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1.
Immunity ; 42(4): 704-18, 2015 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-25840682

RESUMEN

B helper follicular T (Tfh) cells are critical for long-term humoral immunity. However, it remains unclear how these cells are recruited and contribute to secondary immune responses. Here we show that primary Tfh cells segregate into follicular mantle (FM) and germinal center (GC) subpopulations that display distinct gene expression signatures. Restriction of the primary Tfh cell subpopulation in the GC was mediated by downregulation of chemotactic receptor EBI2. Following collapse of the GC, memory T cells persisted in the outer follicle where they scanned CD169(+) subcapsular sinus macrophages. Reactivation and intrafollicular expansion of these follicular memory T cells in the subcapsular region was followed by their extrafollicular dissemination via the lymphatic flow. These data suggest that Tfh cells integrate their antigen-experience history to focus T cell help within the GC during primary responses but act rapidly to provide systemic T cell help after re-exposure to the antigen.


Asunto(s)
Linfocitos B/citología , Linaje de la Célula/inmunología , Centro Germinal/citología , Inmunidad Humoral , Linfocitos T Colaboradores-Inductores/citología , Animales , Linfocitos B/inmunología , Diferenciación Celular , Linaje de la Célula/genética , Movimiento Celular/inmunología , Proliferación Celular , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Centro Germinal/inmunología , Memoria Inmunológica , Ratones , Ratones Noqueados , Cultivo Primario de Células , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/inmunología , Lectina 1 Similar a Ig de Unión al Ácido Siálico/genética , Lectina 1 Similar a Ig de Unión al Ácido Siálico/inmunología , Transducción de Señal , Linfocitos T Colaboradores-Inductores/inmunología
2.
Am J Hum Genet ; 107(2): 175-182, 2020 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-32763188

RESUMEN

Expanded carrier screening (ECS) for recessive monogenic diseases requires prior knowledge of genomic variation, including DNA variants that cause disease. The composition of pathogenic variants differs greatly among human populations, but historically, research about monogenic diseases has focused mainly on people with European ancestry. By comparison, less is known about pathogenic DNA variants in people from other parts of the world. Consequently, inclusion of currently underrepresented Indigenous and other minority population groups in genomic research is essential to enable equitable outcomes in ECS and other areas of genomic medicine. Here, we discuss this issue in relation to the implementation of ECS in Australia, which is currently being evaluated as part of the national Government's Genomics Health Futures Mission. We argue that significant effort is required to build an evidence base and genomic reference data so that ECS can bring significant clinical benefit for many Aboriginal and/or Torres Strait Islander Australians. These efforts are essential steps to achieving the Australian Government's objectives and its commitment "to leveraging the benefits of genomics in the health system for all Australians." They require culturally safe, community-led research and community involvement embedded within national health and medical genomics programs to ensure that new knowledge is integrated into medicine and health services in ways that address the specific and articulated cultural and health needs of Indigenous people. Until this occurs, people who do not have European ancestry are at risk of being, in relative terms, further disadvantaged.


Asunto(s)
Metagenómica/métodos , Grupos de Población/genética , Australia , Variación Genética/genética , Humanos
3.
Global Health ; 19(1): 66, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37658444

RESUMEN

BACKGROUND: During the past two years, the COVID-19 pandemic has cost millions of lives around the globe, caused major morbidity and provoked widespread economic and social disruption. In response, governments have enacted policies to mitigate the impacts of the pandemic. This research focuses in on policies aimed at increasing access to essential health products and services by comparing them to the global rules governing trade, investment and intellectual property. We have assessed whether these rules have or could have constrained countries in responding to this and future crises. The study identifies the nature and scope of the trade-related health sector policies implemented by our sample group of countries, selected because of their systemic significance: the United States, Germany, France, China, South Africa and India. Each policy is placed into one of five broad categories covered by trade and investment rules so that we could assess their consistency with those rules. RESULTS: We found, among other things, that the types of trade-related health measures were quite diverse. The high-income countries in our study were the most active in the policy space and tended to rely on subsidies-based measures while the middle-income countries relied more heavily on export and import measures. Policies directly relevant to intellectual property protection were virtually non-existent. When evaluating the implemented policies against the global trade and investment rules, we found potential constraints under five different types of rules: those governing subsidies, import and export trade barriers, investment measures, government procurement and trade-related intellectual property. CONCLUSIONS: Given the tension between the global rules and the practices of policymaking during the pandemic, we conclude that the tension must be resolved in favor of governments making policy rather than relying on existing exceptions or pushing national governments to comply more exactly with the rules. Although the pandemic itself does not respect national borders, governance still generally occurs at the national level because national governments are often the only entities with both the legal authority and the practical ability to respond.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Pandemias/prevención & control , Inversiones en Salud , Política de Salud , China
4.
PLoS Genet ; 16(1): e1008531, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31895944

