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1.
Mol Cancer ; 21(1): 82, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35317841

RESUMO

BACKGROUND: miR-346 was identified as an activator of Androgen Receptor (AR) signalling that associates with DNA damage response (DDR)-linked transcripts in prostate cancer (PC). We sought to delineate the impact of miR-346 on DNA damage, and its potential as a therapeutic agent. METHODS: RNA-IP, RNA-seq, RNA-ISH, DNA fibre assays, in vivo xenograft studies and bioinformatics approaches were used alongside a novel method for amplification-free, single nucleotide-resolution genome-wide mapping of DNA breaks (INDUCE-seq). RESULTS: miR-346 induces rapid and extensive DNA damage in PC cells - the first report of microRNA-induced DNA damage. Mechanistically, this is achieved through transcriptional hyperactivation, R-loop formation and replication stress, leading to checkpoint activation and cell cycle arrest. miR-346 also interacts with genome-protective lncRNA NORAD to disrupt its interaction with PUM2, leading to PUM2 stabilisation and its increased turnover of DNA damage response (DDR) transcripts. Confirming clinical relevance, NORAD expression and activity strongly correlate with poor PC clinical outcomes and increased DDR in biopsy RNA-seq studies. In contrast, miR-346 is associated with improved PC survival. INDUCE-seq reveals that miR-346-induced DSBs occur preferentially at binding sites of the most highly-transcriptionally active transcription factors in PC cells, including c-Myc, FOXA1, HOXB13, NKX3.1, and importantly, AR, resulting in target transcript downregulation. Further, RNA-seq reveals widespread miR-346 and shNORAD dysregulation of DNA damage, replication and cell cycle processes. NORAD drives target-directed miR decay (TDMD) of miR-346 as a novel genome protection mechanism: NORAD silencing increases mature miR-346 levels by several thousand-fold, and WT but not TDMD-mutant NORAD rescues miR-346-induced DNA damage. Importantly, miR-346 sensitises PC cells to DNA-damaging drugs including PARP inhibitor and chemotherapy, and induces tumour regression as a monotherapy in vivo, indicating that targeting miR-346:NORAD balance is a valid therapeutic strategy. CONCLUSIONS: A balancing act between miR-346 and NORAD regulates DNA damage and repair in PC. miR-346 may be particularly effective as a therapeutic in the context of decreased NORAD observed in advanced PC, and in transcriptionally-hyperactive cancer cells.


Assuntos
MicroRNAs , Neoplasias da Próstata , RNA Longo não Codificante , Ciclo Celular , Dano ao DNA , Humanos , Masculino , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias da Próstata/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/genética
2.
Int J Obes (Lond) ; 44(9): 1958-1969, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32678325

RESUMO

Diet has important effects on normal physiology and the potential deleterious effects of high fat diets and obesity on male reproductive health are being increasingly described. We conducted a histological review of the effects of chronic high fat (HF) diet (using a mouse model fed a 45% fat diet for 21 weeks) with a discovery proteomic study to assess for changes in the abundance of proteins in the testis. Mice on a HF diet became obese and developed glucose intolerance. Using mass spectrometry, we identify 102 proteins affected in the testis of obese mice. These included structural proteins important for the blood testis barrier (filamin A, FLNA), proteins involved in oxidative stress responses (spermatogenesis associated 20, SPATA-20) and lipid homoeostasis (sterol regulatory element-binding protein 2, SREBP2 and apolipoprotein A1, APOA1). In addition, an important regulator protein paraspeckle component 1, PSPC-1, which interacts with the androgen receptor was significantly downregulated. Proteomic data was validated using both Western blotting and immunostaining which confirmed and localised protein expression in both mouse and human testis using biopsy specimens. This study focused mainly on the abnormalities that occurred at the protein level and as a result, we have identified several candidate proteins and conducted pathway analysis around the effects of HF diet on the testis providing novel insights not previously described. Some of the identified targets could be targeted therapeutically and future work is directed in this area.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Gorduras na Dieta/farmacologia , Obesidade/metabolismo , Proteoma/efeitos dos fármacos , Testículo , Animais , Humanos , Masculino , Camundongos , Testículo/efeitos dos fármacos , Testículo/patologia
3.
BJOG ; 127(7): 868-874, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31976622

