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1.
J Biol Chem ; 290(18): 11749-61, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25795775

RESUMO

The RET proto-oncogene, a tyrosine kinase receptor, is widely known for its essential role in cell survival. Germ line missense mutations, which give rise to constitutively active oncogenic RET, were found to cause multiple endocrine neoplasia type 2, a dominant inherited cancer syndrome that affects neuroendocrine organs. However, the mechanisms by which RET promotes cell survival and prevents cell death remain elusive. We demonstrate that in addition to cytoplasmic localization, RET is localized in the nucleus and functions as a tyrosine-threonine dual specificity kinase. Knockdown of RET by shRNA in medullary thyroid cancer-derived cells stimulated expression of activating transcription factor 4 (ATF4), a master transcription factor for stress-induced apoptosis, through activation of its target proapoptotic genes NOXA and PUMA. RET knockdown also increased sensitivity to cisplatin-induced apoptosis. We observed that RET physically interacted with and phosphorylated ATF4 at tyrosine and threonine residues. Indeed, RET kinase activity was required to inhibit the ATF4-dependent activation of the NOXA gene because the site-specific substitution mutations that block threonine phosphorylation increased ATF4 stability and activated its targets NOXA and PUMA. Moreover, chromatin immunoprecipitation assays revealed that ATF4 occupancy increased at the NOXA promoter in TT cells treated with tyrosine kinase inhibitors or the ATF4 inducer eeyarestatin as well as in RET-depleted TT cells. Together these findings reveal RET as a novel dual kinase with nuclear localization and provide mechanisms by which RET represses the proapoptotic genes through direct interaction with and phosphorylation-dependent inactivation of ATF4 during the pathogenesis of medullary thyroid cancer.


Assuntos
Fator 4 Ativador da Transcrição/metabolismo , Apoptose , Proteínas Proto-Oncogênicas c-ret/metabolismo , Fator 4 Ativador da Transcrição/química , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/genética , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Cisplatino/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Fosforilação/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Inibidores de Proteínas Quinases/farmacologia , Proteólise/efeitos dos fármacos , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Treonina/metabolismo , Transcrição Gênica/efeitos dos fármacos
2.
J Transl Med ; 14: 46, 2016 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-26861698

RESUMO

BACKGROUND: The majority of glioblastomas have aberrant receptor tyrosine kinase (RTK)/RAS/phosphoinositide 3 kinase (PI3K) signaling pathways and malignant glioma cells are thought to be addicted to these signaling pathways for their survival and proliferation. However, recent studies suggest that monotherapies or inappropriate combination therapies using the molecular targeted drugs have limited efficacy possibly because of tumor heterogeneities, signaling redundancy and crosstalk in intracellular signaling network, indicating necessity of rationale and methods for efficient personalized combination treatments. Here, we evaluated the growth of colonies obtained from glioma tumor-initiating cells (GICs) derived from glioma sphere culture (GSC) in agarose and examined the effects of combination treatments on GICs using targeted drugs that affect the signaling pathways to which most glioma cells are addicted. METHODS: Human GICs were cultured in agarose and treated with inhibitors of RTKs, non-receptor kinases or transcription factors. The colony number and volume were analyzed using a colony counter, and Chou-Talalay combination indices were evaluated. Autophagy and apoptosis were also analyzed. Phosphorylation of proteins was evaluated by reverse phase protein array and immunoblotting. RESULTS: Increases of colony number and volume in agarose correlated with the Gompertz function. GICs showed diverse drug sensitivity, but inhibitions of RTK and RAF/MEK or PI3K by combinations such as EGFR inhibitor and MEK inhibitor, sorafenib and U0126, erlotinib and BKM120, and EGFR inhibitor and sorafenib showed synergy in different subtypes of GICs. Combination of erlotinib and sorafenib, synergistic in GSC11, induced apoptosis and autophagic cell death associated with suppressed Akt and ERK signaling pathways and decreased nuclear PKM2 and ß-catenin in vitro, and tended to improve survival of nude mice bearing GSC11 brain tumor. Reverse phase protein array analysis of the synergistic treatment indicated involvement of not only MEK and PI3K signaling pathways but also others associated with glucose metabolism, fatty acid metabolism, gene transcription, histone methylation, iron transport, stress response, cell cycle, and apoptosis. CONCLUSION: Inhibiting RTK and RAF/MEK or PI3K could induce synergistic cytotoxicity but personalization is necessary. Examining colonies in agarose initiated by GICs from each patient may be useful for drug sensitivity testing in personalized cancer therapy.


