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1.
EMBO Rep ; 24(12): e57972, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37962001

RESUMO

Mitochondrial and peroxisomal anchored protein ligase (MAPL) is a dual ubiquitin and small ubiquitin-like modifier (SUMO) ligase with roles in mitochondrial quality control, cell death and inflammation in cultured cells. Here, we show that MAPL function in the organismal context converges on metabolic control, as knockout mice are viable, insulin-sensitive, and protected from diet-induced obesity. MAPL loss leads to liver-specific activation of the integrated stress response, inducing secretion of stress hormone FGF21. MAPL knockout mice develop fully penetrant spontaneous hepatocellular carcinoma. Mechanistically, the peroxisomal bile acid transporter ABCD3 is a primary MAPL interacting partner and SUMOylated in a MAPL-dependent manner. MAPL knockout leads to increased bile acid production coupled with defective regulatory feedback in liver in vivo and in isolated primary hepatocytes, suggesting cell-autonomous function. Together, our findings establish MAPL function as a regulator of bile acid synthesis whose loss leads to the disruption of bile acid feedback mechanisms. The consequences of MAPL loss in liver, along with evidence of tumor suppression through regulation of cell survival pathways, ultimately lead to hepatocellular carcinogenesis.


Assuntos
Bile , Proteínas Mitocondriais , Ubiquitina-Proteína Ligases , Animais , Camundongos , Bile/metabolismo , Ácidos e Sais Biliares , Fígado/metabolismo , Camundongos Knockout , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinas
2.
Am J Dermatopathol ; 44(2): 103-105, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34291741

RESUMO

ABSTRACT: The human progenitor-cell antigen CD34 is expressed in dermal dendritic cells and is lost in several disorders affecting dermal collagen. The loss of CD34 immunohistochemical staining has been demonstrated to be helpful in the histologic diagnosis of morphea, lichen sclerosus, and the classic pattern of granuloma annulare. This study characterized CD34 expression in 2 sclerosing disorders affecting the subcutis: lipodermatosclerosis (LDS) and the sclerodermoid form of chronic graft-versus-host disease (ScGVHD). In addition, we applied CD34 staining to the interstitial pattern of granuloma annulare (IGA), which is a diagnostically challenging entity with subtle amounts of dermal collagen degeneration. Fifteen cases of LDS, 6 cases of ScGVHD, and 4 cases of IGA were identified and stained with CD34. All cases of LDS showed loss of CD34 within subcutaneous septa, and 9 cases (60%) also exhibited full-thickness dermal loss of interstitial staining. All 6 cases of ScGVHD showed varying degrees of CD34 loss within the dermis and/or subcutaneous septa. The normal subcutis showed diffuse septal staining with CD34, with a density equal to that seen in the dermis. CD34 staining was lost in areas of dermal inflammation in half of the IGA cases. We conclude that CD34 staining is a useful ancillary test in disease processes affecting the subcutaneous collagen such as LDS and ScGVHD. Its utility also extends to diagnostically challenging disorders of dermal collagen degeneration such as IGA.


Assuntos
Dermatite/diagnóstico , Doença Enxerto-Hospedeiro/diagnóstico , Granuloma Anular/diagnóstico por imagem , Esclerodermia Localizada/diagnóstico , Antígenos CD34/metabolismo , Dermatite/patologia , Doença Enxerto-Hospedeiro/patologia , Granuloma Anular/patologia , Humanos , Estudos Retrospectivos , Esclerodermia Localizada/patologia , Coloração e Rotulagem
3.
BMC Genomics ; 20(1): 941, 2019 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-31810449

RESUMO

BACKGROUND: Phenotypic variability of human populations is partly the result of gene polymorphism and differential gene expression. As such, understanding the molecular basis for diversity requires identifying genes with both high and low population expression variance and identifying the mechanisms underlying their expression control. Key issues remain unanswered with respect to expression variability in human populations. The role of gene methylation as well as the contribution that age, sex and tissue-specific factors have on expression variability are not well understood. RESULTS: Here we used a novel method that accounts for sampling error to classify human genes based on their expression variability in normal human breast and brain tissues. We find that high expression variability is almost exclusively unimodal, indicating that variance is not the result of segregation into distinct expression states. Genes with high expression variability differ markedly between tissues and we find that genes with high population expression variability are likely to have age-, but not sex-dependent expression. Lastly, we find that methylation likely has a key role in controlling expression variability insofar as genes with low expression variability are likely to be non-methylated. CONCLUSIONS: We conclude that gene expression variability in the human population is likely to be important in tissue development and identity, methylation, and in natural biological aging. The expression variability of a gene is an important functional characteristic of the gene itself and the classification of a gene as one with Hyper-Variability or Hypo-Variability in a human population or in a specific tissue should be useful in the identification of important genes that functionally regulate development or disease.


