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1.
AIDS Behav ; 27(4): 1140-1153, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36367613

RESUMO

HIV/HCV prevention among people who inject drugs (PWID) is of key public health importance. We aimed to assess the impact of COVID-19 and associated response measures on HIV/HCV prevention services and socio-economic status of PWID in high-HIV-risk sites. Sites with recent (2011-2019) HIV outbreaks among PWID in Europe North America and Israel, that had been previously identified, were contacted early May 2020. Out of 17 sites invited to participate, 13 accepted. Semi-structured qualitative site reports were prepared covering data from March to May 2020, analyzed/coded and confirmed with a structured questionnaire, in which all sites explicitly responded to all 103 issues reported in the qualitative reports. Opioid maintenance treatment, needle/syringe programs and antiretroviral treatment /hepatitis C treatment continued, but with important reductions and operational changes. Increases in overdoses, widespread difficulties with food and hygiene needs, disruptions in drug supply, and increased homelessness were reported. Service programs rapidly reformed long established, and politically entrenched, restrictive service delivery policies. Future epidemic control measures should include mitigation of negative side-effects on service provision and socio-economic determinants in PWID.


RESUMEN: La prevención del VIH/VHC entre las personas que se inyectan drogas (PWID) es de vital importancia para la salud pública. Nuestro objetivo fue evaluar el impacto de COVID-19 y las medidas de respuesta asociadas en los servicios de prevención del VIH/VHC y el estado socioeconómico de las PWID en sitios de alto riesgo de VIH. Se contactó con sitios con brotes recientes (2011­2019) de VIH entre PWID en Europa, América del Norte e Israel, que habían sido previamente identificados, a principios de mayo de 2020. De los 17 sitios invitados a participar, 13 aceptaron. Se prepararon informes cualitativos semiestructurados del sitio que cubrían los datos de marzo a mayo de 2020, analizados/codificados y confirmados con un cuestionario estructurado, en el que todos los sitios respondieron explícitamente a los 103 asuntos reportados en los informes cualitativos. El tratamiento de mantenimiento con opiáceos, los programas de agujas/jeringas y el tratamiento antirretroviral/tratamiento de la hepatitis C continuaron, pero con importantes reducciones y cambios operativos. Se reportaron aumentos en las sobredosis, dificultades generalizadas con las necesidades alimentarias y de higiene, interrupciones en el suministro de medicamentos y aumento de personas sin hogar. Los programas de servicios reformaron rápidamente las políticas restrictivas de prestación de servicios, establecidas desde hace mucho tiempo y políticamente arraigadas. Las futuras medidas de control de epidemias deben incluir la mitigación de los efectos secundarios negativos en la prestación de servicios y los determinantes socioeconómicos en las PWID.


Assuntos
COVID-19 , Usuários de Drogas , Infecções por HIV , Hepatite C , Abuso de Substâncias por Via Intravenosa , Humanos , Abuso de Substâncias por Via Intravenosa/complicações , Abuso de Substâncias por Via Intravenosa/epidemiologia , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Preparações Farmacêuticas , Israel/epidemiologia , Determinantes Sociais da Saúde , COVID-19/epidemiologia , COVID-19/prevenção & controle , Hepatite C/epidemiologia , Hepatite C/prevenção & controle , Hepacivirus , Surtos de Doenças/prevenção & controle , Europa (Continente)/epidemiologia
2.
J Intellect Disabil Res ; 66(5): 483-498, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35357054

RESUMO

BACKGROUND: Challenging behaviours in people with an intellectual developmental disorder (IDD) are complex and often difficult to understand. The developmental perspective may provide additional insights into the specific behavioural patterns and underlying motives in different emotional reference ages. METHODS: The behaviours of 185 adults with IDD who were admitted to psychiatry were systematically assessed with the Aberrant Behaviour Checklist (ABC) and the Modified Overt Aggression Scale (MOAS). The association of the different behaviours with various emotional reference age groups as assessed with the Scale of Emotional Development - Short (SED-S) was analysed to deduce behavioural patterns typical for a certain level of functioning. RESULTS: Overall, the severity of challenging behaviours decreases in higher emotional reference age groups. Physical aggression was most prevalent in persons in the second phase of emotional development (7-18 months reference age). In SED-S-1 (reference age 0-6 months), the persons appeared to be searching for physical comfort and showed high scores in social withdrawal, stereotypies and aggression towards the self. Persons functioning in SED-S-2 (reference age 7-18 months) scored highest in irritability and physical aggression (searching for security), while those in SED-S-3 (19-36 months) exhibited the searching for autonomy type characterised by defiant and socially inappropriate behaviours. Persons with an emotional reference age of 4-7 years (SED-S-4) showed inappropriate speech, verbal self-regulation and depressive-like behavioural aspects (searching for identity). CONCLUSIONS: The behavioural phenomena exhibited in a certain emotional reference age may support the clinician to differentiate behavioural problems from psychopathological symptoms to yield the proper diagnosis.