Assuntos
Glioma/tratamento farmacológico , Glioma/patologia , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Células-Tronco Neoplásicas/patologia , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/uso terapêutico , Quinases raf/antagonistas & inibidores , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Concentração Inibidora 50 , Masculino , Camundongos Nus , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Quinases raf/metabolismo
3.
J Biomed Inform ; 58 Suppl: S189-S196, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26210361

RESUMO

OBJECTIVE: In recognition of potential barriers that may inhibit the widespread adoption of biomedical software, the 2014 i2b2 Challenge introduced a special track, Track 3 - Software Usability Assessment, in order to develop a better understanding of the adoption issues that might be associated with the state-of-the-art clinical NLP systems. This paper reports the ease of adoption assessment methods we developed for this track, and the results of evaluating five clinical NLP system submissions. MATERIALS AND METHODS: A team of human evaluators performed a series of scripted adoptability test tasks with each of the participating systems. The evaluation team consisted of four "expert evaluators" with training in computer science, and eight "end user evaluators" with mixed backgrounds in medicine, nursing, pharmacy, and health informatics. We assessed how easy it is to adopt the submitted systems along the following three dimensions: communication effectiveness (i.e., how effective a system is in communicating its designed objectives to intended audience), effort required to install, and effort required to use. We used a formal software usability testing tool, TURF, to record the evaluators' interactions with the systems and 'think-aloud' data revealing their thought processes when installing and using the systems and when resolving unexpected issues. RESULTS: Overall, the ease of adoption ratings that the five systems received are unsatisfactory. Installation of some of the systems proved to be rather difficult, and some systems failed to adequately communicate their designed objectives to intended adopters. Further, the average ratings provided by the end user evaluators on ease of use and ease of interpreting output are -0.35 and -0.53, respectively, indicating that this group of users generally deemed the systems extremely difficult to work with. While the ratings provided by the expert evaluators are higher, 0.6 and 0.45, respectively, these ratings are still low indicating that they also experienced considerable struggles. DISCUSSION: The results of the Track 3 evaluation show that the adoptability of the five participating clinical NLP systems has a great margin for improvement. Remedy strategies suggested by the evaluators included (1) more detailed and operation system specific use instructions; (2) provision of more pertinent onscreen feedback for easier diagnosis of problems; (3) including screen walk-throughs in use instructions so users know what to expect and what might have gone wrong; (4) avoiding jargon and acronyms in materials intended for end users; and (5) packaging prerequisites required within software distributions so that prospective adopters of the software do not have to obtain each of the third-party components on their own.


Assuntos
Atitude Frente aos Computadores , Mineração de Dados/estatística & dados numéricos , Registros Eletrônicos de Saúde/estatística & dados numéricos , Processamento de Linguagem Natural , Reconhecimento Automatizado de Padrão/métodos , Software , Mineração de Dados/métodos , Humanos , Pessoa de Meia-Idade , Interface Usuário-Computador
4.
Nat Rev Cancer ; 6(6): 459-71, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16723992

RESUMO

The pivotal role of kinases in signal transduction and cellular regulation has lent them considerable appeal as pharmacological targets across a broad spectrum of cancers. p21-activated kinases (Paks) are serine/threonine kinases that function as downstream nodes for various oncogenic signalling pathways. Paks are well-known regulators of cytoskeletal remodelling and cell motility, but have recently also been shown to promote cell proliferation, regulate apoptosis and accelerate mitotic abnormalities, which results in tumour formation and cell invasiveness. Alterations in Pak expression have been detected in human tumours, which makes them an attractive new therapeutic target.


