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1.
JAMA Netw Open ; 5(6): e2219170, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35763293

RESUMO

Importance: US hepatitis B mortality has been described nationally, but examination subnationally may identify differences in mortality rates and decedent characteristics, including birthplace. Objective: To examine characteristics of decedents with hepatitis B-listed deaths during 2010 to 2019 and compare age-adjusted hepatitis B-listed death rates during 2010 to 2019 vs 2000 to 2009. Design, Setting, and Participants: This cross-sectional study used Multiple Cause of Death data from 50 US states and the District of Columbia (DC) from 2000 to 2019 to assess characteristics of US residents with hepatitis B listed as an underlying cause of death (UCOD) or contributing cause of death on death certificates. Data were analyzed from September 2019 to May 2022. Exposures: Hepatitis B listed as underlying or contributing cause of death. Main Outcomes and Measures: Outcomes of interest were hepatitis B-listed death counts, age-adjusted rates, and characteristics of decedents during 2000 to 2019. The distribution of hepatitis B-listed deaths according to sociodemographic characteristics and UCOD among US- and non-US-born decedents were also examined. Results: A total of 35 280 decedents with hepatitis B listed as the cause of death were identified, including 17 483 deaths during 2010 to 2019. Decedents were 63.3% US-born, and 25.8% of decedents were Asian or Pacific Islander and 46.5% of decedents were White; 28.4% of decedents were listed as having hepatitis C virus (HCV) or HIV coinfection. State-level rates significantly surpassed the overall US rate (0.47 deaths per 100 000 population) in DC (high, 1.78 deaths per 100 000 population), Hawaii, Oklahoma, California, Tennessee, West Virginia, Mississippi, Oregon, Washington, Louisiana, Kentucky, and New York (low, 0.61 deaths per 100 000 population). Median (IQR) age at hepatitis B death was significantly younger in Kentucky (54.0 [46.0-64.0] years), West Virginia (56.0 [47.0-65.0] years), Tennessee (57.0 [50.0-65.0] years), Mississippi (58.0 [50.0-65.0] years), and Ohio (59.0 [50.0-66.0] years) than the national median (60.0 [53.0-69.0] years), which itself was significantly younger than nonhepatitis B-listed deaths (77 [63.0-87.0] years; P < .001). Hepatitis B was the UCOD among approximately 30% of US- and non-US-born decedents with hepatitis B COD. Irrespective of birthplace, most decedents had liver-related UCOD. Compared with non-US-born decedents, US-born decedents more frequently had nonliver conditions listed as UCOD. Liver cancer was the predominant UCOD among non-US-born decedents (37.9% of decedents). From 2000 to 2009 compared with 2010 to 2019, the hepatitis B-listed mortality rate significantly decreased nationally (change, -18.97%) and in 14 states; significant increases were observed in West Virginia (change, 83.78%) and Kentucky (change, 69.44%). Conclusions and Relevance: These findings suggest that US-born decedents constituted two-thirds of all hepatitis B-listed deaths and median age at death was youngest in Appalachian states. Irrespective of birthplace, most decedents had liver-related UCOD; however, US-born decedents more frequently had nonliver UCOD than non-US-born decedents. In addition to addressing liver-related complications, US-born persons with chronic infection may also require diagnosis and management of multiple comorbidities.


Assuntos
Hepatite B , Hepatite C , Causas de Morte , Estudos Transversais , District of Columbia/epidemiologia , Hepatite B/epidemiologia , Hepatite C/epidemiologia , Humanos , Estados Unidos/epidemiologia
2.
Hepatology ; 74(5): 2353-2365, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34097776