Assuntos
Deficiência Intelectual , Comportamento Problema , Adulto , Agressão/psicologia , Criança , Pré-Escolar , Deficiências do Desenvolvimento , Emoções , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/psicologia , Comportamento Problema/psicologia
3.
Ecol Appl ; 29(6): e01951, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31188494

RESUMO

Natural resource managers use data on the spatial range of species to guide management decisions. These data come from survey or monitoring efforts that use a wide variety of tools. Environmental DNA (eDNA) is a surveillance tool that uses genetic markers for detecting species and holds potential as a tool for large-scale monitoring programs. Two challenges of eDNA-based studies are uncertainties created by imperfect capture of eDNA in collection samples (e.g., water field samples) and imperfect detection of eDNA using molecular methods (e.g., quantitative PCR). Occurrence models can be used to address these challenges, thus we use an occurrence model to address two objectives: first, to determine how many samples were required to detect species using eDNA; second, to examine when and where to take samples. We collected water samples from three different habitat types in the Upper Mississippi River when both Bighead Carp and Silver Carp were known to be present based on telemetry detections. Each habitat type (backwater, tributary, and impoundment) was sampled during April, May, and November. Detections of eDNA for both species varied across sites and months, but were generally low, 0-19.3% of samples were positive for eDNA. Overall, we found that eDNA-based sampling holds promise to be a powerful monitoring tool for resource managers; however, limitations of eDNA-based sampling include different biological and ecological characteristics of target species such as seasonal habitat usage patterns as well as aspects of different physical environments that impact the implementation of these methods such as water temperature.


Assuntos
Carpas , Ecossistema , Animais , Ecologia , Mississippi , Rios
4.
Neth Heart J ; 25(1): 24-32, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27752966

RESUMO

BACKGROUND: Without assistance, smokers being admitted to the hospital for coronary heart disease often return to regular smoking within a year. OBJECTIVE: This study assessed the 12-month effectiveness of a telephone and a face-to-face counselling intervention on smoking abstinence among cardiac patients. Differential effects for subgroups varying in their socioeconomic status and intention to quit smoking were also studied. METHODS: A randomised controlled trial was used. During hospital stay, smokers hospitalised for coronary heart disease were assigned to usual care (n = 245), telephone counselling (n = 223) or face-to-face counselling (n = 157). Eligible patients were allocated to an intervention counselling group and received nicotine patches. After 12 months, self-reported continued abstinence was assessed and biochemically verified in quitters. Effects on smoking abstinence were tested using multilevel logistic regression analyses applying the intention-to-treat approach. RESULTS: Compared with usual care, differential effects of telephone and face-to-face counselling on continued abstinence were found in patients with a low socioeconomic status and in patients with a low quit intention. For these patients, telephone counselling increased the likelihood of abstinence threefold (OR = 3.10, 95 % CI 1.32-7.31, p = 0.01), whereas face-to-face counselling increased this likelihood fivefold (OR = 5.30, 95 % CI 2.13-13.17, p < 0.001). Considering the total sample, the interventions did not result in stronger effects than usual care. CONCLUSION: Post-discharge telephone and face-to-face counselling interventions increased smoking abstinence rates at 12 months compared with usual care among cardiac patients of low socioeconomic status and low quit intentions. The present study indicates that patients of high socioeconomic status and high quit motivation require different cessation approaches.

