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1.
Water Sci Technol ; 77(9-10): 2426-2435, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29893731

RESUMO

Municipal solid waste (MSW) landfills now represent one of the most important issues related to the waste management cycle. Knowledge of biogas production is a key aspect for the proper exploitation of this energy source, even in the post-closure period. In the present study, a simple mathematical model was proposed for the simulation of biogas production. The model is based on first-order biodegradation kinetics and also takes into account the temperature variation in time and depth as well as landfill settlement. The model was applied to an operating landfill located in Sicily, in Italy, and the first results obtained are promising. Indeed, the results showed a good fit between measured and simulated data. Based on these promising results, the model can also be considered a useful tool for landfill operators for a reliable estimate of the duration of the post-closure period.


Assuntos
Biocombustíveis , Modelos Teóricos , Eliminação de Resíduos/métodos , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos , Biodegradação Ambiental , Sicília , Gerenciamento de Resíduos
2.
Br J Cancer ; 107(10): 1783-90, 2012 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-23047549

RESUMO

BACKGROUND: Mutations in genes for hereditary non-polyposis colorectal cancer (HNPCC) in ovarian cancer patients remains poorly defined. We sought to estimate the frequency and characteristics of HNPCC gene mutations in a population-based sample of women with epithelial ovarian cancer. METHODS: The analysis included 1893 women with epithelial ovarian cancer ascertained from three population-based studies. Full-germline DNA sequencing of the coding regions was performed on three HNPCC genes, MLH1, MSH2 and MSH6. Collection of demographic, clinical and family history information was attempted in all women. RESULTS: Nine clearly pathogenic mutations were identified, including five in MSH6, two each in MLH1 and MSH2. In addition, 28 unique predicted pathogenic missense variants were identified in 55 patients. Pathogenic mutation carriers had an earlier mean age at diagnosis of ovarian cancer, overrepresentation of cancers with non-serous histologies and a higher number of relatives with HNPCC-related cancers. CONCLUSIONS: Our findings suggest that fewer than 1% of women with ovarian cancer harbour a germline mutation in the HNPCC genes, with overrepresentation of MSH6 mutations. This represents a lower-range estimate due to the large number of predicted pathogenic variants in which pathogenicity could not definitively be determined. Identification of mismatch repair gene mutations has the potential to impact screening and treatment decisions in these women.


Assuntos
Reparo de Erro de Pareamento de DNA , Mutação , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Ovarianas/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Carcinoma Epitelial do Ovário , Neoplasias Colorretais/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética
3.
Oncogene ; 30(19): 2207-18, 2011 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-21242980

RESUMO

The transcriptional activity of the androgen receptor (AR) is regulated by both ligand binding and post-translational modifications, including acetylation and small ubiquitin-like modifier (SUMO)ylation. Histone deacetylases (HDACs) are known to catalyze the removal of acetyl groups from both histones and non-histone proteins. In this study, we report that HDAC4 binds to and inhibits the activity of the AR. This inhibition was found to depend on the SUMOylation, instead of deacetylation, of the AR. Consistently, HDAC4 increases the level of AR SUMOylation in both whole-cell and cell-free assay systems, raising the possibility that the deacetylase may act as an E3 ligase for AR SUMOylation. Knock down of HDAC4 increases the activity of endogenous AR and androgen induction of prostate-specific antigen expression and prostate cancer cell growth, which is associated with decreased SUMOylation of the receptor. Overall, the studies identify HDAC4 as a positive regulator for AR SUMOylation, revealing a deacetylase-independent mechanism of HDAC action in prostate cancer cells.


Assuntos
Antagonistas de Androgênios/farmacologia , Histona Desacetilases/metabolismo , Receptores Androgênicos/efeitos dos fármacos , Proteínas Repressoras/metabolismo , Sumoilação , Sequência de Bases , Biocatálise , Linhagem Celular Tumoral , Primers do DNA , Ensaio de Imunoadsorção Enzimática , Humanos , Receptores Androgênicos/metabolismo , Transdução de Sinais
4.
Oncogene ; 28(3): 445-60, 2009 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-18850005