RESUMO

BACKGROUND AND AIMS: In the USA, HBV is one of the leading causes of chronic liver disease and cirrhosis and is a major cause of liver cancer. We aimed to estimate the prevalence of past and present HBV infection, susceptibility to HBV infection, and vaccine-induced immunity to hepatitis B among the US population during 2013-2018. APPROACH AND RESULTS: Prevalence estimates and 95% CIs were analyzed using 2013-2018 data from the National Health and Nutrition Examination Survey. Serologic testing among noninstitutionalized persons aged ≥ 6 years was used for classifying persons as total hepatitis B core antibody (anti-HBc), indicative of current or previous (ever having had) HBV infection; HBsAg, indicative of current HBV infection; and antibody to ABsAg (anti-HBs), indicative of immunity attributable to hepatitis B vaccination. Persons who tested negative for anti-HBc, HBsAg, and anti-HBs were considered susceptible to HBV infection. Non-US-born residents accounted for 69.1% of the population with chronic HBV infection and were 9.1 times more likely to be living with chronic hepatitis B, compared with US-born persons. Among adults aged ≥ 25 years who resided in US households, an estimated 155.8 million persons (or 73.4%) were susceptible to HBV infection, and an estimated 45.4 million had vaccine-induced immunity to hepatitis B. Men who have sex with men (MSM) were 3.6 times more likely to have ever been infected with HBV; however, MSM were just as likely to have vaccine-induced immunity to hepatitis B as non-MSM. CONCLUSION: Despite increasing immune protection among young persons vaccinated after birth, the estimated prevalence of persons living with chronic hepatitis B in the USA has remained unchanged at 0.3% since 1999.


Assuntos
Imunidade Adaptativa , Características da Família , Vacinas contra Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Hepatite B Crônica/epidemiologia , Hepatite B Crônica/imunologia , Adolescente , Adulto , Criança , Suscetibilidade a Doenças/epidemiologia , Suscetibilidade a Doenças/imunologia , Feminino , Anticorpos Anti-Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/imunologia , Hepatite B Crônica/prevenção & controle , Hepatite B Crônica/virologia , Homossexualidade Masculina , Humanos , Imunogenicidade da Vacina/imunologia , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Prevalência , Testes Sorológicos , Minorias Sexuais e de Gênero , Estados Unidos/epidemiologia , Vacinação , Adulto Jovem
3.
Tob Prev Cessat ; 6: 28, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760863

RESUMO

INTRODUCTION: Bidis are the most commonly smoked tobacco product in India. Understanding bidi smoking is important to reducing overall tobacco smoking and health-related consequences in India. We analyzed 2009-2010 and 2016-2017 Global Adult Tobacco Survey (GATS) India data to examine bidi smoking and its associated sociodemographic correlates and perceptions of dangers of smoking. METHODS: GATS is a nationally representative household survey of adults aged ≥15 years, designed to measure tobacco use and tobacco control indicators. Current bidi smoking was defined as current smoking of one or more bidis during a usual week. We computed bidi smoking prevalence estimates and relative change during 2009-2010 and 2016-2017. Used pooled multilevel logistic regression to identify individual-level determinants of bidi smoking and neighborhood-level and state-level variations. RESULTS: Overall, 9.2% and 7.7% of adults smoked bidis in India during 2009-2010 and 2016-2017, respectively, reflecting 16.4% significant relative decline. In pooled analysis, male, older age, rural residence, lower education level, lower wealth index, less knowledge about harms of smoking, and survey year were associated with increased odds of bidi smoking. Results also showed variance in odds of smoking bidis is associated with neighborhood (15.9%) and state (31.8%) level. CONCLUSIONS: Higher odds of bidi smoking were found among males, older age groups, and among those with lower socioeconomic status. Accordingly, health education interventions designed for these groups across India and other population-level interventions, such as WHO recommendation on increasing price on tobacco products, could help reduce bidi smoking. In addition, state/neighborhood-specific interventions could also help address differential bidi smoking across India.

4.
Tob Induc Dis ; 17: 11, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31582922

RESUMO

INTRODUCTION: Hardened smokers are those who do not want to quit, or find it very difficult to quit. This study assessed the prevalence and predictors of hardened smokers in 19 low- and middle-income countries (LMICs). METHODS: We used nationally representative data from 19 LMICs that conducted the Global Adult Tobacco Survey during 2009-2013. Our analysis is restricted to adults aged ≥25 years. Hardened smokers were defined as daily smokers who smoked for 5 or more years, and who reported the following: no quit attempt in the past year that lasted 24 or more hours; no interest in quitting, or not planning to quit in the next year; and currently smoked within 30 minutes after waking. For each country, the prevalence of hardened smokers was analyzed by sex, age, residence (urban or rural), educational attainment, wealth index, and knowledge of the danger of smoking. Multivariable logistic regression was used to assess predictors of hardened smoking. RESULTS: Prevalence of hardened smokers among adults (aged ≥25 years) ranged from 1.1% (Panama) to 14.3% (Russia). Among current smokers (aged ≥25 years), the proportion of hardened smokers ranged from 7.5% (Mexico) to 38.4% (Romania). Adjusted odds of hardened smokers were significantly higher for males (9 of 19 countries), smokers aged 65 years or older (12 of 19 countries), adults with lower educational attainment (9 of 19 countries), and no knowledge of the danger of smoking (8 of 19 countries). CONCLUSIONS: The spectrum of smokers in the LMICs includes hardened smokers and prevalence varies across population groups. Full implementation of proven tobacco control strategies could reduce hardened smoking in LMICs.

