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1.
Proc Natl Acad Sci U S A ; 117(25): 14202-14208, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513722

RESUMO

FtsK protein contains a fast DNA motor that is involved in bacterial chromosome dimer resolution. During cell division, FtsK translocates double-stranded DNA until both dif recombination sites are placed at mid cell for subsequent dimer resolution. Here, we solved the 3.6-Å resolution electron cryo-microscopy structure of the motor domain of FtsK while translocating on its DNA substrate. Each subunit of the homo-hexameric ring adopts a unique conformation and one of three nucleotide states. Two DNA-binding loops within four subunits form a pair of spiral staircases within the ring, interacting with the two DNA strands. This suggests that simultaneous conformational changes in all ATPase domains at each catalytic step generate movement through a mechanism related to filament treadmilling. While the ring is only rotating around the DNA slowly, it is instead the conformational states that rotate around the ring as the DNA substrate is pushed through.


Assuntos
DNA Bacteriano/metabolismo , DNA/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de Membrana/metabolismo , Translocação Genética/fisiologia , Divisão Celular/fisiologia , Segregação de Cromossomos , Cromossomos Bacterianos/metabolismo , Microscopia Crioeletrônica , DNA/química , DNA Bacteriano/química , Escherichia coli/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Proteínas de Membrana/química , Proteínas de Membrana/genética , Modelos Moleculares , Conformação Proteica
2.
Respir Res ; 21(1): 130, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460750

RESUMO

BACKGROUND: It has been confirmed that NF-κB p65 signaling pathway is involved in the regulation of alveolar hypercoagulation and fibrinolysis inhibition in acute respiratory distress syndrome (ARDS). Whether SN50, a NF-κB cell permeable inhibitor, could attenuate alveolar hypercoagulation and fibrinolysis inhibition in ARDS remains to be elucidated. PURPOSE: We explored the efficacy and potential mechanism of SN50 on alveolar hypercoagulation and fibrinolysis inhibition in ARDS in mice. MATERIALS AND METHODS: Mouse ARDS was made by 50 µl of lipopolysaccharide (LPS) (4 mg/ml) inhalation. Male BALB/c mice were intraperitoneally injected with different does of SN50 1 h before LPS inhalation. Lung tissues were collected for hematoxylin-eosin (HE) staining, wet/dry ratio. Pulmonary expressions of tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1), collagen III, as well as phosphorylated p65 (p-p65), p65 in nucleus (p'-p65), IκBα and IKKα/ß were measured. Bronchoalveolar lavage fluid (BALF) was gathered to test the concentrations of TF, PAI-1, activated protein C (APC) and thrombinantithrombin complex (TAT). DNA binding activity of NF-κB p65 was also determined. RESULTS: After LPS stimulation, pulmonary edema and exudation and alveolar collapse occured. LPS also stimulated higher expressions of TF and PAI-1 in lung tissues, and higher secretions of TF, PAI-1, TAT and low level of APC in BALF. Pulmonary collagen III expression was obviously enhanced after LPS inhalation. At same time, NF-κB signaling pathway was activated with LPS injury, shown by higher expressions of p-p65, p'-p65, p-IKKα/ß, p-Iκα in pulmonary tissue and higher level p65 DNA binding activity. SN50 dose-dependently inhibited TF, PAI-1 and collagen IIIexpressions, and decreased TF, PAI-1, TAT but increased APC in BALF. SN50 treatment attenuated pulmonary edema, exudation and reduced lung tissue damage as well. SN50 application significantly reduced p'-p65 expression and weakened p65 DNA binding activity, but expressions of p-p65, p-IKKα/ß, p-Iκα in cytoplasm of pulmonary tissue were not affected. CONCLUSIONS: SN 50 attenuates alveolar hypercoagulation and fibrinolysis inhibition in ARDS via inhibition of NF-κB p65 translocation. Our data demonstrates that NF-κB p65 pathway is a viable new therapeutic target for ARDS treatment.


