects mice and serves as an ideal model of viral pathogenesis, mainly because experiments can be conducted using animal-biosafety level-2 (A-BSL2) containment. Human thymosin beta-4 (Tß4), a 43-residue peptide with an acetylated N-terminus, is widely expressed in human tissues. Tß4 regulates actin polymerization and functions as an anti-inflammatory molecule and an antioxidant as well as a promoter of wound healing and angiogenesis. These activities led us to test whether Tß4 serves to treat coronavirus infections of humans. To test this possibility, here, we established a BALB/c mouse model of coronavirus infection using mouse CoV MHV-A59 to evaluate the potential protective effect of recombinant human Tß4 (rhTß4). Such a system can be employed under A-BSL2 containment instead of A-BSL3 that is required to study coronaviruses infectious for humans. We found that rhTß4 significantly increased the survival rate of mice infected with MHV-A59 through inhibiting virus replication, balancing the host's immune response, alleviating pathological damage, and promoting repair of the liver. These results will serve as the basis for further application of rhTß4 to the treatment of human CoV diseases such as COVID-19.


Assuntos
Infecções por Coronavirus/tratamento farmacológico , Vírus da Hepatite Murina , Timosina/uso terapêutico , Animais , Anticorpos Antivirais/sangue , Proteína C-Reativa/análise , Citocinas/sangue , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Vírus da Hepatite Murina/imunologia , RNA Viral/análise , Proteínas Recombinantes/uso terapêutico , Replicação Viral/efeitos dos fármacos
10.
Environ Geochem Health ; 43(3): 1287-1304, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32974884

RESUMO

Aim to classify typical hot springs in Guizhou, China and their relevance to health. Assessing geochemical characters of typical hot springs of Guizhou and classifying through hierarchical cluster analysis, an epidemiologic study was conducted to analyze the correlation between hot spring types and health, which showed typical hot springs in Guizhou can be divided into two types, A and B. Type A is rich in fluorine, metasilicic acid, radon components and a large number of essential elements, such as Na, that the human body needs, with trace elements, such as Cr and V, that are essential or possibly essential. Type B is rich in fluorine, metasilicate, strontium components and a large number of essential elements, Ca, Mg, and S, with trace elements, Cu, Mn, Mo, Co, and Ni, that are essential or possibly essential. These hot springs' effects on the health of those bathing in them showed both types were associated with bone and joint diseases. Having bathed in hot springs during the past year was associated with skin symptoms and bone and joint symptoms, and having bathed within the past two weeks was linked to sleep quality and levels of appetite and energy. However, differences do exist between the correlation between the two types and some chronic diseases, with Type A hot springs significantly related to cardiovascular and cerebrovascular diseases and diabetes and Type B to hypertension. This classification of Guizhou's hot springs can guide the future development and use of hot spring physiotherapy.


Assuntos
Promoção da Saúde/métodos , Fontes Termais , Oligoelementos/análise , Água/química , China , Humanos
11.
Nat Immunol ; 9(8): 927-36, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18568028

RESUMO

The transcription factor Ikaros is essential for B cell development. However, its molecular functions in B cell fate specification and commitment have remained elusive. We show here that the transcription factor EBF restored the generation of CD19(+) pro-B cells from Ikaros-deficient hematopoietic progenitors. Notably, these pro-B cells, despite having normal expression of the transcription factors EBF and Pax5, were not committed to the B cell fate. They also failed to recombine variable gene segments at the immunoglobulin heavy-chain locus. Ikaros promoted heavy-chain gene rearrangements by inducing expression of the recombination-activating genes as well as by controlling accessibility of the variable gene segments and compaction of the immunoglobulin heavy-chain locus. Thus, Ikaros is an obligate component of a network that regulates B cell fate commitment and immunoglobulin heavy-chain gene recombination.