RESUMO

Cortactin binds F-actin and promotes cell migration. We showed earlier that cortactin is acetylated. Here, we identify SIRT1 (a class III histone deacetylase) as a cortactin deacetylase and p300 as a cortactin acetylase. We show that SIRT1 deacetylates cortactin in vivo and in vitro and that the SIRT1 inhibitor EX-527 increases amounts of acetylated cortactin in ovarian cancer cells. We also show that p300 acetylates cortactin in vivo and that cells lacking or depleted of p300 express less-acetylated cortactin than do control cells. Deletion analysis mapped the SIRT1-binding domain of cortactin to its repeat region, which also binds F-actin. Mouse embryo fibroblasts (MEFs) lacking sir2alpha (the mouse homolog of SIRT1) migrated more slowly than did wild-type cells. The expression of SIRT1 in sir2alpha-null cells restored migratory capacity, as did expression of a deacetylation-mimetic mutant of cortactin. SIRT1 and cortactin were more abundant in breast tumor tissue than in their normal counterparts, whereas SIRT1 expression inversely correlates with the ratio of acetylation cortactin versus total cortactin. These data suggest that deacetylation of cortactin is associated with high levels of SIRT1 and tumorigenesis. Finally, breast and ovarian cancer cell lines expressing an acetylation mimetic mutant of cortactin are less motile than that of control cells, whereas cells expressing the deacetylation mimetic mutant of cortactin migrate faster than that of control cells in Transwell migration assays. In summary, our results suggest that cortactin is a novel substrate for SIRT1 and p300 and, for the first time, a possible role for SIRT1 in cell motility through deacetylation of cortactin.


Assuntos
Movimento Celular/fisiologia , Cortactina/metabolismo , Sirtuínas/metabolismo , Acetilação , Animais , Western Blotting , Mama/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Ensaios de Migração Celular , Núcleo Celular/metabolismo , Células Cultivadas , Cortactina/genética , Citoplasma/metabolismo , Proteína p300 Associada a E1A/fisiologia , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Técnicas Imunoenzimáticas , Imunoprecipitação , Rim/citologia , Rim/metabolismo , Camundongos , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Sirtuína 1 , Sirtuína 2 , Sirtuínas/genética , Sirtuínas/fisiologia , Cicatrização
5.
Ann N Y Acad Sci ; 1149: 90-3, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19120181

RESUMO

This study aimed to characterize infection with Anaplasma marginale, A. phagocytophilum, A. ovis, and A. platys in humans, animals, and ticks in Sicily, Italy, during 2003-2006. Serologic (competitive ELISA [cELISA]) and indirect immunofluorescence antibody [IFA]; N= 1990) and DNA (polymerase chain reaction [PCR]; N= 2788) tests were conducted on horse, donkey, cattle, sheep, goat, pig, dog, cat, roe deer, wild boar, human, and tick samples. The results reported herein suggested that in Sicily cattle are a major reservoir for A. marginale, dogs for A. platys, and sheep and goats for A. ovis. Domestic animals, such as cattle, horses, donkeys, sheep, dogs, and cats, may serve as reservoir for A. phagocytophilum, but different strains may infect ruminants and humans. All Anaplasma spp. characterized in Sicily had some distinctive genotypes for this region. Low genetic diversity was observed in A. ovis and A. platys, whereas A. marginale and A. phagocytophilum strains showed high genetic diversity. These results expanded our knowledge about the prevalence of Anaplasma spp. in Sicily and provided information to understand the epidemiology of these infections and implement measures to diagnose, treat, and control transmission to humans and animals in this region.


Assuntos
Anaplasmose/diagnóstico , Anaplasmose/fisiopatologia , Animais , Ensaio de Imunoadsorção Enzimática , Humanos , Reação em Cadeia da Polimerase , Sicília
6.
Zoonoses Public Health ; 54(1): 8-15, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17359441

RESUMO

The objective of this study was to characterize the observed prevalence of tick-borne pathogens (TBP) in domestic animals in Sicily, Italy during 2003-2005. Serological (competitive ELISA and indirect immunofluorescence antibody, n = 3299) and DNA tests (polymerase chain reaction and reverse line blot, n = 2565) were conducted on horse, donkey, cattle, sheep, goat, pig and dog samples. Pathogens analysed included Anaplasma, Ehrlichia, Rickettsia, Babesia and Theileria species, and Coxiella burnetii. The most prevalent TBP were Anaplasma and Babesia species. The results reported herein suggested that cattle could serve as the major reservoir for Babesia and Theileria spp. while for Anaplasma spp. cattle, dogs, sheep and goats may be the most important reservoir species. These results expanded our knowledge about the prevalence of TBP in Sicily and provided information to understand the epidemiology of tick-borne diseases and may help to implement measures to diagnose, treat and control transmission to humans and animals in this region.