Assuntos
Fibrinólise/efeitos dos fármacos , Peptídeos/uso terapêutico , Síndrome do Desconforto Respiratório/tratamento farmacológico , Trombofilia/tratamento farmacológico , Fator de Transcrição RelA/antagonistas & inibidores , Translocação Genética/efeitos dos fármacos , Animais , Fibrinólise/fisiologia , Lipopolissacarídeos/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Peptídeos/farmacologia , Alvéolos Pulmonares/efeitos dos fármacos , Alvéolos Pulmonares/metabolismo , Distribuição Aleatória , Síndrome do Desconforto Respiratório/induzido quimicamente , Síndrome do Desconforto Respiratório/metabolismo , Trombofilia/induzido quimicamente , Trombofilia/metabolismo , Fator de Transcrição RelA/metabolismo , Translocação Genética/fisiologia
3.
Ann Hematol ; 99(7): 1561-1564, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32451710

RESUMO

NUT midline carcinoma (NMC) is an aggressive neoplasm and mainly involved in the head and neck area. The defining genetic hallmark on these tumors is that testis-specific nuclear gene (NUTM1) fuses to bromodomain protein family member 4 gene (BRD4), resulting in the formation of BRD4-NUTM1 transcript. Here, we report a case with myeloid neoplasm complicating with eosinophilia (MLN-Eo) and rearrangement of PDGFRA, which co-exists with a new nucleosome assemble protein 1-like 4 gene (NAP1L4) NAP1L4-NUTM1 fusion. The patient have unusually clinical features and therapeutic reaction to imatinib mesylate. The cloned NAP1L4-NUTM1 gene structure is also determined.


Assuntos
Cromossomos Humanos Par 11/genética , Cromossomos Humanos Par 15/genética , Eosinofilia/genética , Transtornos Mieloproliferativos/tratamento farmacológico , Transtornos Mieloproliferativos/genética , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Adulto , Eosinofilia/complicações , Eosinofilia/tratamento farmacológico , Humanos , Síndrome Hipereosinofílica/genética , Síndrome Hipereosinofílica/patologia , Síndrome Hipereosinofílica/terapia , Mesilato de Imatinib/uso terapêutico , Leucemia/genética , Leucemia/patologia , Leucemia/terapia , Masculino , Mutação , Transtornos Mieloproliferativos/complicações , Transtornos Mieloproliferativos/patologia , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/isolamento & purificação , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Indução de Remissão , Translocação Genética/fisiologia
4.
Proc Natl Acad Sci U S A ; 114(45): 11932-11937, 2017 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-29078357

RESUMO

Enzymes that operate on DNA or RNA perform the core functions of replication and expression in all of biology. To gain high-resolution access to the detailed mechanistic behavior of these enzymes, we developed single-molecule picometer-resolution nanopore tweezers (SPRNT), a single-molecule technique in which the motion of polynucleotides through an enzyme is measured by a nanopore. SPRNT reveals two mechanical substates of the ATP hydrolysis cycle of the superfamily 2 helicase Hel308 during translocation on single-stranded DNA (ssDNA). By analyzing these substates at millisecond resolution, we derive a detailed kinetic model for Hel308 translocation along ssDNA that sheds light on how superfamily 1 and 2 helicases turn ATP hydrolysis into motion along DNA. Surprisingly, we find that the DNA sequence within Hel308 affects the kinetics of helicase translocation.


Assuntos
DNA Helicases/metabolismo , Replicação do DNA/fisiologia , DNA de Cadeia Simples/química , Pinças Ópticas , Difosfato de Adenosina/química , Trifosfato de Adenosina/química , Humanos , Cinética , Imagem Individual de Molécula , Translocação Genética/fisiologia
5.
Pathologica ; 112(2): 79-92, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32202535

RESUMO

Follicular lymphoma is a neoplasm derived from follicle center B cells, typically both centrocytes and centroblasts, in variable proportions according to the lymphoma grading. The pattern of growth may be entirely follicular, follicular and diffuse and rarely completely diffuse. It represents the second most common non-Hodgkin lymphoma, after diffuse large B-cell lymphoma and it is the most common low-grade mature B-cell lymphoma in Western countries. In the majority of cases, follicular lymphoma is a nodal tumor, occurring in adults and is frequently associated with the translocation t(14;18)(q32;q21)/IGH-BCL2. However, in recent years the spectrum of follicular lymphoma has expanded and small subsets of follicular lymphoma, which differ from common follicular lymphoma, have been identified and included in the current 2017 WHO classification. The aim of our review is to describe the broad spectrum of follicular lymphoma, pointing out that the identification of distinct clinicopathological variants of follicular lymphoma is relevant for the patient outcomes and treatment.