RESUMEN

Acquired resistance to endocrine therapy is responsible for half of the therapeutic failures in the treatment of breast cancer. Recent findings have implicated increased expression of the ETS transcription factor ELF5 as a potential modulator of estrogen action and driver of endocrine resistance, and here we provide the first insight into the mechanisms by which ELF5 modulates estrogen sensitivity. Using chromatin immunoprecipitation sequencing we found that ELF5 binding overlapped with FOXA1 and ER at super enhancers, enhancers and promoters, and when elevated, caused FOXA1 and ER to bind to new regions of the genome, in a pattern that replicated the alterations to the ER/FOXA1 cistrome caused by the acquisition of resistance to endocrine therapy. RNA sequencing demonstrated that these changes altered estrogen-driven patterns of gene expression, the expression of ER transcription-complex members, and 6 genes known to be involved in driving the acquisition of endocrine resistance. Using rapid immunoprecipitation mass spectrometry of endogenous proteins, and proximity ligation assays, we found that ELF5 interacted physically with members of the ER transcription complex, such as DNA-PKcs. We found 2 cases of endocrine-resistant brain metastases where ELF5 levels were greatly increased and ELF5 patterns of gene expression were enriched, compared to the matched primary tumour. Thus ELF5 alters ER-driven gene expression by modulating the ER/FOXA1 cistrome, by interacting with it, and by modulating the expression of members of the ER transcriptional complex, providing multiple mechanisms by which ELF5 can drive endocrine resistance.


Asunto(s)
Neoplasias de la Mama/genética , Proteínas de Unión al ADN/metabolismo , Elementos de Facilitación Genéticos , Regulación Neoplásica de la Expresión Génica , Receptores de Estrógenos/metabolismo , Factores de Transcripción/metabolismo , Animales , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/secundario , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Femenino , Factor Nuclear 3-alfa del Hepatocito/genética , Factor Nuclear 3-alfa del Hepatocito/metabolismo , Humanos , Células MCF-7 , Ratones , Unión Proteica
5.
Public Health Nurs ; 40(4): 517-527, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36882994

RESUMEN

Taiwan's National Health Insurance (NHI) is a widely acclaimed universal healthcare system. In the past few years, particularly following the COVID-19 outbreak, challenges related to maintaining the NHI system have surfaced. Since 2020, NHI has faced a series of challenges, including excessive patient visits to the hospital emergency department, a lack of an effective primary care and referral system, and a high turnover rate of healthcare workers. We review major problems related to Taiwan's NHI, emphasizing input from frontline healthcare workers. We provide recommendations for potential policies addressing the concerns around NHI, for example, strengthening the role of primary care services under the NHI administration, reducing the high turnover rate of healthcare workers, and increase the premium and copayments. We hope that this policy analysis may allow policymakers and scholars to understand both the merits and critical problems related to NHI from the clinical perspective.


Asunto(s)
COVID-19 , Humanos , Taiwán/epidemiología , Programas Nacionales de Salud , Formulación de Políticas , Servicio de Urgencia en Hospital
6.
Breast Cancer Res ; 22(1): 63, 2020 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-32527287

