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1.
Urology ; 153: 113-118, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33581234

RESUMO

OBJECTIVE: To assess difficulties in filling the International Consultation on Incontinence Questionnaire Bladder Diary (ICIQ-BD), determining the most troublesome items and patients' characteristics (age, education level, and professional activity) related to these difficulties. METHODS: A text composed of a clinical history of a fictitious patient with Lower Urinary Tract Symptoms (LUTS) was designed. 95 healthy volunteers (49 females, 46 males, mean age 45.6 ± 17.3 years) were asked to fill in the ICIQ-BD according to the data from the fictitious clinical history. Filling errors were analyzed, and patients' demographic characteristics tested as predictors. RESULTS: Bladder Sensation Score is the most problematic item of the ICIQ-BD, with only 38% of patients accurately filling this item. No association was found between total number of errors and age or education level, but participants working in less specialized professions had more difficulty in filling the BD (mean: 7.00 vs 3.94 errors, P= .002). CONCLUSION: ICIQ-BD is a reliable tool to assess for LUTS, but filling the Bladder Sensation Score item was more likely to be incorrectly filled by manual workers and volunteers with less intellectually demanding current professions.


Assuntos
Autoavaliação Diagnóstica , Sintomas do Trato Urinário Inferior , Ocupações , Dados de Saúde Gerados pelo Paciente/métodos , Inquéritos e Questionários/normas , Incontinência Urinária , Fatores Etários , Demografia , Escolaridade , Feminino , Voluntários Saudáveis , Humanos , Sintomas do Trato Urinário Inferior/diagnóstico , Sintomas do Trato Urinário Inferior/fisiopatologia , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensação , Incontinência Urinária/diagnóstico , Incontinência Urinária/fisiopatologia
2.
Oncogene ; 31(3): 269-81, 2012 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-21706056

RESUMO

Ezrin is a multifunctional protein that connects the actin cytoskeleton to the extracellular matrix through transmembrane proteins. High ezrin expression is associated with lung metastasis and poor survival in cancer. We screened small molecule libraries for compounds that directly interact with ezrin protein using surface plasmon resonance to identify lead compounds. The secondary functional assays used for lead compound selection included ezrin phosphorylation as measured by immunoprecipitation and in vitro kinase assays, actin binding, chemotaxis, invasion into an endothelial cell monolayer, zebrafish and Xenopus embryonic development, mouse lung organ culture and an in vivo lung metastasis model. Two molecules, NSC305787 and NSC668394, that directly bind to ezrin with low micromolar affinity were selected based on inhibition of ezrin function in multiple assays. They inhibited ezrin phosphorylation, ezrin-actin interaction and ezrin-mediated motility of osteosarcoma (OS) cells in culture. NSC305787 mimicked the ezrin morpholino phenotype, and NSC668394 caused a unique developmental defect consistent with reduced cell motility in zebrafish. Following tail vein injection of OS cells into mice, both molecules inhibited lung metastasis of ezrin-sensitive cells, but not ezrin-resistant cells. The small molecule inhibitors NSC305787 and NSC668394 demonstrate a novel targeted therapy that directly inhibits ezrin protein as an approach to prevent tumor metastasis.


Assuntos
Adamantano/análogos & derivados , Antineoplásicos/farmacologia , Neoplasias Ósseas/patologia , Proteínas do Citoesqueleto/antagonistas & inibidores , Neoplasias Pulmonares/secundário , Osteossarcoma/secundário , Fenóis/farmacologia , Quinolinas/farmacologia , Quinolonas/farmacologia , Actinas/antagonistas & inibidores , Adamantano/química , Adamantano/farmacologia , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Invasividade Neoplásica/patologia , Técnicas de Cultura de Órgãos , Osteossarcoma/metabolismo , Fenóis/química , Fosforilação/efeitos dos fármacos , Quinolinas/química , Quinolonas/química , Ressonância de Plasmônio de Superfície , Xenopus , Peixe-Zebra
3.
Oncogene ; 24(52): 7656-72, 2005 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-16299527

RESUMO

Retroviral insertion mutagenesis screens in mice are powerful tools for efficient identification of oncogenic mutations in an in vivo setting. Many oncogenes identified in these screens have also been shown to play a causal role in the development of human cancers. Sequencing and annotation of the mouse genome, along with recent improvements in insertion site cloning has greatly facilitated identification of oncogenic events in retrovirus-induced tumours. In this review, we discuss the features of retroviral insertion mutagenesis screens, covering the mechanisms by which retroviral insertions mutate cellular genes, the practical aspects of insertion site cloning, the identification and analysis of common insertion sites, and finally we address the potential for use of somatic insertional mutagens in the study of nonhaematopoietic and nonmammary tumour types.