Assuntos
Linfócitos B/fisiologia , Genes de Imunoglobulinas/genética , Fator de Transcrição Ikaros/metabolismo , Cadeias Pesadas de Imunoglobulinas/genética , VDJ Recombinases/genética , Animais , Sítios de Ligação , Diferenciação Celular , Linhagem Celular , Linhagem da Célula , Rearranjo Gênico/genética , Rearranjo Gênico/imunologia , Fator de Transcrição Ikaros/genética , Camundongos
12.
Proc Natl Acad Sci U S A ; 114(47): 12548-12553, 2017 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-29109286

RESUMO

The circadian system regulates numerous physiological processes including immune responses. Here, we show that mice deficient of the circadian clock genes Cry1 and Cry2 [Cry double knockout (DKO)] develop an autoimmune phenotype including high serum IgG concentrations, serum antinuclear antibodies, and precipitation of IgG, IgM, and complement 3 in glomeruli and massive infiltration of leukocytes into the lungs and kidneys. Flow cytometry of lymphoid organs revealed decreased pre-B cell numbers and a higher percentage of mature recirculating B cells in the bone marrow, as well as increased numbers of B2 B cells in the peritoneal cavity of Cry DKO mice. The B cell receptor (BCR) proximal signaling pathway plays a critical role in autoimmunity regulation. Activation of Cry DKO splenic B cells elicited markedly enhanced tyrosine phosphorylation of cellular proteins compared with cells from control mice, suggesting that overactivation of the BCR-signaling pathway may contribute to the autoimmunity phenotype in the Cry DKO mice. In addition, the expression of C1q, the deficiency of which contributes to the pathogenesis of systemic lupus erythematosus, was significantly down-regulated in Cry DKO B cells. Our results suggest that B cell development, the BCR-signaling pathway, and C1q expression are regulated by circadian clock CRY proteins and that their dysregulation through loss of CRY contributes to autoimmunity.


Assuntos
Doenças Autoimunes/imunologia , Autoimunidade/genética , Linfócitos B/imunologia , Relógios Circadianos/imunologia , Criptocromos/imunologia , Animais , Anticorpos Antinucleares/biossíntese , Doenças Autoimunes/genética , Doenças Autoimunes/metabolismo , Doenças Autoimunes/patologia , Linfócitos B/metabolismo , Linfócitos B/patologia , Relógios Circadianos/genética , Complemento C1q/genética , Criptocromos/deficiência , Criptocromos/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/imunologia , Rim/imunologia , Rim/patologia , Pulmão/imunologia , Pulmão/patologia , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/imunologia , Transdução de Sinais , Baço/imunologia , Baço/metabolismo , Baço/patologia
13.
Immunol Rev ; 263(1): 192-209, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25510278

RESUMO

Pre-B cells within the bone marrow represent the normal counterpart for most acute lymphoblastic leukemia (ALL). During normal early B-cell development, survival and proliferation signals are dominated by cytokines, particularly interleukin-7 (IL-7) for murine developing B cells. With expression of a functional pre-B-cell receptor (BCR), cytokine signaling is attenuated and the tonic/autonomous pre-BCR signaling pathway provides proliferation as well as differentiation signals. In this review, we first describe checkpoint mechanisms during normal B-cell development and then discuss how genetic lesions in these pathways function as oncogenic mimicries and allow transformed pre-B cells to bypass checkpoint control. We focus on cytokine receptor signaling that is mimicked by activating lesions in receptor subunits or downstream mediators as well as aberrant activation of non-B lymphoid cytokine receptors. Furthermore, we describe the molecular switch from cytokine receptor to pre-BCR signaling, how this pathway is of particular importance for certain ALL subtypes, and how pre-BCR signaling is engaged by genetic lesions, such as BCR-ABL1. We discuss the transcriptional control mechanisms downstream of both cytokine- and pre-BCR signaling and how normal checkpoint control mechanisms are circumvented in pre-B ALL. Finally, we highlight new therapeutic concepts for targeted inhibition of oncogenic cytokine or pre-BCR signaling pathways.


