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The first draft of the Arabidopsis genome was released more than 20 years ago and despite intensive molecular research, more than 30% of Arabidopsis genes remained uncharacterized or without an assigned function. This is in part due to gene redundancy within gene families or the essential nature of genes, where their deletion results in lethality (i.e., the dark genome). High-throughput plant phenotyping (HTPP) offers an automated and unbiased approach to characterize subtle or transient phenotypes resulting from gene redundancy or inducible gene silencing; however, access to commercial HTPP platforms remains limited. Here we describe the design and implementation of OPEN leaf, an open-source phenotyping system with cloud connectivity and remote bilateral communication to facilitate data collection, sharing and processing. OPEN leaf, coupled with our SMART imaging processing pipeline was able to consistently document and quantify dynamic changes at the whole rosette level and leaf-specific resolution when plants experienced changes in nutrient availability. Our data also demonstrate that VIS sensors remain underutilized and can be used in high-throughput screens to identify and characterize previously unidentified phenotypes in a leaf-specific time-dependent manner. Moreover, the modular and open-source design of OPEN leaf allows seamless integration of additional sensors based on users and experimental needs.
Assuntos
Arabidopsis , Arabidopsis/genética , Computação em Nuvem , Fenótipo , Folhas de Planta/genética , PlantasRESUMO
The development of crops with deeper roots holds substantial promise to mitigate the consequences of climate change. Deeper roots are an essential factor to improve water uptake as a way to enhance crop resilience to drought, to increase nitrogen capture, to reduce fertilizer inputs, and to increase carbon sequestration from the atmosphere to improve soil organic fertility. A major bottleneck to achieving these improvements is high-throughput phenotyping to quantify root phenotypes of field-grown roots. We address this bottleneck with Digital Imaging of Root Traits (DIRT)/3D, an image-based 3D root phenotyping platform, which measures 18 architecture traits from mature field-grown maize (Zea mays) root crowns (RCs) excavated with the Shovelomics technique. DIRT/3D reliably computed all 18 traits, including distance between whorls and the number, angles, and diameters of nodal roots, on a test panel of 12 contrasting maize genotypes. The computed results were validated through comparison with manual measurements. Overall, we observed a coefficient of determination of r2>0.84 and a high broad-sense heritability of Hmean2> 0.6 for all but one trait. The average values of the 18 traits and a developed descriptor to characterize complete root architecture distinguished all genotypes. DIRT/3D is a step toward automated quantification of highly occluded maize RCs. Therefore, DIRT/3D supports breeders and root biologists in improving carbon sequestration and food security in the face of the adverse effects of climate change.
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Botânica/métodos , Produtos Agrícolas/anatomia & histologia , Imageamento Tridimensional/métodos , Fenótipo , Raízes de Plantas/anatomia & histologia , Zea mays/anatomia & histologia , Produtos Agrícolas/genética , Raízes de Plantas/genética , Zea mays/genéticaRESUMO
The development of RAF inhibitors targeting cancers with wild type RAF kinase and/or RAS mutation has been challenging due to the paradoxical activation of the RAS-RAF-MEK-ERK cascade following RAF inhibitor treatment. Herein is the discovery and optimization of a series of RAF inhibitors with a novel spiro structure. The most potent spiro molecule 9 showed excellent in vitro potency against b/c RAF enzymes and RAS mutant H358 cancer cells with minimal paradoxical RAF signaling activation. Compound 9 also exhibited good drug-like properties as demonstrated by in vitro cytochrome P450 (CYP), liver microsome stability (LMS) data and moderate oral pharmacokinetics (PK) profiles in rat and mouse.