Assuntos
Animais Domésticos , Anticorpos Antibacterianos/sangue , Doenças Transmitidas por Carrapatos/veterinária , Carrapatos/microbiologia , Carrapatos/parasitologia , Anaplasma , Anaplasmose/epidemiologia , Animais , Vetores Aracnídeos/microbiologia , Vetores Aracnídeos/parasitologia , Babesia , Babesiose/epidemiologia , Babesiose/veterinária , Bovinos , Reservatórios de Doenças/veterinária , Ehrlichia , Ehrlichiose/epidemiologia , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Cabras , Cavalos , Itália/epidemiologia , Vigilância de Evento Sentinela/veterinária , Estudos Soroepidemiológicos , Ovinos , Suínos , Theileria , Theileriose/epidemiologia , Doenças Transmitidas por Carrapatos/epidemiologia
7.
Int J Artif Organs ; 28(8): 817-26, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16211532

RESUMO

Hydraulic mock circulatory systems have low flexibility to allow tests of different cardiovascular devices and low precision when a reference model must be reproduced. In this paper a new bench is described. It combines the computer model of the environment in which the device will operate and the electro-hydraulic interfaces by which device and computer are connected. A models library provided with basic functions allows implementing many layouts of the bench, which in turn depend both on the device properties and the desired experiment. In case of an apical LVAD evaluation, the bench can reproduce right and left ventricles, pulmonary and systemic circulations, inlet and outlet LVAD cannulas. An interface forces the instantaneous calculated flow at the VAD input and feeds back the measured pressure to the computer; another interface works in a similar -but complementary- way at the VAD output. The paper focuses on the operating principle of the electro hydraulic interfaces which represent a relevant component of the bench, on the RT-Linux-based software architecture, on the models of the basic elements of the bench. A patent is under preparation. At the moment, only a portion of the bench has been developed. It consists of a piston-cylinder mechanism, which mimics the elastance-based mechanism of a natural ventricle, and a hydraulic circuit representing the arterial load according to a modified windkessel model and the venous return according to the Guyton's model. The pump is driven by a real-time simulation of the cardiovascular system. This preliminary layout allowed testing the piston-cylinder mechanism, its control, and the software. This electro-hydraulic interface has been used to reproduce a pulsatile pump working in different modes. The hybrid model approach can support the development of new cardiac assist devices from their computer model to their manufacture.


Assuntos
Simulação por Computador , Coração Auxiliar , Modelos Cardiovasculares , Desenho de Equipamento , Coração/fisiologia , Hemodinâmica , Humanos
8.
Am J Pathol ; 159(2): 431-7, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11485901

RESUMO

Extensive studies have demonstrated that the Akt/AKT1 pathway is essential for cell survival and inhibition of apoptosis; however, alterations of Akt/AKT1 in human primary tumors have not been well documented. In this report, significantly increased AKT1 kinase activity was detected in primary carcinomas of prostate (16 of 30), breast (19 of 50), and ovary (11 of 28). The results were confirmed by Western blot and immunohistochemical staining analyses with phospho-Ser473 Akt antibody. The majority of AKT1-activated tumors are high grade and stage III/lV (13 of 16 prostate, 15 of 19 breast, and 8 of 11 ovarian carcinomas). Previous studies showed that wild-type AKT1 was unable to transform NIH3T3 cells. To demonstrate the biological significance of AKT1 activation in human cancer, constitutively activated AKT1 (Myr-Akt) was introduced into NIH3T3 cells. Overexpression of Myr-Akt in the stably transfected cells resulted in malignant phenotype, as determined by growth in soft agar and tumor formation in nude mice. These data indicate that AKT1 kinase, which is frequently activated in human cancer, is a determinant in oncogenesis and a potential target for cancer intervention.


Assuntos
Transformação Celular Neoplásica , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas , Células 3T3 , Animais , Western Blotting , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Ativação Enzimática , Feminino , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Estadiamento de Neoplasias , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/patologia , Fosfatidilinositol 3-Quinases/análise , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/patologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-akt , Células Tumorais Cultivadas
9.
Br J Pharmacol ; 133(8): 1323-9, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11498518