RESUMEN

BACKGROUND: Basal-like breast cancer (BLBC) is a poorly characterised, heterogeneous disease. Patients are diagnosed with aggressive, high-grade tumours and often relapse with chemotherapy resistance. Detailed understanding of the molecular underpinnings of this disease is essential to the development of personalised therapeutic strategies. Inhibitor of differentiation 4 (ID4) is a helix-loop-helix transcriptional regulator required for mammary gland development. ID4 is overexpressed in a subset of BLBC patients, associating with a stem-like poor prognosis phenotype, and is necessary for the growth of cell line models of BLBC through unknown mechanisms. METHODS: Here, we have defined unique molecular insights into the function of ID4 in BLBC and the related disease high-grade serous ovarian cancer (HGSOC), by combining RIME proteomic analysis, ChIP-seq mapping of genomic binding sites and RNA-seq. RESULTS: These studies reveal novel interactions with DNA damage response proteins, in particular, mediator of DNA damage checkpoint protein 1 (MDC1). Through MDC1, ID4 interacts with other DNA repair proteins (γH2AX and BRCA1) at fragile chromatin sites. ID4 does not affect transcription at these sites, instead binding to chromatin following DNA damage. Analysis of clinical samples demonstrates that ID4 is amplified and overexpressed at a higher frequency in BRCA1-mutant BLBC compared with sporadic BLBC, providing genetic evidence for an interaction between ID4 and DNA damage repair deficiency. CONCLUSIONS: These data link the interactions of ID4 with MDC1 to DNA damage repair in the aetiology of BLBC and HGSOC.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Carcinoma Basocelular/genética , Carcinoma Basocelular/metabolismo , Proteínas Inhibidoras de la Diferenciación/genética , Proteínas Inhibidoras de la Diferenciación/metabolismo , Animales , Apoptosis/fisiología , Neoplasias de la Mama/patología , Carcinoma Basocelular/patología , Diferenciación Celular/fisiología , Línea Celular Tumoral , Proliferación Celular/fisiología , Cromatina/genética , Cromatina/metabolismo , Daño del ADN , Femenino , Xenoinjertos , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Pronóstico , Proteogenómica , Células Tumorales Cultivadas
7.
Global Health ; 15(1): 88, 2019 12 30.
Artículo en Inglés | MEDLINE | ID: mdl-31888688

RESUMEN

BACKGROUND: We present a systematic review describing ex-ante and ex-post evaluations of the impacts of intellectual property provisions in trade treaties on access to medicine in low and middle income countries. These evaluations focused on multilateral and bilateral trade agreements. We ascertained which IP provisions impacting access to medicines were the focus of these evaluations. We provide a further research agenda related to investigating the effect of trade agreement's intellectual property provisions on access to medicines. We followed systematic review guidelines with 7 different databases to identify post-2000 ex ante and ex post evaluations of trade treaties on access to medicines in low and middle-income countries. We included only quantitative ex-ante studies that used structural modeling and simulations to derive quantitative predictions and ex-post studies that utilized empirical data and econometric techniques to quantify the effects of intellectual property provisions in free trade agreements on host country's pharmaceutical industry. The search strategy identified 744 titles after removal of duplicates. We identified 14 studies that fulfilled all eligibility; 7 studies are ex-ante and 7 are ex-post. The studies looked at medicine price and cost, affordability, welfare effects and speed of medicine market launch. Changes in intellectual property policy due to the implementation of trade agreements affect price, medicines expenditure and sales, consumer welfare, and ultimately the affordability, of medicines. The direction and magnitude of the price effects differ between ex-ante and ex-post studies. Further, the reported impacts of policy changes due to trade agreements on medicine access seem clearly multifactorial. CONCLUSION: Both ex ante and ex post methods have advantages and limitations and, on balance, both types report, for the most part, an increase in price and a decrease in consumer welfare with imposition of intellectual property protection in trade agreements. The main differences between these studies are in the magnitude of the changes. There is a gap in our empirical understanding of the mechanisms through which such changes affect access to medicines and which outcomes relevant to access are most affected by which type of changes in intellectual property policy and law.


Asunto(s)
Comercio/legislación & jurisprudencia , Países en Desarrollo , Propiedad Intelectual , Cooperación Internacional/legislación & jurisprudencia , Preparaciones Farmacéuticas/provisión & distribución , Humanos
8.
Int J Health Plann Manage ; 34(1): e6-e10, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30211960

RESUMEN

National Health Insurance (NHI) was implemented in Taiwan in 1995, and has significantly increased coverage to 99% of the population. The implementation of NHI has had large impacts on health disparities. Despite that, the NHI faces multiple challenges, including the condition of "coverage without access" among the Taiwanese aboriginal population, mostly residing in mountainous townships and experiencing lower socioeconomic status, decreased health outcomes, and limited access to adequate high-quality health care services. This paper summarizes the persistent health gap and the differences in health care utilization and health outcomes between the aboriginal population in rural townships and urban populations in Taiwan. Mountainous townships face challenges including lack of access to high-quality health care services and limited medical resources. Further policy recommendations and current progress are highlighted and discussed.