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Neoplasias , Compostos de Espiro , Animais , Linhagem Celular Tumoral , Sistema de Sinalização das MAP Quinases , Camundongos , Mutação , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas B-raf , Proteínas Proto-Oncogênicas p21(ras)/genética , Ratos , Compostos de Espiro/farmacologiaRESUMO
Diabetic peripheral neuropathy (DPN) is the most common complication in both type 1 and type 2 diabetes. Here we studied some phenotypic features of a well-established animal model of type 2 diabetes, the leptin receptor-deficient db(-)/db(-) mouse, and also the effect of long-term (6 mo) treatment with coenzyme Q10 (CoQ10), an endogenous antioxidant. Diabetic mice at 8 mo of age exhibited loss of sensation, hypoalgesia (an increase in mechanical threshold), and decreases in mechanical hyperalgesia, cold allodynia, and sciatic nerve conduction velocity. All these changes were virtually completely absent after the 6-mo, daily CoQ10 treatment in db(-)/db(-) mice when started at 7 wk of age. There was a 33% neuronal loss in the lumbar 5 dorsal root ganglia (DRGs) of the db(-)/db(-) mouse versus controls at 8 mo of age, which was significantly attenuated by CoQ10. There was no difference in neuron number in 5/6-wk-old mice between diabetic and control mice. We observed a strong down-regulation of phospholipase C (PLC) ß3 in the DRGs of diabetic mice at 8 mo of age, a key molecule in pain signaling, and this effect was also blocked by the 6-mo CoQ10 treatment. Many of the phenotypic, neurochemical regulations encountered in lumbar DRGs in standard models of peripheral nerve injury were not observed in diabetic mice at 8 mo of age. These results suggest that reactive oxygen species and reduced PLCß3 expression may contribute to the sensory deficits in the late-stage diabetic db(-)/db(-) mouse, and that early long-term administration of the antioxidant CoQ10 may represent a promising therapeutic strategy for type 2 diabetes neuropathy.
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Diabetes Mellitus Tipo 2/complicações , Neurônios/efeitos dos fármacos , Doenças do Sistema Nervoso Periférico/prevenção & controle , Receptores para Leptina/deficiência , Ubiquinona/análogos & derivados , Fatores Etários , Animais , Western Blotting , Diabetes Mellitus Tipo 2/patologia , Estimulação Elétrica , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Hiperalgesia/patologia , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Condução Nervosa/efeitos dos fármacos , Doenças do Sistema Nervoso Periférico/etiologia , Fosfolipase C beta/metabolismo , Receptores para Leptina/genética , Nervo Isquiático/lesões , Nervo Isquiático/patologia , Estatísticas não Paramétricas , Ubiquinona/farmacologiaRESUMO
Osteoarthritis (OA) treatment is a highly unmet medical need. Development of a disease-modifying OA drug (DMOAD) is challenging with no approved drugs on the market. Inhibition of ADATMS-4/5 is a promising OA therapeutics to target cartilage degradation and potentially can reduce joint pain and restore its normal function. Starting from the reported ADAMTS-5 inhibitor GLPG1972, we applied a scaffold hopping strategy to generate a novel isoindoline amide scaffold. Representative compound 18 showed high potency in ADATMS-4/5 inhibition, as well as good selectivity over a panel of other metalloproteases. In addition, compound 18 exhibited excellent druglike properties and showed better pharmacokinetic (PK) profiles than GLPG1972 cross-species. Compound 18 demonstrated dose-dependent efficacy in two in vivo rat osteoarthritis models.
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The RAS-RAF-MEK-ERK signaling pathway plays a key role to regulate multiple cellular functions. Acquired resistance to the first-generation RAF inhibitors that only targeted the bRAFV600E mutation prompted the need for a new generation of RAF inhibitors to target cancers bearing mutant RAS and wild type RAF activity by inhibition of paradoxical activation. Starting from the company's previously reported RAF inhibitor 1, extensive drug potency and drug-like properties optimizations led to the discovery of molecule 33 (SHR902275) with greatly improved in vitro potency and solubility. Molecule 33 exhibited good DMPK (Drug Metabolism and Pharmacokinetics) properties, excellent permeability, and outstanding mouse/rat oral PK. It was further evaluated in an in vivo RAS mutant Calu6 xenograft mouse model and demonstrated dose dependent efficacy. To achieve high exposure in a toxicity study, pro-drug 48 was also explored.
