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2.
J Intellect Disabil Res ; 62(2): 140-149, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29349928

RESUMO

BACKGROUND: Problem behaviours (PBs) are a common cause for clinician contact in people with disorders of intellectual development and may be a common cause for the prescription of psychotropic medication. We aimed to use a large, multinational sample to define the prevalence of PBs, the associations with psychotropic medication use, and to assess for any potential 'diagnostic overshadowing' by the label of PBs in a population of people with disorders of intellectual development. METHOD: A multinational, multi-setting, cross-sectional service evaluation and baseline audit was completed. Data were collected from UK hospitals, UK community settings, Sri Lanka and Hong Kong. A semi-structured questionnaire was completed by treating clinicians, capturing demographic details, prevalence rates of intellectual disability and psychotropic medication use, alongside psychiatric co-morbidity. RESULTS: A sample size of 358 was obtained, with 65% of included participants treated in an inpatient setting. Psychotropic use was prevalent (90%) in our sample, particularly antipsychotics (74%). The prevalence of PB was high (83%). There was no statistically significant association between psychotropic prescription and recorded psychiatric co-morbidity, suggesting prevalent 'off-label' use for PBs, or poor recording of psychiatric co-morbidity. There was some evidence of possible diagnostic overshadowing due to the PB classification. A higher dose of psychotropic medication was associated with aggression toward others (P = 0.03). CONCLUSIONS: We found evidence of prevalent potential 'off-label' use for psychotropic medication, which may be due to PBs. We also found evidence of potential diagnostic-overshadowing, where symptoms of psychiatric co-morbidity may have been attributed to PBs. Our findings provide renewed importance, across borders and health systems, for clinicians to consider a holistic approach to treating PBs, and attempting to best understand the precipitants and predisposing factors before psychotropic prescribing.


Assuntos
Sintomas Comportamentais , Deficiência Intelectual , Uso Off-Label , Psicotrópicos/uso terapêutico , Adulto , Antipsicóticos/uso terapêutico , Sintomas Comportamentais/diagnóstico , Sintomas Comportamentais/tratamento farmacológico , Sintomas Comportamentais/epidemiologia , Sintomas Comportamentais/etiologia , Comorbidade , Estudos Transversais , Feminino , Hong Kong/epidemiologia , Humanos , Deficiência Intelectual/complicações , Deficiência Intelectual/tratamento farmacológico , Deficiência Intelectual/epidemiologia , Masculino , Pessoa de Meia-Idade , Uso Off-Label/estatística & dados numéricos , Prevalência , Comportamento Problema , Sri Lanka/epidemiologia , Reino Unido/epidemiologia
3.
Anxiety Stress Coping ; 37(2): 157-179, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38053399

RESUMO

BACKGROUND: Self-insights focused on the coping process are implicated in the refinement of capacities for resilience. To advance this research, we must identify key coping self-insights and develop a concise measurement tool. OBJECTIVE: The purpose of this paper is to develop evidence for the construct dimensionality and validity of a measure of coping self-insight. METHODS: Items measuring 13 coping self-insight dimensions were generated via consultation with theoretical work, subject matter experts, and pre-testing items for clarity. Thereafter, the dimensionality of items was assessed with undergraduate students (N = 232) and an online sample (N = 800) via exploratory and confirmatory analyses. Finally, a multi-trait, multi-method approach was used to test discriminant validity in a further sample of students (N = 228). RESULTS: The initial item list was reduced to five key dimensions that balanced data-driven and conceptual considerations. Confirmatory Factor Analysis revealed moderate-to-strong correlations (r = .47-.80) among dimensions. We also demonstrated evidence of internal reliability, convergent, criterion, and discriminant validity. Invariance tests for sub-groups of interest (e.g., sex, sample type) frequently demonstrated metric or scalar invariance, except for age sub-groups. CONCLUSIONS: Findings offer a starting point regarding the types of coping self-insights important for the emergence of resilience and a validated tool for future research.