5.
Tob Control ; 28(1): 117-120, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29622603

RESUMO

BACKGROUND: There is little information on cigarette-purchasing behaviour among smokers globally. Understanding cigarette purchase and point-of-sale patterns can help guide the development and implementation of tobacco-control strategies in retail environments. OBJECTIVE: The purpose of this study was to identify where adults in 19 countries last purchased cigarettes. METHODS: Data were from 19 low-income and middle-income countries that conducted the Global Adult Tobacco Survey (GATS) during 2008-2012. GATS is a nationally representative household survey of adults aged 15 years or older using a standardised protocol to measure tobacco-related behaviours. Data were weighted to yield nationally representative estimates within each country and summarised by using descriptive statistics. RESULTS: Overall prevalence of current cigarette smoking ranged from 3.7% in Nigeria to 38.5% in the Russian Federation. Among current cigarette smokers, locations of last purchase were as follows: stores, from 14.6% in Argentina to 98.7% in Bangladesh (median=66.8%); street vendors, from 0% in Thailand to 35.7% in Vietnam (median=3.0%); kiosks, from 0.1% in Thailand to 77.3% in Argentina (median=16.1%); other locations, from 0.3% in China and Egypt to 57.5% in Brazil (median=2.6%). CONCLUSION: Cigarettes are purchased at various retail locations globally. However, stores and kiosks were the main cigarette purchase locations in 18 of the 19 countries assessed. Knowledge of where cigarette purchases occur could help guide interventions to reduce cigarette accessibility and use.


Assuntos
Fumar Cigarros/epidemiologia , Comércio/estatística & dados numéricos , Saúde Global , Produtos do Tabaco/estatística & dados numéricos , Adulto , Fumar Cigarros/economia , Países em Desenvolvimento , Humanos , Pobreza , Prevalência , Fumantes/estatística & dados numéricos , Inquéritos e Questionários
6.
MMWR Morb Mortal Wkly Rep ; 65(34): 898-901, 2016 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-27584595

RESUMO

Tobacco use is a leading preventable cause of morbidity and mortality, with nearly 6 million deaths caused by tobacco use worldwide every year (1). Cigarette smoking is the most common form of tobacco use in most countries, and the majority of adult smokers initiate smoking before age 18 years (2,3). Limiting access to cigarettes among youths is an effective strategy to curb the tobacco epidemic by preventing smoking initiation and reducing the number of new smokers (3,4). CDC used the Global Youth Tobacco Survey (GYTS) data from 45 countries to examine the prevalence of current cigarette smoking, purchase of cigarettes from retail outlets, and type of cigarette purchases made among school students aged 13-15 years. The results are presented by the six World Health Organization (WHO) regions: African Region (AFR); Eastern Mediterranean Region (EMR); European Region (EUR); Region of the Americas (AMR); South-East Asian Region (SEAR); and Western Pacific Region (WPR). Across all 45 countries, the median overall current cigarette smoking prevalence among students aged 13-15 years was 6.8% (range = 1.7% [Kazakhstan]-28.9% [Timor-Leste]); the median prevalence among boys was 9.7% (2.0% [Kazakhstan]-53.5% [Timor-Leste]), and among girls was 3.5% (0.0% [Bangladesh]-26.3% [Italy]). The proportion of current cigarette smokers aged 13-15 years who reported purchasing cigarettes from a retail outlet such as a store, street vendor, or kiosk during the past 30 days ranged from 14.9% [Latvia] to 95.1% [Montenegro], and in approximately half the countries, exceeded 50%. In the majority of countries assessed in AFR and SEAR, approximately 40% of cigarette smokers aged 13-15 years reported purchasing individual cigarettes. Approximately half of smokers in all but one country assessed in EUR reported purchasing cigarettes in packs. These findings could be used by countries to inform tobacco control strategies in the retail environment to reduce and prevent marketing and sales of tobacco products to youths (5).