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Antineoplásicos/farmacologia , Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Humanos , Camundongos , Camundongos Nus , Modelos Moleculares , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas B-raf/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/metabolismo , Relação Estrutura-AtividadeRESUMO
Stimulator of interferon genes (STING) activation induces type I interferons and pro-inflammatory cytokines which stimulate tumor antigen cross presentation and the adaptive immune responses against tumor. The first-generation of STING agonists, cyclic di-nucleotide (CDN), mimicked the endogenous STING ligand cyclic guanosine monophosphate adenosine monophosphate, and displayed limited clinical efficacy. Here we report the discovery of SHR1032, a novel small molecule non-CDN STING agonist. Compared to the clinical CDN STING agonist ADU-S100, SHR1032 has much higher activity in human cells with different STING haplotypes and robustly induces interferon ß (IFNß) production. When dosed intratumorally, SHR1032 induced strong anti-tumor effects in the MC38 murine syngeneic tumor model. Pharmacodynamic studies showed induction of IFNß, tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) in the tumors and, to a lower extent, in the plasma. More importantly, we found SHR1032 directly causes cell death in acute myeloid leukemia (AML) cells. In conclusion, our findings demonstrate that in addition to their established ability to boost anti-tumor immune responses, STING agonists can directly eradicate AML cells, and SHR1032 may present a new and promising therapeutic agent for cancer patients.
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Leucemia Mieloide Aguda , Proteínas de Membrana , Animais , Apoptose , Citocinas/metabolismo , Humanos , Imunoterapia , Interferon beta/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Proteínas de Membrana/agonistas , Proteínas de Membrana/metabolismo , CamundongosRESUMO
A member of the Janus kinase (JAK) family, Tyrosine Kinase 2 (TYK2), is crucial in mediating various cytokine-signaling pathways such as interleukin-23 (IL23), interleukin-12 (IL12) and type I Interferons (IFN) which contribute to autoimmune disorders (e.g., psoriasis, lupus, and inflammatory bowel disease). Thus, TYK2 represents an attractive target to develop small-molecule therapeutics for the treatment of cytokine-driven inflammatory diseases. Selective inhibition of TYK2 over other JAK isoforms is critical to achieve a favorable therapeutic index in the development of TYK2 inhibitors. However, designing small molecule inhibitors to target the adenosine triphosphate (ATP) binding site of TYK2 kinase has been challenging due to the substantial structural homology of the JAK family catalytic domains. Here, we employed an approach to target the JAK homology 2 (JH2) pseudokinase regulatory domain of the TYK2 protein. We developed a series of small-molecule TYK2 pseudokinase ligands, which suppress the TYK2 catalytic activity through allosteric regulation. The TYK2 pseudokinase-binding small molecules in this study simultaneously achieve high affinity-binding for the TYK2 JH2 domain while also affording significantly reduced affinity for the TYK2 JAK homology 1 (JH1) kinase domain. These TYK2 JH2 selective molecules, although possessing little effect on suppressing the catalytic activity of the isolated TYK2 JH1 catalytic domain in the kinase assays, can still significantly block the TYK2-mediated receptor-stimulated pathways by binding to the TYK2 JH2 domain and allosterically regulating the TYK2 JH1 kinase. These compounds are potent towards human T-cell lines and primary immune cells as well as in human whole-blood specimens. Moreover, TYK2 JH2-binding ligands exhibit remarkable selectivity of TYK2 over JAK isoforms not only biochemically but also in a panel of receptor-stimulated JAK1/JAK2/JAK3-driven cellular functional assays. In addition, the TYK2 JH2-targeting ligands also demonstrate high selectivity in a multi-kinase screening panel. The data in the current study underscores that the TYK2 JH2 pseudokinase is a promising therapeutic target for achieving a high degree of biological selectivity. Meanwhile, targeting the JH2 domain represents an appealing strategy for the development of clinically well-tolerated TYK2 inhibitors that would have superior efficacy and a favorable safety profile compared to the existing Janus kinase inhibitors against autoimmune diseases.
