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1.
Cell ; 171(4): 934-949.e16, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-29033130

RESUMO

The mechanisms by which immune checkpoint blockade modulates tumor evolution during therapy are unclear. We assessed genomic changes in tumors from 68 patients with advanced melanoma, who progressed on ipilimumab or were ipilimumab-naive, before and after nivolumab initiation (CA209-038 study). Tumors were analyzed by whole-exome, transcriptome, and/or T cell receptor (TCR) sequencing. In responding patients, mutation and neoantigen load were reduced from baseline, and analysis of intratumoral heterogeneity during therapy demonstrated differential clonal evolution within tumors and putative selection against neoantigenic mutations on-therapy. Transcriptome analyses before and during nivolumab therapy revealed increases in distinct immune cell subsets, activation of specific transcriptional networks, and upregulation of immune checkpoint genes that were more pronounced in patients with response. Temporal changes in intratumoral TCR repertoire revealed expansion of T cell clones in the setting of neoantigen loss. Comprehensive genomic profiling data in this study provide insight into nivolumab's mechanism of action.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Imunoterapia , Melanoma/terapia , Microambiente Tumoral , Estudo de Associação Genômica Ampla , Humanos , Melanoma/genética , Melanoma/imunologia , Nivolumabe , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Linfócitos T , Transcriptoma
2.
Br J Sociol ; 75(1): 65-72, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37731176

RESUMO

One part of the social construction of race is the symbolic association of given physical features with different races. This research note explores the utility of eye tracking for sociological research on racial perception, that is, for determining what race someone 'looks like.' Results reveal that participants gave greatest attention to targets' hair. This was especially so when targets of all races had straight hair or when a target identified as Black/White mixed-race. The mixed-race results in particular provide physiological evidence of the theory of multiracial dissection. We conclude by suggesting that eye tracking can be useful to sociologists by revealing subconscious tendencies and biases which, once identified, can be consciously addressed in service to reducing social disparities.


Assuntos
Tecnologia de Rastreamento Ocular , Grupos Raciais , Humanos
4.
Int J Mol Sci ; 21(12)2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32580345

RESUMO

The treatment for ovarian cancers includes chemotherapies which use drugs such as cisplatin, paclitaxel, carboplatin, platinum, taxanes, or their combination, and other molecular target therapies. However, these current therapies are often accompanied with side effects. Vernonia calvoana (VC) is a valuable edible medicinal plant that is widespread in West Africa. In vitro data in our lab demonstrated that VC crude extract inhibits human ovarian cancer cells in a dose-dependent manner, suggesting its antitumor activity. From the VC crude extract, we have generated 10 fractions and VC fraction 7 (F7) appears to show the highest antitumor activity towards ovarian cancer cells. However, the mechanisms by which VC F7 exerts its antitumor activity in cancer cells remain largely unknown. We hypothesized that VC F7 inhibits cell proliferation and induces DNA damage and cell cycle arrest in ovarian cells through oxidative stress. To test our hypothesis, we extracted and fractionated VC leaves. The effects of VC F7 were tested in OVCAR-3 cells. Viability was assessed by the means of MTS assay. Cell morphology was analyzed by acridine orange and propidium iodide (AO/PI) dye using a fluorescent microscope. Oxidative stress biomarkers were evaluated by the means of lipid peroxidation, catalase, and glutathione peroxidase assays, respectively. The degree of DNA damage was assessed by comet assay. Cell cycle distribution was assessed by flow cytometry. Data generated from the MTS assay demonstrated that VC F7 inhibits the growth of OVCAR-3 cells in a dose-dependent manner, showing a gradual increase in the loss of viability in VC F7-treated cells. Data obtained from the AO/PI dye assessment revealed morphological alterations and exhibited characteristics such as loss of cellular membrane integrity, cell shrinkage, cell membrane damage, organelle breakdown, and detachment from the culture plate. We observed a significant increase (p < 0.05) in the levels of malondialdhyde (MDA) production in treated cells compared to the control. A gradual decrease in both catalase and glutathione peroxidase activities were observed in the treated cells compared to the control. Data obtained from the comet assay showed a significant increase (p < 0.05) in the percentages of DNA cleavage and comet tail length. The results of the flow cytometry analysis indicated VC F7 treatment caused cell cycle arrest at the S-phase checkpoint. Taken together, our results demonstrate that VC F7 exerts its anticancer activity by inhibiting cell proliferation, inducing DNA damage, and causing cell cycle arrest through oxidative stress in OVAR-3 cells. This finding suggests that VC F7 may be a potential alternative dietary agent for the prevention and/or treatment of ovarian cancer.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Vernonia/química , Apoptose , Ciclo Celular , Proliferação de Células , Ensaio Cometa , Dano ao DNA , Feminino , Humanos , Neoplasias Ovarianas/patologia , Células Tumorais Cultivadas
5.
Adv Exp Med Biol ; 1152: 31-49, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31456178