Assuntos
Resiliência Psicológica , Adulto , Humanos , Psicometria , Reprodutibilidade dos Testes , Capacidades de Enfrentamento , Inquéritos e Questionários , Análise Fatorial
4.
J Environ Monit ; 14(9): 2399-410, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22814382

RESUMO

The definition of the spatial footprint of land-derived nutrient plumes is a key element to the design of initiatives to combat eutrophication in urbanised coastal regions. These plumes, however, are difficult to monitor because of their inherent high-frequency temporal and spatial variability. Biomonitoring with macroalgae provides time-integration of bioavailable nitrogen inputs through the measurement of δ¹5N signatures in tissues, and adequate spatial coverage through translocation to desirable monitoring locations. In this study, we used laboratory incubations to compare three different species of macroalgae as bioindicators, and a field experiment to investigate the applicability of the technique for the large-scale mapping of nutrient plumes. Cladophora valonioides was selected for the field experiment as it showed rapid changes in δ¹5N values in the laboratory incubations, was abundant in shallow depths making collection cost-efficient, and had tough thalli capable of withstanding deployment in open water. Ecklonia radiata also performed well in the laboratory incubations, but field harvest from subtidal depths was comparatively more expensive. Ulva lactuca had fragile thalli, and large nitrogen reserves that acted to mask the isotopic signal of newly acquired nitrogen. Cladophora valonioides was translocated to 246 sites covering an area of ∼445 km² along the highly urbanized temperate coast of Adelaide, South Australia. The resulting isotopic signatures of nitrogen in tissues were spatially interpolated to produce maps of land-derived nutrient plumes, to model probability and standard error in the predictive surface, and to optimize sampling design.


Assuntos
Monitoramento Ambiental/métodos , Modelos Químicos , Nitrogênio/análise , Alga Marinha/química , Água do Mar/química , Austrália do Sul
5.
J Intellect Disabil Res ; 54(7): 650-8, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20136682

RESUMO

AIM: To establish any differences between patients with and without a diagnosis of personality disorders, being treated in a secure inpatient service for offenders with intellectual disability (ID) in the UK. METHOD: A cohort study involving a selected population of people with ID and offending behaviours. Results The study included a total of 138 patients, treated over a 6 year period - 77 with a dissocial or emotionally unstable personality disorder and 61 without. Women were more likely to be in the personality disorder group. Both groups had high prevalence of abuse with no significant differences. Depressive disorders and substance abuse were more common in the personality disorder group, while epilepsy and autistic spectrum disorders were more common in the non-personality disorder group. Rather than differences, what was more striking was the rate and range of these comorbidities across both groups. Although past histories of violence and institutional aggression were no different, compulsory detention under criminal sections and restriction orders were more common in the personality disorder group. There were no differences in treatment outcomes. CONCLUSIONS: Although about half of patients detained in secure units for offenders with ID have a personality disorder, there were more similarities than differences between this group and the rest. While good treatment outcomes supported the case for specialised secure treatment units for people with ID, the case for establishing a more specialised ID-personality disorder unit was less convincing. There is also a need to explore whether there are alternative diagnostic models that can delineate better the group with personality difficulties in this population.


Assuntos
Criminosos/psicologia , Criminosos/estatística & dados numéricos , Deficiência Intelectual , Transtornos da Personalidade , Adulto , Agressão/psicologia , Estudos de Coortes , Crime/psicologia , Crime/estatística & dados numéricos , Diagnóstico Diferencial , Feminino , Psiquiatria Legal , Humanos , Pacientes Internados/estatística & dados numéricos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/epidemiologia , Deficiência Intelectual/terapia , Masculino , Transtornos da Personalidade/diagnóstico , Transtornos da Personalidade/epidemiologia , Transtornos da Personalidade/terapia , Prevalência , Resultado do Tratamento , Reino Unido/epidemiologia
6.
Br J Cancer ; 98(8): 1467-74, 2008 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-18414473

RESUMO

Telomere length is maintained by two known mechanisms, activation of telomerase or alternative lengthening of telomeres (ALT). The ALT pathway is more commonly activated in tumours of mesenchymal origin, although the mechanisms involved in the decision of a cell to activate either telomerase or ALT are unknown at present and no molecular markers exist to define the ALT phenotype. We have previously shown an association between chromatin remodelling, telomerase gene expression and ALT in cell line models. Here, we evaluate these findings and investigate their prognostic significance in a panel of liposarcoma tissue samples to understand the biology underlying the ALT phenotype. Liposarcoma samples were split into three groups: telomerase positive (Tel+); ALT positive; ALT-/Tel-. Differences in telomerase gene expression were evident between the groups with increased expression of hTR in ALT and Tel+ compared to ALT-/Tel- samples and increased hTERT in Tel+ samples only. Investigation of a small panel of chromatin modifications revealed significantly increased binding of acetyl H3 in association with hTR expression. We confirm that the presence of the ALT phenotype is associated with poor prognosis and in addition, for the first time, we show a direct association between hTR expression and poor prognosis in liposarcoma patients.