Assuntos
Comércio/estatística & dados numéricos , Saúde Global/estatística & dados numéricos , Fumar/epidemiologia , Estudantes/estatística & dados numéricos , Produtos do Tabaco/provisão & distribuição , Adolescente , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Produtos do Tabaco/economia
7.
Prev Chronic Dis ; 12: E46, 2015 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-25855989

RESUMO

The role of neighborhood walkability and safety in mediating the association between education and physical activity has not been quantified. We used data from the 2010 and 2012 Communities Putting Prevention to Work Behavioral Risk Factor Surveillance System and structural equation modeling to estimate how much of the effect of education level on physical activity was mediated by perceived neighborhood walkability and safety. Neighborhood walkability accounts for 11.3% and neighborhood safety accounts for 6.8% of the effect. A modest proportion of the important association between education and physical activity is mediated by perceived neighborhood walkability and safety, suggesting that interventions focused on enhancing walkability and safety could reduce the disparity in physical activity associated with education level.


Assuntos
Escolaridade , Exercício Físico/psicologia , Guias como Assunto , Características de Residência/estatística & dados numéricos , Segurança , Caminhada/psicologia , Adulto , Análise de Variância , Sistema de Vigilância de Fator de Risco Comportamental , Estudos Transversais , Feminino , Comportamentos Relacionados com a Saúde , Promoção da Saúde/métodos , Disparidades nos Níveis de Saúde , Humanos , Masculino , Análise Multivariada , Obesidade/prevenção & controle , Meio Social , Inquéritos e Questionários , Uso de Tabaco/prevenção & controle , Estados Unidos
8.
Clin Cancer Res ; 18(24): 6623-33, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22923450

RESUMO

PURPOSE: The hypoxia-inducible factor-1 (HIF-1) plays a critical role in tumor adaptation to hypoxia, and its elevated expression correlates with poor prognosis and treatment failure in patients with cancer. In this study, we determined whether 3,4-dimethoxy-N-[(2,2-dimethyl-2H-chromen-6-yl)methyl]-N-phenylbenzenesulfonamide, KCN1, the lead inhibitor in a novel class of arylsulfonamide inhibitors of the HIF-1 pathway, had antitumorigenic properties in vivo and further defined its mechanism of action. EXPERIMENTAL DESIGN: We studied the inhibitory effect of systemic KCN1 delivery on the growth of human brain tumors in mice. To define mechanisms of KCN1 anti-HIF activities, we examined its influence on the assembly of a functional HIF-1α/HIF-1ß/p300 transcription complex. RESULTS: KCN1 specifically inhibited HIF reporter gene activity in several glioma cell lines at the nanomolar level. KCN1 also downregulated transcription of endogenous HIF-1 target genes, such as VEGF, Glut-1, and carbonic anhydrase 9, in a hypoxia-responsive element (HRE)-dependent manner. KCN1 potently inhibited the growth of subcutaneous malignant glioma tumor xenografts with minimal adverse effects on the host. It also induced a temporary survival benefit in an intracranial model of glioma but had no effect in a model of melanoma metastasis to the brain. Mechanistically, KCN1 did not downregulate the levels of HIF-1α or other components of the HIF transcriptional complex; rather, it antagonized hypoxia-inducible transcription by disrupting the interaction of HIF-1α with transcriptional coactivators p300/CBP. CONCLUSIONS: Our results suggest that the new HIF pathway inhibitor KCN1 has antitumor activity in mouse models, supporting its further translation for the treatment of human tumors displaying hypoxia or HIF overexpression.


Assuntos
Antineoplásicos/farmacologia , Benzopiranos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Proteína de Ligação a CREB/antagonistas & inibidores , Proteína p300 Associada a E1A/antagonistas & inibidores , Glioma/tratamento farmacológico , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Sulfonamidas/farmacologia , Animais , Neoplasias Encefálicas/patologia , Proteína de Ligação a CREB/metabolismo , Linhagem Celular Tumoral , Proteína p300 Associada a E1A/metabolismo , Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genes Reporter , Glioma/patologia , Humanos , Concentração Inibidora 50 , Luciferases de Renilla/biossíntese , Luciferases de Renilla/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Ligação Proteica/efeitos dos fármacos , Elementos de Resposta , Transdução de Sinais/efeitos dos fármacos , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
9.
J Med Chem ; 55(15): 6738-50, 2012 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-22746274