RESUMO

1. The aim of this work was to evaluate the role of leukotrienes in brain damage in vivo in a model of focal cerebral ischaemia in the rat, obtained by permanent occlusion of middle cerebral artery. 2. A significant (P < 0.01) elevation of LTC(4), LTD(4) and LTE(4) (cysteinyl-leukotrienes) levels occurred 4 h after ischaemia induction in the ipsilateral cortices of ischaemic compared to sham-operated animals (3998 +/- 475 and 897 +/- 170 fmol g(-1) tissue, respectively, P < 0.01). 3. The NMDA receptor antagonist MK-801 and the adenosine A(2A) receptor antagonist SCH 58261 were administered in vivo at doses known to reduce infarct size and compared with the leukotriene biosynthesis inhibitor MK-886. 4. MK-886 (0.3 and 2 mg kg(-1) i.v.) and MK-801 (3 mg kg(-1) i.p.) decreased cysteinyl-leukotriene levels (-78%, P < 0.05; -100%, P < 0.01; -92%, P < 0.01, respectively) 4 h after permanent occlusion of the middle cerebral artery, whereas SCH 58261 (0.01 mg kg(-1) i.v.) had no significant effects. 5. MK-886 (2 mg kg(-1) i.v.) was also able to significantly reduce the cortical infarct size by 30% (P < 0.05). 6. We conclude that cysteinyl-leukotriene formation is associated with NMDA receptor activation, and that it represents a neurotoxic event, the inhibition of which is able to reduce brain infarct area in a focal ischaemic event.


Assuntos
Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Cisteína/metabolismo , Leucotrienos/metabolismo , Animais , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Indóis/farmacologia , Inibidores de Lipoxigenase/farmacologia , Masculino , Fármacos Neuroprotetores/farmacologia , Antagonistas de Receptores Purinérgicos P1 , Pirimidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores Purinérgicos P1/metabolismo , Triazóis/farmacologia
10.
Cancer Res ; 61(16): 5985-91, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11507039

RESUMO

We have shown previously that the AKT2 pathway is essential for cell survival and important in malignant transformation. In this study, we demonstrate elevated kinase levels of AKT2 and phosphatidylinositol-3-OH kinase (PI3K) in 32 of 80 primary breast carcinomas. The majority of the cases with the activation are estrogen receptor alpha (ERalpha) positive, which prompted us to examine whether AKT2 regulates ERalpha activity. We found that constitutively activated AKT2 or AKT2 activated by epidermal growth factor or insulin-like growth factor-1 promotes the transcriptional activity of ERalpha. This effect occurred in the absence or presence of estrogen. Activated AKT2 phosphorylates ERalpha in vitro and in vivo, but it does not phosphorylate a mutant ERalpha in which ser-167 was replaced by Ala. The PI3K inhibitor, wortmannin, abolishes both the phosphorylation and transcriptional activity of ERalpha induced by AKT2. However, AKT2-induced ERalpha activity was not inhibited by tamoxifen but was completely abolished by ICI 164,384, implicating that AKT2-activated ERalpha contributes to tamoxifen resistance. Moreover, we found that ERalpha binds to the p85alpha regulatory subunit of PI3K in the absence or presence of estradiol in epithelial cells and subsequently activates PI3K/AKT2, suggesting ERalpha regulation of PI3K/AKT2 through a nontranscriptional and ligand-independent mechanism. These data indicate that regulation between the ERalpha and PI3K/AKT2 pathway (ERalpha-PI3K/AKT2-ERalpha) may play an important role in pathogenesis of human breast cancer and could contribute to ligand-independent breast cancer cell growth.


Assuntos
Neoplasias da Mama/enzimologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas/metabolismo , Receptores de Estrogênio/metabolismo , Androstadienos/farmacologia , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Células COS , Ativação Enzimática , Indução Enzimática , Inibidores Enzimáticos/farmacologia , Células Epiteliais/enzimologia , Células Epiteliais/metabolismo , Antagonistas de Estrogênios/farmacologia , Receptor alfa de Estrogênio , Genes Reporter , Humanos , Fosfatidilinositol 3-Quinases/biossíntese , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas c-akt , Receptores de Estrogênio/antagonistas & inibidores , Receptores de Estrogênio/fisiologia , Tamoxifeno/farmacologia , Transcrição Gênica/fisiologia , Transfecção , Wortmanina
11.
J Biol Chem ; 276(23): 20444-50, 2001 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-11278645

RESUMO

PTEN/MMAC1/TEP-1 (PTEN) tumor suppressor and androgen receptor play important roles in prostatic tumorigenesis by exerting opposite effects on homeostasis of prostatic epithelium. Here, we describe a mutual repression and selective dominance between PTEN and the androgen receptor (AR) in the growth and the apoptosis of prostatic cancer cells. On the one hand, PTEN and an inhibitor of phosphoinositide 3-kinase repressed the transcriptional activity of the AR as well as androgen-induced cell proliferation and production of prostate-specific antigen. On the other hand, androgens protected prostate cancer cells from PTEN-induced apoptosis in an AR-dependent manner. Whereas the repression of the transcriptional activity of the AR by PTEN is likely to involve the down-regulation of AKT, androgens protected prostate cancer cells from PTEN-induced apoptosis without an effect on AKT activity, demonstrating a differential involvement of AKT in the interaction between PTEN and the AR. Our data suggest that the loss of PTEN function may induce tumorigenesis through unopposed activity of the AR as well as contribute to the resistance of prostate cancers to androgen ablation therapy.