Assuntos
Envelhecimento/genética , Mama/química , Metilação de DNA , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Fatores Etários , Química Encefálica , Cadáver , Ilhas de CpG , Epigênese Genética , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Especificidade de Órgãos , Fenótipo
4.
Exp Cell Res ; 330(2): 248-266, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25445790

RESUMO

In cell culture, many adherent mammalian cells undergo substantial actin cytoskeleton rearrangement prior to mitosis as they detach from the extracellular matrix and become spherical. At the end of mitosis, the actin cytoskeleton is required for cytokinesis and the reassembly of interphase structures as cells spread and reattach to substrate. To understand the processes regulating mitotic cytoskeletal remodeling, we studied how mitotic phosphorylation regulates filamin A (FLNa). FLNa is an actin-crosslinking protein that was previously identified as a cyclin-dependent kinase 1 (Cdk1) binding partner and substrate in vitro. Using quantitative label-based mass spectrometry, we find that FLNa serines 1084, 1459 and 1533 are phosphorylated in mitotic HeLa cells and all three sites match the phosphorylation consensus sequence of Cdk1. To investigate the functional role of mitotic FLNa phosphorylation, we mutated serines 1084, 1459 and 1533 to nonphosphorylatable alanine residues and expressed GFP-tagged FLNa(S1084A,S1459A,S1533A) (FLNa-AAA GFP) in a FLNa-deficient human melanoma cell line called M2. M2 cells expressing FLNa-AAA GFP have enhanced FLNa-AAA GFP and actin localization at sites of contact between daughter cells, impaired post-mitotic daughter cell separation and defects in cell migration. Therefore, mitotic phosphorylation of FLNa is important for successful cell division and interphase cell behavior.


Assuntos
Ciclina B1/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Filaminas/metabolismo , Mitose/fisiologia , Citoesqueleto de Actina/fisiologia , Actinas/metabolismo , Proteína Quinase CDC2 , Linhagem Celular Tumoral , Movimento Celular/genética , Movimento Celular/fisiologia , Citocinese/fisiologia , Filaminas/genética , Proteínas de Fluorescência Verde/genética , Células HeLa , Humanos , Melanoma , Mutação , Fosforilação , Pseudópodes/fisiologia
5.
Risk Anal ; 35(10): 1820-36, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25958794

RESUMO

This study uses state-level panel data from a 33-year period to test the hypotheses of offsetting and enhancing behavior with regards to motorcycle helmet legislation. Results presented in this article find no evidence of offsetting behavior and are consistent with the presence of enhancing behavior. State motorcycle helmet laws are estimated to reduce motorcycle crashes by 18.4% to 31.9%. In the absence of any behavioral adaptations among motorcyclists mandatory helmet laws are not expected to have any significant impact on motorcycle crash rates. The estimated motorcycle crash reductions do not appear to be driven by omitted variable bias or nonclassical measurement error in reported crashes. Overall, the results strongly suggest that mandatory helmet laws yield significant changes in motorcycle mobility in the form of reduced risk taking and/or decreased utilization.


Assuntos
Dispositivos de Proteção da Cabeça/estatística & dados numéricos , Assunção de Riscos , Segurança/legislação & jurisprudência , Traumatismos Craniocerebrais/prevenção & controle , Pesquisa Empírica , Humanos , Modelos Teóricos , Motocicletas , Estados Unidos
6.
Sci Signal ; 17(826): eadh4475, 2024 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-38442201

