RESUMO
Genome-wide mechanisms that coordinate expression of subsets of functionally related genes are largely unknown. Recent studies show that receptor tyrosine kinases and components of signal transduction cascades including the extracellular signal-regulated protein kinase (ERK), once thought to act predominantly in the vicinity of plasma membrane and in the cytoplasm, can be recruited to chromatin encompassing transcribed genes. Genome-wide distribution of these transducers and their relationship to transcribing RNA polymerase II (Pol2) could provide new insights about co-regulation of functionally related gene subsets. Chromatin immunoprecipitations (ChIP) followed by deep sequencing, ChIP-Seq, revealed that genome-wide binding of epidermal growth factor receptor, EGFR and ERK pathway components at EGF-responsive genes was highly correlated with characteristic mitogen-induced Pol2-profile. Endosomes play a role in intracellular trafficking of proteins including their nuclear import. Immunofluorescence revealed that EGF-activated EGFR, MEK1/2 and ERK1/2 co-localize on endosomes. Perturbation of endosome internalization process, through the depletion of AP2M1 protein, resulted in decreased number of the EGFR containing endosomes and inhibition of Pol2, EGFR/ERK recruitment to EGR1 gene. Thus, mitogen-induced co-recruitment of EGFR/ERK components to subsets of genes, a kinase module possibly pre-assembled on endosome to synchronize their nuclear import, could coordinate genome-wide transcriptional events to ensure effective cell proliferation.
Assuntos
Receptores ErbB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/genética , Genoma Humano , RNA Polimerase II/genética , Cromatina/metabolismo , Imunoprecipitação da Cromatina , Citoesqueleto/genética , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Endossomos/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Ontologia Genética , Células HeLa/efeitos dos fármacos , Humanos , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 2/genética , MAP Quinase Quinase 2/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , RNA Polimerase II/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Ovarian cancer is the seventh most common cancer among women across the world with very high mortality rates. Histology is considered the gold standard for tumour diagnosis. FTIR spectroscopy is relies on registering biochemical differences in the samples analysed, including biological specimens. Therefore, the Synchrotron radiation based-Fourier transform infrared spectroscopy (SR-FTIR) was used for the preliminary investigation of the molecular composition of the human, non-fixed ovarian neoplastic tissues with different type of biological potential. The study that was carried out on thin tissue sections, placed on barium fluoride infrared windows, was focused on investigating spatial distribution of the biochemical markers in various ovarian tumours. Since the structural constituents of tissues accumulate different molecules which may correspond to the specific type of ovarian tumours, the main goal of this study was to check if the mean intensities of the spectral lines of some bio-molecules can be treated as ovarian cancer bio-indicators. Moreover, an attempt to identify and understand the underlying biochemical changes associated with the disease was carried out. The major spectral differences in the frequency and intensities were identified as bonds of lipids, protein massif and nucleic acids. The results obtained suggest that Fourier transform infrared spectroscopy can be used as a supporting tool in the analysis of neoplastic ovarian tissue.
Assuntos
Neoplasias Ovarianas/diagnóstico , Feminino , Humanos , Projetos Piloto , Espectroscopia de Infravermelho com Transformada de Fourier , VibraçãoRESUMO
Neoplastic and healthy ovarian tissues were analysed to identify the changes in the spatial distribution and concentration of elements using synchrotron induced micro X-ray fluorescence spectroscopy. High-resolution distribution maps of minor and trace elements were drawn. Significant amounts of elements such as P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb were present in all neoplastic tissues analysed. The study showed significant diversifications in elemental distributions depending on the structure of tissue. The efficacy of micro X-ray fluorescence spectroscopy to distinguish between various types of ovarian tumours based on the concentrations of studied elements was confirmed by multivariate discriminant analysis. Our analysis showed that the most important elements for tissue classification are S, Cl, K, Fe, Zn, Br and Rb.