Assuntos
Biomarcadores Tumorais/análise , Linfoma Folicular/patologia , Linfoma Difuso de Grandes Células B/patologia , Translocação Genética/fisiologia , Humanos , Hibridização in Situ Fluorescente/métodos , Linfoma Folicular/diagnóstico , Linfoma Folicular/genética , Linfoma Difuso de Grandes Células B/cirurgia
6.
Adv Anat Pathol ; 26(5): 281-291, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31261248

RESUMO

Cyclin D1, encoded by CCND1, promotes cell cycle progression from G1 to S phase. Its expression is induced by MAPK/ERK pathway as well as translocations/rearrangements involving CCND1 gene. The evaluation of cyclin D1 expression by immunohistochemistry plays an important role in the diagnostic workup of various hematopoietic diseases. In this review, we aimed to discuss the value of cyclin D1 immunostain in the diagnosis and different diagnosis of hematopoietic neoplasms.


Assuntos
Ciclina D1/metabolismo , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/metabolismo , Translocação Genética/fisiologia , Humanos , Imuno-Histoquímica/métodos , Hibridização in Situ Fluorescente/métodos , Linfócitos/metabolismo , Linfócitos/patologia
7.
Mol Plant Microbe Interact ; 31(2): 233-239, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28952399

RESUMO

Salmonella enterica serovar Typhimurium, a human enteric pathogen, has the ability to multiply and survive endophytically in plants. Genes encoding the type III secretion system (T3SS) or its effectors (T3Es) may contribute to its colonization. Two reporter plasmids for T3E translocation into plant cells that are based on hypersensitive response domains of avirulence proteins from the Pantoea agglomerans-beet and Xanthomonas euvesicatoria-pepper pathosystems were employed in this study to investigate the role of T3Es in the interaction of Salmonella ser. Typhimurium 14028 with plants. The T3Es of Salmonella ser. Typhimurium, SipB and SifA, which are translocated into animal cells, could not be delivered by Salmonella ser. Typhimurium into cells of beet roots or pepper leaves. In contrast, these effectors were translocated into plant cells by the phytopathogenic bacteria P. agglomerans pv. betae, Erwinia amylovora, and X. euvesicatoria. Similarly, HsvG, a T3E of P. agglomerans pv. gypsophilae, and XopAU of X. euvesicatoria could be translocated into beet roots and pepper leaves, respectively, by the plant pathogens but not by Salmonella ser. Typhimurium. Mutations in Salmonella ser. Typhimurium T3SS genes invA, ssaV, sipB, or sifA, did not affect its endophytic colonization of lettuce leaves, supporting the notion that S. enterica cannot translocate T3Es into plant cells.


Assuntos
Proteínas de Bactérias/metabolismo , Pantoea/fisiologia , Salmonella enterica , Proteínas de Bactérias/genética , Técnicas Bacteriológicas , Capsicum/microbiologia , Meios de Cultura , Lactuca/microbiologia , Carne , Translocação Genética/genética , Translocação Genética/fisiologia , Xanthomonas
8.
BMC Urol ; 18(1): 60, 2018 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-29890986

RESUMO

BACKGROUND: The preoperative neutrophil-to-lymphocyte ratio (NLR), C-reactive protein/albumin ratio (CRP/Alb ratio) and platelet-to-lymphocyte ratio (PLR) have been demonstrated to predict the clinical outcome of various human cancer, including renal cell carcinoma(RCC). The aim of our study was to explore the prognostic values of these ratios in patients with Xp11.2 translocation/TFE3 gene fusions renal cell carcinoma (Xp11.2 tRCC). METHODS: A retrospective multicentre study was performed in 82 Xp11.2 tRCC patients who underwent radical or partial nephrectomy. The optimal cutoff values of the NLR, CRP/Alb ratio and PLR were determined by the receiver operating characteristic (ROC) analysis. The impact of the NLR, CRP/Alb ratio and PLR, as well as other clinicopathological characteristics, on disease-free survival (DFS) and overall survival (OS) were evaluated using the univariate and multivariate Cox regression analyses. RESULTS: The optimal cutoff values of the NLR, CRP/Alb ratio and PLR were set at 2.45, 140 and 0.08, respectively, according to the ROC analysis. Univariate analyses showed that the NLR, CRP/Alb ratio and PLR all were associated with DFS of Xp11.2 tRCC patients (P < 0.001, P = 0.005 and P = 0.001, respectively) and OS of Xp11.2 tRCC patients (P = 0.016, P = 0.003 and P = 0.014, respectively). Multivariate analysis indicated that the NLR was independently associated with DFS of Xp11.2 tRCC patients (hazard ratio [HR]: 4.25; 95% confidence interval [95% CI]: 1.19-15.18; P = 0.026) along with age (P = 0.004), the pT status (P < 0.001) and the pN status (P < 0.019), and the NLR (HR: 26.26; 95% CI: 1.44-480.3; P = 0.028) also was independently associated with OS in patients with Xp11.2 tRCC, along with age (P = 0.016) and a tumour thrombus (P = 0.007). CONCLUSION: Overall, relatively high NLRs, CRP/Alb ratios and PLRs were associated with a poor prognosis of Xp11.2 tRCC patients; among of them, only the NLR independently predicted the progression of Xp11.2 tRCC, and the NLR may help to identify patients with high metastasis or relapse risk.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Carcinoma de Células Renais/genética , Cromossomos Humanos X/genética , Neoplasias Renais/genética , Linfócitos/metabolismo , Neutrófilos/metabolismo , Adulto , Carcinoma de Células Renais/sangue , Carcinoma de Células Renais/cirurgia , Feminino , Seguimentos , Humanos , Neoplasias Renais/sangue , Neoplasias Renais/cirurgia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Cuidados Pré-Operatórios/métodos , Estudos Retrospectivos , Translocação Genética/fisiologia , Resultado do Tratamento
9.
PLoS Pathog ; 10(5): e1004170, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24874410