RESUMO

The hypoxia inducible factor (HIF) pathway is an attractive target for cancer, as it controls tumor adaptation to growth under hypoxia and mediates chemotherapy and radiation resistance. We previously discovered 3,4-dimethoxy-N-[(2,2-dimethyl-2H-chromen-6-yl)methyl]-N-phenylbenzenesulfonamide as a novel, small-molecule HIF-1 pathway inhibitor in a high-throughput cell-based assay, but its in vivo delivery is hampered by poor aqueous solubility (0.009 µM in water; log P(7.4) = 3.7). Here we describe the synthesis of 12 N-alkyl-N-[(8-R-2,2-dimethyl-2H-chromen-6-yl)methyl]heteroarylsulfonamides, which were designed to possess optimal lipophilicities and aqueous solubilities by in silico calculations. Experimental log P(7.4) values of 8 of the 12 new analogs ranged from 1.2-3.1. Aqueous solubilities of three analogs were measured, among which the most soluble N-[(8-methoxy-2,2-dimethyl-2H-chromen-6-yl)methyl]-N-(propan-2-yl)pyridine-2-sulfonamide had an aqueous solubility of 80 µM, e.g., a solubility improvement of ∼9000-fold. The pharmacological optimization had limited impact on drug efficacy as the compounds retained IC(50) values at or below 5 µM in our HIF-dependent reporter assay.


Assuntos
Antineoplásicos/síntese química , Benzopiranos/síntese química , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Sulfonamidas/síntese química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Benzopiranos/química , Benzopiranos/farmacologia , Hipóxia Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Camundongos , Transdução de Sinais , Solubilidade , Estereoisomerismo , Relação Estrutura-Atividade , Sulfonamidas/química , Sulfonamidas/farmacologia , Transcrição Gênica/efeitos dos fármacos
10.
ACS Med Chem Lett ; 3(8): 620-5, 2012 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-24936238

RESUMO

Hypoxia inducible factors (HIFs) are transcription factors that activate expression of multiple gene products and promote tumor adaptation to a hypoxic environment. To become transcriptionally active, HIFs associate with cofactors p300 or CBP. Previously, we found that arylsulfonamides can antagonize HIF transcription in a bioassay, block the p300/HIF-1α interaction, and exert potent anticancer activity in several animal models. In the present work, KCN1-bead affinity pull down, (14)C-labeled KCN1 binding, and KCN1-surface plasmon resonance measurements provide initial support for a mechanism in which KCN1 can bind to the CH1 domain of p300 and likely prevent the p300/HIF-1α assembly. Using a previously reported NMR structure of the p300/HIF-1α complex, we have identified potential binding sites in the p300-CH1 domain. A two-site binding model coupled with IC50 values has allowed establishment of a modest ROC-based enrichment and creation of a guide for future analogue synthesis.

11.
J Biol Chem ; 285(39): 30328-39, 2010 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-20650901

RESUMO

Filamin A (FLNA) is an integrator of cell mechanics and signaling. The spreading and migration observed in FLNA sufficient A7 melanoma cells but not in the parental FLNA deficient M2 cells have been attributed to FLNA. In A7 and M2 cells, the normal prion (PrP) exists as pro-PrP, retaining its glycosylphosphatidyl-inositol (GPI) anchor peptide signal sequence (GPI-PSS). The GPI-PSS of PrP has a FLNA binding motif and binds FLNA. Reducing PrP expression in A7 cells alters the spatial distribution of FLNA and organization of actin and diminishes cell spreading and migration. Integrin ß1 also binds FLNA. In A7 cells, FLNA, PrP, and integrin ß1 exist as two independent, yet functionally linked, complexes; they are FLNA with PrP or FLNA with integrin ß1. Reducing PrP expression in A7 cells decreases the amount of integrin ß1 bound to FLNA. A PrP GPI-PSS synthetic peptide that crosses the cell membrane inhibits A7 cell spreading and migration. Thus, in A7 cells FLNA does not act alone; the binding of pro-PrP enhances association between FLNA and integrin ß1, which then promotes cell spreading and migration. Pro-PrP is detected in melanoma in situ but not in melanocyte. Invasive melanoma has more pro-PrP. The binding of pro-PrP to FLNA, therefore, contributes to melanomagenesis.