Assuntos
Proteínas de Fusão bcr-abl/metabolismo , Receptores de Células Precursoras de Linfócitos B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Células Precursoras de Linfócitos B/fisiologia , Animais , Antineoplásicos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Citocinas/metabolismo , Proteínas de Fusão bcr-abl/genética , Humanos , Camundongos , Terapia de Alvo Molecular , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos
15.
Blood ; 121(1): 148-55, 2013 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-23152540

RESUMO

The Sox4 transcription factor mediates early B-cell differentiation. Compared with normal pre-B cells, SOX4 promoter regions in Ph(+) ALL cells are significantly hypomethylated. Loss and gain-of-function experiments identified Sox4 as a critical activator of PI3K/AKT and MAPK signaling in ALL cells. ChIP experiments confirmed that SOX4 binds to and transcriptionally activates promoters of multiple components within the PI3K/AKT and MAPK signaling pathways. Cre-mediated deletion of Sox4 had little effect on normal pre-B cells but compromised proliferation and viability of leukemia cells, which was rescued by BCL2L1 and constitutively active AKT and p110 PI3K. Consistent with these findings, high levels of SOX4 expression in ALL cells at the time of diagnosis predicted poor outcome in a pediatric clinical trial (COG P9906). Collectively, these studies identify SOX4 as a central mediator of oncogenic PI3K/AKT and MAPK signaling in ALL.


Assuntos
Regulação Leucêmica da Expressão Gênica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Fatores de Transcrição SOXC/fisiologia , Transdução de Sinais/fisiologia , Animais , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Benzamidas , Sobrevivência Celular/efeitos dos fármacos , Criança , Metilação de DNA , Humanos , Mesilato de Imatinib , Estimativa de Kaplan-Meier , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Estudos Multicêntricos como Assunto/estatística & dados numéricos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/fisiologia , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Regiões Promotoras Genéticas , Modelos de Riscos Proporcionais , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/farmacologia , Pirimidinas/uso terapêutico , Quimera por Radiação , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Fatores de Transcrição SOXC/biossíntese , Fatores de Transcrição SOXC/deficiência , Fatores de Transcrição SOXC/genética , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas/citologia , Células Tumorais Cultivadas/efeitos dos fármacos , Ensaio Tumoral de Célula-Tronco
16.
Hum Reprod ; 30(2): 380-91, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25505012

RESUMO

STUDY QUESTION: How does the placenta protect the fetus from immune rejection by the mother? SUMMARY ANSWER: The placenta can produce IgG that is glycosylated at one of its Fab arms (asymmetric IgG; aIgG) which can interact with other antibodies and certain leukocytes to affect local immune reactions at the junction between the two genetically distinct entities. WHAT IS KNOWN ALREADY: The placenta can protect the semi-allogenic fetus from immune rejection by the immune potent mother. aIgG in serum is increased during pregnancy and returns to the normal range after giving birth. aIgG can react to antigens to form immune complexes which do not cause a subsequent immune effector reaction, including fixing complements, inducing cytotoxicity and phagocytosis, and therefore has been called 'blocking antibody'. STUDY DESIGN, SIZE, DURATION: Eighty-eight human placentas, four trophoblast cell lines (TEV-1, JAR, JEG and BeWo), primary culture of human placental trophoblasts and a gene knock-out mouse model were investigated in this study. PARTICIPANTS/MATERIALS, SETTING, METHODS: The general approach included the techniques of cell culture, immunohistochemistry, in situ hybridization, immuno-electron microscopy, western blot, quantitative PCR, protein isolation, glycosylation analysis, enzyme digestion, gene sequencing, mass spectrophotometry, laser-guided microdissection, enzyme-linked immunosorbent assay, pulse chase assay, double and multiple staining to analyze protein and DNA and RNA analysis at the cellular and molecular levels. MAIN RESULTS AND THE ROLE OF CHANCE: Three major discoveries were made: (i) placental trophoblasts and endothelial cells are capable of producing IgG, a significant portion of which is aberrantly glycosylated at one of its Fab arms to form aIgG; (ii) the asymmetrically glycosylated IgG produced by trophoblasts and endothelial cells can react to immunoglobulin molecules of human, rat, mouse, goat and rabbit at the Fc portion; (iii) asymmetrically glycosylated IgG can react to certain leukocytes in the membrane and cytoplasm, while symmetric IgG from the placenta does not have this property. LIMITATIONS, REASONS FOR CAUTION: Most of the experiments were performed in vitro. The proposed mechanism calls for verification in normal and abnormal pregnancy. WIDER IMPLICATIONS OF THE FINDINGS: This study identified a number of new phenomena suggesting that aIgG produced by the placenta would be able to react to detrimental antibodies and leukocytes and interfere with their immune reactions against the placenta and the fetus. This opens a new dimension for further studies on pregnancy physiology and immunology. Should the mechanism proposed here be confirmed, it will have a direct impact on our understanding of the physiology and pathology of human reproduction and offer new possibilities for the treatment of many diseases including spontaneous abortion, infertility and pre-eclampsia. It also sheds light on the mechanism of immune evasion in general including that of cancer.


