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2.
Otolaryngol Head Neck Surg ; 162(6): 816-817, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32312163

RESUMO

The impact of the coronavirus disease 2019 (COVID-19) pandemic on the management of head and neck cancer must be addressed. Immediate measures to reduce transmission rates and protect patients and providers take priority and necessitate some delays in care, particularly for patients with mild symptoms or less aggressive cancers. However, strict guidelines have yet to be developed, and many unintentional delays in care are to be expected based on the magnitude of the looming public health crisis. The medical complexity of head and neck cancer management may lead to prolonged delays that worsen treatment outcomes. Therefore, those caring for patients with head and neck cancer must take action to reduce these negative impacts as the country rallies to overcome the challenges posed by this pandemic.


Assuntos
Controle de Doenças Transmissíveis/organização & administração , Infecções por Coronavirus/prevenção & controle , Transmissão de Doença Infecciosa/prevenção & controle , Neoplasias de Cabeça e Pescoço/terapia , Pandemias/prevenção & controle , Segurança do Paciente , Pneumonia Viral/prevenção & controle , Gerenciamento Clínico , Surtos de Doenças/estatística & dados numéricos , Feminino , Neoplasias de Cabeça e Pescoço/epidemiologia , Neoplasias de Cabeça e Pescoço/imunologia , Humanos , Hospedeiro Imunocomprometido , Masculino , Avaliação de Resultados em Cuidados de Saúde , Pandemias/estatística & dados numéricos , Medição de Risco , Estados Unidos , Populações Vulneráveis/estatística & dados numéricos
3.
J Biol Chem ; 295(7): 1898-1914, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31792058

RESUMO

The widely expressed bromodomain and extraterminal motif (BET) proteins bromodomain-containing protein 2 (BRD2), BRD3, and BRD4 are multifunctional transcriptional regulators that bind acetylated chromatin via their conserved tandem bromodomains. Small molecules that target BET bromodomains are being tested for various diseases but typically do not discern between BET family members. Genomic distributions and protein partners of BET proteins have been described, but the basis for differences in BET protein function within a given lineage remains unclear. By establishing a gene knockout-rescue system in a Brd2-null erythroblast cell line, here we compared a series of mutant and chimeric BET proteins for their ability to modulate cell growth, differentiation, and gene expression. We found that the BET N-terminal halves bearing the bromodomains convey marked differences in protein stability but do not account for specificity in BET protein function. Instead, when BET proteins were expressed at comparable levels, their specificity was largely determined by the C-terminal half. Remarkably, a chimeric BET protein comprising the N-terminal half of the structurally similar short BRD4 isoform (BRD4S) and the C-terminal half of BRD2 functioned similarly to intact BRD2. We traced part of the BRD2-specific activity to a previously uncharacterized short segment predicted to harbor a coiled-coil (CC) domain. Deleting the CC segment impaired BRD2's ability to restore growth and differentiation, and the CC region functioned in conjunction with the adjacent ET domain to impart BRD2-like activity onto BRD4S. In summary, our results identify distinct BET protein domains that regulate protein turnover and biological activities.


Assuntos
Proteínas de Ciclo Celular/genética , Relação Estrutura-Atividade , Fatores de Transcrição/genética , Acetilação , Motivos de Aminoácidos/genética , Proteínas de Ciclo Celular/ultraestrutura , Diferenciação Celular/genética , Linhagem Celular , Proliferação de Células/genética , Cromatina/genética , Eritroblastos/química , Eritroblastos/metabolismo , Eritroblastos/ultraestrutura , Regulação da Expressão Gênica/genética , Humanos , Domínios Proteicos/genética , Isoformas de Proteínas/genética , Bibliotecas de Moléculas Pequenas/química , Fatores de Transcrição/ultraestrutura
4.
Nature ; 571(7764): 211-218, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31207603

RESUMO

Exhausted CD8+ T (Tex) cells in chronic infections and cancer have limited effector function, high co-expression of inhibitory receptors and extensive transcriptional changes compared with effector (Teff) or memory (Tmem) CD8+ T cells. Tex cells are important clinical targets of checkpoint blockade and other immunotherapies. Epigenetically, Tex cells are a distinct immune subset, with a unique chromatin landscape compared with Teff and Tmem cells. However, the mechanisms that govern the transcriptional and epigenetic development of Tex cells remain unknown. Here we identify the HMG-box transcription factor TOX as a central regulator of Tex cells in mice. TOX is largely dispensable for the formation of Teff and Tmem cells, but it is critical for exhaustion: in the absence of TOX, Tex cells do not form. TOX is induced by calcineurin and NFAT2, and operates in a feed-forward loop in which it becomes calcineurin-independent and sustained in Tex cells. Robust expression of TOX therefore results in commitment to Tex cells by translating persistent stimulation into a distinct Tex cell transcriptional and epigenetic developmental program.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Epistasia Genética , Proteínas de Homeodomínio/metabolismo , Transcrição Genética , Animais , Calcineurina/metabolismo , Sinalização do Cálcio , Retroalimentação Fisiológica , Feminino , Regulação da Expressão Gênica/imunologia , Genótipo , Memória Imunológica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fatores de Transcrição NFATC/metabolismo , Evasão Tumoral
5.
Cell Rep ; 27(2): 400-415.e5, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30970245

