RESUMO
The new biologics have great potential to help patients with hitherto uncurable diseases. But their exorbitant costs challenges the basis of health care systems based on equity.
Assuntos
Produtos Biológicos , Custos de Medicamentos , Humanos , Produtos Biológicos/economiaRESUMO
Genetics is often referred to as the blueprint of life, but it tells only part of the story. We need to put more emphasis on understanding epigenetics as life style, including diet, has a determining role in our health mediated through epigenetics.
Assuntos
Epigenômica , Nível de Saúde , Dieta , Estilo de Vida , HumanosRESUMO
The prospects of PhD students and postdocs have become ever more precarious. Without reforms of academic research and funding, science may experience a major brain drain.
Assuntos
Pesquisadores , Estudantes , Humanos , Escolha da Profissão , Pessoal de SaúdeRESUMO
The pandemic is over, thanks in part to rapid development of vaccines. Why then does it take so long to develop therapies for other major diseases?
Assuntos
Doença Crônica , Pandemias , Pandemias/prevenção & controle , Doença Crônica/terapiaRESUMO
Science often looks for simplicity in explaining reality. In biology, however, a simple explanation is often not a correct one.
RESUMO
When will COVID-19 ever end? Various countries employ different strategies to address this; time will tell what the best response was.
Assuntos
COVID-19 , Humanos , SARS-CoV-2RESUMO
Public funding for basic research rests on a delicate balance between scientists, governments and the public. COVID could further shift this equilibrium towards translation and application.
Assuntos
COVID-19 , Motivação , Governo , Humanos , SARS-CoV-2RESUMO
COVID-19 highlighted the importance of science and scientists to produce vaccines, cures and diagnostics. But scientists need to be careful not to overpromise on what they can deliver.
Assuntos
Pesquisa Biomédica , COVID-19/prevenção & controle , Pandemias , Antivirais , Pesquisa Biomédica/normas , Vacinas contra COVID-19 , Humanos , Saúde Pública , PesquisadoresRESUMO
Frank Gannon looks back before the start of EMBO reports and how and why it was founded 20 years ago.
RESUMO
G9a is an epigenetic regulator that methylates H3K9, generally causing repression of gene expression, and participates in diverse cellular functions. G9a is genetically deregulated in a variety of tumor types and can silence tumor suppressor genes and, therefore, is important for carcinogenesis. Although hypoxia is recognized to be an adverse factor in tumor growth and metastasis, the role of G9a in regulating gene expression in hypoxia has not been described extensively. Here, we show that G9a protein stability is increased in hypoxia via reduced proline hydroxylation and, hence, inefficient degradation by the proteasome. This inefficiency leads to an increase in H3K9me2 at its target promoters. Blocking the methyltransferase activity of G9a inhibited cellular proliferation and migration in vitro and tumor growth in vivo. Furthermore, an increased level of G9a is a crucial factor in mediating the hypoxic response by down-regulating the expression of specific genes, including ARNTL, CEACAM7, GATA2, HHEX, KLRG1, and OGN This down-regulation can be rescued by a small molecule inhibitor of G9a. Based on the hypothesis that the changes in gene expression would influence patient outcomes, we have developed a prognostic G9a-suppressed gene signature that can stratify breast cancer patients. Together, our findings provide an insight into the role G9a plays as an epigenetic mediator of hypoxic response, which can be used as a diagnostic marker, and proposes G9a as a therapeutic target for solid cancers.