RESUMO

Breast cancer is the most common noncutaneous malignancy and the second most lethal form of cancer among women in the United States. It currently affects more than one in ten women worldwide. The chance for a female to be diagnosed with breast cancer during her lifetime has significantly increased from 1 in 11 women in 1975 to 1 in 8 women (Altekruse, SEER Cancer Statistics Review, 1975-2007. National Cancer Institute, Bethesda, 2010). This chance for a female of being diagnosed with cancer generally increases with age (Howlader et al, SEER Cancer Statistics Review, 1975-2010. National Cancer Institute, Bethesda, 2013). Fortunately, the mortality rate from breast cancer has decreased in recent years due to increased emphasis on early detection and more effective treatments in the White population. Although the mortality rates have declined in some ethnic populations, the overall cancer incidence among African American and Hispanic population has continued to grow. The goal of the work presented in this book chapter is to highlight similarities and differences in breast cancer morbidity and mortality rates among non-Hispanic white and non-Hispanic black populations. This book chapter also provides an overview of breast cancer, racial/ethnic disparities in breast cancer, breast cancer incidence and mortality rate linked to hereditary, major risk factors of breast cancer among minority population, breast cancer treatment, and health disparity. A considerable amount of breast cancer treatment research have been conducted, but with limited success for African Americans compared to other ethnic groups. Therefore, new strategies and approaches are needed to promote breast cancer prevention, improve survival rates, reduce breast cancer mortality, and ultimately improve the health outcomes of racial/ethnic minorities. In addition, it is vital that leaders and medical professionals from minority population groups be represented in decision-making in research so that racial disparity in breast cancer can be well-studied, fully addressed, and ultimately eliminated in breast cancer.


Assuntos
Neoplasias da Mama/etnologia , Neoplasias da Mama/epidemiologia , Disparidades nos Níveis de Saúde , Negro ou Afro-Americano , Feminino , Humanos , Estados Unidos/epidemiologia , População Branca
6.
Proc Natl Acad Sci U S A ; 113(25): E3529-37, 2016 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-27261081

RESUMO

Although immune signaling has emerged as a defining feature of the glioma microenvironment, how the underlying structure of the glioma-infiltrating T-cell population differs from that of the blood from which it originates has been difficult to measure directly in patients. High-throughput sequencing of T-cell receptor (TCR) repertoires (TCRseq) provides a population-wide statistical description of how T cells respond to disease. We have defined immunophenotypes of whole repertoires based on TCRseq of the α- and ß-chains from glioma tissue, nonneoplastic brain tissue, and peripheral blood from patients. Using information theory, we partitioned the diversity of these TCR repertoires into that from the distribution of VJ cassette combinations and diversity due to VJ-independent factors, such as selection due to antigen binding. Tumor-infiltrating lymphocytes (TILs) possessed higher VJ-independent diversity than nonneoplastic tissue, stratifying patients according to tumor grade. We found that the VJ-independent components of tumor-associated repertoires diverge more from their corresponding peripheral repertoires than T-cell populations in nonneoplastic brain tissue, particularly for low-grade gliomas. Finally, we identified a "signature" set of TCRs whose use in peripheral blood is associated with patients exhibiting low TIL divergence and is depleted in patients with highly divergent TIL repertoires. This signature is detectable in peripheral blood, and therefore accessible noninvasively. We anticipate that these immunophenotypes will be foundational to monitoring and predicting response to antiglioma vaccines and immunotherapy.