RESUMO

Endemic Burkitt's lymphoma (eBL) arises from the germinal center (GC). It is a common tumor of young children in tropical Africa and its occurrence is closely linked geographically with the incidence of P. falciparum malaria. This association was noted more than 50 years ago. Since then we have learned that eBL contains the oncogenic herpes virus Epstein-Barr virus (EBV) and a defining translocation that activates the c-myc oncogene. However the link to malaria has never been explained. Here we provide evidence for a mechanism arising in the GC to explain this association. Accumulated evidence suggests that eBL arises in the GC when deregulated expression of AID (Activation-induced cytidine deaminase) causes a c-myc translocation in a cell latently infected with Epstein-Barr virus (EBV). Here we show that P. falciparum targets GC B cells via multiple pathways to increase the risk of eBL. 1. It causes deregulated expression of AID, thereby increasing the risk of a c-myc translocation. 2. It increases the number of B cells transiting the GC. 3. It dramatically increases the frequency of these cells that are infected with EBV and therefore protected from c-myc induced apoptosis. We propose that these activities combine synergistically to dramatically increase the incidence of eBL in individuals infected with malaria.


Assuntos
Linfoma de Burkitt/imunologia , Infecções por Vírus Epstein-Barr/imunologia , Herpesvirus Humano 4 , Malária Falciparum/imunologia , Plasmodium falciparum , Animais , Linfoma de Burkitt/parasitologia , Linfoma de Burkitt/virologia , Linhagem Celular , Infecções por Vírus Epstein-Barr/genética , Humanos , Malária Falciparum/genética , Translocação Genética/genética , Translocação Genética/fisiologia
10.
Ann Diagn Pathol ; 25: 37-41, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27806844

RESUMO

INTRODUCTION: Myxoid liposarcoma is the only translocation-associated liposarcoma subtype. It classically originates in the deep soft tissues of the thigh. At distal sites of the extremities, this tumor is exceedingly rare. We present a series of 8 cases occurring in the foot/ankle. RESULTS: Two female and 6 male patients, aged between 32 and 77 years (mean, 54.3 years), were identified. Tumor size ranged from 1.1 to 10 cm (mean, 6.8 cm). Two lesions eroded bone. All tumors were treated by excision and 7 by (neo)adjuvant radiotherapy. R0 status was reached in 2 cases with 1 case followed by metastasis in the groin. All other cases were documented with R1 (n=2) or R2 (n=4) resection status. In 1 patient, the follow-up status was unknown. All other patients were alive 15-135 (mean, 55.8) months after initial diagnosis. We conclude that myxoid liposarcoma at acral sites are exceedingly rare, and in this series, prognosis was good irrespective of resection status. Clinicians and pathologists have to be aware because this sarcoma type shows a peculiar clinical behavior with high radio- and chemosensitivity and metastatic spread to extrapulmonary sites.


Assuntos
Pé/patologia , Lipossarcoma Mixoide/diagnóstico , Lipossarcoma Mixoide/patologia , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/patologia , Sarcoma/patologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Sarcoma/diagnóstico , Coxa da Perna/patologia , Translocação Genética/fisiologia
11.
Blood ; 121(21): 4359-65, 2013 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-23568489