Asunto(s)
Programas Nacionales de Salud , Aceptación de la Atención de Salud/estadística & datos numéricos , Población Rural/estadística & datos numéricos , Política de Salud , Disparidades en el Estado de Salud , Disparidades en Atención de Salud/estadística & datos numéricos , Humanos , Programas Nacionales de Salud/estadística & datos numéricos , Grupos de Población/estadística & datos numéricos , Servicios de Salud Rural/estadística & datos numéricos , Taiwán
9.
PLoS Biol ; 13(12): e1002330, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26717410

RESUMEN

During pregnancy, the ETS transcription factor ELF5 establishes the milk-secreting alveolar cell lineage by driving a cell fate decision of the mammary luminal progenitor cell. In breast cancer, ELF5 is a key transcriptional determinant of tumor subtype and has been implicated in the development of insensitivity to anti-estrogen therapy. In the mouse mammary tumor virus-Polyoma Middle T (MMTV-PyMT) model of luminal breast cancer, induction of ELF5 levels increased leukocyte infiltration, angiogenesis, and blood vessel permeability in primary tumors and greatly increased the size and number of lung metastasis. Myeloid-derived suppressor cells, a group of immature neutrophils recently identified as mediators of vasculogenesis and metastasis, were recruited to the tumor in response to ELF5. Depletion of these cells using specific Ly6G antibodies prevented ELF5 from driving vasculogenesis and metastasis. Expression signatures in luminal A breast cancers indicated that increased myeloid cell invasion and inflammation were correlated with ELF5 expression, and increased ELF5 immunohistochemical staining predicted much shorter metastasis-free and overall survival of luminal A patients, defining a group who experienced unexpectedly early disease progression. Thus, in the MMTV-PyMT mouse mammary model, increased ELF5 levels drive metastasis by co-opting the innate immune system. As ELF5 has been previously implicated in the development of antiestrogen resistance, this finding implicates ELF5 as a defining factor in the acquisition of the key aspects of the lethal phenotype in luminal A breast cancer.


Asunto(s)
Neoplasias de la Mama/metabolismo , Neoplasias Pulmonares/secundario , Pulmón/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Proto-Oncogénicas c-ets/metabolismo , Animales , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/fisiopatología , Neoplasias de la Mama/virología , Permeabilidad Capilar , Proliferación Celular , Proteínas de Unión al ADN , Femenino , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Hemorragia/etiología , Hemorragia/prevención & control , Humanos , Leucocitos/inmunología , Leucocitos/patología , Pulmón/irrigación sanguínea , Pulmón/inmunología , Pulmón/patología , Neoplasias Pulmonares/irrigación sanguínea , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/prevención & control , Depleción Linfocítica , Ratones Transgénicos , Células Mieloides/inmunología , Células Mieloides/patología , Proteínas de Neoplasias/genética , Neovascularización Patológica/etiología , Neovascularización Patológica/prevención & control , Infiltración Neutrófila , Poliomavirus/patogenicidad , Proteínas Proto-Oncogénicas c-ets/genética , Proteínas Recombinantes de Fusión/metabolismo , Análisis de Supervivencia , Factores de Transcripción , Carga Tumoral
10.
Nature ; 491(7424): 399-405, 2012 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-23103869

RESUMEN

Pancreatic cancer is a highly lethal malignancy with few effective therapies. We performed exome sequencing and copy number analysis to define genomic aberrations in a prospectively accrued clinical cohort (n = 142) of early (stage I and II) sporadic pancreatic ductal adenocarcinoma. Detailed analysis of 99 informative tumours identified substantial heterogeneity with 2,016 non-silent mutations and 1,628 copy-number variations. We define 16 significantly mutated genes, reaffirming known mutations (KRAS, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1), and uncover novel mutated genes including additional genes involved in chromatin modification (EPC1 and ARID2), DNA damage repair (ATM) and other mechanisms (ZIM2, MAP2K4, NALCN, SLC16A4 and MAGEA6). Integrative analysis with in vitro functional data and animal models provided supportive evidence for potential roles for these genetic aberrations in carcinogenesis. Pathway-based analysis of recurrently mutated genes recapitulated clustering in core signalling pathways in pancreatic ductal adenocarcinoma, and identified new mutated genes in each pathway. We also identified frequent and diverse somatic aberrations in genes described traditionally as embryonic regulators of axon guidance, particularly SLIT/ROBO signalling, which was also evident in murine Sleeping Beauty transposon-mediated somatic mutagenesis models of pancreatic cancer, providing further supportive evidence for the potential involvement of axon guidance genes in pancreatic carcinogenesis.


