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1.
Cell Death Dis ; 13(9): 766, 2022 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-36064715

RESUMO

Zinc Finger transcription factors are crucial in modulating various cellular processes, including differentiation. Chromatin reader Zinc Finger MYND (Myeloid, Nervy, and DEAF-1) type containing 8 (ZMYND8), an All-Trans Retinoic Acid (ATRA)-responsive gene, was previously shown to play a crucial role in promoting the expression of neuronal-lineage committed genes. Here, we report that ZMYND8 promotes neuronal differentiation by positively regulating canonical MAPT protein-coding gene isoform, a key player in the axonal development of neurons. Additionally, ZMYND8 modulates gene-isoform switching by epigenetically silencing key regulatory regions within the MAPT gene, thereby suppressing the expression of non-protein-coding isoforms such as MAPT213. Genetic deletion of ZMYND8 led to an increase in the MAPT213 that potentially suppressed the parental MAPT protein-coding transcript expression related to neuronal differentiation programs. In addition, ectopic expression of MAPT213 led to repression of MAPT protein-coding transcript. Similarly, ZMYND8-driven transcription regulation was also observed in other neuronal differentiation-promoting genes. Collectively our results elucidate a novel mechanism of ZMYND8-dependent transcription regulation of different neuronal lineage committing genes, including MAPT, to promote neural differentiation.


Assuntos
RNA Longo não Codificante , Diferenciação Celular/genética , Cromatina , Regulação da Expressão Gênica , RNA Longo não Codificante/genética , Tretinoína/farmacologia , Proteínas Supressoras de Tumor/metabolismo
2.
J Biomol Struct Dyn ; 40(1): 249-262, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-32838660

RESUMO

Drug re-purposing might be a fast and efficient way of drug development against the novel coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We applied a bioinformatics approach using molecular dynamics and docking to identify FDA-approved drugs that can be re-purposed to potentially inhibit the non-structural protein 9 (Nsp9) replicase and spike proteins in SARS-CoV-2. We performed virtual screening of FDA-approved compounds, including antiviral, anti-malarial, anti-parasitic, anti-fungal, anti-tuberculosis, and active phytochemicals against the Nsp9 replicase and spike proteins. Selected hit compounds were identified based on their highest binding energy and favorable absorption, distribution, metabolism and excretion (ADME) profile. Conivaptan, an arginine vasopressin antagonist drug exhibited the highest binding energy (-8.4 Kcal/mol) and maximum stability with the amino acid residues present at the active site of the Nsp9 replicase. Tegobuvir, a non-nucleoside inhibitor of the hepatitis C virus, also exhibited maximum stability along with the highest binding energy (-8.1 Kcal/mol) at the active site of the spike proteins. Molecular docking scores were further validated by molecular dynamics using Schrodinger, which supported the strong stability of ligands with the proteins at their active sites through water bridges, hydrophobic interactions, and H-bonding. Our findings suggest Conivaptan and Tegobuvir as potential therapeutic agents against SARS-CoV-2. Further in vitro and in vivo validation and evaluation are warranted to establish how these drug compounds target the Nsp9 replicase and spike proteins.


Assuntos
Antivirais/farmacologia , Reposicionamento de Medicamentos , Proteínas de Ligação a RNA/antagonistas & inibidores , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/antagonistas & inibidores , Proteínas não Estruturais Virais/antagonistas & inibidores , COVID-19 , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular
3.
J Endocr Soc ; 5(11): bvab153, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34703959

RESUMO

Long noncoding RNAs (lncRNAs) have emerged as critical regulators of biological processes. However, the aberrant expression of an isoform from the same lncRNA gene could lead to RNA with altered functions due to changes in their conformations, leading to diseases. Here, we describe a detailed characterization of the gene that encodes long intergenic non-protein-coding RNA 01016 (LINC01016, also known as LncRNA1195) with a focus on its structure, exon usage, and expression in human and macaque tissues. In this study we show that it is among the highly expressed lncRNAs in the testis, exclusively conserved among nonhuman primates, suggesting its recent evolution and is processed into 12 distinct RNAs in testis, cervix, and uterus tissues. Further, we integrate de novo annotation of expressed LINC01016 transcripts and isoform-dependent gene expression analyses to show that human LINC01016 is a multiexon gene, processed through differential exon usage with isoform-specific roles. Furthermore, in cervical, testicular, and uterine cancers, LINC01016 isoforms are differentially expressed, and their expression is predictive of survival in these cancers. This study has revealed an essential aspect of lncRNA biology, rarely associated with coding RNAs, that lncRNA genes are precisely processed to generate isoforms with distinct biological roles in specific tissues.