RESUMO

Chromosomal translocations are common contributors to malignancy, yet little is known about the precise molecular mechanisms by which they are generated. Sequencing translocation junctions in acute leukemias revealed that the translocations were likely mediated by a DNA double-strand break repair pathway termed nonhomologous end-joining (NHEJ). There are major 2 types of NHEJ: (1) the classical pathway initiated by the Ku complex, and (2) the alternative pathway initiated by poly ADP-ribose polymerase 1 (PARP1). Recent reports suggest that classical NHEJ repair components repress translocations, whereas alternative NHEJ components were required for translocations. The rate-limiting step for initiation of alternative NHEJ is the displacement of the Ku complex by PARP1. Therefore, we asked whether PARP1 inhibition could prevent chromosomal translocations in 3 translocation reporter systems. We found that 2 PARP1 inhibitors or repression of PARP1 protein expression strongly repressed chromosomal translocations, implying that PARP1 is essential for this process. Finally, PARP1 inhibition also reduced both ionizing radiation-generated and VP16-generated translocations in 2 cell lines. These data define PARP1 as a critical mediator of chromosomal translocations and raise the possibility that oncogenic translocations occurring after high-dose chemotherapy or radiation could be prevented by treatment with a clinically available PARP1 inhibitor.


Assuntos
Leucemia/genética , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerases/fisiologia , Translocação Genética/genética , Translocação Genética/fisiologia , Doença Aguda , Células Cultivadas , Quebras de DNA de Cadeia Dupla , Fibroblastos/citologia , Fibroblastos/fisiologia , Humanos , Indóis/farmacologia , Leucemia/tratamento farmacológico , Leucemia/prevenção & controle , Ftalazinas/farmacologia , Piperazinas/farmacologia , Poli(ADP-Ribose) Polimerase-1 , Inibidores de Poli(ADP-Ribose) Polimerases , RNA Interferente Pequeno/genética , Translocação Genética/efeitos dos fármacos
12.
Blood ; 122(4): 542-9, 2013 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-23741012

RESUMO

The t(12;21)(p13;q22) translocation is the most common chromosomal abnormality in pediatric leukemia. Although this rearrangement involves 2 well-characterized transcription factors, TEL and AML1, the molecular pathways affected by the result of the translocation remain largely unknown. Also in light of recent studies showing genetic and functional heterogeneities in cells responsible for cancer clone maintenance and propagation, targeting a single common deregulated pathway may be critical for the success of novel therapies. Here we describe a novel signaling pathway that is essential for oncogenic addiction in TEL-AML1 leukemia. Our data indicate a direct role for TEL-AML1, via increasing the activity of RAC1, in regulating the phosphorylation of signal transducer and activator of transcription 3 (STAT3), which results in transcriptional induction of MYC. We demonstrate that human leukemic cell lines carrying this translocation are highly sensitive to treatment with S3I-201, a specific STAT3 inhibitor, and, more interestingly, that primary human leukemic samples are also responsive to the drug in the same concentration range. Thus, STAT3 inhibition represents a promising possible therapeutic strategy for the treatment of TEL-AML1 leukemia.


Assuntos
Transformação Celular Neoplásica/genética , Subunidade alfa 2 de Fator de Ligação ao Core/fisiologia , Proteínas de Fusão Oncogênica/fisiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Fator de Transcrição STAT3/fisiologia , Animais , Apoptose/genética , Apoptose/fisiologia , Proliferação de Células , Células Cultivadas , Cromossomos Humanos Par 12/genética , Cromossomos Humanos Par 21/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas de Fusão Oncogênica/genética , Oncogenes/genética , Oncogenes/fisiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Fator de Transcrição STAT3/genética , Translocação Genética/fisiologia
13.
Exp Dermatol ; 24(6): 418-23, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25739980

RESUMO

Quercetin, glycosylated form of flavonoid compound, has potent antioxidant and anti-inflammatory properties. In this study, we have investigated the effects of quercetin on skin lesion, high-mobility group box (HMGB)1 cascade signalling and inflammation in atopic dermatitis (AD) mouse model. AD-like lesion was induced by the application of house dust mite extract to the dorsal skin of NC/Nga transgenic mouse. After AD induction, quercetin (50 mg/kg, p.o) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes and changes in protein expression by Western blotting for HMGB1, receptor for advanced glycation end products (RAGE), toll-like receptor (TLR)4, nuclear factor (NF)κB, nuclear factor erythroid-2-related factor (Nrf)2, kelch-like ECH-associated protein (Keap)1, extracellular signal-regulated kinase (ERK)1/2, cyclooxygenase (COX)2, tumor necrosis factor (TNF)α, interleukin (IL)-1ß, IL-2Rα and other inflammatory markers in the skin of AD mice. In addition, serum levels of T helper (Th) cytokines (interferon (IFN)γ, IL-4) were measured by enzyme-linked immunosorbent assay. Quercetin treatment attenuated the development of AD-like skin lesions. Histological analysis showed that quercetin inhibited hyperkeratosis, parakeratosis, acanthosis, mast cells and infiltration of inflammatory cells. Furthermore, quercetin treatment downregulated cytoplasmic HMGB1, RAGE, nuclear p-NFκB, p-ERK1/2, COX2, TNFα, IL-1ß, IL-2Rα, IFNγ and IL-4 and upregulated nuclear Nrf2. Our data demonstrated that the HMGB1/RAGE/NFκB signalling might play an important role in skin inflammation, and quercetin treatment could be a promising agent for AD by modulating the HMGB1/RAGE/NFκB signalling and induction of Nrf2 protein.