Asunto(s)
Axones/metabolismo , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patología , Genoma/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Animales , Dosificación de Gen , Regulación Neoplásica de la Expresión Génica , Humanos , Estimación de Kaplan-Meier , Ratones , Mutación , Proteínas/genética , Transducción de Señal
11.
Int J Health Plann Manage ; 33(1): e357-e366, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27723118

RESUMEN

It has been over 20 years since Taiwan's implementation of its National Health Insurance (NHI) program. Under this program, the health insurance coverage rate has reached approximately 99% of the population. Despite guaranteeing the residents of Taiwan equal access regardless of socioeconomic status and background, critical problems and controversies persist, and they continue to challenge the NHI. We analyze the primary issues facing the NHI program with emphasis on financial and consumer behavioral aspects. Furthermore, we apply models from mainland China, South Korea and Singapore to discuss what Taiwan could learn from the systems employed by these countries to modify the NHI. Targeting the needs of the NHI, we have three policy recommendations: separating the NHI scheme into different target populations, strengthening the NHI referral system and regulating the access of overseas citizens to health services while in Taiwan. After two decades in existence, problems persist and there is a continuing need to improve Taiwan's NHI. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Programas Nacionales de Salud/organización & administración , China , Política de Salud , Accesibilidad a los Servicios de Salud/organización & administración , Humanos , Programas Nacionales de Salud/economía , Programas Nacionales de Salud/legislación & jurisprudencia , Programas Nacionales de Salud/estadística & datos numéricos , Derivación y Consulta/organización & administración , República de Corea , Singapur , Factores Socioeconómicos , Taiwán
12.
Circulation ; 133(21): 2076-85, 2016 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-27217433

RESUMEN

Cardiovascular diseases (CVD) represent the highest burden of disease globally. Medicines are a critical intervention used to prevent and treat CVD. This review describes access to medication for CVD from a health system perspective and strategies that have been used to promote access, including providing medicines at lower cost, improving medication supply, ensuring medicine quality, promoting appropriate use, and managing intellectual property issues. Using key evidence in published and gray literature and systematic reviews, we summarize advances in access to cardiovascular medicines using the 5 health system dimensions of access: availability, affordability, accessibility, acceptability, and quality of medicines. There are multiple barriers to access of CVD medicines, particularly in low- and middle-income countries. Low availability of CVD medicines has been reported in public and private healthcare facilities. When patients lack insurance and pay out of pocket to purchase medicines, medicines can be unaffordable. Accessibility and acceptability are low for medicines used in secondary prevention; increasing use is positively related to country income. Fixed-dose combinations have shown a positive effect on adherence and intermediate outcome measures such as blood pressure and cholesterol. We have a new opportunity to improve access to CVD medicines by using strategies such as efficient procurement of low-cost, quality-assured generic medicines, development of fixed-dose combination medicines, and promotion of adherence through insurance schemes that waive copayment for long-term medications. Monitoring progress at all levels, institutional, regional, national, and international, is vital to identifying gaps in access and implementing adequate policies.


Asunto(s)
Fármacos Cardiovasculares/economía , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/economía , Países en Desarrollo/economía , Accesibilidad a los Servicios de Salud/economía , Pobreza/economía , Fármacos Cardiovasculares/uso terapéutico , Enfermedades Cardiovasculares/epidemiología , Humanos
13.
Global Health ; 13(1): 61, 2017 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-28830500

RESUMEN

BACKGROUND: Nepal was struck by devastating earthquakes in April-May 2015, followed by the India-Nepal border blockade later that year. METHODS: We used the United Nations Commodity Trade Statistics (UN Comtrade) database to analyse exports of various health commodities from India to Nepal from January 2011-September 2016. We used time-series regressions of trading volume vs. unit price to ask how well Nepal's trading history with India prior to the earthquake and blockade was able to predict unit prices of health commodities imported into Nepal during and after the earthquake and the blockade. Regression residuals were used to quantify the extent to which the blockade impacted the price of healthcare commodities crossing into Nepal. RESULTS: During the blockade period (September 2015-early February 2016), the volume of all retail medicines traded across the India-Nepal border was reduced by 46.5% compared to same months in 2014-2015. For medical dressings, large volumes were exported from India to Nepal during and shortly after the earthquakes (May-June 2015), but decreased soon thereafter. During the earthquake, the difference between observed and predicted values of unit price (residuals) for all commodities show no statistical outliers. However, during the border blockade, Nepal paid USD 22.3 million more for retail medicines than one would have predicted based on its prior trading history with India, enough to provide healthcare to nearly half of Kathmandu's citizens for 1 year. CONCLUSION: The India-Nepal blockade was a geopolitical natural experiment demonstrating how a land-locked country is vulnerable to the vagaries of its primary trading partner. Although short-lived, the blockade had an immediate impact on traded medicine volumes and prices, and provided a large opportunity cost with implications for public health.