Assuntos
Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Animais , Apoptose , Movimento Celular , Citoesqueleto/metabolismo , Humanos , Modelos Biológicos , Isoformas de Proteínas , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Quinases Ativadas por p21
5.
J Biol Chem ; 288(5): 3428-38, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23250739

RESUMO

ΔEGFR is a potent glioblastoma oncogene which has been studied primarily as a plasma membrane kinase. Using intracranial xenograft studies in mice, we show that blocking ΔEGFR access to the nucleus attenuates its tumorigenicity and, conversely, that promoting nuclear accumulation enhances this, providing the first in vivo evidence that the nuclear actions of ΔEGFR contribute strongly to its oncogenic function. Nuclear actions of ΔEGFR include regulation of gene expression by participation in chromatin-bound complexes, and genome-wide mapping of these sequences by chromatin immunoprecipitation and massively parallel sequencing identified 2294 peaks. Bioinformatic analysis showed enrichment of the E-box motif in the dataset, and c-Myc and ΔEGFR were corecruited to the promoters of and transcriptionally activated a subset of nuclear ΔEGFR chromatin targets. Knockdown of c-Myc decreased the expression of these targets and diminished ΔEGFR-stimulated anchorage-independent colony formation. We conclude that transcriptional regulation of target genes by association with gene regulatory chromatin in cooperation with c-Myc by nuclear ΔEGFR makes a unique contribution to its oncogenicity and propose that this venue provides new targets for therapeutic intervention.


Assuntos
Núcleo Celular/metabolismo , Transformação Celular Neoplásica/metabolismo , Receptores ErbB/metabolismo , Mutação/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Transformação Celular Neoplásica/patologia , Imunoprecipitação da Cromatina , Elementos E-Box/genética , Receptores ErbB/química , Genoma Humano/genética , Glioma/metabolismo , Humanos , Camundongos , Camundongos Nus , Proteínas Mutantes/metabolismo , Sinais de Exportação Nuclear , Sinais de Localização Nuclear/metabolismo , Fenótipo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Multimerização Proteica , Transporte Proteico , Fatores de Transcrição/metabolismo
6.
EMBO Rep ; 11(9): 691-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20651739

RESUMO

High expression of metastasis-associated protein 1 co-regulator (MTA1), a component of the nuclear remodelling and histone deacetylase complex, has been associated with human tumours. However, the precise role of MTA1 in tumorigenesis remains unknown. In this study, we show that induced levels of MTA1 are sufficient to transform Rat1 fibroblasts and that the transforming potential of MTA1 is dependent on its acetylation at Lys626. Underlying mechanisms of MTA1-mediated transformation include activation of the Ras-Raf pathway by MTA1 but not by acetylation-inactive MTA1; this was due to the repression of Galphai2 transcription, which negatively influences Ras activation. We observed that acetylated MTA1-histone deacetylase (HDAC) interaction was required for the recruitment of the MTA1-HDAC complex to the Galphai2 regulatory element and consequently for the repression of Galphai2 transcription and expression leading to activation of the Ras-Raf pathway. The findings presented in this study provide for the first time--to the best of our knowledge--evidence of acetylation-dependent oncogenic activity of a cancer-relevant gene product.


Assuntos
Transformação Celular Neoplásica , Histona Desacetilases/metabolismo , Oncogenes , Proteínas Repressoras/metabolismo , Acetilação , Animais , Linhagem Celular , Movimento Celular , Feminino , Fibroblastos/citologia , Fibroblastos/fisiologia , Subunidade alfa Gi2 de Proteína de Ligação ao GTP/genética , Subunidade alfa Gi2 de Proteína de Ligação ao GTP/metabolismo , Regulação Neoplásica da Expressão Gênica , Histona Desacetilases/genética , Humanos , Lisina/metabolismo , Camundongos , Camundongos Nus , Neoplasias Experimentais , Proteínas Repressoras/genética , Transativadores , Transcrição Gênica , Transplante Heterólogo , Proteínas ras/genética , Proteínas ras/metabolismo
7.
J Gene Med ; 12(12): 968-80, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21104971