Assuntos
Dermatite Atópica/tratamento farmacológico , Proteína HMGB1/genética , NF-kappa B/fisiologia , Quercetina/farmacologia , Receptor para Produtos Finais de Glicação Avançada/fisiologia , Transdução de Sinais/efeitos dos fármacos , Translocação Genética/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Dermatite Atópica/etiologia , Dermatite Atópica/fisiopatologia , Dermatophagoides farinae/patogenicidade , Modelos Animais de Doenças , Feminino , Proteína HMGB1/efeitos dos fármacos , Proteína HMGB1/fisiologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Camundongos Transgênicos , Fator 2 Relacionado a NF-E2/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/fisiologia , NF-kappa B/efeitos dos fármacos , NF-kappa B/genética , Quercetina/uso terapêutico , Receptor para Produtos Finais de Glicação Avançada/efeitos dos fármacos , Receptor para Produtos Finais de Glicação Avançada/genética , Índice de Gravidade de Doença , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Pele/efeitos dos fármacos , Pele/patologia , Receptor 4 Toll-Like/efeitos dos fármacos , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/fisiologia , Translocação Genética/genética , Translocação Genética/fisiologia
14.
J Pathol ; 234(2): 253-61, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24931216

RESUMO

Translocations contribute to the genesis and progression of epithelial tumours and in particular to prostate cancer development. To better understand the contribution of fusion transcripts and visualize the clonal composition of multifocal tumours, we have developed a technology for multiplex in situ detection and identification of expressed fusion transcripts. When compared to immunohistochemistry, TMPRSS2-ERG fusion-negative and fusion-positive prostate tumours were correctly classified. The most prevalent TMPRSS2-ERG fusion variants were visualized, identified, and quantitated in human prostate cancer tissues, and the ratio of the variant fusion transcripts could for the first time be directly determined by in situ sequencing. Further, we demonstrate concurrent in situ detection of gene expression, point mutations, and gene fusions of the prostate cancer relevant targets AMACR, AR, TP53, and TMPRSS2-ERG. This unified approach to in situ analyses of somatic mutations can empower studies of intra-tumoural heterogeneity and future tissue-based diagnostics of mutations and translocations.


Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Mutação Puntual/genética , Neoplasias da Próstata/genética , Serina Endopeptidases/genética , Transativadores/genética , Biomarcadores Tumorais/genética , Expressão Gênica/fisiologia , Humanos , Hibridização in Situ Fluorescente/métodos , Masculino , Proteínas de Fusão Oncogênica/genética , Neoplasias da Próstata/patologia , Transativadores/metabolismo , Regulador Transcricional ERG , Translocação Genética/fisiologia
15.
Proc Natl Acad Sci U S A ; 109(4): 1086-91, 2012 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-22219368

RESUMO

Base excision repair of genotoxic nucleobase lesions in the genome is critically dependent upon the ability of DNA glycosylases to locate rare sites of damage embedded in a vast excess of undamaged DNA, using only thermal energy to fuel the search process. Considerable interest surrounds the question of how DNA glycosylases translocate efficiently along DNA while maintaining their vigilance for target damaged sites. Here, we report the observation of strandwise translocation of 8-oxoguanine DNA glycosylase, MutM, along undamaged DNA. In these complexes, the protein is observed to translocate by one nucleotide on one strand while remaining untranslocated on the complementary strand. We further report that alterations of single base-pairs or a single amino acid substitution (R112A) can induce strandwise translocation. Molecular dynamics simulations confirm that MutM can translocate along DNA in a strandwise fashion. These observations reveal a previously unobserved mode of movement for a DNA-binding protein along the surface of DNA.