Asunto(s)
Comercio , Atención a la Salud , Salud Pública/tendencias , Humanos , India , Nepal
14.
PLoS Pathog ; 10(10): e1004423, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25299404

RESUMEN

Recent studies have shown that virally encoded mRNA sequences of genome maintenance proteins from herpesviruses contain clusters of unusual structural elements, G-quadruplexes, which modulate viral protein synthesis. Destabilization of these G-quadruplexes can override the inhibitory effect on self-synthesis of these proteins. Here we show that the purine-rich repetitive mRNA sequence of Epstein-Barr virus encoded nuclear antigen 1 (EBNA1) comprising G-quadruplex structures, limits both the presentation of MHC class I-restricted CD8(+) T cell epitopes by CD11c(+) dendritic cells in draining lymph nodes and early priming of antigen-specific CD8(+) T-cells. Destabilization of the G-quadruplex structures through codon-modification significantly enhanced in vivo antigen presentation and activation of virus-specific T cells. Ex vivo imaging of draining lymph nodes by confocal microscopy revealed enhanced antigen-specific T-cell trafficking and APC-CD8(+) T-cell interactions in mice primed with viral vectors encoding a codon-modified EBNA1 protein. More importantly, these antigen-specific T cells displayed enhanced expression of the T-box transcription factor and superior polyfunctionality consistent with the qualitative impact of translation efficiency. These results provide an important insight into how viruses exploit mRNA structure to down regulate synthesis of their viral maintenance proteins and delay priming of antigen-specific T cells, thereby establishing a successful latent infection in vivo. Furthermore, targeting EBNA1 mRNA rather than protein by small molecules or antisense oligonucleotides will enhance EBNA1 synthesis and the early priming of effector T cells, to establish a more rapid immune response and prevent persistent infection.


Asunto(s)
Presentación de Antígeno/inmunología , Linfocitos T CD8-positivos/inmunología , Antígenos Nucleares del Virus de Epstein-Barr/genética , ARN Mensajero/genética , Animales , Antígeno CD11c/inmunología , Epítopos de Linfocito T/inmunología , Femenino , Genes MHC Clase I/inmunología , Ratones Endogámicos C57BL , Biosíntesis de Proteínas/genética
15.
Breast Cancer Res ; 17: 83, 2015 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-26070602

RESUMEN

INTRODUCTION: The study of mammalian development has offered many insights into the molecular aetiology of cancer. We previously used analysis of mammary morphogenesis to discover a critical role for GATA-3 in mammary developmental and carcinogenesis. In recent years an important role for microRNAs (miRNAs) in a myriad of cellular processes in development and in oncogenesis has emerged. METHODS: microRNA profiling was conducted on stromal and epithelial cellular subsets microdissected from the pubertal mouse mammary gland. miR-184 was reactivated by transient or stable overexpression in breast cancer cell lines and examined using a series of in vitro (proliferation, tumour-sphere and protein synthesis) assays. Orthotopic xenografts of breast cancer cells were used to assess the effect of miR-184 on tumourigenesis as well as distant metastasis. Interactions between miR-184 and its putative targets were assessed by quantitative PCR, microarray, bioinformatics and 3' untranslated region Luciferase reporter assay. The methylation status of primary patient samples was determined by MBD-Cap sequencing. Lastly, the clinical prognostic significance of miR-184 putative targets was assessed using publicly available datasets. RESULTS: A large number of microRNA were restricted in their expression to specific tissue subsets. MicroRNA-184 (miR-184) was exclusively expressed in epithelial cells and markedly upregulated during differentiation of the proliferative, invasive cells of the pubertal terminal end bud (TEB) into ductal epithelial cells in vivo. miR-184 expression was silenced in mouse tumour models compared to non-transformed epithelium and in a majority of breast cancer cell line models. Ectopic reactivation of miR-184 inhibited the proliferation and self-renewal of triple negative breast cancer (TNBC) cell lines in vitro and delayed primary tumour formation and reduced metastatic burden in vivo. Gene expression studies uncovered multi-factorial regulation of genes in the AKT/mTORC1 pathway by miR-184. In clinical breast cancer tissues, expression of miR-184 is lost in primary TNBCs while the miR-184 promoter is methylated in a subset of lymph node metastases from TNBC patients. CONCLUSIONS: These studies elucidate a new layer of regulation in the PI3K/AKT/mTOR pathway with relevance to mammary development and tumour progression and identify miR-184 as a putative breast tumour suppressor.