4.
Semin Cancer Biol ; 69: 166-177, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-31715247

RESUMO

Nanotechnology has been the latest approach for diagnosis and treatment for cancer, which opens up a new alternative therapeutic drug delivery option to treat disease. Nanoparticles (NPs) display a broad role in cancer diagnosis and has various advantages over the other conventional chemotherapeutic drug delivery. NPs possess more specific and efficient drug delivery to the targeted tissue, cell, or organs and minimize the risk of side effects. NPs undergo passive and active mode of drug targets to tumor area with less elimination of the drug from the system. Size and surface characteristics of nanoparticles play a crucial role in modulating nanocarrier efficiency and the biodistribution of chemo drugs in the body. Several types of nanocarriers, such as polymers, dendrimers, liposome-based, and carbon-based, are studied widely in cancer therapy. Although FDA approved very few nanotechnology drugs for cancer therapy, a large number of studies are undergoing for the development of novel nanocarriers for potent cancer therapy. In this review, we discuss the details of the nano-based therapeutics and diagnostics strategies, and the potential use of nanomedicines in cancer therapy and cancer drug delivery.


Assuntos
Antineoplásicos/administração & dosagem , Sistemas de Liberação de Medicamentos , Nanomedicina , Nanopartículas/administração & dosagem , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/farmacocinética , Humanos , Nanopartículas/química , Neoplasias/patologia , Especificidade de Órgãos , Distribuição Tecidual
5.
Cell Death Dis ; 11(12): 1073, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-33323928

RESUMO

The major challenge in chemotherapy lies in the gain of therapeutic resistance properties of cancer cells. The relatively small fraction of chemo-resistant cancer cells outgrows and are responsible for tumor relapse, with acquired invasiveness and stemness. We demonstrate that zinc-finger MYND type-8 (ZMYND8), a putative chromatin reader, suppresses stemness, drug resistance, and tumor-promoting genes, which are hallmarks of cancer. Reinstating ZMYND8 suppresses chemotherapeutic drug doxorubicin-induced tumorigenic potential (at a sublethal dose) and drug resistance, thereby resetting the transcriptional program of cells to the epithelial state. The ability of ZMYND8 to chemo-sensitize doxorubicin-treated metastatic breast cancer cells by downregulating tumor-associated genes was further confirmed by transcriptome analysis. Interestingly, we observed that ZMYND8 overexpression in doxorubicin-treated cells stimulated those involved in a good prognosis in breast cancer. Consistently, sensitizing the cancer cells with ZMYND8 followed by doxorubicin treatment led to tumor regression in vivo and revert back the phenotypes associated with drug resistance and stemness. Intriguingly, ZMYND8 modulates the bivalent or poised oncogenes through its association with KDM5C and EZH2, thereby chemo-sensitizing the cells to chemotherapy for better disease-free survival. Collectively, our findings indicate that poised chromatin is instrumental for the acquisition of chemo-resistance by cancer cells and propose ZMYND8 as a suitable epigenetic tool that can re-sensitize the chemo-refractory breast carcinoma.