Assuntos
Janus Quinases , TYK2 Quinase , Citocinas , Humanos , Ligantes , Transdução de SinaisRESUMO
Treatment of neuropathic pain is a major clinical problem. This study shows expression of phospholipase ss3 (PLCss3) in mouse and human DRG neurons, mainly in small ones and mostly with a nonpeptidergic phenotype. After spared nerve injury, the pain threshold was strongly reduced, and systemic treatment of such animals with the unselective PLC inhibitor U73122 caused a rapid and long-lasting (48-h) increase in pain threshold. Thus, inhibition of PLC may provide a way to treat neuropathic pain.
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Estrenos/uso terapêutico , Hiperalgesia/tratamento farmacológico , Dor/tratamento farmacológico , Inibidores de Fosfodiesterase/uso terapêutico , Fosfolipase C beta/antagonistas & inibidores , Pirrolidinonas/uso terapêutico , Traumatismos da Medula Espinal/enzimologia , Animais , Modelos Animais de Doenças , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/enzimologia , Gânglios Espinais/lesões , Humanos , Hiperalgesia/enzimologia , Hiperalgesia/etiologia , Camundongos , Camundongos Mutantes , Dor/enzimologia , Dor/etiologia , Limiar da Dor/efeitos dos fármacos , Fosfolipase C beta/genética , Medula Espinal/efeitos dos fármacos , Medula Espinal/enzimologia , Traumatismos da Medula Espinal/complicaçõesRESUMO
Clinical success of IL-17/IL-23 pathway biologics for the treatment of moderate to severe psoriasis suggests that targeting RORγt, a master regulator for the proliferation and function of Th17 cells, could be an effective alternative. However, oral RORγ antagonists (VTP43742, TAK828) with high systemic exposure showed toxicity in phase I/II clinical trials and terminated development. To alleviate the potential safety concerns, identifying compounds with skin-restricted exposure amenable for topical use is of great interest. Systematic structure activity relationship study and multi-parameter optimization led to the discovery of a novel RORγ antagonist (SHR168442) with desired properties for a topical drug. It suppressed the transcription of IL-17 gene, leading to reduction of IL-17 cytokine secretion. It showed high exposure in skin, but low in plasma. Topical application of SHR168442 in Vaseline exhibited excellent efficacy in the imiquimod-induced and IL-23-induced psoriasis-like skin inflammation mouse models and correlated with the reduction of Th17 pathway cytokines, IL-6, TNFα and IL-17A. This work demonstrated restricted skin exposure of RORγ antagonist may provide a new topical treatment option as targeted therapeutics for mild to moderate psoriasis patients and may be suitable for the treatment of any other inflammatory disorders that are accessible locally.
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Benzimidazóis/uso terapêutico , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/antagonistas & inibidores , Psoríase/tratamento farmacológico , Administração Tópica , Animais , Benzimidazóis/química , Benzimidazóis/metabolismo , Benzimidazóis/farmacologia , Sítios de Ligação , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Estabilidade de Medicamentos , Humanos , Imiquimode/toxicidade , Interleucina-17/metabolismo , Interleucina-23/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Simulação de Acoplamento Molecular , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Psoríase/induzido quimicamente , Psoríase/patologia , Ratos , Ratos Sprague-Dawley , Índice de Gravidade de Doença , Pele/efeitos dos fármacos , Pele/patologiaRESUMO
INTRODUCTION: CD73 and adenosine support growth-promoting neovascularization, metastasis, and survival in cells, and promote anti-PD-1 mAb therapy-induced immune escape. Consequently, developing a CD73 inhibitor as monotherapy and a potential beneficial combination partner with immune-checkpoint inhibitors needs investigation. METHODS: CD73 inhibitors were evaluated in vitro with soluble and membrane-bound CD73 enzymes, as well as its PD biomarker responses in human peripheral blood mononuclear cells (PBMC) by flow cytometry and ELISA. The binding modes of the molecules were analyzed via molecular modeling. The anti-tumor activity and synergistic effect of SHR170008 in combination with anti-PD-1 mAb were evaluated in a syngeneic mouse breast cancer model. RESULTS: SHR170008 was discovered during the initial structural modifications on the link between the ribose and the α-phosphate of AMPCP, which significantly improved the stability of the compound confirmed by the