Assuntos
Cromatina/metabolismo , Lipossarcoma/genética , RNA/genética , Telomerase/genética , Telômero , Adulto , Idoso , Idoso de 80 Anos ou mais , Imunoprecipitação da Cromatina , Feminino , Histonas/metabolismo , Humanos , Lipossarcoma/mortalidade , Lipossarcoma/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Regiões Promotoras Genéticas
7.
Ann Oncol ; 19(7): 1340-1346, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18325912

RESUMO

BACKGROUND: Tumour necrosis factor-alpha (TNF-alpha) is an important regulator of the chronic inflammation contributing to tumour progression. Infliximab, an anti-TNF-alpha monoclonal antibody was investigated in this trial of patients with advanced cancer. The primary objectives were to determine the safety profile and biological response of infliximab in a cancer population. Clinical response was a secondary objective. PATIENTS AND METHODS: Forty-one patients received infliximab at 5 mg/kg (n = 21) or 10 mg/kg (n = 20) i.v. at 0 and 2 weeks and then every 4 weeks. Post-treatment samples were measured for changes in plasma and serum TNF-alpha, CCL2, IL-6 and C-reactive protein (CRP). RESULTS: Infliximab was well tolerated with no dose-limiting toxic effects. At both doses of infliximab, neutralisation of serum TNF-alpha was observed after 1 h while plasma CCL2, IL-6 and serum CRP were decreased 24 and 48 h following infliximab administration. Seven patients experienced disease stablisation (range 10-50+ weeks). There was no evidence of disease acceleration in any patient. CONCLUSIONS: Infliximab treatment was safe and well tolerated in patients with advanced cancer. There was evidence of biological activity with baseline TNF-alpha and CCL2 being correlated with infliximab response.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Hipersensibilidade a Drogas , Hipersensibilidade Tardia , Neoplasias/tratamento farmacológico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adulto , Idoso , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Proteína C-Reativa/análise , Quimiocina CCL2/sangue , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Humanos , Hipersensibilidade Tardia/induzido quimicamente , Infliximab , Infusões Intravenosas , Interleucina-6/sangue , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/patologia , Sensibilidade e Especificidade , Estomatite/induzido quimicamente , Resultado do Tratamento , Fator de Necrose Tumoral alfa/sangue
8.
Oncogene ; 25(1): 61-9, 2006 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-16170363

RESUMO

Basal telomerase activity is dependent on expression of the hTERT and hTR genes and upregulation of telomerase gene expression is associated with tumour development. It is therefore possible that signal transduction pathways involved in tumour development and features of the tumour environment itself may influence telomerase gene regulation. The majority of solid tumours contain regions of hypoxia and it has recently been demonstrated that hypoxia can increase telomerase activity by mechanisms that are still poorly defined. Here, we show that hypoxia induces the transcriptional activity of both hTR and hTERT gene promoters. While endogenous hTR expression is regulated at the transcriptional level, hTERT is subject to regulation by alternative splicing under hypoxic conditions, which involves a switch in the splice pattern in favour of the active variant. Furthermore, analysis of the chromatin landscape of the telomerase promoters reveals dynamic recruitment of a transcriptional complex involving the hypoxia-inducible factor-1 transcription factor, p300, RNA polymerase II and TFIIB, to both promoters during hypoxia, which traffics along and remains associated with the hTERT gene as transcription proceeds. These studies show that hTERT and hTR are subject to similar controls under hypoxia and highlight the rapid and dynamic regulation of the telomerase genes in vivo.