Assuntos
Mutagênese Insercional , Retroviridae/genética , Clonagem Molecular , Elementos de DNA Transponíveis , Genes Supressores de Tumor , Testes Genéticos , Humanos , Neoplasias/genética , Proto-Oncogenes
4.
Nucl Med Biol ; 31(6): 747-52, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15246365

RESUMO

The clinical response to antitumor therapy is measured using imaging, such as CT or MRI, 6-12 weeks following chemotherapy treatment. The images at that time reflect both tumor cell death and new growth. Therefore, the amount of tumor cell death caused by chemotherapy cannot be efficiently quantified with current imaging modalities. A quantitative measurement of tumor cell death immediately following chemotherapy is needed to help validate both new agents and to optimize administration of existing therapies. Annexin V is a 36kD protein that binds to exposed phosphatidylserine (PS) on dying cells. In order to synthesize a probe that can detect cell death in vivo, the positron emitter F-18 was conjugated to annexin V via the compound N- succinimidyl-4-[18F]fluorobenzoate, [18F]SFB. The decay corrected radiochemical yield of F-18 labeled annexin V from 18F fluoride was 17.6 +/- 5.6% (n = 4) in three hours. The stepwise radiochemical yield of the conjugation step with annexin V was as high as 70% when a protein concentration of 5 mg/ml was used. Cancer cells treated with the chemotherapeutic agent, etoposide, showed an 88% increase in the binding of F-18 labeled annexin V compared to untreated cells. We conclude that [18F] labeled annexin V can be readily prepared by the conjugation of annexin V with [18F]SFB and that the positron-emitting compound is biologically active in detecting apoptosis.


Assuntos
Anexina A5/síntese química , Morte Celular/fisiologia , Compostos Radiofarmacêuticos/síntese química , Anexina A5/análogos & derivados , Apoptose , Benzoatos , Fluoresceína-5-Isotiocianato , Corantes Fluorescentes , Radioisótopos de Flúor , Humanos , Marcação por Isótopo , Tomografia por Emissão de Pósitrons , Sarcoma de Ewing/diagnóstico por imagem
5.
Oncogene ; 22(15): 2334-42, 2003 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-12700668

RESUMO

The Ewing's sarcoma family of tumors (ESFT) contain a translocation, t(11;22), which results in the novel oncogenic fusion protein EWS/FLI1. Platelet-derived growth factors (PDGF) and their receptors (PDGFR) are involved in the induction and proliferation of numerous solid tumors and are the potential candidates for novel targeted antitumor therapy. Since a relation was reported between PDGF-C and EWS/FLI1, we sought to characterize the PDGF signaling pathway in ESFT. Eight out of nine ESFT cell lines were found to express significant levels of beta-PDGFR. Interestingly, none of the tested cell lines expressed alpha-PDGFR, which is the receptor isotype required for PDGF-C binding. By immunohistochemical staining 47 of 52 (90.4%) archival tumor samples from patients with ESFT were positive for beta-PDGFR. ESFT cell lines were treated with PDGF-AA or PDGF-BB ligands to evaluate downstream signaling. Autophosphorylation of beta-PDGFR and tyrosine phosphorylation of PLC-gamma, PI3Kp85 and Shc were detected only in PDGF-BB-stimulated cells that express beta-PDGFR. Receptor function was further evaluated using chemotaxis assays that showed TC-32 cell migration towards PDGF-BB. A specific PDGFR kinase inhibitor AG1295 blocked beta-PDGFR activation, downstream signaling, growth in cell culture and chemotaxis of TC-32 cells. AG1295 also delayed tumor formation and prolonged survival in an ESFT animal model. We conclude that ESFT express beta-PDGFR and that this is a functional and potentially crucial signaling pathway. Therefore, beta-PDGFRs may provide a novel therapeutic target in ESFT that can be utilized to design better treatment modalities.