Assuntos
Oncogenes , Proteínas Supressoras de Tumor/metabolismo , Animais , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Carcinogênese/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigênese Genética/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genoma Humano , Histona Desmetilases/metabolismo , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Resultado do Tratamento , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia
6.
Cancers (Basel) ; 12(6)2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32532008

RESUMO

Hypoxanthine phosphoribosyl transferase 1 (HPRT1) is traditionally believed to be a housekeeping gene; however, recent reports suggest that it is upregulated in several cancers and is associated with clinical outcomes. HPRT1 is located on chromosome X and encodes the HPRT enzyme, which functions in recycling nucleotides to supply for DNA and RNA synthesis in actively dividing cells. Here, we used transcriptomic analyses to interrogate its expression across all known cancer types and elucidated its role in regulating gene expression in breast cancer. We observed elevated HPRT1 RNA levels in malignant tissues when compared to normal controls, indicating its potential as a diagnostic and prognostic marker. Further, in breast cancer, the subtype-specific analysis showed that its expression was highest in basal and triple-negative breast cancer, and HPRT1 knockdown in breast cancer cells suggested that HPRT1 positively regulates genes related to cancer pathways. Collectively, our results essentially highlight the importance of and change the way in which HPRT1's function is studied in biology, warranting careful examination of its role in cancer.

7.
Int J Mol Sci ; 21(10)2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32466143

RESUMO

Genome-wide RNA sequencing has shown that only a small fraction of the human genome is transcribed into protein-coding mRNAs. While once thought to be "junk" DNA, recent findings indicate that the rest of the genome encodes many types of non-coding RNA molecules with a myriad of functions still being determined. Among the non-coding RNAs, long non-coding RNAs (lncRNA) and enhancer RNAs (eRNA) are found to be most copious. While their exact biological functions and mechanisms of action are currently unknown, technologies such as next-generation RNA sequencing (RNA-seq) and global nuclear run-on sequencing (GRO-seq) have begun deciphering their expression patterns and biological significance. In addition to their identification, it has been shown that the expression of long non-coding RNAs and enhancer RNAs can vary due to spatial, temporal, developmental, or hormonal variations. In this review, we explore newly reported information on estrogen-regulated eRNAs and lncRNAs and their associated biological functions to help outline their markedly prominent roles in estrogen-dependent signaling.


Assuntos
Elementos Facilitadores Genéticos , Estrogênios/metabolismo , RNA Longo não Codificante/metabolismo , Pequeno RNA não Traduzido/metabolismo , Transdução de Sinais , Regulação Neoplásica da Expressão Gênica , Humanos , RNA Longo não Codificante/genética , Pequeno RNA não Traduzido/genética , Ativação Transcricional
8.
Mol Cell Endocrinol ; 510: 110819, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32311422

RESUMO

Recent technical and other advances in genomics provide unique opportunities to improve our understanding of human physiology and disease predisposition through a detailed analysis of gene structure and expression by examining data in public genome and gene-expression repositories. Yet, the vast majority of human genes remain understudied. This is particularly true of genes for long noncoding RNAs (lncRNAs). Here, we describe the detailed characterization of MIR503HG, a lncRNA gene found on the X chromosome in humans. Using information extracted from public databases, we show that human MIR503HG is a 5-exon gene, and that it is highly conserved among 5 non-human primates spanning over 85 million years ago of evolutionary diversification. MIR503HG is transcribed and processed into multiple distinct RNAs in each of these species through differential exon use and alternative RNA splicing, with a higher abundance of transcripts being found in reproductive tissues, especially during the early stages of ovary and testis development, indicating a possible role in reproductive biology. Furthermore, in select reproductive system cancers, MIR503HG transcripts are downregulated, with higher levels of RNA expression being associated with clinical outcomes. Collectively, these investigations show how the use of genomic, gene expression, and other genetic resources can lead to new insights about human biology and disease, and argue that MIR503HG is worthy of additional study.


Assuntos
Regulação da Expressão Gênica , RNA Longo não Codificante/química , RNA Longo não Codificante/genética , Animais , Genoma Humano , Humanos , Primatas , Prognóstico , Ligação Proteica , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
9.
Adv Clin Chem ; 95: 105-147, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32122521