Assuntos
Neoplasias Encefálicas/patologia , Glioma/patologia , Linfócitos do Interstício Tumoral/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Neoplasias Encefálicas/imunologia , Glioma/imunologia , Humanos
7.
Prev Chronic Dis ; 16: E21, 2019 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-30767859

RESUMO

INTRODUCTION: On average, more than 1,700 people in Mississippi die from stroke annually, but data on trends by age, sex, and race in Mississippi are limited. We examined trends in the stroke death rate among adults in Mississippi aged 35 or older by age, sex, and race. METHODS: We used Mississippi Vital Statistics data to calculate age-specific death rates for stroke among people in Mississippi aged 35 or older from 2000 to 2016. We identified cases according to underlying cause-of-death codes from the International Classification of Diseases, Tenth Revision (ICD-10). We used Joinpoint software to calculate annual percentage change (APC) and the average annual percentage change (AAPC) in death rates for stroke by age, sex, and race (non-Hispanic black and non-Hispanic white). RESULTS: Among adults aged 35 or older, the age-adjusted stroke death rate declined 30.7% from 141.3 per 100,000 population in 2000 to 97.9 per 100,000 population in 2016, with an AAPC of -2.4% (95% confidence interval, -3.1% to -1.6%). Stroke death rates declined significantly among both men and women in the first trend segment (2000-2009 for men and 2000-2007 for women) but did not decline in the second trend segment (2009-2016 for men and 2007-2016 for women). Non-Hispanic black men had the smallest decline in stroke death rates during the full study period. Among people aged 55 to 64 and non-Hispanic white men, rates shifted from a significant annual decline during the first segment to a significant annual increase during the second segment. CONCLUSION: Age-adjusted stroke death rates among adults in Mississippi aged 35 or older declined significantly between 2000 and 2016, but trends differed by age, race, and sex. Clinical and community interventions aimed at reducing stroke risk factors, particularly for adults aged 55 to 64, are needed in Mississippi.


Assuntos
Acidente Vascular Cerebral/mortalidade , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Causas de Morte/tendências , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Mississippi/epidemiologia , Distribuição por Sexo , Acidente Vascular Cerebral/etnologia , População Branca/estatística & dados numéricos
8.
Nature ; 484(7395): 519-23, 2012 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-22446628

RESUMO

The 2009 H1N1 influenza pandemic showed the speed with which a novel respiratory virus can spread and the ability of a generally mild infection to induce severe morbidity and mortality in a subset of the population. Recent in vitro studies show that the interferon-inducible transmembrane (IFITM) protein family members potently restrict the replication of multiple pathogenic viruses. Both the magnitude and breadth of the IFITM proteins' in vitro effects suggest that they are critical for intrinsic resistance to such viruses, including influenza viruses. Using a knockout mouse model, we now test this hypothesis directly and find that IFITM3 is essential for defending the host against influenza A virus in vivo. Mice lacking Ifitm3 display fulminant viral pneumonia when challenged with a normally low-pathogenicity influenza virus, mirroring the destruction inflicted by the highly pathogenic 1918 'Spanish' influenza. Similar increased viral replication is seen in vitro, with protection rescued by the re-introduction of Ifitm3. To test the role of IFITM3 in human influenza virus infection, we assessed the IFITM3 alleles of individuals hospitalized with seasonal or pandemic influenza H1N1/09 viruses. We find that a statistically significant number of hospitalized subjects show enrichment for a minor IFITM3 allele (SNP rs12252-C) that alters a splice acceptor site, and functional assays show the minor CC genotype IFITM3 has reduced influenza virus restriction in vitro. Together these data reveal that the action of a single intrinsic immune effector, IFITM3, profoundly alters the course of influenza virus infection in mouse and humans.


Assuntos
Vírus da Influenza A/patogenicidade , Proteínas de Membrana/metabolismo , Infecções por Orthomyxoviridae/mortalidade , Proteínas de Ligação a RNA/metabolismo , Alelos , Sequência de Aminoácidos , Animais , Citocinas/imunologia , Inglaterra/epidemiologia , Deleção de Genes , Humanos , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/crescimento & desenvolvimento , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/crescimento & desenvolvimento , Vírus da Influenza A Subtipo H3N2/patogenicidade , Vírus da Influenza A/classificação , Vírus da Influenza A/crescimento & desenvolvimento , Vírus da Influenza B/classificação , Vírus da Influenza B/crescimento & desenvolvimento , Vírus da Influenza B/patogenicidade , Influenza Humana/complicações , Influenza Humana/epidemiologia , Influenza Humana/mortalidade , Influenza Humana/virologia , Leucócitos/imunologia , Pulmão/patologia , Pulmão/virologia , Proteínas de Membrana/química , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Dados de Sequência Molecular , Infecções por Orthomyxoviridae/complicações , Infecções por Orthomyxoviridae/patologia , Pneumonia Viral/etiologia , Pneumonia Viral/patologia , Pneumonia Viral/prevenção & controle , Polimorfismo de Nucleotídeo Único/genética , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Escócia/epidemiologia , Replicação Viral
9.
Proc Natl Acad Sci U S A ; 111(34): 12550-5, 2014 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-25114226