Assuntos
Apoptose , Divisão Celular , Monoéster Fosfórico Hidrolases/metabolismo , Neoplasias da Próstata/patologia , Receptores Androgênicos/metabolismo , Proteínas Supressoras de Tumor , Antagonistas de Receptores de Andrógenos , Inibidores Enzimáticos/farmacologia , Ensaio de Imunoadsorção Enzimática , Humanos , Masculino , PTEN Fosfo-Hidrolase , Inibidores de Fosfoinositídeo-3 Quinase , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Neoplasias da Próstata/metabolismo , Células Tumorais Cultivadas
12.
Pulm Pharmacol Ther ; 14(1): 3-19, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11162414

RESUMO

This review describes the aspects of leukotriene (LT) pharmacology and biology that are relevant to their important role in asthma. The biosynthesis and metabolism, including transcellular metabolism, of LTB4 and the cysteinyl-LTs (i.e. LTC4, LTD4 and LTE4) are described, and their transport is briefly outlined. The existence, distribution and pharmacological characterization of the receptors (BLT, CysLT1, CysLT2), as well as the transduction mechanisms triggered, are discussed in detail. We also describe their effects on airway smooth muscle tone, hyperresponsiveness and proliferation, on vascular tone and permeability, on mucus secretion, on neural fibers and inflammatory cell functions. Finally, the evidence supporting their role as asthma mediators is reviewed, including the effects of anti LT drugs (both biosynthesis inhibitors and receptor antagonists) in experimental and clinical asthma.


Assuntos
Asma/fisiopatologia , Leucotrienos/farmacologia , Animais , Asma/imunologia , Divisão Celular , Humanos , Inflamação/fisiopatologia , Antagonistas de Leucotrienos , Leucotrienos/biossíntese , Muco/metabolismo , Permeabilidade , Fenômenos Fisiológicos Respiratórios , Transdução de Sinais
13.
Am J Respir Crit Care Med ; 163(1): 266-72, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11208655

RESUMO

Cysteine-containing leukotrienes (cysteinyl-LTs) are potent bronchoconstrictors and play a key role in asthma. We found that histamine and LTD4 markedly constrict strips of human bronchi (HB) with similar efficacy. However, in human airway smooth-muscle (HASM) cells, LTD4, at variance with histamine, elicited only a small, transient change in intracellular calcium ion concentration. HASM cells express both Ca2+-dependent and -independent isoforms of protein kinase C (PKC) (i.e., PKC-alpha and PKC-alpha ). Western blot analysis showed that PKC-alpha is activated by histamine and, to a lesser extent, by LTD4, whereas only LTD4 translocates PKC-alpha. This translocation was specifically inhibited by the LTD4 antagonist pobilukast. Phorbol-dibutyrate ester (PDBu) (a PKC activator) contracted HB strips to the same extent in the presence as in the absence of extra- and intracellular Ca2+. In the absence of Ca2+, LTD4 contracted HB strips to the same extent as did PDBu, suggesting the involvement of a Ca2+-independent PKC in LTD4-mediated signal transduction. PDBu-induced desensitization and the PKC inhibitor H7 abolished the slow and sustained LTD4-triggered contraction of HB strips in the absence of Ca2+, although H7 did not greatly affect the response in the presence of the ion. Thus, in human airways, we identified a novel LTD4 transduction mechanism linked to bronchial smooth-muscle contraction, which is partly independent of Ca2+ and involves the activation of PKC-alpha.