RESUMO

Long noncoding RNAs (lncRNAs) have recently gained considerable attention as key players in biological regulation; however, the mechanisms by which lncRNAs govern various disease processes remain mysterious and are just beginning to be understood. The ease of next-generation sequencing technologies has led to an explosion of genomic information, especially for the lncRNA class of noncoding RNAs. LncRNAs exhibit the characteristics of mRNAs, such as polyadenylation, 5' methyl capping, RNA polymerase II-dependent transcription, and splicing. These transcripts comprise more than 200 nucleotides (nt) and are not translated into proteins. Directed interrogation of annotated lncRNAs from RNA-Seq datasets has revealed dramatic differences in their expression, largely driven by alterations in transcription, the cell cycle, and RNA metabolism. The fact that lncRNAs are expressed cell- and tissue-specifically makes them excellent biomarkers for ongoing biological events. Notably, lncRNAs are differentially expressed in several cancers and show a distinct association with clinical outcomes. Novel methods and strategies are being developed to study lncRNA function and will provide researchers with the tools and opportunities to develop lncRNA-based therapeutics for cancer.


Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , RNA Longo não Codificante/antagonistas & inibidores , Animais , Humanos , Neoplasias/genética , Neoplasias/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
10.
Nat Med ; 25(1): 130-140, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30510251

RESUMO

In T lymphocytes, the Wiskott-Aldrich Syndrome protein (WASP) and WASP-interacting-protein (WIP) regulate T cell antigen receptor (TCR) signaling, but their role in lymphoma is largely unknown. Here we show that the expression of WASP and WIP is frequently low or absent in anaplastic large cell lymphoma (ALCL) compared to other T cell lymphomas. In anaplastic lymphoma kinase-positive (ALK+) ALCL, WASP and WIP expression is regulated by ALK oncogenic activity via its downstream mediators STAT3 and C/EBP-ß. ALK+ lymphomas were accelerated in WASP- and WIP-deficient mice. In the absence of WASP, active GTP-bound CDC42 was increased and the genetic deletion of one CDC42 allele was sufficient to impair lymphoma growth. WASP-deficient lymphoma showed increased mitogen-activated protein kinase (MAPK) pathway activation that could be exploited as a therapeutic vulnerability. Our findings demonstrate that WASP and WIP are tumor suppressors in T cell lymphoma and suggest that MAP-kinase kinase (MEK) inhibitors combined with ALK inhibitors could achieve a more potent therapeutic effect in ALK+ ALCL.


Assuntos
Linfoma de Células T/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Quinase do Linfoma Anaplásico/metabolismo , Animais , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Proteínas do Citoesqueleto/metabolismo , Regulação para Baixo , Ativação Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Guanosina Trifosfato/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Estimativa de Kaplan-Meier , Linfoma de Células T/enzimologia , Linfoma de Células T/patologia , Sistema de Sinalização das MAP Quinases , Camundongos , Ligação Proteica , Fator de Transcrição STAT3/metabolismo , Linfócitos T/imunologia , Proteína da Síndrome de Wiskott-Aldrich/deficiência , Proteína cdc42 de Ligação ao GTP/metabolismo
11.
CNS Neurol Disord Drug Targets ; 17(9): 680-688, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29938622

RESUMO

BACKGROUND AND OBJECTIVE: A steep rise in the incidences of neurodegenerative disorders could be the combined effect of several non-genetic factors such as increased life expectancy, environmental pollutants, lifestyle, and dietary habits, as population-level genetic change require multiple generations. Emerging evidence suggests that chronic over-nutrition induces brain metabolic stress and neuroinflammation, and are individually known to promote neurodegenerative disorders including Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD). Although the association of metabolic disorders such as diabetes, hypertension, dyslipidemia, and atherosclerosis with the dietary habits is well known, neuronal implications of diet and nutritional factors is still in its infancy. Transcriptomics and proteomics-based studies support the view that nutraceuticals target multiple neuroprotective pathways in a slow but effective manner without causing severe adverse effects, and may represent the future of tackling neurodegenerative disorders. CONCLUSION: In this article we i) review the diet/dietary supplement connection with brain metabolic stress and neuroinflammation and ii) summarize current knowledge of the effects of nutraceuticals on neurodegenerative disorders.