Assuntos
Movimento Celular , Proteínas Contráteis/metabolismo , Regulação Neoplásica da Expressão Gênica , Cadeias beta de Integrinas/metabolismo , Melanoma/metabolismo , Proteínas dos Microfilamentos/metabolismo , Príons/metabolismo , Motivos de Aminoácidos , Linhagem Celular Tumoral , Proteínas Contráteis/genética , Filaminas , Glicosilfosfatidilinositóis/genética , Glicosilfosfatidilinositóis/metabolismo , Humanos , Cadeias beta de Integrinas/genética , Melanoma/genética , Proteínas dos Microfilamentos/genética , Príons/genética , Ligação Proteica
12.
Clin Cancer Res ; 15(19): 6128-36, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19789328

RESUMO

PURPOSE: Hypoxia inducible factor-1 (HIF-1), the central mediator of the cellular response to low oxygen, functions as a transcription factor for a broad range of genes that provide adaptive responses to oxygen deprivation. HIF-1 is overexpressed in cancer and has become an important therapeutic target in solid tumors. In this study, a novel HIF-1alpha inhibitor was identified and its molecular mechanism was investigated. EXPERIMENTAL DESIGN: Using a HIF-responsive reporter cell-based assay, a 10,000-member natural product-like chemical compound library was screened to identify novel HIF-1 inhibitors. This led us to discover KC7F2, a lead compound with a central structure of cystamine. The effects of KC7F2 on HIF-1 transcription, translation, and protein degradation processes were analyzed. RESULTS: KC7F2 markedly inhibited HIF-mediated transcription in cells derived from different tumor types, including glioma, breast, and prostate cancers, and exhibited enhanced cytotoxicity under hypoxia. KC7F2 prevented the activation of HIF-target genes such as carbonic anhydrase IX, matrix metalloproteinase 2 (MMP2), endothelin 1, and enolase 1. An investigation into the mechanism of action of KC7F2 showed that it worked through the down-regulation of HIF-1alpha protein synthesis, an effect accompanied by the suppression of the phosphorylation of eukaryotic translation initiation factor 4E binding protein 1 and p70 S6 kinase, key regulators of HIF-1alpha protein synthesis. CONCLUSION: These results show that KC7F2 is a potent HIF-1 pathway inhibitor and its potential as a cancer therapy agent warrants further study.


Assuntos
Antineoplásicos/isolamento & purificação , Antineoplásicos/uso terapêutico , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Biossíntese de Proteínas/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Dissulfetos/isolamento & purificação , Dissulfetos/farmacologia , Dissulfetos/uso terapêutico , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Modelos Biológicos , Neoplasias/patologia , Oxigênio/farmacologia , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/análise , Sulfonamidas/isolamento & purificação , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico
13.
J Clin Invest ; 119(9): 2725-36, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19690385

RESUMO

The cellular prion protein (PrP) is a highly conserved, widely expressed, glycosylphosphatidylinositol-anchored (GPI-anchored) cell surface glycoprotein. Since its discovery, most studies on PrP have focused on its role in neurodegenerative prion diseases, whereas its function outside the nervous system remains unclear. Here, we report that human pancreatic ductal adenocarcinoma (PDAC) cell lines expressed PrP. However, the PrP was neither glycosylated nor GPI-anchored, existing as pro-PrP and retaining its GPI anchor peptide signal sequence (GPI-PSS). We also showed that the PrP GPI-PSS has a filamin A-binding (FLNa-binding) motif and interacted with FLNa, an actin-associated protein that integrates cell mechanics and signaling. Binding of pro-PrP to FLNa disrupted cytoskeletal organization. Inhibition of PrP expression by shRNA in the PDAC cell lines altered the cytoskeleton and expression of multiple signaling proteins; it also reduced cellular proliferation and invasiveness in vitro as well as tumor growth in vivo. A subgroup of human patients with pancreatic cancer was found to have tumors that expressed pro-PrP. Most importantly, PrP expression in tumors correlated with a marked decrease in patient survival. We propose that binding of pro-PrP to FLNa perturbs FLNa function, thus contributing to the aggressiveness of PDAC. Prevention of this interaction could provide an attractive target for therapeutic intervention in human PDAC.