Assuntos
Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica , Regulação da Expressão Gênica , Processamento Pós-Transcricional do RNA , RNA/biossíntese , RNA/genética , Telomerase/biossíntese , Telomerase/genética , Transcrição Gênica , Processamento Alternativo , Western Blotting , Linhagem Celular Tumoral , Cromatina/metabolismo , Imunoprecipitação da Cromatina , DNA Complementar/metabolismo , Éxons , Variação Genética , Humanos , Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Luciferases/metabolismo , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , RNA Polimerase II/metabolismo , Transdução de Sinais , Telômero/metabolismo , Fatores de Tempo , Fator de Transcrição TFIIB/metabolismo , Transfecção , Fator A de Crescimento do Endotélio Vascular , Fatores de Transcrição de p300-CBP/metabolismo
9.
Mol Cell Biol ; 19(12): 8383-92, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10567563

RESUMO

The androgen receptor is unusual among nuclear receptors in that most, if not all, of its activity is mediated via the constitutive activation function in the N terminus. Here we demonstrate that p160 coactivators such as SRC1 (steroid receptor coactivator 1) interact directly with the N terminus in a ligand-independent manner via a conserved glutamine-rich region between residues 1053 and 1123. Although SRC1 is capable of interacting with the ligand-binding domain by means of LXXLL motifs, this interaction is not essential since an SRC1 mutant with no functional LXXLL motifs retains its ability to potentiate androgen receptor activity. In contrast, mutants lacking the glutamine-rich region are inactive, indicating that this region is both necessary and sufficient for recruitment of SRC1 to the androgen receptor. This recruitment is in direct contrast to the recruitment of SRC1 to the estrogen receptor, which requires interaction with the ligand-binding domain.


Assuntos
Proteínas Oncogênicas , Receptores Androgênicos/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células COS , Glutamina/metabolismo , Células HeLa , Histona Acetiltransferases , Humanos , Leucina/metabolismo , Ligantes , Dados de Sequência Molecular , Proteínas Nucleares/metabolismo , Coativador 1 de Receptor Nuclear , Coativador 2 de Receptor Nuclear , Coativadores de Receptor Nuclear , Proteína 1 de Interação com Receptor Nuclear , Estrutura Terciária de Proteína , Receptores Androgênicos/genética , Transativadores/genética , Fatores de Transcrição/genética
10.
Mol Cell Biol ; 19(5): 3895-903, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10207113

RESUMO

Transcriptional activation by the estrogen receptor is mediated through its interaction with coactivator proteins upon ligand binding. By systematic mutagenesis, we have identified a group of conserved hydrophobic residues in the ligand binding domain that are required for binding the p160 family of coactivators. Together with helix 12 and lysine 366 at the C-terminal end of helix 3, they form a hydrophobic groove that accommodates an LXXLL motif, which is essential for mediating coactivator binding to the receptor. Furthermore, we demonstrated that the high-affinity binding of motif 2, conserved in the p160 family, is due to the presence of three basic residues N terminal to the core LXXLL motif. The recruitment of p160 coactivators to the estrogen receptor is therefore likely to depend not only on the LXXLL motif making hydrophobic interactions with the docking surface on the receptor, but also on adjacent basic residues, which may be involved in the recognition of charged residues on the receptor to allow the initial docking of the motif.


Assuntos
Ligantes , Receptores de Estrogênio/química , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Ligação Competitiva , Células COS , Proteínas de Ligação a DNA/análise , Estradiol/metabolismo , Histona Acetiltransferases , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese/genética , Mutação/genética , Coativador 1 de Receptor Nuclear , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Ligação Proteica , Estrutura Secundária de Proteína , Receptores de Estrogênio/genética , Alinhamento de Sequência , Transfecção
11.
Leukemia ; 19(3): 381-9, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15674365

RESUMO

Telomere loss is rapid during the progression of chronic myeloid leukaemia (CML) and correlates with prognosis. We therefore sought to measure expression of the major telomerase components (hTR and hTERT) in CD34+ cells from CML patients and normal controls, to determine if their altered expression may contribute to telomere attrition in vivo. High-purity (median 94.1%) BCR-ABL+ CD34+ cells from CML (n=16) and non-CML (n=14) patients were used. CML samples had a small increase in telomerase activity (TA) compared to normal samples (approximately 1.5-fold, P=0.004), which was inversely correlated with the percentage of G0 cells (P=0.02) suggesting TA may not be elevated on a cell-to-cell basis in CML. Consistent with this, hTERT mRNA expression was not significantly elevated; however, altered mRNA splicing appeared to play a significant role in determining overall full length, functional hTERT levels. Interestingly, Q-RT-PCR for hTR demonstrated a mean five-fold reduction in levels in the chronic phase (CP) CML samples (P=0.002), raising the possibility that telomere homeostasis is disrupted in CML. In summary, the molecular events regulating telomerase gene expression and telomere maintenance during the CP of CML may influence the disease progression observed in these patients.