RESUMO

BACKGROUND: Inhibition of tumor angiogenesis is a promising approach for cancer therapy and the Tie-2/angiopoietin pathway appears to play an important role. In the present study, we have developed strategies to explore the therapeutic potential of blocking the Tie-2/angiopoietin pathway by sTie-2. METHODS: Ehrlich ascites tumor (EAT) cells were stably transfected to overexpress a truncated form of sTie-2. Transfectants were characterized for their in vitro growth behavior and transplanted into nude mice. Furthermore, recombinant sTie-2 produced by the baculovirus expression system was used to sequester angiopoietins in the murine ascites carcinoma model. The effect of sTie-2 treatment alone or in combination with sFLT-1 on the weight of the animal, ascites cell number and volume was studied. RESULTS: EAT cells stably transfected with a truncated form of sTie-2 showed no change in cell proliferation in vitro and colony forming in soft agar compared to control cells. However, sTie-2 transfected EAT cells transplanted into nude mice reduced tumor burden and demonstrated a reduction in ascites formation and peritoneal angiogenesis. Recombinant sTie-2 showed angiogenic activity in the tube formation and wound healing assay in vitro. sTie-2 treatment alone or in combination with sFLT-1 in an ascites tumor mouse model resulted in reduced peritoneal angiogenesis, with a concomitant decrease in tumor cell number, volume of ascites and the number of invasive tumor cells, as assayed by CD31 staining. CONCLUSIONS: The findings of the present study demonstrate an important role for the Tie-2/angiopoietin pathway in the formation of tumor vasculature and suggest that sTie-2 might yield useful anticancer therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Ehrlich/patologia , Carcinoma de Ehrlich/terapia , Neovascularização Patológica/prevenção & controle , Receptor TIE-2/uso terapêutico , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/uso terapêutico , Angiopoietina-2 , Animais , Carcinoma de Ehrlich/metabolismo , Proliferação de Células/efeitos dos fármacos , Camundongos , Camundongos Nus , Neovascularização Patológica/tratamento farmacológico , Receptor TIE-2/genética , Solubilidade , Transfecção/métodos , Transplantes , Resultado do Tratamento
8.
J Gene Med ; 11(5): 422-34, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19266483

RESUMO

BACKGROUND: Vascular endothelial growth factor (VEGF) is known to play a major role in angiogenesis. A soluble form of Flt-1, a VEGF receptor, is potentially useful as an antagonist of VEGF, and accumulating evidence suggests the applicability of sFlt-1 in tumor suppression. In the present study, we have developed and tested strategies targeted specifically to VEGF for the treatment of ascites formation. METHODS: As an initial strategy, we produced recombinant sFLT-1 in the baculovirus expression system and used it as a trap to sequester VEGF in the murine ascites carcinoma model. The effect of the treatment on the weight of the animal, cell number, ascites volume and proliferating endothelial cells was studied. The second strategy involved, producing Ehrlich ascites tumor (EAT) cells stably transfected with vectors carrying cDNA encoding truncated form of Flt-1 and using these cells to inhibit ascites tumors in a nude mouse model. RESULTS: The sFLT-1 produced by the baculovirus system showed potent anti-angiogenic activity as assessed by rat cornea and tube formation assay. sFLT-1 treatment resulted in reduced peritoneal angiogenesis with a concomitant decrease in tumor cell number, volume of ascites, amount of free VEGF and the number of invasive tumor cells as assayed by CD31 staining. EAT cells stably transfected with truncated form of Flt-1 also effectively reduced the tumor burden in nude mice transplanted with these cells, and demonstrated a reduction in ascites formation and peritoneal angiogenesis. CONCLUSIONS: The inhibition of peritoneal angiogenesis and tumor growth by sequestering VEGF with either sFlt-1 gene expression by recombinant EAT cells or by direct sFLT-1 protein therapy is shown to comprise a potential therapy.