Assuntos
Brônquios/fisiologia , Cálcio/fisiologia , Leucotrieno D4/fisiologia , Músculo Liso/citologia , Músculo Liso/fisiologia , Humanos , Contração Muscular , Músculo Liso/química , Proteína Quinase C/análise
14.
J Neurooncol ; 54(1): 15-22, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11763418

RESUMO

Human glioblastomas (gliomas) are characterized as highly invasive and rapidly growing brain tumors. In this study, we present data on in vitro effect of ascorbyl stearate (Asc-S), a liphophilic derivative of ascorbic acid on cell proliferation, transformation, apoptosis and modulation of expression of insulin-like growth factor-I receptor (IGF-IR) in human glioblastoma multiforme (T98G) cells. Asc-S showed significant inhibition of fetal bovine serum and human recombinant insulin-like growth factor-I (IGF-I) dependent cell proliferation in a dose dependent manner. Treatment of T98G cells with 0, 50, 100 and 150 microM Asc-S for 24h slowed down the cell multiplication cycle with significant accumulation of cells at late S/G2-M phase of cycle. Asc-S treatment (100 microM) reversed the transformed phenotype as determined by clonogenecity in soft agar and also induced apoptosis of T98G. These changes were found to be associated with significant decrease in IGF-IR expression in dose and time dependent manner compared to untreated controls. The data clearly demonstrate that Asc-S has antiproliferative and apoptotic effect on T98G cells probably through modulation of IGF-IR expression and consequent facilitation of programmed cell death.


Assuntos
Antineoplásicos/farmacologia , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Receptor IGF Tipo 1/genética , Ágar , Apoptose/efeitos dos fármacos , Western Blotting , Neoplasias Encefálicas/patologia , Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Clonais , Meios de Cultura , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/patologia , Humanos , Imuno-Histoquímica , Hibridização In Situ , Receptor IGF Tipo 1/biossíntese
15.
Oncogene ; 19(47): 5338-47, 2000 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-11103935

RESUMO

Upregulation of the cyclin-dependent kinase inhibitor p21WAF1/CIP1 and subsequent cell growth arrest or senescence is one mechanism by which normal cells are believed to respond to stress induced by the constitutively activated GTPase Ras. We hypothesize that in the absence of p21, the onset of Ras-dependent oncogenesis is accelerated. To test this hypothesis, we crossed MMTV/v-Ha-ras transgenic mice into a p21-deficient background. By 63 days of age, all 8 ras/p21-/- mice developed either malignant (mammary and/or salivary adenocarcinomas) or benign (Harderian hyperplasia) tumors. In contrast, by the same age, only one out of nine of the ras/p21+/+ mice developed a tumor. Furthermore, by 94 days of age, half of the ras/p21-/- mice, but none of the ras/p21+/+ mice, developed mammary tumors. p21-deficiency also accelerated the development of salivary (T50=66 days for ras/p21-/- vs T50=136 days for ras/p21+/+) and Harderian (T50=52 days for ras/p21-/- vs T50>221 days for ras/p21+/+) tumors. Furthermore, two out of the eight ras/p21-/- mice had metastatic lesions, one in its lungs, the other in its abdomen. None of the nine ras/p21+/+ mice had metastatic lesions. By 4 months of age, the mammary tumor multiplicity was 10-fold greater in ras/p21-/- (average 3.40 tumors/mouse) than in ras/p21+/+ (average 0.33 tumor/mouse) mice. However, once the tumors appeared, their growth rate, apoptosis level, and mitotic index were not affected by the loss of p21, suggesting that loss of p21 is critical in early but not late events of Ras oncogenesis. Altogether, the results show that tumor onset in MMTV/v-Ha-ras mice is p21-dependent with loss of p21 associated with earlier tumor appearance and increased tumor multiplicity and aggressiveness.


Assuntos
Carcinoma Ductal de Mama/fisiopatologia , Ciclinas/fisiologia , Genes ras/fisiologia , Neoplasias Mamárias Animais/fisiopatologia , Proteína Oncogênica p21(ras)/fisiologia , Adenocarcinoma/etiologia , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adenocarcinoma/fisiopatologia , Animais , Carcinoma Ductal de Mama/etiologia , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/patologia , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/genética , Modelos Animais de Doenças , Feminino , Expressão Gênica , Masculino , Neoplasias Mamárias Animais/etiologia , Neoplasias Mamárias Animais/genética , Neoplasias Mamárias Animais/patologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Proteína Oncogênica p21(ras)/genética , Neoplasias das Glândulas Salivares/etiologia , Neoplasias das Glândulas Salivares/genética , Neoplasias das Glândulas Salivares/patologia , Neoplasias das Glândulas Salivares/fisiopatologia
16.
Mol Endocrinol ; 14(11): 1882-96, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11075819