Assuntos
Proteínas de Fusão bcr-abl/genética , Regulação Enzimológica da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , Células-Tronco Neoplásicas/enzimologia , Telomerase/genética , Processamento Alternativo/genética , Antígenos CD34/análise , Antígenos CD34/biossíntese , Ciclo Celular , Linhagem Celular Tumoral , Proteínas de Fusão bcr-abl/sangue , Humanos , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Células-Tronco Neoplásicas/citologia , RNA Mensageiro/genética , Telomerase/metabolismo
12.
J Natl Cancer Inst ; 87(22): 1694-704, 1995 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-7473818

RESUMO

BACKGROUND: The molecular genetic analysis of invasive breast cancer has identified breast cancer as a genetically complex disease. Ductal carcinoma in situ (DCIS) is thought to represent a preinvasive step in breast cancer progression, yet we know little about its biologic behavior or the genetic alterations present. Because of the increasing diagnosis of DCIS by mammography screening and the debate over how DCIS should be managed, there is a clear need to define the molecular events underlying the development of DCIS. PURPOSE: Our purpose was to identify patterns of genetic alterations in DCIS. METHODS: A group of 30 formalin-fixed, paraffin-embedded blocks of tissue collected from 1987 through 1989 from 21 patients with DCIS was studied. Chromosomal imbalances were determined by interphase cytogenetic analysis using the fluorescence in situ hybridization (FISH) technique. DNA probes were used that recognize chromosome-specific repetitive sequence loci at the centromeres of chromosomes 1, 3, 4, 6, 7, 8, 9, 10, 11, 16, 17, and 18. FISH was also used to detect ERBB2 gene amplification in DCIS. To complement the FISH studies, microsatellite analysis of markers near the BRCA1 region of chromosome 17 was done on tissue microdissected from multiple areas of DCIS. Chromosomal imbalances were determined by comparisons of chromosomal indices (total number of hybridization spots per total number of nuclei counted) of normal and DCIS tissue, using the two-sided Mann-Whitney test. RESULTS: Using FISH, we have identified patterns of DNA loss and gain of certain chromosome-specific centromeric markers in DCIS. We observed frequent gains of markers on chromosomes 3, 10, and 17 as well as loss of chromosome 18-specific centromeric sequences. ERBB2 gene amplification was detected in tumors from four of 15 patients studied and was clearly limited to the tumor cells within the ducts. Because of the availability of topologically distinct regions of tumors from individuals, we were able to show that paired tumor specimens from individuals share genetic alterations and also have unique ones, suggesting clonal diversity within tumors. The combination of FISH and microsatellite analyses suggested that alterations in chromosome 17 may be quite complex; three of five patients whose samples were analyzed had allelic imbalance at markers on the long arm of chromosome 17. CONCLUSIONS: FISH and microsatellite analyses are useful in detecting extensive genetic alterations in DCIS. Examinations of DCIS tissue using these techniques have identified chromosomes 1, 3, 10, 16, 17, and 18 as candidate sites worthy of immediate study. IMPLICATIONS: This approach may give direction to future research aimed at precisely mapping loci altered in DCIS and help in understanding the biologic events associated with tumor progression or recurrence.


Assuntos
Neoplasias da Mama/genética , Carcinoma in Situ/genética , Carcinoma Ductal de Mama/genética , DNA de Neoplasias/genética , Interfase/genética , Neoplasias da Mama/patologia , Carcinoma in Situ/patologia , Carcinoma Ductal de Mama/patologia , Sondas de DNA , Progressão da Doença , Feminino , Humanos , Hibridização in Situ Fluorescente , Sequências Repetitivas de Ácido Nucleico/genética
13.
Cancer Res ; 61(1): 27-32, 2001 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11196173

RESUMO

The immortal phenotype of most human cancers is attributable to telomerase expression. However, a number of immortal cell lines and tumors achieve telomere maintenance in the absence of telomerase via alternative mechanisms known as ALT (alternative lengthening of telomeres). Here we show that the promoter of the telomerase RNA gene (hTERC) is methylated in three of five ALT cell lines and is associated with a total absence of hTERC expression in the three lines. Treatment with 5-azacytidine in combination with trichostatin A resulted in partial demethylation of the hTERC promoter and expression of the gene. Partial methylation was detected in tumors (5%) and in immortal cell lines (27%). Cell lines with partial methylation express hTERC. Only in ALT cell lines does there appear to be a strong correlation between hTERC promoter hypermethylation and lack of hTERC expression.