Assuntos
Ascite/patologia , Ascite/terapia , Comunicação Parácrina , Transfecção , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/uso terapêutico , Animais , Baculoviridae , Proliferação de Células , Camundongos , Neovascularização Patológica , Ratos , Proteínas Recombinantes/metabolismo , Reprodutibilidade dos Testes , Solubilidade
9.
Cancer Res ; 67(15): 7132-8, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17671180

RESUMO

Previously, we have shown that metastasis-associated protein 1 (MTA1) overexpression in transgenic mice was accompanied by high incidence of spontaneous B-cell lymphomas including diffuse large B-cell lymphomas (DLBCL). To understand the molecular basis of lymphoma in MTA1-transgenic (MTA1-TG) mice, we wished to identify a putative MTA1 target with a causal role in B-cell lymphogenesis. Using chromatin immunoprecipitation assays, we identified paired box gene 5 (Pax5), a molecule previously implicated in B-cell lymphogenesis, as a potential downstream effector of MTA1. Lymphomas from MTA1-TG mice also showed up-regulation of Pax5. We also found that MTA1 acetylated on Lys(626) interacted with p300 histone acetyltransferase, and that acetylated MTA1 was recruited to the Pax5 promoter to stimulate Pax5 transcription. Global gene profiling identified down-regulation of a set of genes, including those downstream of Pax5 and directly implicated in the B-cell lymphogenesis. Significance of these murine studies was established by evidence showing a widespread up-regulation of both MTA1 and Pax5 in DLBCL from humans. These observations provide in vivo genetic evidence for a role of MTA1 in lymphomagenesis.


Assuntos
Regulação Neoplásica da Expressão Gênica/fisiologia , Linfoma de Células B/genética , Linfoma Difuso de Grandes Células B/genética , Fator de Transcrição PAX5/genética , Fatores de Transcrição/fisiologia , Animais , Northern Blotting , Imunoprecipitação da Cromatina , Perfilação da Expressão Gênica , Histona Desacetilase 1 , Histona Desacetilases/genética , Humanos , Linfoma de Células B/patologia , Linfoma Difuso de Grandes Células B/patologia , Camundongos , Camundongos Transgênicos , Mutagênese Sítio-Dirigida , Plasmídeos , Regiões Promotoras Genéticas , Proteínas Repressoras , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transativadores , Ativação Transcricional , Transfecção , Células Tumorais Cultivadas
10.
Cancer Res ; 67(15): 7062-7, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17671172

RESUMO

Metastasis-associated protein 1 (MTA1), a component of the nuclear remodeling complex and the founding homologue of the MTA family, has been implicated in metastasis, but definitive causative evidence in an animal model system is currently lacking. Here, we show that MTA1 overexpression in transgenic mice is accompanied by a high incidence of spontaneous B cell lymphomas including diffuse large B cell lymphomas (DLBCL). Lymphocytes and lymphoma cells from MTA1-TG mice are hyperproliferative. Lymphomas were transplantable and of clonal origin and were characterized by down-regulation of p27Kip1 as well as up-regulation of Bcl2 and cyclin D1. The significance of these murine studies was established by evidence showing a widespread up-regulation of MTA1 in DLBCL from humans. These findings reveal a previously unrecognized role for the MTA1 pathway in the development of spontaneous B cell lymphomas, and offer a potential therapeutic target in B cell lymphomas. These observations suggest that MTA1-TG mice represent a new model of spontaneous DLBCL associated with high tumor incidence and could be used for therapeutic intervention studies.


Assuntos
Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/fisiologia , Linfoma de Células B/genética , Linfoma Difuso de Grandes Células B/genética , Fatores de Transcrição/genética , Animais , Southern Blotting , Proliferação de Células , Feminino , Histona Desacetilases/genética , Humanos , Linfonodos/patologia , Linfoma de Células B/etiologia , Linfoma de Células B/patologia , Linfoma Difuso de Grandes Células B/etiologia , Linfoma Difuso de Grandes Células B/patologia , Masculino , Camundongos , Camundongos Nus , Camundongos Transgênicos , Metástase Neoplásica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transativadores , Células Tumorais Cultivadas
11.
Mol Endocrinol ; 21(8): 1847-60, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17505058