Assuntos
Neoplasias Ósseas/patologia , Proteínas de Neoplasias/fisiologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Receptor beta de Fator de Crescimento Derivado de Plaquetas/fisiologia , Sarcoma de Ewing/patologia , Animais , Becaplermina , Neoplasias Ósseas/metabolismo , Divisão Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Classe Ib de Fosfatidilinositol 3-Quinase , Progressão da Doença , Inibidores Enzimáticos/farmacologia , Humanos , Isoenzimas/metabolismo , Camundongos , Camundongos SCID , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Transplante de Neoplasias , Fosfatidilinositol 3-Quinases/metabolismo , Fosfolipase C gama , Fosforilação/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-sis , Receptor beta de Fator de Crescimento Derivado de Plaquetas/biossíntese , Receptor beta de Fator de Crescimento Derivado de Plaquetas/efeitos dos fármacos , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Proteínas Recombinantes/farmacologia , Sarcoma de Ewing/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas/citologia , Células Tumorais Cultivadas/metabolismo , Fosfolipases Tipo C/metabolismo , Tirfostinas/farmacologia
6.
Mech Dev ; 102(1-2): 45-55, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11287180

RESUMO

Wnt-4 signaling plays a critical role in kidney development and is associated with the epithelial conversion of the metanephric mesenchyme. Furthermore, secreted Frizzled-related proteins (sFRPs) that can bind Wnts are normally expressed in the developing metanephros, and function in other systems as modulators of Wnt signaling. sfrp-1 is distributed throughout the medullary and cortical stroma in the metanephros, but is absent from condensed mesenchyme and primitive tubular epithelia of the developing nephron where wnt-4 is highly expressed. In contrast, sfrp-2 is expressed in primitive tubules. To determine their role in kidney development, recombinant sFRP-1, sFRP-2 or combinations of both were applied to cultures of 13-dpc rat metanephroi. Both tubule formation and bud branching were markedly inhibited by sFRP-1, but concurrent sFRP-2 treatment restored some tubular differentiation and bud branching. sFRP-2 itself showed no effect on cultures of metanephroi. In cultures of isolated, induced rat metanephric mesenchymes, sFRP-1 blocked events associated with epithelial conversion (tubulogenesis and expression of lim-1, sfrp-2 and E-cadherin); however, it had no demonstrable effect on early events (compaction of mesenchyme and expression of wt1). As shown herein, sFRP-1 binds Wnt-4 with considerable avidity and inhibits the DNA-binding activity of TCF, an effector of Wnt signaling, while sFRP-2 had no effect on TCF activation. These observations suggest that sFRP-1 and sFRP-2 compete locally to regulate Wnt signaling during renal organogenesis. The antagonistic effect of sFRP-1 may be important either in preventing inappropriate development within differentiated areas of the medulla or in maintaining a population of cortical blastemal cells to facilitate further renal expansion. On the other hand, sFRP-2 might promote tubule formation by permitting Wnt-4 signaling in the presence of sFRP-1.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Membrana , Proteínas/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Animais , Caderinas/biossíntese , Diferenciação Celular , Núcleo Celular/metabolismo , Células Cultivadas , DNA/metabolismo , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Epitélio/metabolismo , Receptores Frizzled , Proteínas de Homeodomínio/biossíntese , Immunoblotting , Imuno-Histoquímica , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intracelular , Rim/embriologia , Túbulos Renais/embriologia , Proteínas com Homeodomínio LIM , Mesoderma/metabolismo , Camundongos , Néfrons/embriologia , Ligação Proteica , Biossíntese de Proteínas , Ratos , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Fatores de Tempo , Fatores de Transcrição , Proteínas Wnt , Proteína Wnt4
7.
Blood ; 96(13): 4350-6, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11110712