RESUMO

Glioblastomas (GBMs) diffusely infiltrate the brain, making complete removal by surgical resection impossible. The mixture of neoplastic and nonneoplastic cells that remain after surgery form the biological context for adjuvant therapeutic intervention and recurrence. We performed RNA-sequencing (RNA-seq) and histological analysis on radiographically guided biopsies taken from different regions of GBM and showed that the tissue contained within the contrast-enhancing (CE) core of tumors have different cellular and molecular compositions compared with tissue from the nonenhancing (NE) margins of tumors. Comparisons with the The Cancer Genome Atlas dataset showed that the samples from CE regions resembled the proneural, classical, or mesenchymal subtypes of GBM, whereas the samples from the NE regions predominantly resembled the neural subtype. Computational deconvolution of the RNA-seq data revealed that contributions from nonneoplastic brain cells significantly influence the expression pattern in the NE samples. Gene ontology analysis showed that the cell type-specific expression patterns were functionally distinct and highly enriched in genes associated with the corresponding cell phenotypes. Comparing the RNA-seq data from the GBM samples to that of nonneoplastic brain revealed that the differentially expressed genes are distributed across multiple cell types. Notably, the patterns of cell type-specific alterations varied between the different GBM subtypes: the NE regions of proneural tumors were enriched in oligodendrocyte progenitor genes, whereas the NE regions of mesenchymal GBM were enriched in astrocytic and microglial genes. These subtype-specific patterns provide new insights into molecular and cellular composition of the infiltrative margins of GBM.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Glioblastoma/genética , Glioblastoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/classificação , Meios de Contraste , Feminino , Glioblastoma/classificação , Humanos , Biópsia Guiada por Imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , RNA Neoplásico/genética , Análise de Sequência de RNA , Transcriptoma , Microambiente Tumoral
10.
Nucleic Acids Res ; 42(6): 3580-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24423864

RESUMO

PR-Set7/Set8/KMT5a is the sole histone H4 lysine 20 monomethyltransferase (H4K20me1) in metazoans and is essential for proper cell division and genomic stability. We unexpectedly discovered that normal cellular levels of monomethylated histone H3 lysine 9 (H3K9me1) were also dependent on PR-Set7, but independent of its catalytic activity. This observation suggested that PR-Set7 interacts with an H3K9 monomethyltransferase to establish the previously reported H4K20me1-H3K9me1 trans-tail 'histone code'. Here we show that PR-Set7 specifically and directly binds the C-terminus of the Riz1/PRDM2/KMT8 tumor suppressor and demonstrate that the N-terminal PR/SET domain of Riz1 preferentially monomethylates H3K9. The PR-Set7 binding domain was required for Riz1 nuclear localization and maintenance of the H4K20me1-H3K9me1 trans-tail 'histone code'. Although Riz1 can function as a repressor, Riz1/H3K9me1 was dispensable for the repression of genes regulated by PR-Set7/H4K20me1. Frameshift mutations resulting in a truncated Riz1 incapable of binding PR-Set7 occur frequently in various aggressive cancers. In these cancer cells, expression of wild-type Riz1 restored tumor suppression by decreasing proliferation and increasing apoptosis. These phenotypes were not observed in cells expressing either the Riz1 PR/SET domain or PR-Set7 binding domain indicating that Riz1 methyltransferase activity and PR-Set7 binding domain are both essential for Riz1 tumor suppressor function.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Código das Histonas , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/enzimologia , Proteínas de Ligação a DNA/química , Regulação da Expressão Gênica , Células HEK293 , Células HeLa , Histona-Lisina N-Metiltransferase/química , Humanos , Proteínas Nucleares/química , Domínios e Motivos de Interação entre Proteínas , Fatores de Transcrição/química , Proteínas Supressoras de Tumor/química
11.
J Neurosci ; 34(33): 10924-36, 2014 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-25122893