5.
Hernia ; 24(6): 1371-1378, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32170456

RESUMO

PURPOSE: Laparoscopic inguinal hernia repair (IHR) may lead to early postoperative pain. Therefore, opioid and non-opioid analgesic agents are often administered in the post-anesthesia care unit (PACU). To reduce the postoperative cumulative need of analgesic medication, as well as to accelerate the physical recovery time, the transversus abdominis plane (TAP) block has recently been studied. The TAP block is a regional anesthesia technique. Even though there is evidence about the efficacy of the block used in procedure such as an open inguinal hernia repair, the evidence regarding its use for the TAPP (transabdominal preperitoneal) technique remains low. We aim to provide more sufficient evidence regarding this topic. METHODS: A monocentric retrospective observational study investigating the effect of the TAP block prior to primary IHR in TAPP technique was conducted. The data of 838 patients who were operated on using this technique from June 2007 to February 2019 were observed. 72 patients were excluded because of insufficient information regarding their analgesic medication protocol. The patients' data were taken from their files. RESULTS: The patients in the TAP block group (n = 364) did not differ statistically significantly compared to the control group (n = 402) in terms of gender, BMI and age. Individuals of the TAP block group experienced less postoperative pain in the PACU (p < 0.001) and received less analgesic medication (morphine, oxycodone, piritramide, acetaminophen; p < 0.001). CONCLUSION: We assume that the TAP block is a sufficient approach to reduce postoperative pain and analgesic medication administration for IHR in TAPP technique.


Assuntos
Músculos Abdominais/efeitos dos fármacos , Amidinas/uso terapêutico , Anestesia Local/métodos , Hérnia Inguinal/tratamento farmacológico , Bloqueio Nervoso/métodos , Músculos Abdominais/cirurgia , Amidinas/farmacologia , Feminino , Hérnia Inguinal/cirurgia , Humanos , Masculino , Estudos Retrospectivos
7.
Curr Biol ; 7(6): 375-86, 1997 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-9197238

RESUMO

BACKGROUND: The retinoblastoma protein (Rb) needs to be phosphorylated by cyclin-dependent kinases (CDKs) before mammalian cells can enter the S phase of the cell cycle. As protein phosphatase 1 (PP1) activates Rb and is itself a target for inhibitory phosphorylation by CDKs in vitro, we asked whether any effects of PP1 on cell cycle progression depend on its phosphorylation and are mediated through Rb. RESULTS: Using electrotransfer of recombinant protein into Rb-positive and Rb-negative cells, we have compared the effects of a wild-type PP1 catalytic subunit, PP1alpha, and a constitutively active mutant of this subunit (PP1alphaT320A) on G1 progression, proliferation rates, and cell viability. In treated cells, PP1alpha levels were elevated 6-16-fold and remained stable for at least 48 hours. In Rb-positive cells, PP1alphaT320A, but not PP1alpha, caused cell cycle arrest in late G1, which was associated with a lack of Rb phosphorylation. In Rb-negative cells, neither wild-type nor mutant phosphatase caused any change in cell cycle progression. Increased cell death was observed in both Rb-positive and Rb-negative cells, however, upon introduction of excess PP1alpha. CONCLUSIONS: The difference between the effects of wild-type and mutant forms of PP1alpha suggests that PP1alpha has the potential to arrest cell growth in G1 unless it is inactivated by periodic phosphorylation at Thr320, presumably by CDKs that regulate passage through the G1-S cell cycle transition. Together, the effects in both cell types suggest that PP1alpha requires functional Rb to induce growth arrest, and that possibly another pool of PP1alpha induces cell death. This identifies PP1 as a potential target for therapeutic anti-proliferative strategies.


Assuntos
Interfase/fisiologia , Fosfoproteínas Fosfatases/metabolismo , Proteína do Retinoblastoma/metabolismo , Morte Celular , Eletroporação , Ativação Enzimática , Fase G1/fisiologia , Células HL-60 , Humanos , Mutação , Osteossarcoma , Fosfoproteínas Fosfatases/genética , Fosforilação , Conformação Proteica , Proteína Fosfatase 1 , Fase S/fisiologia , Soroalbumina Bovina/genética , Soroalbumina Bovina/metabolismo , Fatores de Tempo , Células Tumorais Cultivadas
8.
Oncogene ; 20(43): 6111-22, 2001 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-11593419