RESUMO

We have previously shown that pretreatment of mice with keratinocyte growth factor (KGF), an epithelial tissue repair factor, can ameliorate graft-versus-host disease (GVHD) after intensive chemoradiotherapeutic conditioning and allogeneic bone marrow transplantation (BMT). To determine whether this effect was dependent on a KGF-mediated mechanism affecting repair of conditioning-induced epithelial cell injury, we studied GVHD in the absence of conditioning using BALB/c severe combined immune-deficient (SCID) recipients given C57BL/6 T cells. KGF (5 mg/kg per day, subcutaneously) given either before or after T-cell transfer enhanced body weights and extended survival. KGF-treated recipients had elevated serum levels of the Th2 cytokine interleukin 13 (IL-13) on day 6 after T-cell transfer concomitant with reduced levels of the inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interferon gamma (IFN-gamma). A 3-day KGF pretreatment also depressed the secondary in vitro mixed lymphocyte response (MLR) of C57BL/6 splenocytes taken 7 days after in vivo alloimmunization with irradiated BALB/c spleen cells. To determine whether KGF would inhibit host-antidonor-mediated BM rejection, pan-T-cell-depleted BALB/c BM cells were infused into sublethally irradiated C57BL/6 mice and administered KGF either before or before and after BMT. Surprisingly, all KGF schedules tested actually resulted in enhanced alloengraftment. The presence of KGF receptor on donor antihost alloreactive T cells could not be detected by binding studies with radiolabeled KGF, reverse transcriptase-polymerase chain reaction, and Western blotting. Therefore, the mechanism of action of KGF on inhibiting T-cell-mediated immune effects may not be due to a direct effect of KGF on T cells. These studies demonstrate that KGF, by mechanisms independent of repair of conditioning-induced injury, has great potential as an anti-GVHD therapeutic agent with the added benefit of inhibiting the rejection of pan-T-cell-depleted donor BM allografts. (Blood. 2000;96:4350-4356)


Assuntos
Transplante de Medula Óssea , Fatores de Crescimento de Fibroblastos , Sobrevivência de Enxerto/efeitos dos fármacos , Doença Enxerto-Hospedeiro/prevenção & controle , Substâncias de Crescimento/uso terapêutico , Condicionamento Pré-Transplante/efeitos adversos , Animais , Avaliação Pré-Clínica de Medicamentos , Células Epiteliais/efeitos da radiação , Fator 10 de Crescimento de Fibroblastos , Fator 7 de Crescimento de Fibroblastos , Substâncias de Crescimento/farmacologia , Imunização , Interferon gama/sangue , Interleucina-13/sangue , Teste de Cultura Mista de Linfócitos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos SCID , Quimera por Radiação , Lesões Experimentais por Radiação/tratamento farmacológico , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Células Th2/metabolismo , Fator de Necrose Tumoral alfa/análise , Irradiação Corporal Total/efeitos adversos
8.
Mol Cell ; 6(4): 961-7, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11090634

RESUMO

Caspases are cysteine proteases essential to apoptosis. We have identified two families of caspase-like proteins, Paracaspases (found in metazoans and Dictyostelium) and metacaspases (found in plants, fungi, and protozoa). Metazoan paracaspase prodomains contain a death domain and immunoglobulin domains. Several plant metacaspase prodomains contain zinc finger motifs resembling those in the plant hypersensitive response/cell death protein Isd-1. The human paracaspase prodomain binds Bcl10, a protein involved in the t(1;14)(p22;q32) translocation of mucosa-associated lymphoid tissue (MALT) lymphoma. Another MALT lymphoma translocation, t(11;18)(q21;q21), fuses the IAP-2 gene to the MLT1/MALT1 locus, which encodes the human paracaspase. We find that this fusion activates NF-kappaB and that the caspase domain is required for this function, since mutation of the conserved catalytic cysteine attenuates NF-kappaB activation.


Assuntos
Caspases/genética , Linfoma de Zona Marginal Tipo Células B/enzimologia , Linfoma de Zona Marginal Tipo Células B/genética , Sequência de Aminoácidos , Animais , Caspases/química , Mapeamento Cromossômico , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 14 , Clonagem Molecular , Dictyostelium/enzimologia , Dictyostelium/genética , Humanos , Dados de Sequência Molecular , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Transfecção , Translocação Genética , Dedos de Zinco
9.
Curr Biol ; 10(21): 1319-28, 2000 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-11084331