RESUMO

Glioma growth is driven by signaling that ultimately regulates protein synthesis. Gliomas are also complex at the cellular level and involve multiple cell types, including transformed and reactive cells in the brain tumor microenvironment. The distinct functions of the various cell types likely lead to different requirements and regulatory paradigms for protein synthesis. Proneural gliomas can arise from transformation of glial progenitors that are driven to proliferate via mitogenic signaling that affects translation. To investigate translational regulation in this system, we developed a RiboTag glioma mouse model that enables cell-type-specific, genome-wide ribosome profiling of tumor tissue. Infecting glial progenitors with Cre-recombinant retrovirus simultaneously activates expression of tagged ribosomes and delivers a tumor-initiating mutation. Remarkably, we find that although genes specific to transformed cells are highly translated, their translation efficiencies are low compared with normal brain. Ribosome positioning reveals sequence-dependent regulation of ribosomal activity in 5'-leaders upstream of annotated start codons, leading to differential translation in glioma compared with normal brain. Additionally, although transformed cells express a proneural signature, untransformed tumor-associated cells, including reactive astrocytes and microglia, express a mesenchymal signature. Finally, we observe the same phenomena in human disease by combining ribosome profiling of human proneural tumor and non-neoplastic brain tissue with computational deconvolution to assess cell-type-specific translational regulation.


Assuntos
Neoplasias Encefálicas/metabolismo , Transformação Celular Neoplásica/metabolismo , Glioma/metabolismo , Ribossomos/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Transformação Celular Neoplásica/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Glioma/patologia , Humanos , Camundongos , Ribossomos/genética
12.
J Neurooncol ; 123(3): 359-72, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25724916

RESUMO

The term "biomarker" historically refers to a single parameter, such as the expression level of a gene or a radiographic pattern, used to indicate a broader biological state. Molecular indicators have been applied to several aspects of cancer therapy: to describe the genotypic and phenotypic state of neoplastic tissue for prognosis, to predict susceptibility to anti-proliferative agents, to validate the presence of specific drug targets, and to evaluate responsiveness to therapy. For glioblastoma (GBM), immunohistochemical and radiographic biomarkers accessible to the clinical lab have informed traditional regimens, but while immunotherapies have emerged as potentially disruptive weapons against this diffusely infiltrating, heterogeneous tumor, biomarkers with strong predictive power have not been fully established. The cancer immunotherapy field, through the recently accelerated expansion of trials, is currently leveraging this wealth of clinical and biological data to define and revise the use of biomarkers for improving prognostic accuracy, personalization of therapy, and evaluation of responses across the wide variety of tumors. Technological advancements in DNA sequencing, cytometry, and microscopy have facilitated the exploration of more integrated, high-dimensional profiling of the disease system-incorporating both immune and tumor parameters-rather than single metrics, as biomarkers for therapeutic sensitivity. Here we discuss the utility of traditional GBM biomarkers in immunotherapy and how the impending transformation of the biomarker paradigm-from single markers to integrated profiles-may offer the key to bringing predictive, personalized immunotherapy to GBM patients.


Assuntos
Biomarcadores Tumorais/imunologia , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/terapia , Glioblastoma/terapia , Imunoterapia/métodos , Humanos , Imunoterapia/tendências
13.
Toxicol Pathol ; 43(7): 959-83, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26239651

RESUMO

PEGylation (the covalent binding of one or more polyethylene glycol molecules to another molecule) is a technology frequently used to improve the half-life and other pharmaceutical or pharmacological properties of proteins, peptides, and aptamers. To date, 11 PEGylated biopharmaceuticals have been approved and there is indication that many more are in nonclinical or clinical development. Adverse effects seen with those in toxicology studies are mostly related to the active part of the drug molecule and not to polyethylene glycol (PEG). In 5 of the 11 approved and 10 of the 17 PEGylated biopharmaceuticals in a 2013 industry survey presented here, cellular vacuolation is histologically observed in toxicology studies in certain organs and tissues. No other effects attributed to PEG alone have been reported. Importantly, vacuolation, which occurs mainly in phagocytes, has not been linked with changes in organ function in these toxicology studies. This article was authored through collaborative efforts of industry toxicologists/nonclinical scientists to address the nonclinical safety of large PEG molecules (>10 kilo Dalton) in PEGylated biopharmaceuticals. The impact of the PEG molecule on overall nonclinical safety assessments of PEGylated biopharmaceuticals is discussed, and toxicological information from a 2013 industry survey on PEGylated biopharmaceuticals under development is summarized. Results will contribute to the database of toxicological information publicly available for PEG and PEGylated biopharmaceuticals.