RESUMO

Protein phosphatase 1 (PP1) plays important roles in many different aspects of cellular activities including cell cycle control. One important function of PP1 is to activate the retinoblastoma protein pRB. Here we show that pRB is one of PP1's downstream targets during apoptosis. When HL-60 cells synchronized at the G1/S boundary were treated with pro-apoptotic cytosine arabinoside (araC), PP1alpha protein increased twofold and PP1 activity about 30% within 1 h. This was followed by pRB dephosphorylation, pRB cleavage by caspases, DNA fragmentation, the appearance of cells with <2n DNA content and finally, dying and dead cells. In vitro, pRB was protected from caspase-3 digestion by prior Cdk-mediated phosphorylation, whereas PP1alpha converted phospho-pRB into an efficient substrate for caspase-3. Introduction of active PP1alpha into HL-60 cells by electroporation was sufficient to induce characteristics of apoptosis. Similarly, araC-resistant cells, normally unable to die in response to araC, initiated apoptosis when electroporated with active PP1alpha. This was also accompanied by pRB cleavage. In contrast, introduction of inhibitor-2 delayed the onset of araC-induced apoptosis, whereas concomitant introduction of PP1alpha and inhibitor-2 completely prevented PP1alpha-induced apoptosis. These results suggest that dephosphorylation of key proteins by PP1alpha may be crucial for the initiation of apoptosis and further support the concept of PP1 serving as a potential target for anti-cancer therapy.


Assuntos
Apoptose/efeitos dos fármacos , Fosfoproteínas Fosfatases/metabolismo , Proteína do Retinoblastoma/metabolismo , Antimetabólitos Antineoplásicos/farmacologia , Western Blotting , Caspase 3 , Caspases/metabolismo , Citarabina/farmacologia , Fragmentação do DNA , Citometria de Fluxo , Vetores Genéticos , Células HL-60 , Humanos , Fosforilação , Testes de Precipitina , Ligação Proteica , Proteína Fosfatase 1 , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Fatores de Tempo
9.
Biochim Biophys Acta ; 915(2): 217-24, 1987 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-3115293

RESUMO

Previous studies in our laboratory have shown that rat heart glycogen phosphorylase (1,4-alpha-D-glucan: orthophosphate alpha-D-glucosyltransferase, EC 2.4.1.1) separates into two forms upon ion-exchange chromatography. Both forms could be shown to have the same subunit Mr and to incorporate one molecule of phosphate per subunit. The studies reported here were done to check whether both forms are native isoenzymes and, further, which form might represent the heart-specific phosphorylase. Firstly, the iso-electric points of the purified enzymes are compared with those associated with phosphorylase activity in crude extracts from rat heart. Two out of four major bands coincided with the bands of purified phosphorylase Ib and IIb (isoelectric points: 5.5 and 6.25), indicating apparent identity. Secondly, antibodies to rat skeletal muscle phosphorylase reacted with rat heart phosphorylase I, whereas phosphorylase II was neither inhibited nor precipitated by the antibody. Thirdly, peptide maps obtained after proteolytic digestion of SDS-denatured phosphorylase I and II showed different patterns. In addition to the kinetic differences between these two forms reported earlier, phosphorylase IIa was inhibited by glucose 6-phosphate, whereas phosphorylase Ia was not. These results suggest that phosphorylase II is a heart-specific isoenzyme which is presumably encoded by a different gene.


Assuntos
Isoenzimas/metabolismo , Miocárdio/enzimologia , Fosforilases/metabolismo , Animais , Imunodifusão , Imunoeletroforese , Técnicas Imunológicas , Focalização Isoelétrica , Isoenzimas/genética , Isoenzimas/isolamento & purificação , Masculino , Músculos/enzimologia , Fragmentos de Peptídeos , Peptídeo Hidrolases/metabolismo , Fosforilases/genética , Fosforilases/isolamento & purificação , Fosforilação , Ratos , Ratos Endogâmicos , Tripsina/metabolismo
10.
Gene ; 69(1): 131-4, 1988 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-2852144

RESUMO

The amino acid sequences of mammalian protein phosphatase 1 and 2A were compared pairwise with every sequence in the National Biomedical Research Foundation protein sequence database using an exhaustive searching programme [Coulson et al., Comp. J. 30 (1987) 420-424]. The N-terminal half of the protein encoded by an open reading frame, orf 221, in bacteriophage lambda (nt 43,224-43,886 in the map of Daniels et al. [in Hendrix et al. (Eds.), Lambda II. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 1983, pp. 519-676] shows 35% identity to either protein phosphatase 1 or 2A in this region. If conservative replacements are included the overall homology rises to 49%. A gene in phi 80 also shows 35% identity with the mammalian protein phosphatases. The results indicate that orf 221 of phage lambda and the homologous phi 80 gene may encode protein phosphatases. The possible roles of protein phosphorylation in the propagation of bacteriophage are discussed.