Assuntos
Neoplasias Ovarianas/classificação , Espectrometria por Raios X/métodos , Síncrotrons , Oligoelementos/análise , Feminino , Humanos , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Oligoelementos/metabolismoRESUMO
RATIONALE: Previous studies have demonstrated behaviors indicative of anxiolysis in rats pretreated with the nociceptin receptor (opioid receptor like-1, ORL-1) agonist, Ro64-6198. OBJECTIVES: The aim of this study was to examine the effects of Ro64-6198 in anxiety models across three species: rat, guinea pig, and mouse. In addition, the receptor specificity of Ro64-6198 was studied, using the ORL-1 receptor antagonist, J-113397, and ORL-1 receptor knockout (KO) mice. Finally, neurological studies examined potential side effects of Ro64-6198 in the rat and mouse. RESULTS: Ro64-6198 (3-10 mg/kg) increased punished responding in a rat conditioned lick suppression test similarly to chlordiazepoxide (6 mg/kg). This effect of Ro64-6198 was attenuated by J-113397 (10 mg/kg), but not the mu opioid antagonist, naltrexone (3 mg/kg). In addition, Ro64-6198 (1-3 mg/kg) reduced isolation-induced vocalizations in rat and guinea pig pups. Ro64-6198 (3 mg/kg) increased the proportion of punished responding in a mouse Geller-Seifter test in wild-type (WT) but not ORL-1 KO mice, whereas diazepam (1-5.6 mg/kg) was effective in both genotypes. In rats, Ro64-6198 reduced locomotor activity (LMA) and body temperature and impaired rotarod, beam walking, and fixed-ratio (FR) performance at doses of 10-30 mg/kg, i.e., three to ten times higher than an anxiolytic dose. In WT mice, Ro64-6198 (3-10 mg/kg) reduced LMA and rotarod performance, body temperature, and FR responding, but these same measures were unaffected in ORL-1 KO mice. Haloperidol (0.3-3 mg/kg) reduced these measures to a similar extent in both genotypes. These studies confirm the potent, ORL-1 receptor-mediated, anxiolytic-like effects of Ro64-6198, extending the findings across three species. Ro64-6198 has target-based side effects, although the magnitude of these effects varies across species.
Assuntos
Ansiolíticos/farmacologia , Nível de Alerta/efeitos dos fármacos , Imidazóis/farmacologia , Receptores Opioides/agonistas , Compostos de Espiro/farmacologia , Animais , Ansiolíticos/toxicidade , Benzimidazóis/farmacologia , Clordiazepóxido/farmacologia , Condicionamento Clássico/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Cobaias , Imidazóis/toxicidade , Masculino , Camundongos , Camundongos Knockout , Atividade Motora/efeitos dos fármacos , Antagonistas de Entorpecentes , Piperidinas/farmacologia , Ratos , Especificidade da Espécie , Compostos de Espiro/toxicidade , Vocalização Animal/efeitos dos fármacos , Receptor de NociceptinaRESUMO
The present studies were designed to assess whether the novel muscarinic M(2) receptor antagonist 4-cyclohexyl-alpha-[4[[4-methoxyphenyl]sulphinyl]-phenyl]-1-piperazineacetonitrile (SCH 57790) could increase acetylcholine release in the central nervous system (CNS) and enhance cognitive performance in rodents and nonhuman primates. In vivo microdialysis studies show that SCH 57790 (0.1-10 mg/kg, p.o.) produced dose-related increases in acetylcholine release from rat hippocampus, cortex, and striatum. SCH 57790 (0.003-1.0 mg/kg) increased retention times in young rat passive avoidance responding when given either before or after training. Also, SCH 57790 reversed scopolamine-induced deficits in mice in a passive avoidance task. In a working memory operant task in squirrel monkeys, administration of SCH 57790 (0.01-0.03 mg/kg) improved performance under a schedule of fixed-ratio discrimination with titrating delay. The effects observed with SCH 57790 in behavioral studies were qualitatively similar to the effects produced by the clinically used cholinesterase inhibitor donepezil, suggesting that blockade of muscarinic M(2) receptors is a viable approach to enhancing cognitive performance.