Assuntos
Metilação de DNA , Regulação Neoplásica da Expressão Gênica/genética , Regiões Promotoras Genéticas/genética , RNA Neoplásico/genética , Telomerase/genética , Telômero/genética , Biópsia , Northern Blotting , Regulação Enzimológica da Expressão Gênica/genética , Humanos , Neoplasias/enzimologia , Neoplasias/genética , RNA Neoplásico/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Telomerase/biossíntese , Células Tumorais Cultivadas
14.
Oncogene ; 14(9): 1013-21, 1997 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-9070649

RESUMO

Telomere length is maintained by the enzyme, telomerase, which has been linked to cellular immortality and tumour progression. However, the reasons for the high levels of telomerase found in human tumours are unknown. We have mapped the human telomerase RNA gene, (hTR), to chromosome 3q26.3 and show the hTR gene to be amplified in four carcinomas, (2/33 cervix, 1/31 head and neck, 1/9 lung). In addition, increased copy numbers of the hTR locus was also observed in 97% of tumours. By in situ hybridisation, the histological distribution of high levels of hTR expression could be demonstrated in a lung tumour and its metastasis with hTR amplification. These results are the first report of genetic alterations involving a known component of telomerase in human cancer. Indeed, it is also the first report of the amplification of a specific locus within the chromosome 3q region frequently subject to copy number gains in human tumours. In addition, we also show for the first time the histological distribution of the RNA component of telomerase in human tumours.


Assuntos
Carcinoma/genética , Cromossomos Humanos Par 3 , Telomerase/genética , Mapeamento Cromossômico , Feminino , Amplificação de Genes , Neoplasias de Cabeça e Pescoço/genética , Humanos , Hibridização In Situ , Neoplasias Pulmonares/genética , RNA Neoplásico/análise , Telomerase/análise , Distribuição Tecidual , Neoplasias do Colo do Útero/genética
15.
Oncogene ; 16(10): 1345-50, 1998 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-9546436

RESUMO

Variation in telomerase activity is correlated with cellular senescence and tumour progression. However, although the enzymatic activity of telomerase has been well studied, very little is known about how expression of telomerase genes is regulated in mammalian cells. We have therefore cloned the promoter regions of the human (hTR), and mouse, (terc), telomerase RNA genes in order to identify the regulatory elements controlling telomerase RNA gene transcription. 1.76 kb encompassing the hTR gene promoter region was sequenced, as was 4 kb encompassing the terc promoter. No significant sequence similarity could be detected in comparisons between human and mouse 5'-regions, flanking the transcribed sequences. However, both the human and mouse telomerase RNA genes are within CpG islands and may therefore be under the regulation of DNA methylation. Transient expression of hTR-reporter gene constructs in HeLa and GM847 cells identified the elements responsible for promoter activity are contained in a 231 bp region upstream of the transcriptional start site. Transient expression of terc-reporter gene constructs in Swiss3T3 and A9 cells identified the elements responsible for promoter activity are contained in a 73 bp region upstream of the transcriptional start site. These studies have implications for novel transcription targeted cancer therapies.