Assuntos
Reparo do DNA/fisiologia , DNA-Formamidopirimidina Glicosilase/metabolismo , DNA/metabolismo , Geobacillus stearothermophilus/enzimologia , Modelos Moleculares , Translocação Genética/fisiologia , Cristalização , DNA-Formamidopirimidina Glicosilase/química , DNA-Formamidopirimidina Glicosilase/genética , Escherichia coli , Geobacillus stearothermophilus/genética , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Conformação de Ácido Nucleico , Conformação Proteica , Transporte Proteico/fisiologia , Síncrotrons , Difração de Raios X
16.
J Neurosci ; 33(6): 2507-11, 2013 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-23392678

RESUMO

Studies in cultured cells have demonstrated the existence of higher-order epigenetic mechanisms, determining the relationship between expression of the gene and its position within the cell nucleus. It is unknown, whether such mechanisms operate in postmitotic, highly differentiated cell types, such as neurons in vivo. Accordingly, we examined whether the intranuclear positions of Bdnf and Trkb genes, encoding the major neurotrophin and its receptor respectively, change as a result of neuronal activity, and what functional consequences such movements may have. In a rat model of massive neuronal activation upon kainate-induced seizures we found that elevated neuronal expression of Bdnf is associated with its detachment from the nuclear lamina, and translocation toward the nucleus center. In contrast, the position of stably expressed Trkb remains unchanged after seizures. Our study demonstrates that activation-dependent architectural remodeling of the neuronal cell nucleus in vivo contributes to activity-dependent changes in gene expression in the brain.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Epigênese Genética/fisiologia , Receptor trkB/fisiologia , Convulsões/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/fisiologia , Núcleo Celular/genética , Núcleo Celular/metabolismo , Masculino , Ratos , Ratos Wistar , Convulsões/genética , Translocação Genética/fisiologia
17.
Med Sci (Paris) ; 30(1): 55-63, 2014 Jan.
Artigo em Francês | MEDLINE | ID: mdl-24472460

RESUMO

Complex chromosomal rearrangements (CCR) include diverse structural anomalies leading to complex karyotypes which are difficult to interpret. Although karyotype analysis has been able to identify a large number of these rearrangements and to distinguish de novo and familial events, it is the advent of molecular cytogenetic and sequence analysis techniques which have led to an understanding of the molecular mechanisms underlying the formation of CCR. The diversity and high level of complexity inherent to CCR raises questions about their origin, their ties to chromosome instability and their impact in pathology. Today it is possible to precisely characterize CCR and to offer carriers sophisticated diagnostic techniques, such as preimplantation diagnosis. However, the meiotic segregation of these rearrangements remains very complex.


Assuntos
Instabilidade Cromossômica/fisiologia , Aberrações Cromossômicas , Translocação Genética/fisiologia , Animais , Aberrações Cromossômicas/classificação , Aberrações Cromossômicas/estatística & dados numéricos , Análise Citogenética/métodos , Análise Citogenética/tendências , Fertilidade/genética , Humanos
18.
J Cell Biochem ; 114(11): 2569-76, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23744730

RESUMO

One of the most frequent chromosomal translocation found in patients with acute myeloid leukemia (AML) is the t(8;21). This translocation involves the RUNX1 and ETO genes. The breakpoints regions for t(8;21) are located at intron 5 and intron 1 of the RUNX1 and ETO gene respectively. To date, no homologous sequences have been found in these regions to explain their recombination. The breakpoint regions of RUNX1 gene are characterized by the presence of DNasaI hypersensitive sites and topoisomerase II cleavage sites, but no information exists about complementary regions of ETO gene. Here, we report analysis of chromatin structure of ETO breakpoint regions. Chromatin immunoprecipitation (ChIP) were performed with antibodies specific to acetylated histone H3, H4, and total histone H1. Nucleosomal distribution at the ETO locus was evaluated by determining total levels of histone H3. Our data show that in myeloid cells, the breakpoint regions at the ETO gene are enriched in hyperacetylated histone H3 compared to a control region of similar size where no translocations have been described. Moreover, acetylated H4 associates with both the whole ETO breakpoint regions as well as the control intron. Interestingly, we observed no H1 association either at the breakpoint regions or the control region of the ETO gene. Our data indicate that a common chromatin structure enriched in acetylated histones is present in breakpoint regions involved in formation of (8;21) leukemic translocation.