Assuntos
Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Hipóxia/genética , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células , Intervalo Livre de Doença , Epigênese Genética , Feminino , Perfilação da Expressão Gênica , Humanos , Células MCF-7 , Neoplasias Mamárias Experimentais/genética , Camundongos , Camundongos Endogâmicos C57BL , Prognóstico , Prolina/química , Processamento de Proteína Pós-Traducional , RNA Interferente Pequeno/metabolismo , Recidiva , Microambiente TumoralRESUMO
Osteogenesis imperfecta (OI) is a group of genetic disorders characterized by bone fragility and deformity. OI type VI is unique owing to the mineralization defects observed in patient biopsies. Furthermore, it has been reported to respond less well to standard therapy with bisphosphonates [1]. Others and we have previously identified SERPINF1 mutations in patients with OI type VI. SERPINF1 encodes pigment epithelium derived factor (PEDF), a secreted collagen-binding glycoprotein that is absent in the sera of patients with OI type VI. Serpinf1 null mice show increased osteoid and decreased bone mass, and thus recapitulate the OI type VI phenotype. We tested whether restoration of circulating PEDF in the blood could correct the phenotype of OI type VI in the context of protein replacement. To do so, we utilized a helper-dependent adenoviral vector (HDAd) to express human SERPINF1 in the mouse liver and assessed whether PEDF secreted from the liver was able to rescue the bone phenotype observed in Serpinf1(-/-) mice. We confirmed that expression of SERPINF1 in the liver restored the serum level of PEDF. We also demonstrated that PEDF secreted from the liver was biologically active by showing the expected metabolic effects of increased adiposity and impaired glucose tolerance in Serpinf1(-/-) mice. Interestingly, overexpression of PEDF in vitro increased mineralization with a concomitant increase in the expression of bone gamma-carboxyglutamate protein, alkaline phosphatase and collagen, type I, alpha I, but the increased serum PEDF level did not improve the bone phenotype of Serpinf1(-/-) mice. These results suggest that PEDF may function in a context-dependent and paracrine fashion in bone homeostasis.
Assuntos
Osso e Ossos/fisiologia , Proteínas do Olho/sangue , Proteínas do Olho/genética , Fígado/metabolismo , Fatores de Crescimento Neural/sangue , Fatores de Crescimento Neural/genética , Osteogênese Imperfeita/fisiopatologia , Osteogênese Imperfeita/terapia , Serpinas/sangue , Serpinas/genética , Ácido 1-Carboxiglutâmico/genética , Adenoviridae/genética , Fosfatase Alcalina/genética , Animais , Densidade Óssea , Colágeno Tipo I/genética , Técnicas de Transferência de Genes , Intolerância à Glucose , Células HEK293 , Homeostase , Humanos , Camundongos , Camundongos Knockout , Mutação , Fatores de Crescimento Neural/deficiência , Fenótipo , Serpinas/deficiênciaRESUMO
Methylation of CpG dinucleotides is generally associated with epigenetic silencing of transcription and is maintained through cellular division. Multiple CpG sequences are rare in mammalian genomes, but frequently occur at the transcriptional start site of active genes, with most clusters of CpGs being hypomethylated. We reported previously that the proximal region of the trefoil factor 1 (TFF1, also known as pS2) and oestrogen receptor alpha (ERalpha) promoters could be partially methylated by treatment with deacetylase inhibitors, suggesting the possibility of dynamic changes in DNA methylation. Here we show that cyclical methylation and demethylation of CpG dinucleotides, with a periodicity of around 100 min, is characteristic for five selected promoters, including the oestrogen (E2)-responsive pS2 gene, in human cells. When the pS2 gene is actively transcribed, DNA methylation occurs after the cyclical occupancy of ERalpha and RNA polymerase II (polII). Moreover, we report conditions that provoke methylation cycling of the pS2 promoter in cell lines in which pS2 expression is quiescent and the proximal promoter is methylated. This coincides with a low-level re-expression of ERalpha and of pS2 transcripts.
Assuntos
Metilação de DNA , DNA/metabolismo , Regulação da Expressão Gênica , Regiões Promotoras Genéticas/genética , Linhagem Celular Tumoral , Ilhas de CpG/genética , DNA/genética , Metilação de DNA/efeitos dos fármacos , Doxorrubicina/farmacologia , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , RNA Polimerase II/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , Fator Trefoil-1 , Proteínas Supressoras de Tumor/genéticaRESUMO
Processes that regulate gene transcription are directly under the influence of the genome organization. The epigenome contains additional information that is not brought by DNA sequence, and generates spatial and functional constraints that complement genetic instructions. DNA methylation on CpGs constitutes an epigenetic mark generally correlated with transcriptionally silent condensed chromatin. Replication of methylation patterns by DNA methyltransferases maintains genome stability through cell division. Here we present evidence of an unanticipated dynamic role for DNA methylation in gene regulation in human cells. Periodic, strand-specific methylation/demethylation occurs during transcriptional cycling of the pS2/TFF1 gene promoter on activation by oestrogens. DNA methyltransferases exhibit dual actions during these cycles, being involved in CpG methylation and active demethylation of 5mCpGs through deamination. Inhibition of this process precludes demethylation of the pS2 gene promoter and its subsequent transcriptional activation. Cyclical changes in the methylation status of promoter CpGs may thus represent a critical event in transcriptional achievement.