metabolite identification study. Further modifications on the adenine base of AMPCP improved the potency due to forming stronger interactions with CD73 protein. It exhibited potent inhibitory activities on soluble and endogenous membrane-bound CD73 enzymes, and induced IFNγ production, reversed AMP-suppressed CD25+ and CD8+/CD25+ expression, and enhanced granzyme B production on CD8+ T cells in human PBMC. SHR170008 showed dose-dependent anti-tumor efficacy with suppression of adenosine in the tumors in EMT6 mouse breast tumor model. The increase of adenosine in tumor tissue by anti-PD-1 mAb alone was suppressed by SHR170008 in the combination groups. Simultaneous inhibition of CD73 and PD-1 neutralization synergistically enhanced antitumor immunity and biomarkers in response, and exposures of SHR170008 were correlated with the efficacy readouts. CONCLUSION: Our findings suggest that CD73 may serve as an immune checkpoint by generating adenosine, which suppresses the antitumor activity of anti-PD-1 mAb, and inhibition of CD73 may be a potential beneficial combination partner with immune-checkpoint inhibitors to improve their therapeutic outcomes in general.
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RORγ is a dual-functional drug target, which involves not only induction of inflammation but also promotion of cancer immunity. The development of agonists of RORγ promoting Th17 cell differentiation could provide a novel mechanism of action (MOA) as an immune-activating anticancer agent. Herein, we describe new 2-(ortho-substituted benzyl)-indole derivatives as RORγ agonists by scaffold hopping based on clinical RORγ antagonist VTP-43742. Interestingly, subtle structural differences of the compounds led to the opposite biological MOA. After rational optimization for structure-activity relationship and pharmacokinetic profile, we identified a potent RORγ agonist compound 17 that was able to induce the production of IL-17 and IFNγ in tumor tissues and elicit antitumor efficacy in MC38 syngeneic mouse colorectal tumor model. This is the first comprehensive work to demonstrate the in vivo antitumor efficacy of an RORγ agonist.
Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Indóis/farmacologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/agonistas , Administração Oral , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Disponibilidade Biológica , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Indóis/administração & dosagem , Indóis/química , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Relação Estrutura-AtividadeRESUMO
Systems for collecting image data in conjunction with computer vision techniques are a powerful tool for increasing the temporal resolution at which plant phenotypes can be measured non-destructively. Computational tools that are flexible and extendable are needed to address the diversity of plant phenotyping problems. We previously described the Plant Computer Vision (PlantCV) software package, which is an image processing toolkit for plant phenotyping analysis. The goal of the PlantCV project is to develop a set of modular, reusable, and repurposable tools for plant image analysis that are open-source and community-developed. Here we present the details and rationale for major developments in the second major release of PlantCV. In addition to overall improvements in the organization of the PlantCV project, new functionality includes a set of new image processing and normalization tools, support for analyzing images that include multiple plants, leaf segmentation, landmark identification tools for morphometrics, and modules for machine learning.
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As a tumor suppressor protein, p53 plays a crucial role in cancer development. Direct associations between p53, apoptosis and drug response suggest that targeting genes/gene products downstream of p53 may have clinical benefits. The completion of the human genome project and the availability of microarray technology have led to new ways in which to define the global regulatory network of p53 and to search for oncogenes in the p53 pathway. A crucial step toward antitumor drug discovery is the mapping of p53 transcriptomes onto cancer phenomes. In this review, recent developments in the genome-wide search of p53 target genes are discussed, along with current efforts in high-throughput antitumor target discovery in the p53 pathway and recent progress in the pharmacological modulation of targets downstream of p53 for effective cancer therapy.