RESUMO

OBJECTIVE: To explore the healthcare experiences of parents whose baby died either before, during or shortly after birth between 20+0 and 23+6  weeks of gestation in order to identify practical ways to improve healthcare provision. DESIGN: Qualitative interview study. SETTING: England through two parent support organisations and four NHS Trusts. SAMPLE: A purposive sample of parents. METHODS: Thematic analysis of semi-structured in-depth narrative interviews. MAIN OUTCOME MEASURES: Parents' healthcare experiences. RESULTS: The key overarching theme to emerge from interviews with 38 parents was the importance of the terminology used to refer to the death of their baby. Parents who were told they were 'losing a baby' rather than 'having a miscarriage' were more prepared for the realities of labour, the birth experience and for making decisions around seeing and holding their baby. Appropriate terminology validated their loss, and impacted on parents' health and wellbeing immediately following bereavement and in the longer term. CONCLUSION: For parents experiencing the death of their baby at the margins between miscarriage, stillbirth and neonatal death, ensuring the use of appropriate terminology that reflects parents' preferences is vital. This helps to validate their loss and prepare them for the experiences of labour and birth. Reflecting parents' language preferences combined with compassionate bereavement care is likely to have a positive impact on parents' experiences and improve longer-term outcomes. TWEETABLE ABSTRACT: Describing baby loss shortly before 24 weeks of gestation as a 'miscarriage' does not prepare parents for labour and birth, seeing their baby and making memories.


Assuntos
Aborto Espontâneo/psicologia , Luto , Pesar , Pais/psicologia , Sistemas de Apoio Psicossocial , Natimorto/psicologia , Adaptação Psicológica , Adulto , Feminino , Idade Gestacional , Necessidades e Demandas de Serviços de Saúde , Humanos , Lactente , Morte do Lactente , Masculino , Gravidez , Pesquisa Qualitativa , Terminologia como Assunto , Reino Unido
4.
BJOG ; 127(13): 1665-1675, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32437088

RESUMO

OBJECTIVE: To review quality of care in births planned in midwifery-led settings, resulting in an intrapartum-related perinatal death. DESIGN: Confidential enquiry. SETTING: England, Scotland and Wales. SAMPLE: Intrapartum stillbirths and intrapartum-related neonatal deaths in births planned in alongside midwifery units, freestanding midwifery units or at home, sampled from national perinatal surveillance data for 2015/16 (alongside midwifery units) and 2013-16 (freestanding midwifery units and home births). METHODS: Multidisciplinary panels reviewed medical notes for each death, assessing and grading quality of care by consensus, with reference to national standards and guidance. Data were analysed using thematic analysis and descriptive statistics. RESULTS: Sixty-four deaths were reviewed, 30 stillbirths and 34 neonatal deaths. At the start of labour care, 23 women were planning birth in an alongside midwifery unit, 26 in a freestanding midwifery unit and 15 at home. In 75% of deaths, improvements in care were identified that may have made a difference to the outcome for the baby. Improvements in care were identified that may have made a difference to the mother's physical and psychological health and wellbeing in 75% of deaths. Issues with care were identified around risk assessment and decisions about planning place of birth, intermittent auscultation, transfer during labour, resuscitation and neonatal transfer, follow up and local review. CONCLUSIONS: These confidential enquiry findings do not address the overall safety of midwifery-led settings for healthy women with straightforward pregnancies, but suggest areas where the safety of care can be improved. Maternity services should review their care with respect to our recommendations. TWEETABLE ABSTRACT: Confidential enquiry of intrapartum-related baby deaths highlights areas where care in midwifery-led settings can be made even safer.