Assuntos
Acetilcolina/metabolismo , Cognição/efeitos dos fármacos , Antagonistas Muscarínicos/farmacologia , Piperazinas/farmacologia , Receptores Muscarínicos/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Células CHO , Cricetinae , Frequência Cardíaca/efeitos dos fármacos , Masculino , Camundongos , Microdiálise , Estrutura Molecular , Piperazinas/química , Ratos , Ratos Sprague-Dawley , Receptor Muscarínico M2 , Saimiri , Escopolamina/farmacologia , Fatores de TempoRESUMO
These studies were conducted in order to establish the dose dependency and relative peripheral versus central activity of four prototypical cholinergic antagonists on the rodent passive avoidance response, a widely used animal model of retention. Subcutaneous administration of 0.1 to 100mg/kg revealed a potency profile of scopolamine > atropine methylscopolamine >/= methylatropine for the impairment of passive avoidance responding. A series of neurological assessments of the doses used indicated that side effects alone were not sufficient to impair passive avoidance responding. Although inactive when delivered peripherally, methylatropine was able to produce retention deficits at 10nmol (3.66µg) when administered intracerebrally. To further evaluate whether systemic methylatropine could enter the central nervous system, either scopolamine or atropine was administered subcutaneously in mice and rats pretreated with 10-100mg/kg methylatropine. The deficit-producing effects of scopolamine and atropine were abolished with methylatropine. Thus methylatropine is an exclusive peripheral antagonist; its ability to block the deficit-producing effects of scopolamine and atropine may occur through a change in blood-brain barrier permeability or through uncharacterized pharmacokinetic properties.
RESUMO
Felbamate is a novel anticonvulsant agent recently approved by the FDA for treatment of epilepsy in the US. While the mechanism of action of felbamate has not been fully eludicated, recent evidence has accumulated to suggest that felbamate may act at the strychnine-insensitive glycine binding site on the NMDA receptor complex. Since this receptor has been strongly implicated in cognitive processes, the current study was designed to investigate the potential effects of felbamate on learning performance. Doses of felbamate up to 1000mg/kg, administered subcutaneously (s.c.), did not produce deleterious effects on performance in either mice or rats, using a passive avoidance task. In contrast, the non-competitive NMDA antagonist dizocilpine produced performance deficits at doses from 0.1 to 1.0mg/kg s.c. in both rats and mice. Felbamate and dizocilpine prevented NMDA-induced convulsions with ED(50)s of 20.3 and 0.82mg/kg s.c., respectively. Calculations for the therapeutic index (ratio of the deficit-producing to anticonvulsant doses) for dizocilpine resulted in less than a 1-fold separation in dose, while the therapeutic index for felbamate was greater than 50. Taken together, these results indicate that felbamate does not produce cognitive deficits at doses more than 50 times the dose needed to block seizure activity in animals.
RESUMO
The young rat at post-natal day 18-22 exhibits a natural deficit in passive-avoidance responding that can be corrected with the acute systemic administration of different cholinomimetic drugs, such as tacrine. In order to evaluate the generality of this apparent cholinergic hypofunction, different doses of the anticholinergic agent tropicamide, were administered either systemically or dropped directly into the eye of young or adult rats. Tropicamide produced mydriasis in a dose-dependent manner. The ED50 for tropicamide dropped into the eye was 0.025% for adult rats and 0.12% for young rats. When doses between 0.3 and 100 mg/kg were delivered systemically, the mean time course for recovery to baseline pupil size was accelerated in young rats. The average time to recovery across all doses was 112 +/- 27 min (mean+/-SE) for young rats and 274 +/- 70 min for adults. When subcutaneous tacrine was given immediately to young rats after training in a passive-avoidance response (PAR) task, retention was enhanced at testing 24 hours later in a dose-dependent manner. The response latencies were statistically different from saline-treated controls at doses of 0.003 and 0.01 mg/kg. This was not observed in adult rats. Taken together these results suggest that the PAR, along with the mydriacyl response of the young rat to tropicamide, may be regulated by a system of subsensitive cholinergic receptors.