Assuntos
Bacteriófago lambda/genética , Colífagos/genética , Genes Virais , Genes , Fosfoproteínas Fosfatases/genética , Sequência de Aminoácidos , Animais , Dados de Sequência Molecular , Músculos/enzimologia , Proteína Fosfatase 1 , Coelhos , Homologia de Sequência do Ácido Nucleico
11.
FEBS Lett ; 223(2): 340-6, 1987 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-2822491

RESUMO

A 1.5 kb clone containing the full-length coding sequence of a type-1 protein phosphatase catalytic subunit has been isolated from a rabbit skeletal muscle cDNA library constructed in lambda gt10. The protein sequence deduced from the cDNA contains 311 residues and has a molecular mass of 35.4 kDa. A single mRNA species at 1.6 kb was visualized by Northern blotting. The type-1 protein phosphatase was strikingly homologous to protein phosphatase 2A, 49% of the amino acids between residues 11 and 280 being identical. The first 10 and last 31 residues were dissimilar. Residues 1-101 of the type-1 protein phosphatase also showed 21% sequence identity with a region of mammalian alkaline phosphatases.


Assuntos
Fosfoproteínas Fosfatases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA/genética , Dados de Sequência Molecular , Músculos/fisiologia , Fragmentos de Peptídeos/análise , Proteína Fosfatase 2 , RNA Mensageiro/genética , Coelhos , Homologia de Sequência do Ácido Nucleico
12.
Front Biosci ; 4: D22-42, 1999 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9872729

RESUMO

Regulating the cell number is critically important for the development and maintenance of a multi-cellular organism. The cell number can be altered by inducing cell proliferation and/or programmed cell death (apoptosis). These two processes are linked by cell cycle-regulatory pathways, and protein phosphorylation and proteolytic degradation play key roles in both. Protein dephosphorylation has been a rather neglected aspect of cell cycle control. Recent advances in this field make it imperative to provide a view of the cell cycle from a phosphatase's vantage point. Although a number of protein phosphatases may be instrumental in cell cycle and apoptosis control, the emphasis here will be on the prototypical Ser/Thr-specific protein phosphatase PP1. Experiments will be considered in their historical context. The major goal of this review will be to re-evaluate the hypothesis that PP1 - and other protein phosphatases - may function as negative growth regulators. Currently available evidence suggests that PP1 activity is required for exit from mitosis, yet may also block cell cycle progression and facilitate apoptosis. Where appropriate, results highlighting the role of the other major phosphatase, PP2A, will also be discussed. This review will conclude with some unresolved issues including the question whether PP1 might be a suitable target for anti-cancer strategies.


Assuntos
Ciclo Celular/fisiologia , Fosfoproteínas Fosfatases/fisiologia , Fosforilação , Apoptose , Contagem de Células , Proteínas de Ciclo Celular/fisiologia , Divisão Celular , Transformação Celular Neoplásica/patologia , Genes Supressores de Tumor/fisiologia , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosfoproteínas Fosfatases/metabolismo , Processamento de Proteína Pós-Traducional
13.
J Heart Valve Dis ; 9(6): 844-6, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11128796

RESUMO

All mechanical heart valves are thrombogenic, and are associated with thromboembolic complications becomes ineffective. when anticoagulation Controversy exists with regard to the appropriate and safe anticoagulation regimen of gravid women with mechanical heart valve prostheses. While oral anticoagulants such as warfarin may be associated with fetal complications, the role of low-molecular weight heparin (LMWH) and heparinoids (and their respective appropriate dosage) have still to be determined. In developing countries such as Saudi Arabia, the prevalence of rheumatic fever is high, as is the percentage of female patients with mechanical heart valves and who are of child-bearing age. Thus, the issue of adequate anticoagulation on one hand, and avoidance of warfarin-induced embryopathy on the other hand, is crucial. To date, few reports are available of LMWH as sole anticoagulant in patients with mechanical heart valves. We report a case of massive valve thrombosis with subsequent pulmonary edema after warfarin anticoagulation was changed to LMWH during pregnancy, and administered at too low a dose.