RESUMO

We recently reported that the breast carcinoma amplified sequence-3 (BCAS3) gene is regulated by estrogen receptor (ER) alpha. However, the role of ERalpha coactivators in the regulation of BCAS3 expression remains unknown, and information regarding the function of the BCAS3 protein is lacking. Here, we define the contribution of ERalpha coactivators to BCAS3 regulation and identify BCAS3 itself as an ERalpha coactivator in breast cancer cells. We found that PELP1 (proline-, glutamic acid-, and leucine-rich protein-1), a newly described ERalpha coregulator, is recruited to BCAS3 chromatin and activates its expression. Analysis of the BCAS3 sequence for functional motifs and evidence from biochemical fractionation suggested that BCAS3 acts as a transcriptional coactivator. Results from chromatin immunoprecipitation, reporter assays, and expression studies further validated the coactivator function of BCAS3 for ERalpha. BCAS3 physically associated with histone H3 and histone acetyltransferase complex protein P/CAF (p300/CBP-associated factor) and possessed histone acetyltransferase activity. Unexpectedly, BCAS3 required PELP1 to function as a coactivator in ERalpha transactivation activity. In brief, these results highlight a mechanism whereby ERalpha activation triggers a positive feedback loop leading to signal amplification in the cell.


Assuntos
Estrogênios/fisiologia , Regulação Neoplásica da Expressão Gênica/fisiologia , Proteínas de Neoplasias/genética , Transativadores/fisiologia , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas Correpressoras , Feminino , Histona Acetiltransferases/metabolismo , Humanos , Camundongos , Camundongos Nus , Proteínas de Neoplasias/biossíntese , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas , Fatores de Transcrição de p300-CBP
12.
J Am Med Inform Assoc ; 25(3): 300-308, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29346583

RESUMO

OBJECTIVE: Finding relevant datasets is important for promoting data reuse in the biomedical domain, but it is challenging given the volume and complexity of biomedical data. Here we describe the development of an open source biomedical data discovery system called DataMed, with the goal of promoting the building of additional data indexes in the biomedical domain. MATERIALS AND METHODS: DataMed, which can efficiently index and search diverse types of biomedical datasets across repositories, is developed through the National Institutes of Health-funded biomedical and healthCAre Data Discovery Index Ecosystem (bioCADDIE) consortium. It consists of 2 main components: (1) a data ingestion pipeline that collects and transforms original metadata information to a unified metadata model, called DatA Tag Suite (DATS), and (2) a search engine that finds relevant datasets based on user-entered queries. In addition to describing its architecture and techniques, we evaluated individual components within DataMed, including the accuracy of the ingestion pipeline, the prevalence of the DATS model across repositories, and the overall performance of the dataset retrieval engine. RESULTS AND CONCLUSION: Our manual review shows that the ingestion pipeline could achieve an accuracy of 90% and core elements of DATS had varied frequency across repositories. On a manually curated benchmark dataset, the DataMed search engine achieved an inferred average precision of 0.2033 and a precision at 10 (P@10, the number of relevant results in the top 10 search results) of 0.6022, by implementing advanced natural language processing and terminology services. Currently, we have made the DataMed system publically available as an open source package for the biomedical community.

13.
Clin Cancer Res ; 12(3 Pt 2): 1001s-1007s, 2006 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-16467116

RESUMO

Selective estrogen receptor (ER) modulators have been the most commonly used neoadjuvant therapy for hormone-dependent breast cancer. However, resistance to endocrine therapy, either inherent or acquired during treatment, presents a major challenge in disease management. The causes of resistance to hormone therapy are not well understood and are the subject of active investigation. It is increasingly clear that decreasing sensitivity of ER-positive breast cancer cells to antiestrogens is caused by several factors. Cross talk between ER and growth factor signaling has emerged as a critical factor in endocrine resistance. Here, we present evidence that receptor tyrosine kinase signaling also plays a role in resistance by controlling the subcellular localization of ER signaling components. Localization of ER in either the nuclear or cytoplasmic compartments has functional implications. Recent work suggests that dynein light chain 1, a recently identified substrate of p21-activated kinase 1, modulates ER transactivation functions through a novel ER coactivator function. Likewise, receptor tyrosine kinase signaling can also alter the expression of ER coregulators such as metastasis-associated antigen 1, leading to hormonal independence. Furthermore, proline-, glutamic acid-, leucine-rich protein 1, an ER coactivator involved in both genomic and nongenomic signaling pathways, is activated by epidermal growth factor receptor and plays a prominent role in resistance to tamoxifen. These recent advances suggest new targeted therapeutic approaches that may lead to either reversion or prevention of endocrine resistance in breast tumors.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Receptor Cross-Talk/fisiologia , Transdução de Sinais/fisiologia , Animais , Feminino , Humanos , Receptores Proteína Tirosina Quinases/metabolismo , Receptores de Estrogênio/metabolismo
15.
Sci Data ; 4: 170059, 2017 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-28585923