Assuntos
Encéfalo/fisiopatologia , Suplementos Nutricionais , Encefalite/patologia , Nutrientes/metabolismo , Estresse Fisiológico/fisiologia , Animais , Encéfalo/metabolismo , Encefalite/terapia , Humanos
12.
Steroids ; 133: 93-95, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29317255

RESUMO

Long noncoding RNAs (lncRNAs) are implicated in several biological processes, including but not limited to cardiovascular physiology, reproduction, differentiation, metabolism, DNA repair, and inflammation. Under normal physiological conditions, expression of lncRNAs is tissue-specific and tightly regulated. In contrast, prevalent cancer types exhibit aberrant expression of lncRNAs. In this context, lncRNAs can drive cancer cell characteristics by controlling gene expression programs related to tumor suppressive and oncogenic functions. Hence, they can be excellent biomarkers and targets for therapeutic intervention in cancers. Understanding the molecular mechanisms by which lncRNAs drive cancer progression will improve our understanding of the etiology of cancer and suggest new ways to treat this disease. This review will provide a perspective on the role of lncRNAs in cancer initiation and progression.


Assuntos
Neoplasias/genética , RNA Longo não Codificante/genética , Humanos
13.
Cold Spring Harb Mol Case Stud ; 3(3): a001719, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28487884

RESUMO

Gene-expression profiling and next-generation sequencing have defined diffuse large B-cell lymphoma (DLBCL), the most common lymphoma diagnosis, as a heterogeneous group of subentities. Despite ongoing explosions of data illuminating disparate pathogenic mechanisms, however, the five-drug chemoimmunotherapy combination R-CHOP remains the frontline standard treatment. This has not changed in 15 years, since the anti-CD20 monoclonal antibody rituximab was added to the CHOP backbone, which first entered use in the 1970s. At least a third of patients are not cured by R-CHOP, and relapsed or refractory DLBCL is fatal in ∼90%. Targeted small-molecule inhibitors against distinct molecular pathways activated in different subgroups of DLBCL have so far translated poorly into the clinic, justifying the ongoing reliance on R-CHOP and other long-established chemotherapy-driven combinations. New drugs and improved identification of biomarkers in real time, however, show potential to change the situation eventually, despite some recent setbacks. Here, we review established and putative molecular drivers of DLBCL identified through large-scale genomics, highlighting among other things the care that must be taken when differentiating drivers from passengers, which is influenced by the promiscuity of activation-induced cytidine deaminase. Furthermore, we discuss why, despite having so much genomic data available, it has been difficult to move toward personalized medicine for this umbrella disorder and some steps that may be taken to hasten the process.


Assuntos
Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Anticorpos Monoclonais Murinos/administração & dosagem , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Perfilação da Expressão Gênica/métodos , Genômica , Humanos , Medicina de Precisão , Prednisona/administração & dosagem , Rituximab/administração & dosagem , Vincristina/administração & dosagem
14.
Blood ; 127(10): 1297-306, 2016 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-26747246

RESUMO

Increasing evidence suggests that Rho family GTPases could have a critical role in the biology of T-cell lymphoma. In ALK-rearranged anaplastic large cell lymphoma (ALCL), a specific subtype of T-cell lymphoma, the Rho family GTPases Cdc42 and Rac1 are activated by the ALK oncogenic activity. In vitro studies have shown that Cdc42 and Rac1 control rather similar phenotypes of ALCL biology such as the proliferation, survival, and migration of lymphoma cells. However, their role and possible redundancy in ALK-driven lymphoma development in vivo are still undetermined. We genetically deleted Cdc42 or Rac1 in a mouse model of ALK-rearranged ALCL to show that either Cdc42 or Rac1 deletion impaired lymphoma development, modified lymphoma morphology, actin filament distribution, and migration properties of lymphoma cells. Cdc42 or Rac1 deletion primarily affected survival rather than proliferation of lymphoma cells. Apoptosis of lymphoma cells was equally induced following Cdc42 or Rac1 deletion, was associated with upregulation of the proapoptotic molecule Bid, and was blocked by Bcl2 overexpression. Remarkably, Cdc42/Rac1 double deletion, but not Cdc42 or Rac1 single deletions, completely prevented NPM-ALK lymphoma dissemination in vivo. Thus, Cdc42 and Rac1 have nonredundant roles in controlling ALK-rearranged lymphoma survival and morphology but are redundant for lymphoma dissemination, suggesting that targeting both GTPases could represent a preferable therapeutic option for ALCL treatment.