RESUMO

Estrogens are mitogens that stimulate the growth of both normal and transformed epithelial cells of the female reproductive system. The effect of estrogens is mediated through the estrogen receptors, which are ligand-regulated transcription factors. Tamoxifen, a selective estrogen receptor modulator, functions as an estrogen receptor antagonist in breast but an agonist in uterus. In the current study, we show that coexpression of a constitutively active MEKK1, but not RAF or MEKK2, significantly increases the transcriptional activity of the receptor in endometrial and ovarian cancer cells. The expression of wild-type MEKK1 and an active Rac1, which functions upstream of MEKK1, also increased the activity of the receptor while coexpression of dominant negative MEKK1 blocked the Rac1 induction, indicating that endogenous MEKK1 is capable of activating the receptor. Additional experiments demonstrated that the MEKK1-induced activation was mediated through both Jun N-terminal kinases and p38/Hog1 and was independent of the known phosphorylation sites on the receptor. p38, but not Jun N-terminal kinases, efficiently phosphorylated the receptor in immunocomplex kinase assays, suggesting a differential involvement of the two kinases in the receptor activation. More importantly, the expression of the constitutively active MEKK1 increased the agonistic activity of 4-hydroxytamoxifen to a level comparable to that of 17beta-estradiol and fully blocked its antagonistic activity. These findings suggest that the uterine-specific agonistic activity of the tamoxifen compound may be determined by the status of kinases acting downstream of MEKK1.


Assuntos
Neoplasias do Endométrio/tratamento farmacológico , Antagonistas de Estrogênios/farmacologia , MAP Quinase Quinase Quinase 1 , Neoplasias Ovarianas/tratamento farmacológico , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Estrogênio/metabolismo , Tamoxifeno/análogos & derivados , Neoplasias do Endométrio/metabolismo , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Receptor alfa de Estrogênio , Feminino , Flavonoides/farmacologia , Humanos , Imidazóis/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno , MAP Quinase Quinase Quinase 2 , MAP Quinase Quinase Quinases/efeitos dos fármacos , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neoplasias Ovarianas/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-raf/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-raf/genética , Proteínas Proto-Oncogênicas c-raf/metabolismo , Piridinas/farmacologia , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/genética , Tamoxifeno/farmacologia , Transcrição Gênica , Células Tumorais Cultivadas , Proteínas Quinases p38 Ativadas por Mitógeno
17.
Mol Pharmacol ; 57(6): 1182-9, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10825389

RESUMO

We report the identification of a novel pharmacological profile for the leukotriene (LT)C(4) binding site we previously identified in human lung parenchyma (HLP). We used a series of classic cysteinyl-LT (CysLT)(1) receptor antagonists belonging to different chemical classes and the dual CysLT(1)-CysLT(2) antagonist BAY u9773 for both binding and functional studies. Because the presence of (S)-decyl-glutathione interfered with cysteinyl-LT binding, with a kinetic protocol we avoided the use of this compound. By means of heterologous dissociation time courses, we demonstrated that zafirlukast, iralukast, and BAY u9773 selectively competed only for (3)H-LTD(4) binding sites, whereas pobilukast, pranlukast, and CGP 57698 dissociated both (3)H-LTC(4) and (3)H-LTD(4) from their binding sites. Thus, with binding studies, we have been able to identify a pharmacological profile for LTC(4) distinct from that of LTD(4) receptor (CysLT(1)) in HLP. On the contrary, in functional studies, all of the classic antagonists tested were able to revert both LTC(4)- and LTD(4)-induced contractions of isolated HLP strips. Thus, LTD(4) and LTC(4) contract isolated HLP strips through the same CysLT(1) receptor. The results of kinetic binding studies, coupled to a sophisticated data analysis, confirm our hypothesis that HLP membranes contain two cysteinyl-LT high-affinity binding sites with different pharmacological profiles. In functional studies, however, LTD(4)- and LTC(4)-induced contractions are mediated by the same CysLT(1) receptor. In conclusion, the specific LTC(4) high-affinity binding site cannot be classified as one of the officially recognized CysLT receptors, and it is not implicated in LTC(4)-induced HLP strip contractions.


Assuntos
Leucotrieno C4/metabolismo , Leucotrieno D4/metabolismo , Pulmão/metabolismo , Proteínas de Membrana , Receptores de Leucotrienos/metabolismo , Ligação Competitiva , Estudos de Avaliação como Assunto , Humanos , Técnicas In Vitro , Cinética , Antagonistas de Leucotrienos , Leucotrieno C4/farmacologia , Leucotrieno D4/farmacologia , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/fisiologia , Contração Muscular/efeitos dos fármacos , Receptores de Leucotrienos/agonistas , Fatores de Tempo
18.
Oncogene ; 19(19): 2324-30, 2000 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-10822383