Assuntos
Parto Domiciliar/normas , Tocologia/normas , Morte Perinatal , Qualidade da Assistência à Saúde , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Recém-Nascido , Gravidez , Reino Unido
5.
BJOG ; 126(6): 745-753, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30576088

RESUMO

OBJECTIVE: To investigate whether less invasive methods of autopsy would be acceptable to bereaved parents and likely to increase uptake. DESIGN: Mixed methods study. SETTING: Bereaved parents recruited prospectively across seven hospitals in England and retrospectively through four parent support organisations. SAMPLE: Eight hundred and fifty-nine surveys and 20 interviews with bereaved parents. METHODS: Cross-sectional survey and qualitative semi-structured telephone interviews. MAIN OUTCOME MEASURES: Likely uptake, preferences, factors impacting decision-making, views on different autopsy methods. RESULTS: Overall, 90.5% of participants indicated that they would consent to some form of less invasive autopsy [either minimally invasive autopsy (MIA), non-invasive autopsy (NIA) or both]; 53.8% would consent to standard autopsy, 74.3% to MIA and 77.3% to NIA. Regarding parental preferences, 45.5% preferred MIA, 30.8% preferred NIA and 14.3% preferred standard autopsy. Participants who indicated they would decline standard autopsy but would consent to a less invasive option were significantly more likely to have a lower educational level (odds ratio 0.49; 95% CI 0.35-0.70; P = 0.000062). Qualitative findings suggest that parents value NIA because of the lack of any incision and MIA is considered a good compromise as it enables tissue sampling while easing the parental burden associated with consenting to standard autopsy. CONCLUSION: Less invasive methods of autopsy are acceptable alternatives for bereaved parents, and if offered, are likely to increase uptake and improve parental experience. Further health economic, validation and implementation studies are now required to assess the viability of offering these in routine widespread clinical care. TWEETABLE ABSTRACT: Mixed methods UK study finds less invasive methods of autopsy are acceptable alternatives for bereaved parents, and if offered, are likely to increase uptake and improve parental experience.


Assuntos
Feto Abortado/patologia , Autopsia/métodos , Anormalidades Congênitas , Morte Fetal/etiologia , Pais/psicologia , Morte Perinatal/etiologia , Natimorto , Luto , Anormalidades Congênitas/diagnóstico , Anormalidades Congênitas/patologia , Aconselhamento/métodos , Estudos Transversais , Tomada de Decisões , Inglaterra , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Gravidez , Complicações na Gravidez/psicologia , Pesquisa Qualitativa , Natimorto/psicologia
6.
Br J Cancer ; 111(7): 1338-49, 2014 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-25072260

RESUMO

BACKGROUND: Surgery is considered to be the first line treatment for solid tumours. Recently, retrospective studies reported that general anaesthesia was associated with worse long-term cancer-free survival when compared with regional anaesthesia. This has important clinical implications; however, the mechanisms underlying those observations remain unclear. We aim to investigate the effect of anaesthetics isoflurane and propofol on prostate cancer malignancy. METHODS: Prostate cancer (PC3) cell line was exposed to commonly used anaesthetic isoflurane and propofol. Malignant potential was assessed through evaluation of expression level of hypoxia-inducible factor-1α (HIF-1α) and its downstream effectors, cell proliferation and migration as well as development of chemoresistance. RESULTS: We demonstrated that isoflurane, at a clinically relevant concentration induced upregulation of HIF-1α and its downstream effectors in PC3 cell line. Consequently, cancer cell characteristics associated with malignancy were enhanced, with an increase of proliferation and migration, as well as development of chemoresistance. Inhibition of HIF-1α neosynthesis through upper pathway blocking by a PI-3K-Akt inhibitor or HIF-1α siRNA abolished isoflurane-induced effects. In contrast, the intravenous anaesthetic propofol inhibited HIF-1α activation induced by hypoxia or CoCl2. Propofol also prevented isoflurane-induced HIF-1α activation, and partially reduced cancer cell malignant activities. CONCLUSIONS: Our findings suggest that modulation of HIF-1α activity by anaesthetics may affect cancer recurrence following surgery. If our data were to be extrapolated to the clinical setting, isoflurane but not propofol should be avoided for use in cancer surgery. Further work involving in vivo models and clinical trials is urgently needed to determine the optimal anaesthetic regimen for cancer patients.