Assuntos
Avaliação Pré-Clínica de Medicamentos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Polietilenoglicóis/toxicidade , Animais , Humanos , Polietilenoglicóis/química
14.
Biochem J ; 459(3): 505-12, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24576085

RESUMO

The tandem PHD (plant homeodomain) fingers of the CHD4 (chromodomain helicase DNA-binding protein 4) ATPase are epigenetic readers that bind either unmodified histone H3 tails or H3K9me3 (histone H3 trimethylated at Lys9). This dual function is necessary for the transcriptional and chromatin remodelling activities of the NuRD (nucleosome remodelling and deacetylase) complex. In the present paper, we show that calixarene-based supramolecular hosts disrupt binding of the CHD4 PHD2 finger to H3K9me3, but do not affect the interaction of this protein with the H3K9me0 (unmodified histone H3) tail. A similar inhibitory effect, observed for the association of chromodomain of HP1γ (heterochromatin protein 1γ) with H3K9me3, points to a general mechanism of methyl-lysine caging by calixarenes and suggests a high potential for these compounds in biochemical applications. Immunofluorescence analysis reveals that the supramolecular agents induce changes in chromatin organization that are consistent with their binding to and disruption of H3K9me3 sites in living cells. The results of the present study suggest that the aromatic macrocyclic hosts can be used as a powerful new tool for characterizing methylation-driven epigenetic mechanisms.


Assuntos
Calixarenos/farmacologia , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Desenho de Fármacos , Histonas/antagonistas & inibidores , Indicadores e Reagentes/farmacologia , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/antagonistas & inibidores , Modelos Moleculares , Autoantígenos/química , Autoantígenos/genética , Autoantígenos/metabolismo , Calixarenos/síntese química , Calixarenos/química , Proteínas Cromossômicas não Histona/antagonistas & inibidores , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Epigênese Genética/efeitos dos fármacos , Células HEK293 , Histonas/metabolismo , Proteínas de Homeodomínio/antagonistas & inibidores , Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Prolina Dioxigenases do Fator Induzível por Hipóxia/antagonistas & inibidores , Prolina Dioxigenases do Fator Induzível por Hipóxia/química , Prolina Dioxigenases do Fator Induzível por Hipóxia/genética , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Indicadores e Reagentes/síntese química , Indicadores e Reagentes/química , Lisina/análogos & derivados , Lisina/metabolismo , Metilação , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/química , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Processamento de Proteína Pós-Traducional , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/química , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo
15.
Proc Natl Acad Sci U S A ; 109(3): 787-92, 2012 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-22215588

RESUMO

CHD4 is a catalytic subunit of the NuRD (nucleosome remodeling and deacetylase) complex essential in transcriptional regulation, chromatin assembly and DNA damage repair. CHD4 contains tandem plant homeodomain (PHD) fingers connected by a short linker, the biological function of which remains unclear. Here we explore the combinatorial action of the CHD4 PHD1/2 fingers and detail the molecular basis for their association with chromatin. We found that PHD1/2 targets nucleosomes in a multivalent manner, concomitantly engaging two histone H3 tails. This robust synergistic interaction displaces HP1γ from pericentric sites, inducing changes in chromatin structure and leading to the dispersion of the heterochromatic mark H3K9me3. We demonstrate that recognition of the histone H3 tails by the PHD fingers is required for repressive activity of the CHD4/NuRD complex. Together, our data elucidate the molecular mechanism of multivalent association of the PHD fingers with chromatin and reveal their critical role in the regulation of CHD4 functions.