RESUMO

Global changes in chromatin organization and the cessation of transcription during mitosis are thought to challenge the resumption of appropriate transcription patterns after mitosis. The acetyl-lysine binding protein BRD4 has been previously suggested to function as a transcriptional "bookmark" on mitotic chromatin. Here, genome-wide location analysis of BRD4 in erythroid cells, combined with data normalization and peak characterization approaches, reveals that BRD4 widely occupies mitotic chromatin. However, removal of BRD4 from mitotic chromatin does not impair post-mitotic activation of transcription. Additionally, histone mass spectrometry reveals global preservation of most posttranslational modifications (PTMs) during mitosis. In particular, H3K14ac, H3K27ac, H3K122ac, and H4K16ac widely mark mitotic chromatin, especially at lineage-specific genes, and predict BRD4 mitotic binding genome wide. Therefore, BRD4 is likely not a mitotic bookmark but only a "passenger." Instead, mitotic histone acetylation patterns may constitute the actual bookmarks that restore lineage-specific transcription patterns after mitosis.


Assuntos
Histonas/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Acetilação , Animais , Cromatina/genética , Cromatina/metabolismo , Histonas/genética , Camundongos , Mitose/fisiologia , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Transcrição Genética
6.
Cancers (Basel) ; 9(10)2017 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-29035291

RESUMO

Anaplastic large cell lymphoma expressing anaplastic lymphoma kinase (ALK+ ALCL) is a distinct subtype of non-Hodgkin lymphoma. In this review, we discuss the historical findings that led to its classification as a unique disease, despite its varied clinical presentation and histology. We discuss the molecular mechanisms underlying ALK+ ALCL pathology and the questions that remain in the field. Finally, we visit how decades of ALK+ ALCL research has yielded more precise drugs that hold promise for the future.

7.
Mol Cell ; 66(1): 102-116.e7, 2017 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-28388437

RESUMO

Bromodomain and extraterminal motif (BET) proteins are pharmacologic targets for the treatment of diverse diseases, yet the roles of individual BET family members remain unclear. We find that BRD2, but not BRD4, co-localizes with the architectural/insulator protein CCCTC-binding factor (CTCF) genome-wide. CTCF recruits BRD2 to co-bound sites whereas BRD2 is dispensable for CTCF occupancy. Disruption of a CTCF/BRD2-occupied element positioned between two unrelated genes enables regulatory influence to spread from one gene to another, suggesting that CTCF and BRD2 form a transcriptional boundary. Accordingly, single-molecule mRNA fluorescence in situ hybridization (FISH) reveals that, upon site-specific CTCF disruption or BRD2 depletion, expression of the two genes becomes increasingly correlated. HiC shows that BRD2 depletion weakens boundaries co-occupied by CTCF and BRD2, but not those that lack BRD2. These findings indicate that BRD2 supports boundary activity, and they raise the possibility that pharmacologic BET inhibitors can influence gene expression in part by perturbing domain boundary function.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Células-Tronco Embrionárias/metabolismo , Elementos Facilitadores Genéticos , Proteínas Repressoras/metabolismo , Transcrição Genética , Animais , Sítios de Ligação , Fator de Ligação a CCCTC , Sistemas CRISPR-Cas , Linhagem Celular , Cromatina/genética , Proteínas Cromossômicas não Histona/genética , Fator de Transcrição GATA1/genética , Fator de Transcrição GATA1/metabolismo , Edição de Genes/métodos , Hibridização in Situ Fluorescente , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Estrogênicos/genética , Receptores Estrogênicos/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras/genética , Imagem Individual de Molécula/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção
8.
Blood ; 129(7): 823-831, 2017 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-27879258