Asunto(s)
Neoplasias de la Mama/genética , Perfilación de la Expresión Génica , Genes Supresores de Tumor , Glándulas Mamarias Animales/metabolismo , MicroARNs/genética , Maduración Sexual/genética , Animales , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular , Transformación Celular Neoplásica/genética , Análisis por Conglomerados , Epigénesis Genética , Femenino , Regulación Neoplásica de la Expresión Génica , Silenciador del Gen , Humanos , Ratones , Metástasis de la Neoplasia , Pronóstico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Interferencia de ARN , Serina-Treonina Quinasas TOR/metabolismo
16.
PLoS Biol ; 10(12): e1001461, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23300383

RESUMEN

We have previously shown that during pregnancy the E-twenty-six (ETS) transcription factor ELF5 directs the differentiation of mammary progenitor cells toward the estrogen receptor (ER)-negative and milk producing cell lineage, raising the possibility that ELF5 may suppress the estrogen sensitivity of breast cancers. To test this we constructed inducible models of ELF5 expression in ER positive luminal breast cancer cells and interrogated them using transcript profiling and chromatin immunoprecipitation of DNA followed by DNA sequencing (ChIP-Seq). ELF5 suppressed ER and FOXA1 expression and broadly suppressed ER-driven patterns of gene expression including sets of genes distinguishing the luminal molecular subtype. Direct transcriptional targets of ELF5, which included FOXA1, EGFR, and MYC, accurately classified a large cohort of breast cancers into their intrinsic molecular subtypes, predicted ER status with high precision, and defined groups with differential prognosis. Knockdown of ELF5 in basal breast cancer cell lines suppressed basal patterns of gene expression and produced a shift in molecular subtype toward the claudin-low and normal-like groups. Luminal breast cancer cells that acquired resistance to the antiestrogen Tamoxifen showed greatly elevated levels of ELF5 and its transcriptional signature, and became dependent on ELF5 for proliferation, compared to the parental cells. Thus ELF5 provides a key transcriptional determinant of breast cancer molecular subtype by suppression of estrogen sensitivity in luminal breast cancer cells and promotion of basal characteristics in basal breast cancer cells, an action that may be utilised to acquire antiestrogen resistance.


Asunto(s)
Neoplasias de la Mama/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Estrógenos/farmacología , Proteínas Proto-Oncogénicas c-ets/metabolismo , Animales , Sitios de Unión , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Adhesión Celular/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Inmunoprecipitación de Cromatina , ADN de Neoplasias/metabolismo , Proteínas de Unión al ADN , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Genoma Humano/genética , Humanos , Ratones , Modelos Biológicos , Fenotipo , Unión Proteica/efectos de los fármacos , Unión Proteica/genética , Proteínas Proto-Oncogénicas c-ets/genética , Análisis de Secuencia de ADN , Factores de Transcripción , Transcripción Genética/efectos de los fármacos
17.
18.
BMC Genomics ; 15: 476, 2014 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-24929644

RESUMEN

BACKGROUND: Free circulating DNA (fcDNA) has many potential clinical applications, due to the non-invasive way in which it is collected. However, because of the low concentration of fcDNA in blood, genome-wide analysis carries many technical challenges that must be overcome before fcDNA studies can reach their full potential. There are currently no definitive standards for fcDNA collection, processing and whole-genome sequencing. We report novel detailed methodology for the capture of high-quality methylated fcDNA, library preparation and downstream genome-wide Next-Generation Sequencing. We also describe the effects of sample storage, processing and scaling on fcDNA recovery and quality. RESULTS: Use of serum versus plasma, and storage of blood prior to separation resulted in genomic DNA contamination, likely due to leukocyte lysis. Methylated fcDNA fragments were isolated from 5 donors using a methyl-binding protein-based protocol and appear as a discrete band of ~180 bases. This discrete band allows minimal sample loss at the size restriction step in library preparation for Next-Generation Sequencing, allowing for high-quality sequencing from minimal amounts of fcDNA. Following sequencing, we obtained 37 × 10(6)-86 × 10(6) unique mappable reads, representing more than 50% of total mappable reads. The methylation status of 9 genomic regions as determined by DNA capture and sequencing was independently validated by clonal bisulphite sequencing. CONCLUSIONS: Our optimized methods provide high-quality methylated fcDNA suitable for whole-genome sequencing, and allow good library complexity and accurate sequencing, despite using less than half of the recommended minimum input DNA.