RESUMO

The translation elongation factor eEF1A promotes protein synthesis. Its methylation by METTL13 increases its activity, supporting tumor growth. However, in some cancers, a high abundance of eEF1A isoforms is associated with a good prognosis. Here, we found that eEF1A2 exhibited oncogenic or tumor-suppressor functions depending on its interaction with METTL13 or the phosphatase PTEN, respectively. METTL13 and PTEN competed for interaction with eEF1A2 in the same structural domain. PTEN-bound eEF1A2 promoted the ubiquitination and degradation of the mitosis-promoting Aurora kinase A in the S and G2 phases of the cell cycle. eEF1A2 bridged the interactions between the SKP1-CUL1-FBXW7 (SCF) ubiquitin ligase complex, the kinase GSK3ß, and Aurora-A, thereby facilitating the phosphorylation of Aurora-A in a degron site that was recognized by FBXW7. Genetic ablation of Eef1a2 or Pten in mice resulted in a greater abundance of Aurora-A and increased cell cycling in mammary tumors, which was corroborated in breast cancer tissues from patients. Reactivating this pathway using fimepinostat, which relieves inhibitory signaling directed at PTEN and increases FBXW7 expression, combined with inhibiting Aurora-A with alisertib, suppressed breast cancer cell proliferation in culture and tumor growth in vivo. The findings demonstrate a therapeutically exploitable, tumor-suppressive role for eEF1A2 in breast cancer.


Assuntos
Aurora Quinase A , Neoplasias da Mama , Neoplasias Mamárias Animais , PTEN Fosfo-Hidrolase , Fator 1 de Elongação de Peptídeos , Animais , Feminino , Humanos , Camundongos , Aurora Quinase A/genética , Aurora Quinase A/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteína 7 com Repetições F-Box-WD/genética , Glicogênio Sintase Quinase 3 beta , Neoplasias Mamárias Animais/genética , Neoplasias Mamárias Animais/metabolismo , Neoplasias Mamárias Animais/patologia , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fator 1 de Elongação de Peptídeos/genética , Fator 1 de Elongação de Peptídeos/metabolismo
7.
Nat Genet ; 31(3): 301-5, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12053177

RESUMO

We have found that EEF1A2, the gene encoding protein elongation factor EEF1A2 (also known as eEF-1 alpha 2), is amplified in 25% of primary ovarian tumors and is highly expressed in approximately 30% of ovarian tumors and established cell lines. We have also demonstrated that EEF1A2 has oncogenic properties: it enhances focus formation, allows anchorage-independent growth and decreases the doubling time of rodent fibroblasts. In addition, EEF1A2 expression made NIH3T3 fibroblasts tumorigenic and increased the growth rate of ES-2 ovarian carcinoma cells xenografted in nude mice. Thus, EEF1A2 and the process of protein elongation are likely to be critical in the development of ovarian cancer.


Assuntos
Neoplasias Ovarianas/genética , Fator 1 de Elongação de Peptídeos/genética , Células 3T3 , Animais , Carcinoma/genética , Divisão Celular , Linhagem Celular , Cromossomos Humanos Par 20 , Feminino , Fibroblastos/fisiologia , Humanos , Camundongos , Camundongos Nus , Regiões Promotoras Genéticas , Ratos , Células Tumorais Cultivadas
8.
Exp Cell Res ; 317(17): 2503-11, 2011 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-21851817

RESUMO

The study of in vitro morphogenesis is fundamental to understanding neoplasia since the dysregulation of morphogenic pathways that create multi-cellular organisms is a common hallmark of oncogenesis. The in vitro culture of human breast epithelial cells on reconstituted basement membranes recapitulate some features of in vivo breast development, including the formation of a three-dimensional structure termed an acinus. Importantly, the capacity to disrupt in vitro acinar morphogenesis is a common property of human breast oncogenes. In this report, we find that phosphatidylinositol 4-kinase IIIß (PI4KIIIß), a lipid kinase that phosphorylates phosphatidylinositol (PI) to PI(4)P, disrupts in vitro mammary acinar formation. The PI4KIIIß protein localizes to the basal surface of acini created by human MCF10A cells and ectopic expression of PI4KIIIß induces multi-acinar devlopment. Furthermore, expression of an oncogenic PI4KIIIß activator, eEF1A2 (eukaryotic elongation factor 1 alpha 2), phenocopies the PI4KIIIß multi-acinar phenotype. Ectopic expression of PI4KIIIß or eEF1A2 alters the localization of PI(4)P and PI(4,5)P(2) within acini, indicating the importance of these lipids in acinar development. Our work shows that PI4KIIIß, eEF1A2 and PI(4)P likely play an important role in mammary neoplasia and acinar development.