Assuntos
Anestésicos Inalatórios/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Isoflurano/farmacologia , Propofol/farmacologia , Neoplasias da Próstata/patologia , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Docetaxel , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Masculino , Invasividade Neoplásica , Fosforilação , Neoplasias da Próstata/cirurgia , Processamento de Proteína Pós-Traducional , Transporte Proteico/efeitos dos fármacos , Taxoides/farmacologia , Regulação para Cima/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
7.
BJOG ; 121 Suppl 4: 41-6, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25236632

RESUMO

Established in 1952, the programme of surveillance and Confidential Enquiries into Maternal Deaths in the UK is the longest running such programme worldwide. Although more recently instituted, surveillance and confidential enquiries into perinatal deaths are also now well established nationally. Recent changes to funding and commissioning of the Enquiries have enabled both a reinvigoration of the processes and improvements to the methodology with an increased frequency of future reporting. Close engagement with stakeholders and a regulator requirement for doctors to participate have both supported the impetus for involvement of all professionals leading to greater potential for improved quality of care for women and babies.


Assuntos
Mortalidade Materna , Auditoria Médica/organização & administração , Mortalidade Perinatal , Vigilância da População , Humanos , Bem-Estar Materno , Qualidade da Assistência à Saúde , Natimorto , Reino Unido
8.
Br J Cancer ; 108(10): 1925-30, 2013 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-23632485

RESUMO

Since they were first described in the 1990s, circulating microRNAs (miRNAs) have provided an active and rapidly evolving area of current research that has the potential to transform cancer diagnostics and therapeutics. In particular, miRNAs could provide potential new biomarkers for prostate cancer, the most common cause of cancer in UK men. Current diagnostic tests for prostate cancer have low specificity and poor sensitivity. Further, although many prostate cancers are so slow growing as not to pose a major risk to health, there is currently no test to distinguish between these and cancers that will become aggressive and life threatening. Circulating miRNAs are highly stable and are both detectable and quantifiable in a range of accessible bio fluids, thus have the potential to be useful diagnostic, prognostic and predictive biomarkers. This review aims to summarise the current understanding of circulating miRNAs in prostate cancer patients and their potential role as biomarkers.


Assuntos
Biomarcadores Tumorais/sangue , MicroRNAs/sangue , Neoplasias da Próstata/diagnóstico , Transporte Biológico/fisiologia , Humanos , Masculino , Terapia de Alvo Molecular , Prognóstico , Neoplasias da Próstata/sangue , Neoplasias da Próstata/genética , Neoplasias da Próstata/terapia
9.
J Endocrinol ; 256(3)2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36622663

RESUMO

Breast cancer (BC) is the most diagnosed cancer in women worldwide. In estrogen receptor (ER)-positive disease, anti-estrogens and aromatase inhibitors (AI) improve patient survival; however, many patients develop resistance. Dysregulation of apoptosis is a common resistance mechanism; thus, agents that can reinstate the activity of apoptotic pathways represent promising therapeutics for advanced drug-resistant disease. Emerging targets in this scenario include microRNAs (miRs). To identify miRs modulating apoptosis in drug-responsive and -resistant BC, a high-throughput miR inhibitor screen was performed, followed by high-content screening microscopy for apoptotic markers. Validation demonstrated that miR-361-3p inhibitor significantly increases early apoptosis and reduces proliferation of drug-responsive (MCF7), plus AI-/antiestrogen-resistant derivatives (LTED, TamR, FulvR), and ER- cells (MDA-MB-231). Importantly, proliferation-inhibitory effects were observed in vivo in a xenograft model, indicating the potential clinical application of miR-361-3p inhibition. RNA-seq of tumour xenografts identified FANCA as a direct miR-361-3p target, and validation suggested miR-361-3p inhibitor effects might be mediated in part through FANCA modulation. Moreover, miR-361-3p inhibition resulted in p53-mediated G1 cell cycle arrest through activation of p21 and reduced BC invasion. Analysis of publicly available datasets showed miR-361-3p expression is significantly higher in primary breast tumours vspaired normal tissue and is associated with decreased overall survival. In addition, miR-361-3p inhibitor treatment of BC patient explants decreased levels of miR-361-3p and proliferation marker, Ki67. Finally, miR-361-3p inhibitor showed synergistic effects on BC growth when combined with PARP inhibitor, Olaparib. Together, these studies identify miR-361-3p inhibitor as a potential new treatment for drug-responsive and -resistant advanced BC.