RESUMO

BACKGROUND: Survivin is a mammalian protein that carries a motif typical of the inhibitor of apoptosis (IAP)proteins, first identified in baculoviruses. Although baculoviral IAP proteins regulate cell death, the yeast Survivin homolog Bir1 is involved in cell division. To determine the function of Survivin in mammals, we analyzed the pattern of localization of Survivin protein during the cell cycle, and deleted its gene by homologous recombination in mice. RESULTS: In human cells, Survivin appeared first on centromeres bound to a novel para-polar axis during prophase/metaphase, relocated to the spindle midzone during anaphase/telophase, and disappeared at the end of telophase. In the mouse, Survivin was required for mitosis during development. Null embryos showed disrupted microtubule formation, became polyploid, and failed to survive beyond 4.5days post coitum. This phenotype, and the cell-cycle localization of Survivin, resembled closely those of INCENP. Because the yeast homolog of INCENP, Sli15, regulates the Aurora kinase homolog Ipl1p, and the yeast Survivin homolog Bir1 binds to Ndc10p, a substrate of Ipl1p, yeast Survivin, INCENP and Aurora homologs function in concert during cell division. CONCLUSIONS: In vertebrates, Survivin and INCENP have related roles in mitosis, coordinating events such as microtubule organization, cleavage-furrow formation and cytokinesis. Like their yeast homologs Bir1 and Sli15, they may also act together with the Aurora kinase.


Assuntos
Autoantígenos , Ciclo Celular , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas Associadas aos Microtúbulos , Proteínas/genética , Proteínas/metabolismo , Sequência de Aminoácidos , Animais , Núcleo Celular/metabolismo , Centrômero/metabolismo , Proteína B de Centrômero , Cromossomos/metabolismo , Proteínas do Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/metabolismo , Embrião de Mamíferos/metabolismo , Corantes Fluorescentes , Deleção de Genes , Genótipo , Células HeLa , Humanos , Proteínas Inibidoras de Apoptose , Camundongos , Microscopia de Fluorescência , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Mitose , Dados de Sequência Molecular , Proteínas de Neoplasias , Alinhamento de Sequência , Survivina , Tubulina (Proteína)/metabolismo
10.
Mol Cell ; 6(2): 211-23, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10983970

RESUMO

Baculoviral IAP repeat proteins (BIRPs) may affect cell death, cell division, and tumorigenesis. The C. elegans BIRP BIR-1 was localized to chromosomes and to the spindle midzone. Embryos and fertilized oocytes lacking BIR-1 had defects in chromosome behavior, spindle midzone formation, and cytokinesis. We observed indistinguishable defects in fertilized oocytes and embryos lacking the Aurora-like kinase AIR-2. AIR-2 was not present on chromosomes in the absence of BIR-1. Histone H3 phosphorylation and HCP-1 staining, which marks kinetochores, were reduced in the absence of either BIR-1 or AIR-2. We propose that BIR-1 localizes AIR-2 to chromosomes and perhaps to the spindle midzone, where AIR-2 phosphorylates proteins that affect chromosome behavior and spindle midzone organization. The human BIRP survivin, which is upregulated in tumors, could partially substitute for BIR-1 in C. elegans. Deregulation of bir-1 promotes changes in ploidy, suggesting that similar deregulation of mammalian BIRPs may contribute to tumorigenesis.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans/fisiologia , Ciclo Celular/fisiologia , Cromossomos/fisiologia , Proteínas de Helminto/metabolismo , Proteínas Associadas aos Microtúbulos , Proteínas Serina-Treonina Quinases/metabolismo , Fuso Acromático/fisiologia , Animais , Aurora Quinase B , Aurora Quinases , Caenorhabditis elegans/genética , Divisão Celular , Mapeamento Cromossômico , Embrião não Mamífero/fisiologia , Feminino , Genes de Helmintos , Proteínas de Helminto/genética , Humanos , Proteínas Inibidoras de Apoptose , Masculino , Dados de Sequência Molecular , Proteínas de Neoplasias , Oócitos/fisiologia , Proteínas/metabolismo , Espermatozoides/fisiologia , Survivina
11.
J Biol Chem ; 275(6): 4374-82, 2000 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-10660608