Assuntos
Neoplasias da Mama/genética , Carcinoma de Células Acinares/genética , Fator 1 de Elongação de Peptídeos/genética , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma de Células Acinares/metabolismo , Carcinoma de Células Acinares/patologia , Feminino , Humanos , Antígenos de Histocompatibilidade Menor , Fator 1 de Elongação de Peptídeos/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Células Tumorais Cultivadas
9.
Ann Otol Rhinol Laryngol ; 121(10): 635-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23130536

RESUMO

OBJECTIVES: We assessed the use of transoral robot-assisted lingual tonsillectomy and uvulopalatopharyngoplasty for the surgical management of tongue base obstruction in patients with obstructive sleep apnea. METHODS: In a prospective, nonrandomized trial using historical controls, patients underwent drug-induced sleep endoscopy, transoral robot-assisted lingual tonsillectomy with uvulopalatopharyngoplasty, and preoperative and postoperative polysomnography. RESULTS: Twenty patients have completed the study to date. The rate of surgical success was 45%, and the rate of surgical response was 65%. The mean preoperative apnea-hypopnea index of 55.6 decreased by 56.7%, to a mean postoperative value of 24.1 (p < 0.001), and the minimum arterial oxygen saturation increased from the mean preoperative value of 75.8% to the mean postoperative value of 81.7% (p = 0.013). The mean Epworth Sleepiness Scale score improved from 13.4 to 5.9 (p = 0.003). One patient had postoperative bleeding that required cauterization, resulting in a major complication rate of 4.2%. CONCLUSIONS: Transoral robot-assisted lingual tonsillectomy with uvulopalatopharyngoplasty is a novel technique for the surgical management of obstructive sleep apnea that results in a significant decrease in the apnea-hypopnea index, a significant improvement in minimum arterial oxygen saturation, and a significant improvement in the Epworth Sleepiness Scale score and has an acceptable complication rate.


Assuntos
Palato Mole/cirurgia , Faringe/cirurgia , Robótica , Apneia Obstrutiva do Sono/cirurgia , Tonsilectomia/métodos , Úvula/cirurgia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Complicações Pós-Operatórias , Estudos Prospectivos , Índice de Gravidade de Doença
10.
J Cell Biol ; 172(7): 973-81, 2006 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-16567498

RESUMO

The conversion of an epithelial cell to a mesenchymal cell is critical to metazoan embryogenesis and a defining structural feature of organ development. Current interest in this process, which is described as an epithelial-mesenchymal transition (EMT), stems from its developmental importance and its involvement in several adult pathologies. Interest and research in EMT are currently at a high level, as seen by the attendance at the recent EMT meeting in Vancouver, Canada (October 1-3, 2005). The meeting, which was hosted by The EMT International Association, was the second international EMT meeting, the first being held in Port Douglas, Queensland, Australia in October 2003. The EMT International Association was formed in 2002 to provide an international body for those interested in EMT and the reverse process, mesenchymal-epithelial transition, and, most importantly, to bring together those working on EMT in development, cancer, fibrosis, and pathology. These themes continued during the recent meeting in Vancouver. Discussion at the Vancouver meeting spanned several areas of research, including signaling pathway activation of EMT and the transcription factors and gene targets involved. Also covered in detail was the basic cell biology of EMT and its role in cancer and fibrosis, as well as the identification of new markers to facilitate the observation of EMT in vivo. This is particularly important because the potential contribution of EMT during neoplasia is the subject of vigorous scientific debate (Tarin, D., E.W. Thompson, and D.F. Newgreen. 2005. Cancer Res. 65:5996-6000; Thompson, E.W., D.F. Newgreen, and D. Tarin. 2005. Cancer Res. 65:5991-5995).


Assuntos
Diferenciação Celular/fisiologia , Células Epiteliais/fisiologia , Mesoderma/fisiologia , Animais , Células Epiteliais/citologia , Epitélio/embriologia , Feminino , Humanos , Mesoderma/citologia , Invasividade Neoplásica/patologia , Invasividade Neoplásica/fisiopatologia , Neoplasias/patologia , Neoplasias/fisiopatologia , Transdução de Sinais/fisiologia
11.
BMC Cell Biol ; 11: 86, 2010 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-21083909

RESUMO

BACKGROUND: Filopodia are actin-based cellular projections that have a critical role in initiating and sustaining directional migration in vertebrate cells. Filopodia are highly dynamic structures that show a rich diversity in appearance and behavior. While there are several mathematical models of filopodia initiation and growth, testing the capacity of these theoretical models in predicting empirical behavior has been hampered by a surprising shortage of quantitative data related to filopodia. Neither is it clear how quantitatively robust the cellular filopodial network is and how perturbations alter it. RESULTS: We have measured the length and interfilopodial separation distances of several thousand filopodia in the rodent cell line Rat2 and measured these parameters in response to genetic, chemical and physical perturbation. Our work shows that length and separation distance have a lognormal pattern distribution over their entire detection range (0.4 µm to 50 µm). CONCLUSIONS: We find that the lognormal distribution of length and separation is robust and highly resistant to perturbation. We also find that length and separation are independent variables. Most importantly, our empirical data is not entirely in agreement with predictions made based on existing theoretical models and that filopodial size and separation are an order of magnitude larger than what existing models suggest.