Assuntos
Fragmentos Fab das Imunoglobulinas/metabolismo , Imunoglobulina G/metabolismo , Imunomodulação , Modelos Imunológicos , Placenta/imunologia , Adulto , Animais , Especificidade de Anticorpos , Linhagem Celular , Células Cultivadas , Cruzamentos Genéticos , Endotélio Vascular/citologia , Endotélio Vascular/imunologia , Endotélio Vascular/metabolismo , Endotélio Vascular/ultraestrutura , Feminino , Humanos , Fragmentos Fab das Imunoglobulinas/análise , Imunoglobulina G/análise , Leucócitos/citologia , Leucócitos/imunologia , Leucócitos/metabolismo , Leucócitos/ultraestrutura , Camundongos Knockout , Microscopia Imunoeletrônica , Placenta/citologia , Placenta/metabolismo , Placenta/ultraestrutura , Placentação , Gravidez , Trofoblastos/citologia , Trofoblastos/imunologia , Trofoblastos/metabolismo , Trofoblastos/ultraestrutura
17.
Lab Invest ; 94(11): 1283-95, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25264708

RESUMO

The liver has the extraordinary properties of regeneration and immune tolerance; however, the mechanisms governing these abilities are poorly understood. To address these questions, we examined the possible expression of immunoglobulins in the human and rat liver and the relationship of IgG expression to hepatocyte proliferation, metastasis, apoptosis and immune tolerance. Immunohistochemistry, in situ hybridization, laser-guided microdissection and reverse transcription-PCR were performed to examine the expression of IgG in normal human and rat liver, severe combined immunodeficient mouse (SCID) liver and human liver cancers and corresponding cell lines. Small interfering RNA (siRNA) was transfected into cultured hepatocarcinoma cells to downregulate the expression of IgG heavy chain genes. Cell proliferation and apoptosis were assayed with flow cytometry. Cell metastasis was assayed with a Transwell cell assay. Partial hepatectomy (70%) was performed in rats to examine the relationship between hepatocyte IgG and hepatocyte proliferation. IgG, together with essential enzymes for its synthesis, were expressed in the cytoplasm of hepatocytes of normal adult human and hepatoma patients and rat livers, SCID mouse liver and BRL-3A, L-02 and HepG-2 cell lines. Downregulation of IgG inhibited cell proliferation and metastasis and promoted apoptosis. Postsurgery livers expressed significantly more IgG than the livers before surgery and decreased to the original levels when hepatocytes stopped regeneration. IgA and IgM but not IgD and IgE were also positive in hepatocytes. Our findings demonstrate that normal and malignant hepatocytes are capable of synthesizing immunoglobulin, which has important roles in hepatocyte proliferation, apoptosis and cancer growth with profound clinical implications.


Assuntos
Carcinoma Hepatocelular/imunologia , Hepatócitos/metabolismo , Imunoglobulina G/biossíntese , Neoplasias Hepáticas Experimentais/imunologia , Regeneração Hepática/imunologia , Animais , Apoptose , Regulação para Baixo , Células Hep G2 , Hepatectomia , Humanos , Imunoglobulina A/metabolismo , Imunoglobulina M/metabolismo , Fígado/imunologia , Fígado/metabolismo , Fígado/cirurgia , Masculino , Camundongos SCID , Metástase Neoplásica , RNA Mensageiro/metabolismo , RNA Interferente Pequeno , Ratos Sprague-Dawley
18.
Biol Reprod ; 91(5): 128, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25273527