Asunto(s)
Metilación de ADN , ADN/sangre , ADN/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Anciano , Composición de Base , ADN/química , ADN/aislamiento & purificación , Contaminación de ADN , Femenino , Biblioteca de Genes , Voluntarios Sanos , Humanos , Persona de Mediana Edad , Reproducibilidad de los Resultados , Factores de Riesgo , Análisis de Secuencia de ADN
19.
Alcohol Clin Exp Res ; 38(4): 994-1001, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24460866

RESUMEN

BACKGROUND: Alcohol abuse is the world's third leading cause of disease and disability, and one potential sequel of chronic abuse is alcohol-related brain damage (ARBD). This clinically manifests as cognitive dysfunction and pathologically as atrophy of white matter (WM) in particular. The mechanism linking chronic alcohol intoxication with ARBD remains largely unknown but it is also complicated by common comorbidities such as liver damage and nutritional deficiencies. Liver cirrhosis, in particular, often leads to hepatic encephalopathy (HE), a primary glial disease. METHODS: In a novel transcriptomic study, we targeted the WM only of chronic alcoholics in an attempt to tease apart the pathogenesis of ARBD. Specifically, in alcoholics with and without HE, we explored both the prefrontal and primary motor cortices, 2 regions that experience differential levels of neuronal loss. RESULTS: Our results suggest that HE, along with 2 confounders, gray matter contamination, and low RNA quality are major drivers of gene expression in ARBD. All 3 exceeded the effects of alcohol itself. In particular, low-quality RNA samples were characterized by an up-regulation of translation machinery, while HE was associated with a down-regulation of mitochondrial energy metabolism pathways. CONCLUSIONS: The findings in HE alcoholics are consistent with the metabolic acidosis seen in this condition. In contrast non-HE alcoholics had widespread but only subtle changes in gene expression in their WM. Notwithstanding the latter result, this study demonstrates that significant confounders in transcriptomic studies of human postmortem brain tissue can be identified, quantified, and "removed" to reveal disease-specific signals.


Asunto(s)
Alcoholismo/genética , Alcoholismo/metabolismo , Transcriptoma/fisiología , Sustancia Blanca/metabolismo , Anciano , Anciano de 80 o más Años , Alcoholismo/epidemiología , Estudios de Cohortes , Comorbilidad , Factores de Confusión Epidemiológicos , Femenino , Humanos , Masculino , Persona de Mediana Edad
20.
J Immunol ; 188(12): 6238-46, 2012 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-22586040

RESUMEN

MicroRNAs (miRNAs) are ∼22-nt small RNAs that are important regulators of mRNA turnover and translation. Recent studies have shown the importance of the miRNA pathway in HIV-1 infection, particularly in maintaining latency. Our initial in vitro studies demonstrated that HIV-1-infected HUT78 cells expressed significantly higher IL-10 levels compared with uninfected cultures. IL-10 plays an important role in the dysregulated cytotoxic T cell response to HIV-1, and in silico algorithms suggested that let-7 miRNAs target IL10 mRNA. In a time course experiment, we demonstrated that let-7 miRNAs fall rapidly following HIV-1 infection in HUT78 cells with concomitant rises in IL-10. To show a direct link between let-7 and IL-10, forced overexpression of let-7 miRNAs resulted in significantly reduced IL-10 levels, whereas inhibition of the function of these miRNAs increased IL-10. To demonstrate the relevance of these results, we focused our attention on CD4(+) T cells from uninfected healthy controls, chronic HIV-1-infected patients, and long-term nonprogressors. We characterized miRNA changes in CD4(+) T cells from these three groups and demonstrated that let-7 miRNAs were highly expressed in CD4(+) T cells from healthy controls and let-7 miRNAs were significantly decreased in chronic HIV-1 infected compared with both healthy controls and long-term nonprogressors. We describe a novel mechanism whereby IL-10 levels can be potentially modulated by changes to let-7 miRNAs. In HIV-1 infection, the decrease in let-7 miRNAs may result in an increase in IL-10 from CD4(+) T cells and provide the virus with an important survival advantage by manipulating the host immune response.


Asunto(s)
Linfocitos T CD4-Positivos/metabolismo , Regulación de la Expresión Génica/genética , Infecciones por VIH/genética , Interleucina-10/biosíntesis , MicroARNs/metabolismo , Adulto , Linfocitos T CD4-Positivos/virología , Citometría de Flujo , Regulación de la Expresión Génica/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Humanos , Interleucina-10/análisis , Interleucina-10/inmunología , Masculino , MicroARNs/genética , MicroARNs/inmunología , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/análisis , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
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