Assuntos
Pseudópodes/fisiologia , Citoesqueleto de Actina/ultraestrutura , Animais , Bradicinina/farmacologia , Linhagem Celular , Antígenos de Histocompatibilidade Menor , Modelos Biológicos , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Polilisina/farmacologia , Pseudópodes/metabolismo , Pseudópodes/ultraestrutura , Ratos
12.
Mol Biol Cell ; 31(17): 1904-1916, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32583740

RESUMO

Cell shape is regulated by cell adhesion and cytoskeletal and membrane dynamics. Cell shape, adhesion, and motility have a complex relationship and understanding them is important in understanding developmental patterning and embryogenesis. Here we show that the lipid kinase phosphatidylinositol 4-kinase III beta (PI4KIIIß) regulates cell shape, migration, and focal adhesion (FA) number. PI4KIIIß generates phosphatidylinositol 4-phosphate (PI4P) from phosphatidylinositol and is highly expressed in a subset of human breast cancers. PI4KIIIß and the PI4P it generates regulate a variety of cellular functions, ranging from control of Golgi structure, fly fertility, and Akt signaling. Here, we show that loss of PI4KIIIß expression decreases cell migration and alters cell shape in NIH3T3 fibroblasts. The changes are accompanied by an increase in the number of FA in cells lacking PI4KIIIß. Furthermore, we find that PI4P-containing vesicles move to the migratory leading edge during migration and that some of these vesicles tether to and fuse with FA. Fusion is associated with FA disassembly. This suggests a novel regulatory role for PI4KIIIß and PI4P in cell adhesion and cell shape maintenance.


Assuntos
Adesão Celular/fisiologia , Forma Celular/fisiologia , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , 1-Fosfatidilinositol 4-Quinase/metabolismo , Animais , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Movimento Celular/fisiologia , Adesões Focais/fisiologia , Complexo de Golgi/metabolismo , Humanos , Fosfatos de Inositol/metabolismo , Camundongos , Células NIH 3T3 , Fosfatos de Fosfatidilinositol/metabolismo , Transdução de Sinais/fisiologia
13.
Biochem J ; 409(1): 53-64, 2008 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17908054

RESUMO

LRP1 [LDL (low-density lipoprotein) receptor-related protein 1]-null CHO cells (Chinese-hamster ovary cells) (13-5-1 cells) exhibited accelerated cell growth and severe tumour progression after they were xenografted into nude mice. Reconstitution of LRP1 expression in these cells, either with the full-length protein or with a minireceptor, reduced growth rate as well as suppressed tumour development. We tested the role of the tyrosine residue in the FXNPXY63 motif within the LRP1 cytoplasmic domain in signal transduction and cell growth inhibition by site-specific mutagenesis. The LRP1 minireceptors harbouring Tyr63 to alanine or Tyr63 to phenylalanine substitution had diametrically opposite effects on cell growth, cell morphology and tumour development in mice. The Y63F-expressing cells showed suppressed cell growth and tumour development, which were associated with decreased beta-catenin and cadherin concentrations in the cells. On the other hand, the Y63A-expressing cells lacked inhibition on cell growth and tumour development, which were associated with hyperactivation of ERKs (extracellular-signal-regulated kinases), FAK (focal adhesion kinase) and cyclin D1 in the cells. The mutant Y63A minireceptor also exhibited reduced capacity in binding to the Dab2 (disabled 2) adaptor protein. In addition, the Y63A mutant showed increased caveolar localization, and cells expressing Y63A had altered caveolae architecture. However, tyrosine to alanine substitution at the other NPXY29 motif had no effect on cell growth or tumorigenesis. These results suggest that the FXNPXY63 motif of LRP1 not only governs cellular localization of the receptor but also exerts multiple functional effects on signalling pathways involved in cell growth regulation.