Assuntos
Neoplasias da Mama , MicroRNAs , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Resistencia a Medicamentos Antineoplásicos/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Antagonistas de Estrogênios/farmacologia , Inibidores da Aromatase/farmacologia , Inibidores da Aromatase/uso terapêutico , Apoptose/genética , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral
10.
J Exp Psychol Appl ; 27(2): 324-337, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33271046

RESUMO

Advances in head mounted displays (HMDs) have increased the interest in cinematic virtual reality as an art form. However, the freedom of a viewer in 360 video presents challenges in ensuring that audiences do not inadvertently miss important events and locations. We examined whether the high level of immersion provided by HMDs encourages participants to synchronize their attention during viewing. Sixty-four participants watched the 360° documentary Clouds Over Sidra (VRSE.works, 2015) using either an HMD or via a flat screen tablet display. We used intersubject correlation (ISC) analysis to measure attentional synchrony over the course of the video and to examine whether spatial and temporal factors led to different amounts of correlation both within and between groups. We found significantly greater ISC for the HMD compared to the tablet group. This effect was greatest for scenes with a unidirectional focus and at the start of scenes. We discuss our results in terms of the visual properties and the motor affordances of HMDs versus tablets. Our results show the value of HMDs in increasing attentional synchrony and may provide producers of 360° content insight in how to encourage or discourage synchronization of viewing direction. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Óculos Inteligentes , Realidade Virtual , Atenção , Humanos
11.
Nat Commun ; 12(1): 4068, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210968

RESUMO

SARS-CoV-2 attacks various organs, most destructively the lung, and cellular entry requires two host cell surface proteins: ACE2 and TMPRSS2. Downregulation of one or both of these is thus a potential therapeutic approach for COVID-19. TMPRSS2 is a known target of the androgen receptor, a ligand-activated transcription factor; androgen receptor activation increases TMPRSS2 levels in various tissues, most notably prostate. We show here that treatment with the antiandrogen enzalutamide-a well-tolerated drug widely used in advanced prostate cancer-reduces TMPRSS2 levels in human lung cells and in mouse lung. Importantly, antiandrogens significantly reduced SARS-CoV-2 entry and infection in lung cells. In support of this experimental data, analysis of existing datasets shows striking co-expression of AR and TMPRSS2, including in specific lung cell types targeted by SARS-CoV-2. Together, the data presented provides strong evidence to support clinical trials to assess the efficacy of antiandrogens as a treatment option for COVID-19.


Assuntos
Antagonistas de Androgênios/farmacologia , Benzamidas/farmacologia , Tratamento Farmacológico da COVID-19 , Nitrilas/farmacologia , Feniltioidantoína/farmacologia , Serina Endopeptidases/metabolismo , Internalização do Vírus/efeitos dos fármacos , Enzima de Conversão de Angiotensina 2/síntese química , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , COVID-19/metabolismo , COVID-19/virologia , Regulação para Baixo/efeitos dos fármacos , Feminino , Humanos , Pulmão/metabolismo , Pulmão/virologia , Masculino , Camundongos , SARS-CoV-2/efeitos dos fármacos , Serina Endopeptidases/genética
13.
Curr Genomics ; 10(1): 18-25, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19721807

RESUMO

Prostate tumour growth is almost always dependent upon the androgen receptor pathway and hence therapies aimed at blocking this signalling axis are useful tools in the management of this disease. Unfortunately such therapies invariably fail; and the tumour progresses to an "androgen-independent" stage. In such cases androgen receptor expression is almost always maintained and much evidence exists to suggest that it may still be driving growth. One mechanism by which the receptor is thought to remain active is mutation. This review summarises the present data on androgen receptor mutations in prostate cancer, and how such substitutions offer a growth advantage by affecting cofactor interactions or by reducing ligand specificity. Such alterations appear to have a subsequent effect upon gene expression suggesting that tumours may "behave" differently dependent upon the ligand promoting growth and if a mutation is present.