Assuntos
Linfoma Difuso de Grandes Células B/metabolismo , Neuropeptídeos/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Animais , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/genética , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Sobrevivência Celular/genética , Deleção de Genes , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Neuropeptídeos/genética , Proteínas de Fusão Oncogênica/genética , Proteínas Tirosina Quinases/genética , Proteína cdc42 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/genética
15.
Chem Biol ; 17(8): 903-13, 2010 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-20797619

RESUMO

Altered histone acetylation is associated with several diseases, including cancer. We report here that, unlike in most cancers, histones are found to be highly hyperacetylated in oral squamous cell carcinoma (OSCC; oral cancer) patient samples. Mechanistically, overexpression, as well as enhanced autoacetylation, of p300 induced by nucleophosmin (NPM1) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) causes the hyperacetylation, which is nitric oxide (NO) signal dependent. Inhibition of the histone acetyltransferase (HAT) activity of p300 by a water-soluble, small molecule inhibitor, Hydrazinocurcumin (CTK7A), substantially reduced the xenografted oral tumor growth in mice. These results, therefore, not only establish an epigenetic target for oral cancer, but also implicate a HAT inhibitor (HATi) as a potential therapeutic molecule.


Assuntos
Curcumina/análogos & derivados , Histona Acetiltransferases/antagonistas & inibidores , Histonas/metabolismo , Hidrazinas/química , Hidrazinas/farmacologia , Neoplasias Bucais/metabolismo , Óxido Nítrico/metabolismo , Água/química , Acetilação/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Curcumina/química , Curcumina/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Células HeLa , Histona Acetiltransferases/metabolismo , Humanos , Camundongos , Camundongos Nus , Neoplasias Bucais/enzimologia , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Proteínas Nucleares/metabolismo , Nucleofosmina , Solubilidade , Regulação para Cima/efeitos dos fármacos , Fatores de Transcrição de p300-CBP/metabolismo
16.
Mol Cell Biol ; 29(18): 5115-27, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19581289

RESUMO

Nucleophosmin (NPM1) is a multifunctional protein involved in the regulation of centrosome duplication, ribosome biogenesis, genomic stability, histone chaperone function, and transcription. Overexpression of NPM1 is associated with cancers of diverse histological origins. Here, we have found that p300-mediated acetylation of NPM1 modulates its subcellular localization and augments its oncogenic potential. Acetylated NPM1 is predominantly localized in the nucleoplasm, where it associates with transcriptionally active RNA polymerase II. Deacetylation of NPM1 is brought about by human SIRT1 and reduces its transcriptional activation potential. Remarkably, increased levels of acetylated NPM1 were found in grade II and III oral squamous cell carcinoma (OSCC) patient samples. Small interfering RNA (siRNA)-mediated knockdown of NPM1 in an OSCC cell line, followed by microarray analysis and chromatin immunoprecipitation experiments, revealed that some of the genes involved in oral cancer malignancy are regulated by NPM1 and have acetylated NPM1 localized at their promoters. Either suppression of p300 by siRNA or mutation of acetylatable lysine residues of NPM1 resulted in reduced occupancy of acetylated NPM1 on the target gene promoter concomitant with its decreased transcript levels. These observations suggest that acetylated NPM1 transcriptionally regulates genes involved in cell survival and proliferation during carcinogenesis.


Assuntos
Núcleo Celular/metabolismo , Regulação Neoplásica da Expressão Gênica , Genes Neoplásicos , Neoplasias Bucais/genética , Proteínas Nucleares/metabolismo , Ativação Transcricional/genética , Acetilação , Linhagem Celular Tumoral , Proteína p300 Associada a E1A/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Bucais/enzimologia , Neoplasias Bucais/patologia , Nucleofosmina , Regiões Promotoras Genéticas/genética , Transporte Proteico , RNA Polimerase II/metabolismo , Sirtuína 1 , Sirtuínas/metabolismo , Fator de Necrose Tumoral alfa/genética
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