Assuntos
Cromossomos Humanos Par 21/metabolismo , Cromossomos Humanos Par 8/metabolismo , Histonas/metabolismo , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , Translocação Genética/fisiologia , Acetilação , Imunoprecipitação da Cromatina , Cromossomos Humanos Par 21/genética , Cromossomos Humanos Par 8/genética , Células HL-60 , Humanos , Proteínas Proto-Oncogênicas/metabolismo , Proteína 1 Parceira de Translocação de RUNX1 , Fatores de Transcrição/metabolismo , Translocação Genética/genética
19.
Prostate ; 72(9): 991-7, 2012 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-22024950

RESUMO

BACKGROUND: Overexpression of anti-apoptotic Bcl-2 plays a role in prostate cancer progression, particularly in transformation to androgen-independent disease. Androgen-independent prostate cancers have been shown to harbor Bcl-2 gene copy number gains frequently suggesting that this genetic alteration might play a role in Bcl-2 overexpression. The relation of Bcl-2 overexpression and copy number gains or translocation of the BCL-2 gene in prostate cancer under hormone-naïve conditions is unknown. METHODS: Prostate cancers of 3,261 hormone-naïve patients undergoing radical prostatectomy were arrayed in a TMA with one tissue core (diameter 0.6 mm) per tumor. Bcl-2 immunohistochemistry, analyzed for Bcl-2 expression level (negative, low, and high), was correlated with clinical, histopathological and molecular (Ki67, p53) tumor features, and biochemical failure. Cancers with high-level Bcl-2 expression were evaluated for genetic aberrations by fluorescence in situ hybridization (FISH). RESULTS: Bcl-2 expression was significantly up-regulated in tumors with aggressive phenotype as indicated by high Gleason score (P < 0.0001), advanced stage (P < 0.0001), and high proliferation index (P = 0.0114). The different Bcl-2 expression levels translated into significantly different survival curves showing better outcome for patients with lower Bcl-2 levels. The prognostic information obtained from the anti-apoptotic Bcl-2 was independent from the proliferation index (Ki67) of the cancer. FISH analysis detected no copy number gains or translocation of the Bcl-2 gene. CONCLUSION: Bcl-2 overexpression in prostate cancers under hormone-naïve conditions is not associated with increased copy numbers of the gene. This suggests that these frequently detected genetic alterations in androgen-independent tumors occur late in prostate cancer progression.


Assuntos
Dosagem de Genes/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/genética , Neoplasias da Próstata/cirurgia , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/genética , Translocação Genética/fisiologia , Idoso , Progressão da Doença , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia
20.
Ann Hematol ; 91(8): 1235-43, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22373549

RESUMO

ETV6 is an important hematopoietic regulatory factor and ETV6 gene rearrangement is involved in a wide variety of hematological malignancies. In this study, we sought to investigate the incidence of ETV6-associated fusion genes in B- and T-lineage acute lymphoblastic leukemia (ALL) by multiplex-nested reverse transcription-polymerase chain reaction (RT-PCR) in 176 adult ALL patients. Total RNA was extracted from bone marrow samples of ALL patients including 136 B- and 40 T-lineage ALL, and ETV6 fusion genes were detected by multiplex-nested RT-PCR. Changes of ETV6 fusion gene mRNA transcript levels were examined by real-time RT-PCR. We detected a total of 15 ETV6 gene rearrangements with a positive rate of 8.5%, involving seven ETV6-associated fusion genes in 13 B-ALL (13/136, 9.6%) and 2 T-ALL patients (2/40, 5.0%). ETV6-RUNX1 were observed in six cases (3.4%), ETV6-JAK2 in three cases (1.7%), ETV6-ABL1 in two cases (1.1%), and ETV6-ABL2, ETV6-NCOA2, ETV6-SYK, and PAX5-ETV6 each in one case (0.6%). ETV6-JAK2 was found in both B-ALL and T-ALL patients. Furthermore, real-time quantitative RT-PCR assays showed that the ETV6-RUNX1 mRNA transcript levels decreased during conventional chemotherapy or hematopoietic stem cell transplantation. This study shows that multiplex-nested RT-PCR is an effective and accurate tool to identify ETV6 rearrangements in adult ALL, which provides some clues into the diagnosis and prognosis of ALL but also molecular markers for the detection of minimal residual disease in adult ALL.


Assuntos
Mutação , Proteínas de Fusão Oncogênica/análise , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Repressoras/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Análise Mutacional de DNA/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Mutação/fisiologia , Neoplasia Residual/diagnóstico , Neoplasia Residual/genética , Proteínas de Fusão Oncogênica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Proteínas Proto-Oncogênicas c-ets/metabolismo , Proteínas Repressoras/metabolismo , Sensibilidade e Especificidade , Translocação Genética/fisiologia , Adulto Jovem , Variante 6 da Proteína do Fator de Translocação ETS
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