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Marcação de Genes , Genes p53/efeitos dos fármacos , Terapia Genética , Neoplasias/terapia , Animais , Desenho de Fármacos , HumanosRESUMO
Food security is currently one of the major challenges that we are facing as a species. Understanding plant responses and adaptations to limited water availability is key to maintain or improve crop yield, and this is even more critical considering the different projections of climate change. In this work, we combined two high-throughput -'omic' platforms ('phenomics' and 'ionomics') to begin dissecting time-dependent effects of water limitation in Arabidopsis leaves and ultimately seed yield. As proof of concept, we acquired high-resolution images with visible, fluorescence, and near infrared cameras and used commercial and open source algorithms to extract the information contained in those images. At a defined point, samples were also taken for elemental profiling. Our results show that growth, biomass and photosynthetic efficiency were affected mostly under severe water limitation regimes and these differences were exacerbated at later developmental stages. The elemental composition and seed yield, however, changed across the different water regimes tested and these changes included under- and over- accumulation of elements compared with well-watered plants. Our results demonstrate that the combination of phenotyping techniques can be successfully used to identify specific bottlenecks during plant development that could compromise biomass, yield, and the nutritional quality of plants.
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A new subseries of substituted piperidines as p53-HDM2 inhibitors exemplified by 21 has been developed from the initial lead 1. Research focused on optimization of a crucial HDM2 Trp23-ligand interaction led to the identification of 2-(trifluoromethyl)thiophene as the preferred moiety. Further investigation of the Leu26 pocket resulted in potent, novel substituted piperidine inhibitors of the HDM2-p53 interaction that demonstrated tumor regression in several human cancer xenograft models in mice. The structure of HDM2 in complex with inhibitors 3, 10, and 21 is described.
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The temporal gene expression profile during the entire process of apoptosis and cell cycle progression in response to p53 in human ovarian cancer cells was explored with cDNA microarrays representing 33 615 individual human genes. A total of 1501 genes (4.4%) were found to respond to p53 (approximately 80% of these were repressed by p53) using 2.5-fold change as a cutoff. It was anticipated that most of p53 responsive genes resulted from the secondary effect of p53 expression at late stage of apoptosis. To delineate potential p53 direct and indirect target genes during the process of apoptosis and cell cycle progression, microarray data were combined with global p53 DNA-binding site analysis. Here we showed that 361 out of 1501 p53 responsive genes contained p53 consensus DNA-binding sequence(s) in their regulatory region, approximately 80% of which were repressed by p53. This is the first time that a large number of p53-repressed genes have been identified to contain p53 consensus DNA-binding sequence(s) in their regulatory region. Hierarchical cluster analysis of these genes revealed distinct temporal expression patterns of transcriptional activation and repression by p53. More genes were activated at early time points, while more repressed genes were found after the onset of apoptosis. A small-scale quantitative chromatin immunoprecipitation analysis indicated that in vivo p53-DNA interaction was detected in eight out of 10 genes, most of which were repressed by p53 at the early onset of apoptosis, suggesting that a portion of p53 target genes in the human genome could be negatively regulated by p53 via sequence-specific DNA binding. The approaches and genes described here should aid the understanding of global gene regulatory network of p53.
Assuntos
Apoptose/genética , Ciclo Celular/genética , Neoplasias Ovarianas/genética , Transcrição Gênica , Proteína Supressora de Tumor p53/genética , Adenoviridae/genética , Sequência de Aminoácidos , Sítios de Ligação , Cromatina/metabolismo , Análise por Conglomerados , Sequência Conservada , Feminino , Perfilação da Expressão Gênica , Genoma Humano , Humanos , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Ovarianas/patologia , Testes de Precipitina , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transfecção/métodos , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismoRESUMO
Survivin is an inhibitor of apoptosis protein, which is over-expressed in most tumors. Aberrant expression of survivin and loss of wild-type p53 in many tumors prompted us to investigate a possible link between these two events. Here we show that wild-type p53 represses survivin expression at both mRNA and protein levels. Transient transfection analyses revealed that the expression of wild-type p53, but not mutant p53, was associated with strong repression of the survivin promoter in various cell types. The over-expression of exogenous survivin protein rescues cells from p53-induced apoptosis in a dose-dependent manner, suggesting that loss of survivin mediates, at least, in part the p53-dependent apoptotic pathway. In spite of the presence of two putative p53-binding sites in the survivin promoter, deletion and mutation analyses suggested that neither site is required for transcriptional repression of survivin expression. This was confirmed by chromatin immunoprecipitation assays. Further analyses suggested that the modification of chromatin within the survivin promoter could be a molecular explanation for silencing of survivin gene transcription by p53.