RESUMO

The placenta is known to protect the fetus from infection and maternal rejection. In a previous study, we demonstrated that placental trophoblasts can synthesize immunoglobulin G (IgG). In this study, we investigated the distribution of immunoglobulins (IgG, IgM, and IgA), IgG receptors (FcRn and FcgammaRIII), and complement proteins in placental trophoblasts at the ultrastructural level. In addition, we studied the mRNA expression of IgG1 heavy chain (IGHG1), recombination activating gene 1 (RAG1), RAG2, and activation-induced cytidine deaminase (AID) with nested RT-PCR in primary cultured trophoblasts. The mRNA transcripts of IGHG1, RAG1, RAG2, and AID were all identified in primary trophoblasts, further establishing the IgG-producing capacity of trophoblasts. At the ultrastructural level with colloidal gold-labeled antibodies, IgG was found to be distributed in two distinct locations in syncytiotrophoblasts. For one, it was colocalized with FcRn in endosome displaying low electron density, and for the other it was colocalized with complement C1q in medium-electron density irregular structures that have not been reported previously. This characteristic distribution suggests that IgG is likely processed through two molecular mechanisms in syncytiotrophoblasts: receptor-bound transportation across the syncytiotrophoblast and formation of immune complexes with locally produced IgG. The latter mechanism is probably aimed at neutralizing detrimental maternal anti-paternal major histocompatibility complex antibodies. Our findings support the hypothesis that placenta-produced IgG can selectively react with maternal anti-fetus antibodies and provide a mechanism of fetomaternal tolerance to protect the fetus from maternal immune rejection.


Assuntos
Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Placenta/imunologia , Placenta/metabolismo , Células Cultivadas , Feminino , Humanos , Imuno-Histoquímica , Microscopia Eletrônica , Placenta/ultraestrutura , Gravidez , Distribuição Tecidual , Trofoblastos/metabolismo , Trofoblastos/ultraestrutura
19.
Clin Genitourin Cancer ; 22(2): 347-353, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38195301

RESUMO

BACKGROUND: CD70 is commonly overexpressed in renal cell carcinoma and is minimally expressed in normal human tissue, making it a potential therapeutic target for patients with advanced renal cell carcinoma. The expression frequency of CD70 in metastatic renal cell carcinoma is not well established. MATERIALS AND METHODS: We assessed CD70 immunohistochemistry in 391 primary renal tumors and 72 metastatic renal cell carcinomas on a tissue microarray including 26 sets of paired primary and metastatic tumors. RESULTS: CD70 was frequently overexpressed in clear cell carcinoma, with a significantly lower expression rate in papillary renal cell carcinoma (P < .0001). No expression of CD70 was detected in other types of renal tumors and normal renal parenchyma. In clear cell renal cell carcinoma, CD70 expression was significantly correlated with hypoxia pathway proteins, corroborating with a recent study suggesting that CD70 is a downstream target gene of hypoxia-inducible factor. While higher expression levels were observed in males and non-Caucasians, CD70 expression was not associated with tumor grade, sarcomatoid differentiation, stage, or cancer-specific survival. Further, analysis of 26 paired primary and metastatic tumors from same individuals revealed a concordance rate of 85%. CONCLUSION: Our findings validated CD70 as a promising therapeutic target for patients with metastatic clear cell renal cell carcinoma. The utility of primary tumor tissue as surrogate samples for metastatic clear cell carcinoma awaits future CD70-targeted clinical trials.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Masculino , Humanos , Carcinoma de Células Renais/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Rim/patologia , Hipóxia , Biomarcadores Tumorais , Ligante CD27/metabolismo
20.
Innovation (Camb) ; 5(3): 100603, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38745762

RESUMO

The vaccine-induced innate immune response is essential for the generation of an antibody response. To date, how Ad5-vectored vaccines are influenced by preexisting anti-Ad5 antibodies during activation of the early immune response remains unclear. Here, we investigated the specific alterations in GP1,2-specific IgG-related elements of the early immune response at the genetic, molecular, and cellular levels on days 0, 1, 3, and 7 after Ad5-EBOV vaccination. In a causal multiomics analysis, distinct early immune responses associated with GP1,2-specific IgG were observed in Ad5-EBOV recipients with a low level of preexisting anti-Ad5 antibodies. This study revealed the correlates of the Ad5-EBOV-induced IgG response and provided mechanistic evidence for overcoming preexisting Ad5 immunity during the administration of Ad5-vectored vaccines.

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