RESUMO

Secreted Frizzled-related protein-1 (sFRP-1) contains a cysteine-rich domain homologous to the putative Wnt-binding site of Frizzleds. To facilitate the biochemical and biological analysis of sFRP-1, we developed a mammalian recombinant expression system that yields approximately 3 mg of purified protein/liter of conditioned medium. Using this recombinant protein, we demonstrated that sFRP-1 and Wg (wingless) interact in enzyme-linked immunosorbent and co-precipitation assays. Surprisingly, a derivative lacking the cysteine-rich domain retained the ability to bind Wg. Cross-linking experiments performed with radioiodinated sFRP-1 provided definitive evidence that sFRP-1 and Wg bind directly to each other. Besides detecting a cross-linked complex consistent in size with 1:1 stoichiometry of sFRP-1 and Wg, we also observed a larger complex whose size suggested the presence of a second sFRP-1 molecule. The formation of both complexes was markedly enhanced by an optimal concentration of exogenous heparin, emphasizing the potential importance of heparan-sulfate proteoglycan in Wnt binding and signaling. sFRP-1 exerted a biphasic effect on Wg activity in an armadillo stabilization assay, increasing armadillo level at low concentrations but reducing it at higher concentrations. These results provide new insights about the Wnt binding and biological activity of sFRPs.


Assuntos
Antígenos CD/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Drosophila , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais , Transativadores , Proteínas de Peixe-Zebra , Animais , Antígenos CD/genética , Proteínas do Domínio Armadillo , Sítios de Ligação , Proteínas de Transporte/genética , Linhagem Celular , Reagentes de Ligações Cruzadas , Cães , Drosophila , Ensaio de Imunoadsorção Enzimática , Proteína-1 Reguladora de Fusão , Heparina/farmacologia , Humanos , Proteínas de Insetos/metabolismo , Ligação Proteica , Proteínas Recombinantes/metabolismo , Fatores de Transcrição , Proteínas Wnt , Proteína Wnt1
12.
Proc Natl Acad Sci U S A ; 96(18): 10170-5, 1999 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-10468581

RESUMO

Inhibitors of apoptosis (IAPs) are a family of proteins that bear baculoviral IAP repeats (BIRs) and regulate apoptosis in vertebrates and Drosophila melanogaster. The yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe both encode a single IAP, designated BIR1 and bir1, respectively, each of which bears two BIRs. In rich medium, BIR1 mutant S. cerevisiae underwent normal vegetative growth and mitosis. Under starvation conditions, however, BIR1 mutant diploids formed spores inefficiently, instead undergoing pseudohyphal differentiation. Most spores that did form failed to survive beyond two divisions after germination. bir1 mutant S. pombe spores also died in the early divisions after spore germination and became blocked at the metaphase/anaphase transition because of an inability to elongate their mitotic spindle. Rather than inhibiting caspase-mediated cell death, yeast IAP proteins have roles in cell division and appear to act in a similar way to the IAPs from Caenorhabditis elegans and the mammalian IAP Survivin.


Assuntos
Proteínas Fúngicas/metabolismo , Saccharomyces cerevisiae/fisiologia , Schizosaccharomyces/fisiologia , Sequência de Aminoácidos , Animais , Divisão Celular/fisiologia , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Humanos , Meiose , Microscopia Eletrônica , Dados de Sequência Molecular , Sequências Repetitivas de Aminoácidos , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Schizosaccharomyces/citologia , Schizosaccharomyces/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Esporos Fúngicos , Vacúolos/fisiologia , Vacúolos/ultraestrutura
14.
Cell Death Differ ; 5(7): 569-76, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10200511

RESUMO

IAPs were identified as baculoviral proteins that could inhibit the apoptotic response of insect cells to infection. Of the viral IAPs, OpIAP and CpIAP can inhibit apoptosis, whereas AcIAP cannot. OpIAP and some mammalian homologues can inhibit mammalian cell death. Two mammalian IAPs bind to TNFRII associated factors (TRAFs), but the significance of this is unclear. Here we show that Drosophila cellular IAPs and two baculoviral IAPs (OpIAP and CpIAP) can inhibit mammalian cell death induced by overexpression of Caspases 1 and 2. IAPs must act on conserved components of the apoptotic mechanism, but as none of these IAPs could bind TRAF proteins, TRAFs are not likely to be important for IAP mediated apoptosis inhibition. As OpIAP protected against death induced by ligation of TNF receptor family members, but not by factor nor serum withdrawal from dependent cells, it can inhibit certain apoptotic pathways without affecting others.