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Apoptose , Proteínas Cromossômicas não Histona/genética , Inibidores de Cisteína Proteinase/genética , Proteínas Associadas aos Microtúbulos , Proteína Supressora de Tumor p53/genética , Adenoviridae , Antibióticos Antineoplásicos/farmacologia , Sequência de Bases , Western Blotting , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Inibidores de Cisteína Proteinase/metabolismo , Primers do DNA/química , Doxorrubicina/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Inibidoras de Apoptose , Luciferases/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Dados de Sequência Molecular , Proteínas de Neoplasias , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Testes de Precipitina , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , RNA Neoplásico/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Survivina , Transcrição Gênica , Transfecção , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismoRESUMO
To determine if A1 adenosine receptors mediate breast tumorigenesis, we evaluated A1 receptor expression in human tumor cell lines and human primary breast tumor tissues using both quantitative RT-PCR and Western blot analysis. A1 receptor mRNA expression is upregulated in all breast tumor cell lines examined (n=7) compared to normal mammary epithelial cells/cell lines (n=3) as determined by quantitative RT-PCR analysis. Western blot analysis indicates that protein expression of A1 adenosine receptor is higher in 15 (62.5%) of 24 human primary breast tumor tissues than in matched normal breast tissue. To explore its cellular function, the A1 adenosine receptor was depleted by small interfering RNA (siRNA) in MDA-MB-468 human breast tumor cells. Depletion of A1 receptors in MDA-MB-468 breast tumor cells attenuated both cell growth and cell proliferation as measured by cell number counts and [(14)C]-thymidine incorporation, respectively. Cell cycle analysis indicated that depletion of A1 receptors by siRNA impairs G(1) checkpoint, leading to marked accumulation of cells in G(2)/M phase, in agreement with the inhibitory effect on cell proliferation. Further supporting this finding, synchronization studies of Hela cells in various cell cycle phases suggest that A1 receptor expression is suppressed in G(2)/M cells and depletion of A1 receptor expression by siRNA produced differential expression of several key cell cycle regulators, i.e., accumulation of the cyclin-dependent kinase inhibitor p27 with concomitant reduction of CDK4 and cyclin E proteins. In addition to the impact on cell cycle progression, depletion of A1 receptors by siRNA results in substantial cell death and apoptosis as determined by FACS analysis and annexin V staining method. Together these findings suggest that the A1 adenosine receptor may contribute to tumor cell growth and survival in breast tumor cells.
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Apoptose , Neoplasias da Mama/patologia , Carcinoma/patologia , Proliferação de Células , Interferência de RNA , Receptor A1 de Adenosina/metabolismo , Mama/citologia , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , RNA Mensageiro/metabolismoRESUMO
BACKGROUND: Genome wide transcriptome maps can provide tools to identify candidate genes that are over-expressed or silenced in certain disease tissue and increase our understanding of the structure and organization of the genome. Expressed Sequence Tags (ESTs) from the public dbEST and proprietary Incyte LifeSeq databases were used to derive a transcript map in conjunction with the working draft assembly of the human genome sequence. RESULTS: Examination of ESTs derived from brain tissues (excluding brain tumor tissues) suggests that these genes are distributed on chromosomes in a non-random fashion. Some regions on the genome are dense with brain-enriched genes while some regions lack brain-enriched genes, suggesting a significant correlation between distribution of genes along the chromosome and tissue type. ESTs from brain tumor tissues have also been mapped to the human genome working draft. We reveal that some regions enriched in brain genes show a significant decrease in gene expression in brain tumors, and, conversely that some regions lacking in brain genes show an increased level of gene expression in brain tumors. CONCLUSIONS: This report demonstrates a novel approach for tissue specific transcriptome mapping using EST-based quantitative assessment.