Assuntos
Proteínas Contráteis/metabolismo , Proteínas dos Microfilamentos/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Príons/metabolismo , Citoesqueleto de Actina/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células , Proteínas Contráteis/antagonistas & inibidores , Proteínas Contráteis/genética , Citoesqueleto/metabolismo , Citoesqueleto/patologia , Regulação para Baixo , Filaminas , Humanos , Camundongos , Camundongos Nus , Proteínas dos Microfilamentos/antagonistas & inibidores , Proteínas dos Microfilamentos/genética , Invasividade Neoplásica , Transplante de Neoplasias , Neoplasias Pancreáticas/genética , Príons/antagonistas & inibidores , Príons/genética , Prognóstico , Ligação Proteica , Precursores de Proteínas/metabolismo , RNA Interferente Pequeno/genética , Transdução de Sinais , Transplante Heterólogo
14.
Biochem J ; 406(2): 333-41, 2007 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-17497959

RESUMO

The normal PrP(C) (cellular prion protein) contains sLe(X) [sialyl-Le(X) (Lewis X)] and Le(X). sLe(X) is a ligand of selectins. To examine whether PrP(C) is a ligand of selectins, we generated three human PrP(C)-Ig fusion proteins: one with Le(X), one with sLe(X), and the other with neither Le(X) nor sLe(X). Only Le(X)-PrP(C)-Ig binds E-, L- and P-selectins. Binding is Ca(2+)-dependent and occurs with nanomolar affinity. Removal of sialic acid on sLe(X)-PrP(C)-Ig enables the fusion protein to bind all selectins. These findings were confirmed with brain-derived PrP(C). The selectins precipitated PrP(C) in human brain in a Ca(2+)-dependent manner. Treatment of brain homogenates with neuraminidase increased the amounts of PrP(C) precipitated. Therefore the presence of sialic acid prevents the binding of PrP(C) in human brain to selectins. Hence, human brain PrP(C) interacts with selectins in a manner that is distinct from interactions in peripheral tissues. Alternations in these interactions may have pathological consequences.


Assuntos
Antígenos CD15/metabolismo , Oligossacarídeos/metabolismo , Príons/metabolismo , Selectinas/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/imunologia , Encéfalo/metabolismo , Antígeno CD24/genética , Antígeno CD24/metabolismo , Cálcio/farmacologia , Linhagem Celular , Epitopos/imunologia , Regulação da Expressão Gênica , Humanos , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Antígenos do Grupo Sanguíneo de Lewis , Antígenos CD15/imunologia , Ligantes , Camundongos , Neuraminidase/metabolismo , Oligossacarídeos/imunologia , Polissacarídeos/metabolismo , Príons/genética , Príons/imunologia , Ligação Proteica , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Antígeno Sialil Lewis X
15.
J Biol Chem ; 281(16): 10698-705, 2006 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-16478730

RESUMO

We compared the biochemical properties of a wild type recombinant normal human cellular prion protein, rPrP(c), with a recombinant mutant human prion protein that has three additional octapeptide repeats, rPrP(8OR). Monoclonal antibodies that are specific for the N terminus of rPrP(c) react much better with rPrP(8OR) than rPrP(c), suggesting that the N terminus of rPrP(8OR) is more exposed and hence more available for antibody binding. The N terminus of PrP(c) contains a glycosaminoglycan binding motif. Accordingly, rPrP(8OR) also binds more glycosaminoglycan than rPrP(c). In addition, the divalent cation copper modulates the conformations of rPrP(c) and rPrP(8OR) differently. When compared with rPrP(c), rPrP(8OR) is also more susceptible to oxidative damage. Furthermore, the abnormalities associated with rPrP(8OR) are recapitulated, but even more profoundly, in another insertion mutant, which has five extra octapeptide repeats, rPrP(10OR). Therefore, insertion mutants appear to share common features, and the degree of abnormality is proportional to the number of insertions. Any of these anomalies may contribute to the pathogenesis of inherited human prion disease.


Assuntos
Mutação , Oxigênio/química , Príons/química , Motivos de Aminoácidos , Anticorpos Monoclonais/química , Cálcio/metabolismo , Carbono/química , Cátions , Cobre/química , DNA Complementar/metabolismo , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Epitopos , Glicosaminoglicanos/química , Humanos , Ligantes , Espectroscopia de Ressonância Magnética , Modelos Genéticos , Mutagênese Sítio-Dirigida , Oxigênio/metabolismo , Peptídeos/química , Proteínas PrPC/química , Príons/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/química
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