Assuntos
Apoptose , Proteínas de Drosophila , Proteínas de Insetos/metabolismo , Proteínas Virais/metabolismo , Animais , Drosophila , Células HeLa , Humanos , Proteínas Inibidoras de Apoptose , Proteínas de Insetos/genética , Insetos , Mamíferos , Células PC12 , Proteínas/metabolismo , Ratos , Fator 2 Associado a Receptor de TNF , Células Tumorais Cultivadas , Proteínas Virais/genética
15.
Oncogene ; 15(21): 2541-51, 1997 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-9399642

RESUMO

p27kip1 is a general inhibitor of Cdks that preferentially accumulates and functions during G1 phase, before the restriction point of the mammalian cell cycle. We observed that injection of purified p27kip1 into Xenopus oocytes potently inhibits the G2/M transition and activation/dephosphorylation of the maturation promoting factor (MPF, p34cdc2/cyclin B complex) kinase associated with germinal vesicle breakdown (GVBD) induced by progesterone or insulin. Addition of exogenous p27kip1 in vitro to lysates of hormonally matured oocytes blocked the enzymatic activity of the activated MPF kinase present in those extracts. Interestingly, the isolated amino-terminal region of p27kip1 (p27N), encompassing only the Cdk binding site, exhibited a similar inhibitory behavior in vitro and a weaker inhibitory effect in vivo than the complete p27kip1 protein. Surprisingly, the remaining carboxy-terminal region of p27kip1 (p27C) actually induced GVBD when injected alone into the oocytes, and also accelerated the kinetics of insulin- or progesterone-induced GVBD. Consistent with the in vivo observations, p27C formed a complex with, and activated, the MPF kinase in lysates of immature oocytes, although this activation was blocked by simultaneous addition of p27N or complete p27kip1. Active MPF was able to phosphorylate p27C only in the absence of p27N or whole p27kip1, suggesting that the inhibitory activity associated with the amino terminus is dominant over the activation produced by p27C. These results demonstrate the functional interaction of p27kip1 with cyclin B/p34cdc2 complexes during G2/M progression in oocytes, and suggest that the amino and carboxy terminal portions of this protein may play opposite regulatory roles, reminiscent of the corresponding N- and C-terminal portions of p21waf. We speculate that accumulation of a truncated, C-terminal p27 fragment may play a physiological regulatory role in progression through G2 and later stages of the cell cycle.


Assuntos
Proteínas de Ciclo Celular , Fase G2 , Proteínas Associadas aos Microtúbulos/fisiologia , Mitose , Proteínas Supressoras de Tumor , Animais , Proteína Quinase CDC2/fisiologia , Ciclina B/fisiologia , Inibidor de Quinase Dependente de Ciclina p27 , Feminino , Meiose , Oócitos/fisiologia , Proteínas de Xenopus , Xenopus laevis
16.
J Biol Chem ; 272(35): 21669-72, 1997 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-9268291

RESUMO

A variant form of p27 was unexpectedly detected in a synchronized culture of NIH3T3 cells treated with serum. The expression levels of this form of p27 which lacked its amino (NH2)-terminal region reached maximum during G2/M phase. Since the appearance of the NH2-terminal truncated form of p27 coincided with increased expression of Cdc2, we hypothesized that p27 may play a role in regulating Cdc2 catalytic activity. To test this hypothesis, wild type p27, as well as the amino-terminal (Np27) and carboxyl-terminal (Cp27), were individually expressed, purified, and examined for their ability to regulate CDC2 kinase activity in vitro. Our data showed that both p27 and Np27 inhibited CDC2 kinase activity. However, in marked contrast, Cp27 enhanced the CDC2 kinase activity. In vitro kinase assays showed that Cp27 and p27 were phosphorylated by CDC2, whereas Np27 was not. In addition, we demonstrated that deletion of the putative CDC2 phosphorylation site in the carboxyl-terminal domain of Cp27 diminished activation of CDC2 kinase activity otherwise stimulated by Cp27. A similar deletion did not have any effect on the inhibitory function of p27. Together these results suggest that the carboxyl-terminal domain of p27 may activate CDC2 kinase activity in vivo during G2/M and that this effect may be regulated by serine/threonine phosphorylation.