Assuntos
Anticoagulantes/administração & dosagem , Enoxaparina/administração & dosagem , Próteses Valvulares Cardíacas/efeitos adversos , Valva Mitral , Complicações Hematológicas na Gravidez/prevenção & controle , Trombose/etiologia , Adulto , Dilatação e Curetagem , Feminino , Implante de Prótese de Valva Cardíaca , Humanos , Valva Mitral/cirurgia , Gravidez , Complicações Cardiovasculares na Gravidez , Complicações Hematológicas na Gravidez/cirurgia , Cuidados Pré-Operatórios , Trombose/prevenção & controle , Trombose/cirurgia , Falha de Tratamento
14.
Leukemia ; 28(1): 59-69, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23958923

RESUMO

Owing to their clinical success, there is growing interest in novel bispecific antibodies (bsAbs) for retargeting of T cells to tumor cells including for the treatment of acute myeloid leukemia (AML). One potential target for retargeting of T cells to AML blasts is the surface molecule CD33. Here we describe a novel modular targeting platform that consists of a universal effector module (EM) and individual target modules (TMs). Both modules can form an immune complex via a peptide epitope. The resulting targeting complex can functionally replace a conventional bsAb. By fusion of a costimulatory domain (for example, the extracellular CD137 ligand domain) to the TM, the targeting complex can even provide a costimulatory signal to the redirected T cells at their side of interaction with the tumor cell. Furthermore, we observed that an efficient killing of tumor cells expressing low levels of the tumor target CD33 becomes critical at low effector-to-target cell ratios but can be improved by costimulation via CD137 using our novel targeting system.


Assuntos
Leucemia Mieloide Aguda/imunologia , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Linfócitos T/imunologia , Animais , Linhagem Celular , Ensaio de Imunoadsorção Enzimática , Humanos , Leucemia Mieloide Aguda/patologia , Ativação Linfocitária , Masculino
16.
Cell Death Differ ; 17(11): 1795-804, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20489726

RESUMO

Persistently hyperphosphorylated Akt contributes to human oncogenesis and resistance to therapy. Triciribine (TCN) phosphate (TCN-P), the active metabolite of the Akt phosphorylation inhibitor TCN, is in clinical trials, but the mechanism by which TCN-P inhibits Akt phosphorylation is unknown. Here we show that in vitro, TCN-P inhibits neither Akt activity nor the phosphorylation of Akt S473 and T308 by mammalian target of rapamycin or phosphoinositide-dependent kinase 1. However, in intact cells, TCN inhibits EGF-stimulated Akt recruitment to the plasma membrane and phosphorylation of Akt. Surface plasmon resonance shows that TCN, but not TCN, binds Akt-derived pleckstrin homology (PH) domain (K(D): 690 nM). Furthermore, nuclear magnetic resonance spectroscopy shows that TCN-P, but not TCN, binds to the PH domain in the vicinity of the PIP3-binding pocket. Finally, constitutively active Akt mutants, Akt1-T308D/S473D and myr-Akt1, but not the transforming mutant Akt1-E17K, are resistant to TCN and rescue from its inhibition of proliferation and induction of apoptosis. Thus, the results of our studies indicate that TCN-P binds to the PH domain of Akt and blocks its recruitment to the membrane, and that the subsequent inhibition of Akt phosphorylation contributes to TCN-P antiproliferative and proapoptotic activities, suggesting that this drug may be beneficial to patients whose tumors express persistently phosphorylated Akt.


Assuntos
Acenaftenos/metabolismo , Acenaftenos/farmacologia , Membrana Celular/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ribonucleotídeos/metabolismo , Ribonucleotídeos/farmacologia , Proteínas Quinases Dependentes de 3-Fosfoinositídeo , Animais , Apoptose , Linhagem Celular Tumoral , Fator de Crescimento Epidérmico/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Imunofluorescência , Amplificação de Genes , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Espectroscopia de Ressonância Magnética , Proteínas de Membrana/metabolismo , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Fosforilação/efeitos dos fármacos , Reação em Cadeia da Polimerase , Proteínas Serina-Treonina Quinases/metabolismo , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-akt/química , Transdução de Sinais , Ressonância de Plasmônio de Superfície , Serina-Treonina Quinases TOR/metabolismo
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