RESUMO

We previously demonstrated that AKT2, a member of protein kinase B family, is activated by a number of growth factors via Ras and PI 3-kinase signaling pathways. Here, we report the frequent activation of AKT2 in human primary ovarian cancer and induction of apoptosis by inhibition of phosphoinositide-3-OH kinase (PI 3-kinase)/Akt pathway. In vitro AKT2 kinase assay analyses in 91 ovarian cancer specimens revealed elevated levels of AKT2 activity (>3-fold) in 33 cases (36.3%). The majority of tumors displaying activated AKT2 were high grade and stages III and IV. Immunostaining and Western blot analyses using a phospho-ser-473 Akt antibody that detects the activated form of AKT2 (AKT2 phosphorylated at serine-474) confirmed the frequent activation of AKT2 in ovarian cancer specimens. Phosphorylated AKT2 in tumor specimens localized to the cell membrane and cytoplasm but not the nucleus. To address the mechanism of AKT2 activation, we measured in vitro PI 3-kinase activity in 43 ovarian cancer specimens, including the 33 cases displaying elevated AKT2 activation. High levels of PI 3-kinase activity were observed in 20 cases, 15 of which also exhibited AKT2 activation. The remaining five cases displayed elevated AKT1 activation. Among the cases with elevated AKT2, but not PI 3-kinase activity (18 cases), three showed down-regulation of PTEN protein expression. Inhibition of PI 3-kinase/AKT2 by wortmannin or LY294002 induces apoptosis in ovarian cancer cells exhibiting activation of the PI 3-kinase/AKT2 pathway. These findings demonstrate for the first time that activation of AKT2 is a common occurrence in human ovarian cancer and that PI 3-kinase/Akt pathway may be an important target for ovarian cancer intervention.


Assuntos
Apoptose/fisiologia , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Supressoras de Tumor , Adenocarcinoma Mucinoso/metabolismo , Adenocarcinoma Mucinoso/patologia , Adenocarcinoma Papilar/metabolismo , Adenocarcinoma Papilar/patologia , Adenossarcoma/metabolismo , Adenossarcoma/patologia , Sequência de Aminoácidos , Western Blotting , Cromonas/farmacologia , Sequência Conservada , Cistadenocarcinoma/metabolismo , Cistadenocarcinoma/patologia , Feminino , Fibroma/metabolismo , Fibroma/patologia , Histonas/metabolismo , Humanos , Dados de Sequência Molecular , Morfolinas/farmacologia , Proteínas Oncogênicas/metabolismo , PTEN Fosfo-Hidrolase , Inibidores de Fosfoinositídeo-3 Quinase , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/imunologia , Proteínas Proto-Oncogênicas c-akt , Tumor da Célula Tecal/metabolismo , Tumor da Célula Tecal/patologia
19.
Int J Antimicrob Agents ; 13(4): 305-7, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10755246

RESUMO

Forty two paraplegic and quadriplegic hospitalized spinal cord injured patients with urinary tract infections (UTI) were included in a double blind, randomized treatment study comparing 7 days ofloxacin (300 mg bd) with trimethoprim-sulphamethoxazole (TMPSMX; 160-800 mg bd) or an alternative, chosen because of resistance to TMPSMX. The 4-day clinical cure rate, defined as an asymptomatic patient with sterile urine, was 90% (19/21) with ofloxacin, significantly greater than 48% (10/21) for the comparison group (P=0.003) and the rate at end of therapy was 90% (19/21) with ofloxacin, against 57% (12/21) (P=0.015). Bacterial biofilms were detected on bladder epithelial cells in 39/41 (95%) patients. The biofilm score fell significantly following ofloxacin therapy (P < 0.001) or alternative therapy (P < 0.001). Ofloxacin treatment led to significantly more biofilm eradication than the other antibiotic group on day 4 (62 vs. 24%) (P=0.005) and day 7 (67 vs. 35%) (P=0.014). The study showed that ofloxacin was better than TMPSMX and alternatives at relieving clinical infection and eradicating bladder cell biofilms.


Assuntos
Anti-Infecciosos Urinários/farmacologia , Biofilmes/efeitos dos fármacos , Ofloxacino/farmacologia , Traumatismos da Medula Espinal/complicações , Infecções Urinárias/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Idoso , Anti-Infecciosos Urinários/administração & dosagem , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ofloxacino/administração & dosagem , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/urina , Combinação Trimetoprima e Sulfametoxazol/farmacologia , Bexiga Urinária/microbiologia , Infecções Urinárias/microbiologia , Infecções Urinárias/urina , Urotélio/microbiologia
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