Assuntos
Proteína Quinase CDC2/metabolismo , Proteínas de Ciclo Celular , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Supressoras de Tumor , Células 3T3 , Animais , Sítios de Ligação , Inibidor de Quinase Dependente de Ciclina p27 , Ativação Enzimática , Técnicas In Vitro , Camundongos , Proteínas Associadas aos Microtúbulos/química , Fosforilação
17.
Proc Natl Acad Sci U S A ; 94(13): 6770-5, 1997 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-9192640

RESUMO

Frizzled polypeptides are integral membrane proteins that recently were shown to function as receptors for Wnt signaling molecules. Here, we report the identification of a novel, secreted 36-kDa protein that contains a region homologous to a putative Wnt-binding domain of Frizzleds. This protein, called Frizzled-related protein (FRP), was first identified as a heparin-binding polypeptide that copurified with hepatocyte growth factor/scatter factor in conditioned medium from a human embryonic lung fibroblast line. Degenerate oligonucleotides, based on the NH2-terminal sequence of the purified protein, were used to isolate corresponding cDNA clones. These encoded a 313-amino acid polypeptide, containing a cysteine-rich domain of approximately 110 residues that was 30-40% identical to the putative ligand-binding domain of Frizzled proteins. A 4.4-kb transcript of the FRP gene is present in many organs, both in the adult and during embryogenesis, and homologs of the gene are detectable in DNA from several vertebrate species. In biosynthetic studies, FRP was secreted but, like Wnts, tended to remain associated with cells. When coexpressed with several Wnt family members in early Xenopus embryos, FRP antagonized Wnt-dependent duplication of the embryonic dorsal axis. These results indicate that FRP may function as an inhibitor of Wnt action during development and in the adult.


Assuntos
Proteínas de Drosophila , Heparina/metabolismo , Proteínas de Membrana/genética , Proteínas/isolamento & purificação , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas de Peixe-Zebra , Sequência de Aminoácidos , Animais , Linhagem Celular , Clonagem Molecular , Receptores Frizzled , Humanos , Dados de Sequência Molecular , Proteínas/genética , Proteínas/metabolismo , Receptores Acoplados a Proteínas G , Alinhamento de Sequência , Proteínas Wnt , Xenopus
18.
Biochem Biophys Res Commun ; 232(2): 273-7, 1997 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-9125162

RESUMO

The molecular mechanism by which cell surface receptors stimulate the serine/threonine kinase activity of c-Jun N-terminal kinases (JNKs) was investigated using a transient cotransfection experiments in COS-7 cells. Our data demonstrate that JNK activity is potently induced by platelet derived growth factor (PDGF) upon expression of beta PDGFR wild type (beta RWT). However, PDGF failed to mediate JNK activation in cells expressing beta PDGFR mutant lacking the binding site for phosphatidylinositol-3 (PI-3) kinase but not for phospholipase C gamma (PLC gamma) or Syp. Consistent with this result, a PI-3 kinase inhibitor, wortmannin inhibited activation of JNK by PDGF. Furthermore, overexpression of P110 the catalytic domain of PI-3 kinase was sufficient for activation of JNKs which could be efficiently inhibited by dominant negative forms of Ras, Rac but not of RhoA or Cdc42. Taken together all of these findings suggest that activation of JNK by PDGF involves receptor association with PI-3 kinase activity, which in turn acts on a ras- and rac-dependent pathway.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas Quinases Ativadas por Mitógeno , Fosfotransferases (Aceptor do Grupo Álcool)/fisiologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Androstadienos/farmacologia , Animais , Células COS , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Ativação Enzimática/efeitos dos fármacos , Proteínas de Ligação ao GTP/fisiologia , Proteínas Quinases JNK Ativadas por Mitógeno , Ligantes , Fosfatidilinositol 3-Quinases , Fosforilação , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/farmacologia , Receptor beta de Fator de Crescimento Derivado de Plaquetas , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores do Fator de Crescimento Derivado de Plaquetas/fisiologia , Tirosina/metabolismo , Wortmanina , Proteínas rho de Ligação ao GTP
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