RESUMO

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase physiologically expressed by fetal neural cells. However, aberrantly expressed ALK is involved in the pathogenesis of diverse malignancies, including distinct types of lymphoma, lung carcinoma, and neuroblastoma. The aberrant ALK expression in nonneural cells results from chromosomal translocations that create novel fusion proteins. These protein hybrids compose the proximal part of a partner gene, including its promoter region, and the distal part of ALK, including the coding sequence for the entire kinase domain. ALK was first identified in a subset of T-cell lymphomas with anaplastic large cell lymphoma (ALCL) morphology (ALK+ ALCL), the vast majority of which harbor the well-characterized nucleophosmin (NPM)-ALK fusion protein. NPM-ALK co-opts several intracellular signal transduction pathways, foremost being the STAT3 pathway, normally activated by cytokines from the interleukin-2 (IL-2) family to promote cell proliferation and to inhibit apoptosis. Many genes and proteins modulated by NPM-ALK are also involved in evasion of antitumor immune response, protection from hypoxia, angiogenesis, DNA repair, cell migration and invasiveness, and cell metabolism. In addition, NPM-ALK uses epigenetic silencing mechanisms to downregulate tumor suppressor genes to maintain its own expression. Importantly, NPM-ALK is capable of transforming primary human CD4+ T cells into immortalized cell lines indistinguishable from patient-derived ALK+ ALCL. Preliminary clinical studies indicate that inhibition of NPM-ALK induces long-lasting complete remissions in a large subset of heavily pretreated adult patients and the vast majority of children with high-stage ALK+ ALCL. Combining ALK inhibition with other novel therapeutic modalities should prove even more effective.


Assuntos
Transformação Celular Neoplásica/genética , Linfoma Anaplásico de Células Grandes/genética , Linfoma de Células T/genética , Proteínas de Fusão Oncogênica/genética , Proteínas Tirosina Quinases/genética , Quinase do Linfoma Anaplásico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Citocinas/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Linfoma Anaplásico de Células Grandes/tratamento farmacológico , Linfoma Anaplásico de Células Grandes/metabolismo , Linfoma Anaplásico de Células Grandes/patologia , Linfoma de Células T/tratamento farmacológico , Linfoma de Células T/metabolismo , Linfoma de Células T/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Terapia de Alvo Molecular/métodos , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Fusão Oncogênica/antagonistas & inibidores , Proteínas de Fusão Oncogênica/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos
9.
Drug Discov Today Technol ; 19: 23-28, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27769353

RESUMO

Pharmacologic inhibitors of the bromodomain and extra-terminal motif (BET) protein family are in clinical trials for the treatment of hematologic malignancies, yet the functions of individual BET proteins remain largely uncharacterized. We review the molecular roles of BETs in the context of erythropoiesis. Studies in this lineage have provided valuable insights into their mechanisms of action, and helped define the individual and overlapping functions of BET protein family members BRD2, BRD3, and BRD4. These studies have important ramifications for our understanding of the molecular and physiologic roles of BET proteins, and provide a framework for elucidating some of the beneficial and adverse effects of pharmacologic inhibitors.


Assuntos
Eritropoese/fisiologia , Proteínas Nucleares/metabolismo , Domínios Proteicos , Fatores de Transcrição/metabolismo , Animais , Cromatina/metabolismo , Humanos , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/química , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/química
10.
Breast Cancer Res Treat ; 111(3): 511-21, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17978871

RESUMO

Besides functioning as a chemotactic factor, CCL5 has been associated with progression of disease in women with breast cancer, immune modulation and metastasis. Here we asked whether CCL5 produced by tumor cells contributed to growth or metastasis of breast cancer. For this purpose, we used two murine mammary carcinomas, the 4T1 tumor which is metastatic and constitutively expresses CCL5, and the 168 tumor which is not metastatic and does not constitutively express CCL5. RNA interference was used to inhibit CCL5 expression from the 4T1 tumor, and a CCL5 transgene was used to express CCL5 by the 168 tumor. Six different clones of 4T1 that exhibited stable reduction in CCL5 expression, and three different clones of 168 that exhibited stable CCL5 expression were compared to the parental tumors and vector transfected controls. Significantly, in both models, tumor-derived CCL5 expression did not correlate with MHC expression, growth rate, or metastatic ability of the tumors. These results show that tumor-derived CCL5 expression alone does not make a significant contribution to breast cancer progression.


Assuntos
Quimiocina CCL5/metabolismo , Neoplasias Mamárias Animais/imunologia , Animais , Linhagem Celular Tumoral , Proliferação de Células , Quimiocina CCL5/genética , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Antígenos de Histocompatibilidade/metabolismo , Neoplasias Mamárias Animais/genética , Neoplasias Mamárias Animais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Metástase Neoplásica , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fatores de Tempo , Transfecção
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