14.
Emerg Med J ; 26(4): 283-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19307392

RESUMO

BACKGROUND: The liver is the second most commonly injured intra-abdominal organ in children. CT scanning is currently regarded as the "gold standard" in screening for intra-abdominal injury following blunt trauma. However, the risks associated with performing CT in children are not insignificant and, in addition, CT is not always readily available. This study investigates the utility of alanine aminotransferase (ALT) in screening for liver injury in paediatric trauma. METHODS: Two groups of patients were compiled from a prospectively identified trauma registry-one with liver injuries and another with intra-abdominal injuries other than to the liver. Inclusion in the study required that an initial ALT level had been obtained after injury. Where CT had been performed, a paediatric radiologist blind to the ALT results graded the severity of the liver injuries. The study groups were compared and a receiver operating characteristic (ROC) curve generated to derive the optimum ALT threshold to identify liver injury. RESULTS: 51 patients with liver injury and 65 with other intra-abdominal injuries were identified. An ALT level of > or =104 IU/l gave a sensitivity of 96% and a specificity of 80%. When liver injuries were stratified to identify only clinically significant liver injuries (grades III, IV and V), this ALT threshold identified 100% of patients with 70% specificity. CONCLUSIONS: In this sample, ALT appears to be a useful predictor for the presence or absence of liver injury. In haemodynamically stable children with clinical suspicion of isolated liver injury, identification of a normal ALT level (<104 IU/l) may reduce the need for unnecessary transportation for CT scanning with subsequent radiation exposure.


Assuntos
Alanina Transaminase/sangue , Fígado/lesões , Ferimentos não Penetrantes/diagnóstico , Biomarcadores/sangue , Criança , Ensaios Enzimáticos Clínicos/métodos , Feminino , Humanos , Escala de Gravidade do Ferimento , Masculino , Estudos Prospectivos , Sensibilidade e Especificidade
15.
Oncogene ; 26(12): 1757-68, 2007 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-16964284

RESUMO

Prohibitin (PHB) is a cell cycle regulatory protein, known to repress E2F1-mediated gene activation via recruitment of transcriptional regulatory factors such as retinoblastoma and histone deacetylase 1 (HDAC1). We previously identified PHB as a target protein of androgen signaling in prostate cancer cells and showed that downregulation of PHB is required for androgen-induced cell cycle entry in these cells. We now present evidence that PHB, which has 54% homology at the protein level to the oestrogen receptor corepressor REA (repressor of oestrogen receptor activity), can repress androgen receptor (AR)-mediated transcription and androgen-dependent cell growth. Depletion of endogenous PHB resulted in an increase in expression of the androgen-regulated prostate-specific antigen gene. The repression appears to be specific to androgen and closely related receptors, as it is also evident for the glucocorticoid and progesterone, but not oestrogen, receptors. In spite of interaction of PHB with HDAC1, HDAC activity is not required for this repression. Although AR and PHB could be co-immunoprecipitated, no direct interaction was detectable, suggesting that PHB forms part of a repressive complex with the AR. Competition with the co-activator SRC1 further suggests that formation of a complex with AR, PHB and other cofactors is the mechanism by which repression is achieved. It appears then that repression of AR activity is one mechanism by which PHB inhibits androgen-dependent growth of prostate cells. Further, this study implies that the AR itself could, by mediating downregulation of a corepressor, be involved in the progression of prostate tumours to the hormone refractory stage.