Assuntos
Proteínas de Homeodomínio/química , Proteínas de Homeodomínio/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Nucleossomos/metabolismo , Proteínas Repressoras/metabolismo , Sequência de Aminoácidos , Células HEK293 , Heterocromatina/metabolismo , Histonas/metabolismo , Humanos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/química , Modelos Moleculares , Dados de Sequência Molecular , Processamento de Proteína Pós-Traducional , Estrutura Terciária de Proteína , Transcrição Gênica
16.
BMC Cancer ; 14: 278, 2014 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-24758297

RESUMO

BACKGROUND: The transcription factor GATA3 is a favorable prognostic indicator in estrogen receptor-α (ERα)-positive breast tumors in which it participates with ERα and FOXA1 in a complex transcriptional regulatory program driving tumor growth. GATA3 mutations are frequent in breast cancer and have been classified as driver mutations. To elucidate the contribution(s) of GATA3 alterations to cancer, we studied two breast cancer cell lines, MCF7, which carries a heterozygous frameshift mutation in the second zinc finger of GATA3, and T47D, wild-type at this locus. METHODS: Immunofluorescence staining and subcellular fractionation were employed to verify cellular localization of GATA3 in T47D and MCF7 cells. To test protein stability, cells were treated with translation inhibitor, cycloheximide or proteasome inhibitor, MG132, and GATA3 abundance was measured over time using immunoblot. GATA3 turn-over in response to hormone was determined by treating the cells with estradiol or ERα agonist, ICI 182,780. DNA binding ability of recombinant GATA3 was evaluated using electrophoretic mobility shift assay and heparin chromatography. Genomic location of GATA3 in MCF7 and T47D cells was assessed by chromatin immunoprecipitation coupled with next-generation sequencing (ChIP-seq). RESULTS: GATA3 localized in the nucleus in T47D and MCF7 cells, regardless of the mutation status. The truncated protein in MCF7 had impaired interaction with chromatin and was easily released from the nucleus. Recombinant mutant GATA3 was able to bind DNA to a lesser degree than the wild-type protein. Heterozygosity for the truncating mutation conferred protection from regulated turnover of GATA3, ERα and FOXA1 following estrogen stimulation in MCF7 cells. Thus, mutant GATA3 uncoupled protein-level regulation of master regulatory transcription factors from hormone action. Consistent with increased protein stability, ChIP-seq profiling identified greater genome-wide accumulation of GATA3 in MCF7 cells bearing the mutation, albeit with a similar distribution across the genome, comparing to T47D cells. CONCLUSIONS: We propose that this specific, cancer-derived mutation in GATA3 deregulates physiologic protein turnover, stabilizes GATA3 binding across the genome and modulates the response of breast cancer cells to estrogen signaling.


Assuntos
Neoplasias da Mama/genética , Estrogênios/farmacologia , Fator de Transcrição GATA3/genética , Transcrição Gênica/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Receptor alfa de Estrogênio/metabolismo , Estrogênios/metabolismo , Feminino , Fator de Transcrição GATA3/metabolismo , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Humanos , Células MCF-7 , Mutação , Estabilidade Proteica/efeitos dos fármacos
17.
Mol Ther Methods Clin Dev ; 32(4): 101342, 2024 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-39429724

RESUMO

Mesial temporal lobe epilepsy (mTLE) is the most prevalent type of epilepsy in adults. First and subsequent generations of anti-epileptic therapy regimens fail to decrease seizures in a large number of patients suffering from mTLE, leaving surgical ablation of part of the hippocampus as the only therapeutic option to potentially reach seizure freedom. GluK2 has recently been identified as a promising target for the treatment of mTLE using gene therapy. Here, we engineered an adeno-associated virus serotype 9 vector expressing a cluster of two synthetic microRNAs (miRNAs), expressed from the human synapsin promoter, that target GRIK2 mRNA. Intra-hippocampal delivery of this vector in a mouse model of mTLE significantly reduced GRIK2 expression and daily seizure frequency. This treatment also improved the animals' health, reduced their anxiety, and restored working memory. Focal administration of the vector to the hippocampus of cynomolgus monkeys in GLP toxicology studies led to the selective transduction of hippocampal neurons with little exposure elsewhere in the brain and no transduction outside the central nervous system. Expression of miRNAs in hippocampal neurons resulted in substantially decreased GRIK2 mRNA expression. These data suggest that the intra-hippocampal delivery of a GMP-grade AAV9 encoding a synthetic miRNAs targeting GRIK2 is a promising treatment strategy for mTLE.