Assuntos
Regiões Promotoras Genéticas , RNA não Traduzido , RNA/biossíntese , RNA/genética , Telomerase/biossíntese , Telomerase/genética , Animais , Sequência de Bases , Linhagem Celular , Células Cultivadas , Clonagem Molecular/métodos , Genes Reporter , Células HeLa , Humanos , Luciferases/biossíntese , Masculino , Mamíferos , Camundongos , Dados de Sequência Molecular , RNA Longo não Codificante , Proteínas Recombinantes de Fusão/biossíntese , Sequências Reguladoras de Ácido Nucleico , Mapeamento por Restrição , Transcrição Gênica , Transfecção
16.
Mol Endocrinol ; 6(12): 2229-35, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1491700

RESUMO

We have used a DNA-binding site selection assay to determine a consensus binding sequence for the androgen receptor (AR). A purified fusion protein containing the AR DNA-binding domain was incubated with a pool of random sequence oligonucleotides, and complexes were isolated by gel mobility shift assays. Individually selected sites were characterised by nucleotide sequencing and compiled to give a consensus AR-binding element. This sequence is comprised of two 6-basepair (bp) asymmetrical elements separated by a 3-bp spacer, 5'-GGA/TACANNNTGTTCT-3', similar to that described for the glucocorticoid response element. Inspection of the consensus revealed a slight preference for G or A nucleotides at the +1 position in the spacer and for A and T nucleotides in the 3'-flanking region. Therefore, a series of oligonucleotides was designed in which the spacer and flanking nucleotides were changed to the least preferred sequence. Competition experiments with these oligonucleotides and the AR fusion protein indicated that an oligonucleotide with both the spacer and flanking sequences changed had greater than 3-fold less affinity than the consensus sequence. The functional activity of these oligonucleotides was also assessed by placing them up-stream of a reporter gene in a transient transfection assay and correlated with the affinity with which the AR fusion protein bound to DNA. Therefore, sequences surrounding the two 6-bp half-sites influence both the binding affinity for the receptor and the functional activity of the response element.


Assuntos
DNA/metabolismo , Receptores Androgênicos/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , Neoplasias da Mama , Sequência Consenso , Humanos , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , Reação em Cadeia da Polimerase , Ligação Proteica , Ratos , Proteínas Recombinantes de Fusão/metabolismo , Células Tumorais Cultivadas
17.
Mol Endocrinol ; 7(2): 232-40, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8469236

RESUMO

We have generated mutant mouse estrogen receptors which differ in their sensitivity to estrogen and the antiestrogen 4-hydroxytamoxifen. Mutation of the glycine at position 525 and the methionine and/or serine at positions 521/522 virtually abolishes the ability of the receptor to bind estradiol and stimulate transcription. In contrast, the mutant receptors retain the partial agonist activity exhibited by the wild-type receptor in the presence of 4-hydroxytamoxifen. The mutations do not affect the expression and DNA-binding activity of the receptor, but do abolish the estrogen-induced increase in the mobility of the receptor-DNA complex observed with the wild-type receptor. Other mutant receptors that were able to bind and stimulate transcription in the presence of estradiol also failed to show the agonist-induced increase in the mobility of the receptor-DNA complex, suggesting that it is unlikely to reflect the formation of a hormone-dependent transcriptional activation function.


Assuntos
Estradiol/farmacologia , Receptores de Droga , Receptores de Estrogênio/efeitos dos fármacos , Tamoxifeno/análogos & derivados , Células 3T3/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Chlorocebus aethiops , DNA/metabolismo , Camundongos , Receptores de Estrogênio/química , Receptores de Estrogênio/genética , Tamoxifeno/farmacologia , Transcrição Gênica
18.
Neoplasia ; 2(3): 197-201, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10935505

RESUMO

Telomerase, the enzyme that maintains the ends of chromosomes, is absent from the majority of somatic cells but is present and active in most tumours. The gene for the reverse transcriptase component of telomerase (hTERT) has recently been identified. A cDNA clone of this gene was used as a probe to identify three genomic bacterial artificial chromosome (BAC) clones, one of which was used as a probe to map hTERT by fluorescence in situ hybridization (FISH) to chromosome 5p15.33. This BAC probe was further used to look at copy number of the hTERT region in immortal cell lines. We found that 10/15 immortal cell lines had a modal copy number of 3 or more per cell, with one cell line (CaSki) having a modal copy number of 11. This suggests that increases in copy number of the hTERT gene region do occur, and may well be one route to upregulating telomerase levels in tumour cells. 5p15 gains and amplifications have been documented for various tumour types, including non-small cell lung carcinoma, squamous cell carcinoma of head and neck, and uterine cervix cancer, making hTERT a potential target.