RESUMO

Today's science increasingly requires effective ways to find and access existing datasets that are distributed across a range of repositories. For researchers in the life sciences, discoverability of datasets may soon become as essential as identifying the latest publications via PubMed. Through an international collaborative effort funded by the National Institutes of Health (NIH)'s Big Data to Knowledge (BD2K) initiative, we have designed and implemented the DAta Tag Suite (DATS) model to support the DataMed data discovery index. DataMed's goal is to be for data what PubMed has been for the scientific literature. Akin to the Journal Article Tag Suite (JATS) used in PubMed, the DATS model enables submission of metadata on datasets to DataMed. DATS has a core set of elements, which are generic and applicable to any type of dataset, and an extended set that can accommodate more specialized data types. DATS is a platform-independent model also available as an annotated serialization in schema.org, which in turn is widely used by major search engines like Google, Microsoft, Yahoo and Yandex.

16.
Clin Cancer Res ; 11(8): 2822-31, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15837729

RESUMO

Steroid hormone receptors are ligand-dependent transcription factors that control a variety of essential physiologic and developmental processes in humans. The functional activity of a steroid receptor is regulated not only by hormones but also by an array of regulatory proteins such as coactivators, corepressors, and chromatin modifiers. Contrary to an earlier notion that corepressors and coactivators exist in separate complexes, these molecules, which have apparently opposite functions, are increasingly being found in the same complex, which allows for efficient transcriptional control mechanisms. These control mechanisms are in turn regulated by an array of post-translational modifications under the influence of upstream and local signaling networks. Because the outcome of steroidal hormone receptor transcriptional complexes is measured in terms of the expression of target genes, any dysregulation of coregulator complexes perturbs normal homeostasis and could contribute to the development and maintenance of malignant phenotypes. Increasing evidence implicating steroid hormone receptors and their coregulators in various pathophysiologic conditions has elicited interest in their structure and biology. Further advances in this field of study should open up a unique window for novel targeted therapies for diseases such as cancer. Here we briefly review the clinical relevance of corepressors, with a particular focus on their role in the development of cancerous phenotypes.


Assuntos
Neoplasias/patologia , Receptores de Esteroides/metabolismo , Proteínas Repressoras/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Correpressor 2 de Receptor Nuclear , PPAR gama/metabolismo , Receptores de Esteroides/genética , Transativadores/metabolismo
17.
Breast Cancer Res ; 7(1): 5-12, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15642175

RESUMO

The p21-activated kinases signal through a number of cellular pathways fundamental to growth, differentiation and apoptosis. A wealth of information has accumulated at an impressive pace in the recent past, both with regard to previously identified targets for p21-activated kinases that regulate the actin cytoskeleton and cellular stress pathways and with regard to newly identified targets and their role in cancer. Emerging data also provide new clues towards a previously unappreciated link between these various cellular processes. The present review attempts to provide a quick tutorial to the reader about the evolving significance of p21-activated kinases and small GTPases in breast cancer, using information from mouse models, tissue culture studies, and human materials.


Assuntos
Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Animais , Apoptose , Neoplasias da Mama/fisiopatologia , Diferenciação Celular , Proliferação de Células , Modelos Animais de Doenças , Feminino , GTP Fosfo-Hidrolases/metabolismo , Humanos , Neovascularização Patológica , Células Tumorais Cultivadas , Quinases Ativadas por p21
18.
Neoplasia ; 15(1): 73-84, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23359207