Assuntos
Antagonistas de Receptores de Andrógenos , Androgênios/fisiologia , Regulação para Baixo , Proteínas Repressoras/fisiologia , Sequência de Aminoácidos , Animais , Células COS , Chlorocebus aethiops , Humanos , Microscopia Confocal , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proibitinas , Proteínas Repressoras/química , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
16.
Mol Cell Biol ; 21(1): 39-50, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11113179

RESUMO

The transcriptional activity of nuclear receptors is mediated by coactivator proteins, including steroid receptor coactivator 1 (SRC1) and its homologues and the general coactivators CREB binding protein (CBP) and p300. SRC1 contains an activation domain (AD1) which functions via recruitment of CBP and and p300. In this study, we have used yeast two-hybrid and in vitro interaction-peptide inhibition experiments to map the AD1 domain of SRC1 to a 35-residue sequence potentially containing two alpha-helices. We also define a 72-amino-acid sequence in CBP necessary for SRC1 binding, designated the SRC1 interaction domain (SID). We show that in contrast to SRC1, direct binding of CBP to the estrogen receptor is weak, suggesting that SRC1 functions primarily as an adaptor to recruit CBP and p300. In support of this, we show that the ability of SRC1 to enhance ligand-dependent nuclear receptor activity in transiently transfected cells is dependent upon the integrity of the AD1 region. In contrast, the putative histone acetyltransferase domain, the Per-Arnt-Sim basic helix-loop-helix domain, the glutamine-rich domain, and AD2 can each be removed without loss of ligand-induced activity. Remarkably, a construct corresponding to residues 631 to 970, which contains only the LXXLL motifs and the AD1 region of SRC1, retained strong coactivator activity in our assays.


Assuntos
Proteínas Nucleares/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Sítios de Ligação , Proteína de Ligação a CREB , Linhagem Celular , Genes Reporter , Histona Acetiltransferases , Humanos , Dados de Sequência Molecular , Mutação , Proteínas Nucleares/química , Proteínas Nucleares/genética , Coativador 1 de Receptor Nuclear , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Receptores de Estrogênio/metabolismo , Elementos de Resposta/genética , Saccharomyces cerevisiae/genética , Termodinâmica , Transativadores/química , Transativadores/genética , Fatores de Transcrição/química , Fatores de Transcrição/genética , Transfecção , Técnicas do Sistema de Duplo-Híbrido
17.
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
18.
Oncogenesis ; 6(5): e333, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28504694

RESUMO

Prohibitin (PHB) is a tumour suppressor molecule with pleiotropic activities across several cellular compartments including mitochondria, cell membrane and the nucleus. PHB and the steroid-activated androgen receptor (AR) have an interplay where AR downregulates PHB, and PHB represses AR. Additionally, their cellular locations and chromatin interactions are in dynamic opposition. We investigated the mechanisms of cell cycle inhibition by PHB and how this is modulated by AR in prostate cancer. Using a prostate cancer cell line overexpressing PHB, we analysed the gene expression changes associated with PHB-mediated cell cycle arrest. Over 1000 gene expression changes were found to be significant and gene ontology analysis confirmed PHB-mediated repression of genes essential for DNA replication and synthesis, for example, MCMs and TK1, via an E2F1 regulated pathway-agreeing with its G1/S cell cycle arrest activity. PHB is known to inhibit E2F1-mediated transcription, and the PHB:E2F1 interaction was seen in LNCaP nuclear extracts, which was then reduced by androgen treatment. Upon two-dimensional western blot analysis, the PHB protein itself showed androgen-mediated charge differentiation (only in AR-positive cells), indicating a potential dephosphorylation event. Kinexus phosphoprotein array analysis indicated that Src kinase was the main interacting intracellular signalling hub in androgen-treated LNCaP cells, and that Src inhibition could reduce this AR-mediated charge differentiation. PHB charge change may be associated with rapid dissociation from chromatin and E2F1, allowing the cell cycle to proceed. The AR and androgens may deactivate the repressive functions of PHB upon E2F1 leading to cell cycle progression, and indicates a role for AR in DNA replication licensing.