Assuntos
Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/química , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Alanina/química , Motivos de Aminoácidos , Animais , Células CHO , Proliferação de Células , Cricetinae , Cricetulus , Citoplasma/metabolismo , Análise Mutacional de DNA , Humanos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/fisiologia , Camundongos , Camundongos Nus , Transplante de Neoplasias , Transdução de Sinais , Tirosina/química
14.
Int J Cancer ; 123(8): 1761-9, 2008 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-18661515

RESUMO

Ovarian epithelial carcinomas (OECs) frequently exhibit amplifications at the 20q13 locus which is the site of several oncogenes, including the eukaryotic elongation factor EEF1A2 and the transcription factor ZNF217. We reported previously that overexpressed ZNF217 induces neoplastic characteristics in precursor cells of OEC. Unexpectedly, ZNF217, which is a transcriptional repressor, enhanced expression of eEF1A2. In our study, array comparative genomic hybridization, single nucleotide polymorphism and Affymetrix analysis of ZNF217-overexpressing cell lines confirmed consistently increased expression of eEF1A2 but not of other oncogenes, and revealed early changes in EEF1A2 gene copy numbers and increased expression at crisis during immortalization. We defined the influence of eEF1A2 overexpression on immortalized ovarian surface epithelial cells, and investigated interrelationships between effects of ZNF217 and eEF1A2 on cellular phenotypes. Lentivirally induced eEF1A2 overexpression caused delayed crisis, apoptosis resistance and increases in serum-independence, saturation densities and anchorage independence. siRNA to eEF1A2 reversed apoptosis resistance and reduced anchorage independence in eEF1A2-overexpressing lines. Remarkably, siRNA to eEF1A2 was equally efficient in inhibiting both anchorage independence and resistance to apoptosis conferred by ZNF217 overexpression. Our data define neoplastic properties that are caused by eEF1A2 in nontumorigenic ovarian cancer precursor cells, and suggest that eEF1A2 plays a role in mediating ZNF217-induced neoplastic progression.


Assuntos
Transformação Celular Neoplásica/genética , Neoplasias Ovarianas/genética , Fator 1 de Elongação de Peptídeos/genética , Lesões Pré-Cancerosas/genética , Transativadores/genética , Apoptose/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Feminino , Dosagem de Genes , Expressão Gênica , Humanos , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Fator 1 de Elongação de Peptídeos/biossíntese , Fator 1 de Elongação de Peptídeos/sangue , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/patologia , RNA Interferente Pequeno/genética , Transativadores/biossíntese
15.
Mol Cancer Res ; 5(9): 933-42, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17855662

RESUMO

Heat shock protein 90 (Hsp90) is a member of the heat shock family of molecular chaperones that regulate protein conformation and activity. Hsp90 regulates multiple cell signaling pathways by controlling the abundance and activity of several important protein kinases and cell cycle-related proteins. In this report, we show that inhibition of Hsp90 by geldanamycin or its derivative, 17-allylamino-17-desmethoxygeldamycin, leads to activation of the Rho GTPase and a dramatic increase in actin stress fiber formation in human tumor cell lines. Inactivation of Rho prevents geldanamycin-induced actin reorganization. Hsp90 inactivation does not alter the appearance of filopodia or lamellipodia and tubulin architecture is not visibly perturbed. Our observations suggest that Hsp90 has an important and specific role in regulating Rho activity and Rho-dependent actin cytoskeleton remodeling.


Assuntos
Actinas/fisiologia , Antibióticos Antineoplásicos/farmacologia , Benzoquinonas/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lactamas Macrocíclicas/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Actinas/efeitos dos fármacos , Adenocarcinoma/enzimologia , Adenocarcinoma/patologia , Linhagem Celular Tumoral , Movimento Celular , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Feminino , Proteínas Ativadoras de GTPase/efeitos dos fármacos , Proteínas Ativadoras de GTPase/metabolismo , Células HeLa , Humanos , Invasividade Neoplásica , Neoplasias do Colo do Útero/enzimologia , Neoplasias do Colo do Útero/patologia , Quinases Associadas a rho
16.
Gynecol Oncol ; 108(3): 561-8, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18164751