Assuntos
Envelhecimento/fisiologia , Aprendizagem da Esquiva/fisiologia , Midríase/fisiopatologia , Tacrina/farmacologia , Tropicamida/farmacologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Relação Dose-Resposta a Droga , Injeções Subcutâneas , Antagonistas Muscarínicos/administração & dosagem , Antagonistas Muscarínicos/farmacologia , Midríase/induzido quimicamente , Soluções Oftálmicas , Ratos , Ratos Sprague-Dawley , Tacrina/administração & dosagem , Fatores de Tempo , Tropicamida/administração & dosagemRESUMO
Felbamate (2-phenyl-1,3-propanediol dicarbamate) is a novel antiepileptic agent with a unique structure and mechanism of action, possibly involving binding sites at the N-methyl-D-aspartate receptor (NMDA) complex. A monocarbomate metabolite of felbamate (SCH 54388) was compared to felbamate using a mouse passive-avoidance paradigm (PAR). SCH 54388 was markedly free of toxic side effects up to doses of 300 mg/kg, sc. SCH 54388 reduced the deficit-producing effects of either scopolamine, a cholinergic antagonist, or dizocilpine (MK-801), an NMDA receptor channel blocker, in a dose-dependent manner. The effective dose range of SCH 54388 was between 0.01 and 10 mg/kg, sc. SCH 54388 was also orally active at doses between 0.1 and 10 mg/kg. Felbamate also reduced scopolamine and dizocilpine antagonism, but was less potent than SCH 54388, reducing scopolamine-induced deficits at 1 to 3 mg/kg, sc. in a dose-dependent manner and reducing deficits induced by dizocilpine at doses of 0.1 and 3 mg/kg, SC. The reduction of dizocilpine-induced deficits by felbamate was not dose dependent. These results suggest that SCH 54388 has a mechanism of action involving either directly or indirectly, glutaminergic and cholinergic central neuronal systems.
Assuntos
Anticonvulsivantes/farmacologia , Aprendizagem da Esquiva/efeitos dos fármacos , Maleato de Dizocilpina/antagonistas & inibidores , Antagonistas de Aminoácidos Excitatórios/farmacologia , Antagonistas Muscarínicos/farmacologia , Propilenoglicóis/farmacologia , Escopolamina/antagonistas & inibidores , Animais , Maleato de Dizocilpina/administração & dosagem , Maleato de Dizocilpina/farmacologia , Relação Dose-Resposta a Droga , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Felbamato , Injeções Subcutâneas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Antagonistas Muscarínicos/administração & dosagem , Fenilcarbamatos , Escopolamina/administração & dosagem , Escopolamina/farmacologiaRESUMO
High-dose rate brachytherapy preoperative treatment has been described. The proposal of a protocol contains an outline of patient qualifications for this kind of treatment, as well as necessary laboratory and diagnostic imaging examinations. Methods of brachytherapy (low-dose rate and high-dose rate), methods of surgery and postoperative management of patients with endometrial cancer are discussed.
Assuntos
Braquiterapia/métodos , Neoplasias do Endométrio/radioterapia , Neoplasias do Endométrio/cirurgia , Terapia Combinada , Neoplasias do Endométrio/diagnóstico por imagem , Neoplasias do Endométrio/patologia , Feminino , Humanos , Cuidados Pré-Operatórios , RadiografiaRESUMO
Promising results have been obtained using brachytherapy in the treatment of brain tumors. Between November 99 and August 2000, 28 patients with brain tumors (15 newly diagnosed gliomas, 11 recurrent gliomas, 2 metastases) underwent implantation of temporary iridium 192 sources with stereotactic technique. This group received external beam radiation therapy (45 Gy) following implantation. Patients were followed-up with CT scans every 3 months. Serious complications occurred in two patients (postradiation brain oedema). Median survival has not been assessed due to short follow-up period and small number of patients. Further clinical assessment is required especially long-term follow-up. Brachytherapy appears to be a useful technique for the treatment of selected brain tumors.
Assuntos
Biópsia/métodos , Braquiterapia/métodos , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Glioma/patologia , Glioma/radioterapia , Radioisótopos de Irídio/uso terapêutico , Técnicas Estereotáxicas , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radioterapia Adjuvante , Radioterapia Conformacional , Cirurgia Assistida por Computador , Fatores de Tempo , Resultado do TratamentoRESUMO
The role of preoperative brachytherapy in the treatment of cervical cancer are discussed. Authors described a group of 45 patients with preliminary diagnosis of Io and IIo A sec FIGO tumour. Qualification system to combined treatment and diagnostic procedure are described. Authors discussed methods of LDR therapy. Tubes of 226Ra in Paris technique and afterloading 137Cs Selectron LDR/MDR (of Nucletron BV) were used. Postoperative histopathologic results are compared to preoperative diagnoses established on the basis of clinical examination, US and MRI. Preliminary assessment of tolerance and efficacy of these methods of treatment is made.