19.
J Neurol ; 264(2): 316-326, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27896433

RESUMO

Disability measures in multiple sclerosis (MS) rely heavily on ambulatory function, and current metrics fail to capture potentially important variability in walking behavior. We sought to determine whether remote step count monitoring using a consumer-friendly accelerometer (Fitbit Flex) can enhance MS disability assessment. 99 adults with relapsing or progressive MS able to walk ≥2-min were prospectively recruited. At 4 weeks, study retention was 97% and median Fitbit use was 97% of days. Substudy validation resulted in high interclass correlations between Fitbit, ActiGraph and manual step count tally during a 2-minute walk test, and between Fitbit and ActiGraph (ICC = 0.76) during 7-day home monitoring. Over 4 weeks of continuous monitoring, daily steps were lower in progressive versus relapsing MS (mean difference 2546 steps, p < 0.01). Lower average daily step count was associated with greater disability on the Expanded Disability Status Scale (EDSS) (p < 0.001). Within each EDSS category, substantial variability in step count was apparent (i.e., EDSS = 6.0 range 1097-7152). Step count demonstrated moderate-strong correlations with other walking measures. Lower average daily step count is associated with greater MS disability and captures important variability in real-world walking activity otherwise masked by standard disability scales, including the EDSS. These results support remote step count monitoring as an exploratory outcome in MS trials.


Assuntos
Acelerometria/métodos , Avaliação da Deficiência , Esclerose Múltipla Crônica Progressiva/diagnóstico , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Telemedicina/métodos , Caminhada , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial/métodos , Esclerose Múltipla Crônica Progressiva/fisiopatologia , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Estudos Prospectivos , Reprodutibilidade dos Testes , Caminhada/fisiologia
20.
Arch Dis Child Fetal Neonatal Ed ; 91(1): F56-60, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16174665

RESUMO

OBJECTIVE: To determine if exposure to more than one course of antenatal glucocorticoids is associated with changes in infant blood pressure and myocardial wall thickness in the first month after birth. DESIGN: Prospective cohort study. SETTING: Tertiary neonatal intensive care unit. PARTICIPANTS: Mothers who were eligible for but declined to enter a randomised trial of repeated doses of antenatal glucocorticoids (ACTORDS)-that is, who had a singleton, twin, or triplet pregnancy at <32 weeks gestation, had received an initial course of glucocorticoids seven or more days previously, and were considered to be at continued risk of preterm birth. MAIN OUTCOME MEASURES: Blood pressure daily for the first week then weekly until 4 weeks of age. End diastolic interventricular septal and left ventricular posterior wall (EDIVS and EDLVPW) thickness at 48-72 hours after birth. RESULTS: Thirty seven women were enrolled and delivered 50 infants. Thirty mothers (39 infants) were exposed to one course of glucocorticoids, and seven mothers (11 infants) to more than one course. Blood pressures were higher in the first week after birth in infants exposed to multiple courses of glucocorticoids, and in infants with a latency between last exposure and delivery of less than seven days. Systolic blood pressure on day 1 was >2SD above published normal ranges in 67% of babies exposed to multiple courses and 24% of babies exposed to a single course of glucocorticoids (p = 0.04). There was no difference between groups in thickness of the EDIVS or EDLVPW. However, 44/50 (88%) babies had EDIVS and 49/50 (98%) babies had EDLVPW thickness >2 SD above the expected mean for birth weight and gestation. EDIVS but not EDLVPW thickness increased with increasing latency (mean 0.02 mm/day, p = 0.03). CONCLUSION: Future randomised trials should assess the long term effects of exposure to antenatal glucocorticoids, particularly multiple courses, on the cardiovascular status of the infant.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Cardiomegalia/induzido quimicamente , Glucocorticoides/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal , Adulto , Esquema de Medicação , Feminino , Coração/efeitos dos fármacos , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/induzido quimicamente , Pessoa de Meia-Idade , Miocárdio/patologia , Trabalho de Parto Prematuro/prevenção & controle , Assistência Perinatal/métodos , Gravidez
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