RESUMO

OBJECTIVE: To determine whether eukaryotic elongation factor 1 alpha 2 (eEF1A2), a transforming gene previously shown to be highly expressed in primary human ovarian tumours, is a prognostic marker. METHODS: We have used an antibody specific for eEF1A2 to measure eEF1A2 protein expression in 500 primary ovarian tumours in a tissue microarray. We have also ectopically expressed eEF1A2 in SK-OV-3 cells, a clear cell carcinoma line that does not normally express eEF1A2. RESULTS: We have shown that eEF1A2 has high expression levels in approximately 30% of all primary ovarian tumours. 50% of serous tumours, 30% of endometrioid, 19% of mucinous and 8% of clear cell tumours highly express eEF1A2. Ectopic expression of eEF1A2 in the SK-OV-3 clear cell carcinoma line enhances their in vitro proliferative capacity and ability to form tumour-like spheroids in hanging drop culture. Expression of eEF1A2 did not alter sensitivity to anoikis, cisplatin, or taxol. In serous cancer, eEF1A2 is an independent prognostic marker for survival and high eEF1A2 protein expression was associated with increased probability of 20-year survival. CONCLUSIONS: eEF1A2 is highly expressed in ovarian carcinomas. Its expression enhances cell growth in vitro, and eEF1A2 expression is likely to be a useful ovarian cancer prognostic factor in ovarian cancer patients with serous tumours.


Assuntos
Biomarcadores Tumorais/imunologia , Neoplasias Ovarianas/imunologia , Fator 1 de Elongação de Peptídeos/imunologia , Adenocarcinoma de Células Claras/imunologia , Adenocarcinoma de Células Claras/mortalidade , Adenocarcinoma de Células Claras/patologia , Adenocarcinoma Mucinoso/imunologia , Adenocarcinoma Mucinoso/mortalidade , Adenocarcinoma Mucinoso/patologia , Anticorpos/análise , Carcinoma Endometrioide/imunologia , Carcinoma Endometrioide/mortalidade , Carcinoma Endometrioide/patologia , Proliferação de Células , Cistadenocarcinoma Seroso/imunologia , Cistadenocarcinoma Seroso/mortalidade , Cistadenocarcinoma Seroso/patologia , Feminino , Citometria de Fluxo , Humanos , Ontário/epidemiologia , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Valor Preditivo dos Testes , Prognóstico , Análise de Sobrevida
17.
Mol Endocrinol ; 21(9): 2124-35, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17579210

RESUMO

Runx2/CBFA1/AML3 is a master regulator of the osteoblast lineage and has been shown to directly control the transcription of numerous osteoblast-specific genes including alkaline phosphatase, osteopontin, and type I collagen. In its absence, ossification does not occur during development resulting in animals with cartilaginous skeletons and no osteoblasts. In humans, loss of one copy of Runx2 causes cleidocranial dysplasia characterized by malformations of the facial and cranial bones and the clavicle. Despite its important role in osteoblast biology, relatively little is known about the transcriptional regulation of the Runx2 gene. In the present study, we show that CCAAT/enhancer binding protein beta (C/EBPbeta) is a negative regulator of Runx2 expression and acts by directly binding a C/EBP element located at -591/-576 within the osteoblast-specific Runx2 P1 promoter. Ectopic expression of C/EBPbeta in C3H10T1/2 cells causes a reduction in Runx2 expression concomitant with a decrease in osteogenic potential during all-trans retinoic acid (ATRA)-induced differentiation. In nondifferentiating cells, C/EBPbeta can be found occupying the C/EBP negative response element within the Runx2 P1 promoter. ATRA, the effects of which are mediated by retinoic acid receptor alpha and gamma in C3H10T1/2 cells, stimulates the dissociation of C/EBPbeta from this element and promotes Runx2 expression. Thus, ATRA initiates osteoblastic differentiation of C3H10T1/2 cells, at least in part, by triggering the dissociation of C/EBPbeta from the Runx2 promoter.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/fisiologia , Diferenciação Celular/fisiologia , Subunidade alfa 1 de Fator de Ligação ao Core/antagonistas & inibidores , Regulação para Baixo/fisiologia , Osteoblastos/citologia , Tretinoína/antagonistas & inibidores , Animais , Subunidade alfa 1 de Fator de Ligação ao Core/biossíntese , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Camundongos , Camundongos Endogâmicos C3H , Células NIH 3T3
18.
Accid Anal Prev ; 111: 173-183, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29223026

RESUMO

This study uses repeated cross-sections of individual level crash data to study the effectiveness of motorcycle helmet legislation. Results suggest that motorcycle helmet laws reduce average individual fatality risks by 20.5%. From a policy standpoint, large states such as Florida and Texas can reduce annual motorcycle fatalities by an average 100 deaths through reinstating universal helmet laws. Valuing these fatality reductions at the U.S. DOT suggested $9.4 million value of a statistical life yields aggregate annual state benefits of approximately $940 million. The effectiveness of helmet legislation can be attributed to the technological efficacy of helmets as well as enhancing behavior in the form of reduced risk taking among motorcyclists. Specifically, motorcyclists who use helmets in order to comply with mandatory helmet laws are 29.8% less likely to receive a traffic citation for risky driving behavior (speeding, alcohol, etc.), travel at a 6 mph lower average speed, and have a 47.4% reduction in the probability of "severely" damaging their motorcycle in a crash.