RESUMO

The hepatocyte growth factor receptor (c-Met) and a constitutively active mutant of the epidermal growth factor receptor (ΔEGFR/EGFRvIII) are frequently overexpressed in glioblastoma (GBM) and promote tumorigenesis. The mechanisms underlying elevated hepatocyte growth factor (HGF) production in GBM are not understood. We found higher, coordinated mRNA expression levels of HGF and c-Met in mesenchymal (Mes) GBMs, a subtype associated with poor treatment response and shorter overall survival. In an HGF/c-Met-dependent GBM cell line, HGF expression declined upon silencing of c-Met using RNAi or by inhibiting its activity with SU11274. Silencing c-Met decreased anchorage-independent colony formation and increased the survival of mice bearing intracranial GBM xenografts. Consistent with these findings, c-Met activation by ΔEGFR also elevated HGF expression, and the inhibition of ΔEGFR with AG1478 reduced HGF levels. Interestingly, c-Met expression was required for ΔEGFR-mediated HGF production, anchorage-independent growth, and in vivo tumorigenicity, suggesting that these pathways are coupled. Using an unbiased mass spectrometry-based screen, we show that signal transducer and activator of transcription 3 (STAT3) Y705 is a downstream target of c-Met signaling. Suppression of STAT3 phosphorylation with WP1193 reduced HGF expression in ΔEGFR-expressing GBM cells, whereas constitutively active STAT3 partially rescued HGF expression and colony formation in c-Met knockdown cells expressing ΔEGFR. These results suggest that the c-Met/HGF signaling axis is enhanced by ΔEGFR through increased STAT3-dependent HGF expression and that targeting c-Met in Mes GBMs may be an important strategy for therapy.


Assuntos
Neoplasias Encefálicas/metabolismo , Receptores ErbB/metabolismo , Glioblastoma/metabolismo , Fator de Crescimento de Hepatócito/biossíntese , Proteínas Proto-Oncogênicas c-met/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Cianoacrilatos/metabolismo , Receptores ErbB/genética , Glioblastoma/genética , Glioblastoma/patologia , Células HEK293 , Fator de Crescimento de Hepatócito/genética , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Camundongos , Camundongos Nus , Fosforilação/genética , Proteínas Proto-Oncogênicas c-met/genética , Piridinas/metabolismo , Interferência de RNA , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Células Tumorais Cultivadas
20.
Proc Natl Acad Sci U S A ; 104(14): 5866-71, 2007 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-17389360

RESUMO

Transcription, splicing, and translation are potentially coordinately regulatable in a temporospatial-dependent manner, although supporting experimental evidence for this notion is scarce. Yeast two-hybrid screening of a mammary gland cDNA library with human p21-activated kinase 1 (Pak1) as bait identified polyC-RNA-binding protein 1 (PCBP1), which controls translation from mRNAs containing the DICE (differentiation control element). Mitogenic stimulation of human cells phosphorylated PCBP1 on threonines 60 and 127 in a Pak1-sensitive manner. Pak1-dependent phosphorylation of PCBP1 released its binding and translational inhibition from a DICE-minigene. Overexpression of PCBP1 also inhibited the translation of the endogenous L1 cell adhesion molecule mRNA, which contains two DICE motifs in the 3' untranslated region. We also found that Pak1 activation led to an increased nuclear retention of PCBP1, recruitment to the eukaryotic translation initiation factor 4E (eIF4E) promoter, and stimulation of eIF4E expression in a Pak1-sensitive manner. Moreover, mitogenic stimulation promoted Pak1- and PCBP1-dependent alternative splicing and exon inclusion from a CD44 minigene. The alternative splicing functions of PCBP1 were in turn mediated by its intrinsic interaction with Caper alpha, a U2 snRNP auxiliary factor-related protein previously implicated in RNA splicing. These findings establish the principle that a single coregulator can function as a signal-dependent and coordinated regulator of transcription, splicing, and translation.


Assuntos
Ribonucleoproteínas Nucleares Heterogêneas/fisiologia , Biossíntese de Proteínas , Splicing de RNA , Transdução de Sinais , Transcrição Gênica , DNA Complementar , Proteínas de Ligação a DNA , Ativação Enzimática , Fator de Iniciação 4E em Eucariotos/metabolismo , Feminino , Biblioteca Gênica , Humanos , Receptores de Hialuronatos/metabolismo , Cinética , Modelos Biológicos , Fosforilação , Regiões Promotoras Genéticas , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Ligação a RNA , Técnicas do Sistema de Duplo-Híbrido , Quinases Ativadas por p21
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