Assuntos
Mapeamento Cromossômico , Cromossomos Humanos Par 5 , Hibridização in Situ Fluorescente , RNA , Telomerase/genética , Proteínas de Ligação a DNA , Dosagem de Genes , Humanos , Células Tumorais Cultivadas
19.
Neoplasia ; 2(6): 531-9, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11228546

RESUMO

Expression of the human telomerase RNA component gene, hTERC is essential for telomerase activity. The hTERC gene is expressed during embryogenesis and then downregulated during normal development, leaving most adult somatic cells devoid of hTERC expression. During oncogenesis, however, hTERC is re-expressed consequently contributing to the unrestricted proliferative capacity of many human cancers. Thus the identification of the molecular basis for the regulation of the telomerase RNA component gene in normal cells and its deregulation in cancer cells is of immediate interest. We have previously cloned the hTERC promoter and in this study have identified several transcription factors that modulate the expression of hTERC. We demonstrate that NF-Y binding to the CCAAT region of the hTERC promoter is essential for promoter activity. Sp1 and the retinoblastoma protein (pRb) are activators of the hTERC promoter and Sp3 is a potent repressor. These factors appear to act in a species-specific manner. Whereas Sp1 and Sp3 act on the human, bovine, and mouse TERC promoters, pRb activates only the human and bovine promoter, and NF-Y is only essential for the human TERC gene.


Assuntos
Fator de Ligação a CCAAT/metabolismo , Proteínas de Ligação a DNA/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , RNA/genética , Proteína do Retinoblastoma/farmacologia , Fator de Transcrição Sp1/farmacologia , Telomerase/genética , Fatores de Transcrição/farmacologia , Animais , Sequência de Bases , Sítios de Ligação , Bovinos , Primers do DNA/química , Ensaio de Desvio de Mobilidade Eletroforética , Células HeLa/efeitos dos fármacos , Células HeLa/enzimologia , Humanos , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Reação em Cadeia da Polimerase , RNA/metabolismo , RNA Mensageiro/metabolismo , Deleção de Sequência , Fator de Transcrição Sp3 , Telomerase/metabolismo , Transcrição Gênica , Transfecção
20.
Endocrinology ; 141(9): 3080-6, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10965877

RESUMO

Homologs of mammalian PTH1 and PTH2 receptors, and a novel PTH3 receptor have been identified in zebrafish (zPTH1, zPTH2, and zPTH3). zPTH1 receptor ligand specificity is similar to that of mammalian PTH1 receptors. The zPTH2 receptor is selective for PTH over PTH-related protein (PTHrP); however, PTH produces only modest cAMP accumulation. A PTH2 receptor-selective peptide, tuberoinfundibular peptide of 39 residues (TIP39), has recently been purified from bovine hypothalamus. The effect of TIP39 has not previously been examined on zebrafish receptors. The zPTH3 receptor was initially described as PTHrP selective based on comparison with the effects of human PTH. We have now examined the ligand specificity of the zebrafish PTH-recognizing receptors expressed in COS-7 cells using a wide range of ligands. TIP39 is a potent agonist for stimulation of cAMP accumulation at two putative splice variants of the zPTH2 receptor (EC50, 2.6 and 5.2 nM); in comparison, PTH is a partial agonist [maximal effect (Emax) of PTH peptides ranges from 28-49% of the TIP39 Emax]. As TIP39 is much more efficacious than any known PTH-like peptide, a homolog of TIP39 may be the zPTH2 receptor's endogenous ligand. At the zPTH3 receptor, rat PTH-(1-34) and rat PTH-(1-84) (EC50, 0.22 and 0.45 nM) are more potent than PTHrP (EC50, 1.5 nM), and rPTH-(1-34) binds with high affinity (3.2 nM). PTH has not been isolated from fish. PTHrP-like peptides, which have been identified in fish, may be the natural ligands for zPTH1 and zPTH3 receptors.


Assuntos
Neuropeptídeos/farmacologia , Proteína Relacionada ao Hormônio Paratireóideo , Hormônio Paratireóideo/farmacologia , Fragmentos de Peptídeos/farmacologia , Proteínas/farmacologia , Receptores de Hormônios Paratireóideos/efeitos dos fármacos , Peixe-Zebra/metabolismo , Animais , Células COS , Células Cultivadas , AMP Cíclico/metabolismo , Humanos , Indicadores e Reagentes , Ligantes , Camundongos , Ensaio Radioligante , Teriparatida/farmacologia
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