Assuntos
Acidentes de Trânsito/mortalidade , Traumatismos Craniocerebrais/prevenção & controle , Dispositivos de Proteção da Cabeça/estatística & dados numéricos , Motocicletas/legislação & jurisprudência , Políticas , Assunção de Riscos , Traumatismos Craniocerebrais/etiologia , Traumatismos Craniocerebrais/mortalidade , Florida , Humanos , Probabilidade , Comportamento de Redução do Risco , Tecnologia , Texas , Meios de Transporte , Viagem
19.
FEBS Lett ; 581(8): 1661-72, 2007 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-17408621

RESUMO

Substantial actin remodelling occurs prior to mitosis as cells alter their shape in preparation for cytokinesis. In mammalian cells, mitosis is initiated by a heterodimer of cyclin B1 and the cyclin dependent kinase 1 (Cdk1) serine/threonine kinase. In this report. we show that human cyclin B1 binds the actin cross-linking protein Filamin-A (FLNa). The proteins co-immunoprecipitate and co-localize in mitotic human cells. We find that cyclin B1/Cdk1 can phosphorylate FLNa in vitro and reduce its ability to gelate actin. We have also identified serine 1436 as one FLNa residue phosphorylated by cyclin B1/Cdk1 in vitro. Our results suggest a role for cyclin B1/Cdk1 in FLNa-dependent actin remodelling.


Assuntos
Actinas/metabolismo , Proteína Quinase CDC2/metabolismo , Proteínas Contráteis/metabolismo , Ciclina B/metabolismo , Proteínas dos Microfilamentos/metabolismo , Sequência de Aminoácidos , Proteínas Contráteis/análise , Ciclina B/análise , Ciclina B1 , Filaminas , Humanos , Proteínas dos Microfilamentos/análise , Dados de Sequência Molecular , Fosforilação , Mapeamento de Interação de Proteínas , Serina/metabolismo , Técnicas do Sistema de Duplo-Híbrido
20.
Vector Borne Zoonotic Dis ; 7(4): 497-506, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18021024

RESUMO

Japanese encephalitis virus (JEV) appears nearly annually in the Torres Strait in far northern Queensland, Australia, and is a threat to invade the Australian mainland. Surveillance has involved the use of sentinel pigs that develop detectable viremias and antibody titers to JEV. However, pigs are amplifying hosts for JEV, and thus pose a health risk to the public and to pig handlers who bleed the pigs. A remote mosquito trap system would not have these risks. We report on trials using a remote mosquito trap system for the surveillance of JEV in the Torres Strait. The Mosquito Magnet (MM) Pro, MM Liberty Plus, and a novel updraft trap, the NAQS Mozzie Trap, were run at Badu and Moa islands in the Torres Strait and at Bamaga in the northern Cape York Peninsula from 2002-2005. TaqMan real-time polymerase chain reaction (PCR) was used to detect JEV nucleic acid in weekly mosquito collections. Sentinel pigs located at Badu were also bled and the serum processed by reverse transcriptase (RT)-PCR for JEV antigen and enzyme-linked immunosorbent assay (ELISA) for anti-JEV antibodies. JEV was detected in mosquito collections each year but not in each trap. No JEV was detected in trapped mosquitoes before detection in sentinel pigs. The mosquito trap system cost ca. AU$10,000 per site, about AU$5,000 less than a pig-based system. However, trap failures caused by mosquito-clogged motors, electrical faults, and blocked gas lines reduced the efficacy of some mosquito traps. Nonetheless, a remote mosquito trap system, employing stand alone traps and PCR for viral antigen detection, can be a safe, economical way to detect arbovirus activity in remote areas.


Assuntos
Culex/virologia , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Controle de Mosquitos/instrumentação , Animais , Custos e Análise de Custo , Vírus da Encefalite Japonesa (Espécie)/isolamento & purificação , Encefalite Japonesa/epidemiologia , Geografia , Humanos , Controle de Mosquitos/economia , Controle de Mosquitos/métodos , Reação em Cadeia da Polimerase , Vigilância da População/métodos , Queensland/epidemiologia , Vigilância de Evento Sentinela , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia
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