18.
PLoS Pathog ; 7(10): e1002337, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22046135

RESUMO

To replicate, viruses must gain access to the host cell's resources. Interferon (IFN) regulates the actions of a large complement of interferon effector genes (IEGs) that prevent viral replication. The interferon inducible transmembrane protein family members, IFITM1, 2 and 3, are IEGs required for inhibition of influenza A virus, dengue virus, and West Nile virus replication in vitro. Here we report that IFN prevents emergence of viral genomes from the endosomal pathway, and that IFITM3 is both necessary and sufficient for this function. Notably, viral pseudoparticles were inhibited from transferring their contents into the host cell cytosol by IFN, and IFITM3 was required and sufficient for this action. We further demonstrate that IFN expands Rab7 and LAMP1-containing structures, and that IFITM3 overexpression is sufficient for this phenotype. Moreover, IFITM3 partially resides in late endosomal and lysosomal structures, placing it in the path of invading viruses. Collectively our data are consistent with the prediction that viruses that fuse in the late endosomes or lysosomes are vulnerable to IFITM3's actions, while viruses that enter at the cell surface or in the early endosomes may avoid inhibition. Multiple viruses enter host cells through the late endocytic pathway, and many of these invaders are attenuated by IFN. Therefore these findings are likely to have significance for the intrinsic immune system's neutralization of a diverse array of threats.


Assuntos
Citosol/virologia , Vírus da Influenza A/efeitos dos fármacos , Influenza Humana/imunologia , Interferon gama/farmacologia , Proteínas de Membrana/metabolismo , Proteínas de Ligação a RNA/metabolismo , Internalização do Vírus/efeitos dos fármacos , Animais , Galinhas , Citosol/efeitos dos fármacos , Citosol/metabolismo , Células HeLa , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A/crescimento & desenvolvimento , Vírus da Influenza A/patogenicidade , Influenza Humana/virologia , Interferon gama/imunologia , Proteínas de Membrana/imunologia , Proteínas de Ligação a RNA/imunologia , Replicação Viral
19.
Front Health Serv ; 3: 1040992, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36926501

RESUMO

Objective: Scaling evidence-based interventions (EBIs) from pilot phase remains a pressing challenge in efforts to address health-related social needs (HRSN) and improve population health. This study describes an innovative approach to sustaining and further spreading DULCE (Developmental Understanding and Legal Collaboration for Everyone), a universal EBI that supports pediatric clinics to implement the American Academy of Pediatrics' Bright Futures™ guidelines for infants' well-child visits (WCVs) and introduces a new quality measure of families' HRSN resource use. Methods: Between August 2018 and December 2019, seven teams in four communities in three states implemented DULCE: four teams that had been implementing DULCE since 2016 and three new teams. Teams received monthly data reports and individualized continuous quality improvement (CQI) coaching for six months, followed by lighter-touch support via quarterly group calls (peer-to-peer learning and coaching). Run charts were used to study outcome (percent of infants that received all WCVs on time) and process measures (percent of families screened for HRSN and connected to resources). Results: Integrating three new sites was associated with an initial regression of outcome: 41% of infants received all WCVs on time, followed by improvement to 48%. Process performance was sustained or improved: among 989 participating families, 84% (831) received 1-month WCVs on time; 96% (946) were screened for seven HRSN, 54% (508) had HRSN, and 87% (444) used HRSN resources. Conclusion: An innovative, lighter-touch CQI approach to a second phase of scale-up resulted in sustainment or improvements in most processes and outcomes. Outcomes-oriented CQI measures (family receipt of resources) are an important addition to more traditional process-oriented indicators.

20.
Nat Commun ; 14(1): 5146, 2023 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-37620372

RESUMO

Radiation therapy (RT) increases tumor response to CTLA-4 inhibition (CTLA4i) in mice and in some patients, yet deep responses are rare. To identify rational combinations of immunotherapy to improve responses we use models of triple negative breast cancer highly resistant to immunotherapy in female mice. We find that CTLA4i promotes the expansion of CD4+ T helper cells, whereas RT enhances T cell clonality and enriches for CD8+ T cells with an exhausted phenotype. Combination therapy decreases regulatory CD4+ T cells and increases effector memory, early activation and precursor exhausted CD8+ T cells. A combined gene signature comprising these three CD8+ T cell clusters is associated with survival in patients. Here we show that targeting additional immune checkpoints expressed by intratumoral T cells, including PD1, is not effective, whereas CD40 agonist therapy recruits resistant tumors into responding to the combination of RT and CTLA4i, indicating the need to target different immune compartments.


Assuntos
Linfócitos T CD8-Positivos , Neoplasias de Mama Triplo Negativas , Feminino , Animais , Camundongos , Humanos , Imunoterapia , Antígenos CD40 , Terapia Combinada , Neoplasias de Mama Triplo Negativas/radioterapia
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