RESUMO
BACKGROUND: Previous qualitative studies suggested that the false negative rate of the T cell spot test for tuberculosis infection (T-SPOT.TB) is associated with many risk factors in tuberculosis patients. However, more precise quantitative studies are lacking. The purpose of this study was to investigate the factors affecting quantified spot-forming cells (SFCs) to early secreted antigenic target 6 kDa (ESAT-6) or culture filtrate protein 10 kDa (CFP-10) in patients with active tuberculosis. METHODS: We retrospectively analyzed the data of 360 patients who met the inclusion criteria. Using the SFCs to ESAT-6 or CFP-10 levels as dependent variables, variables with statistical significance in the univariate analysis were subjected to optimal scaling regression analysis. The combination of ESAT-6 and CFP-10 (i.e., T-SPOT.TB) was analyzed by the exact logistic regression model. RESULTS: The results showed that the SFCs to ESAT-6 regression model had statistical significance (P < 0.001) and that previous treatment and CD4+ and platelet counts were its independent risk factors (all P < 0.05). Their importance levels were 0.095, 0.596 and 0.100, respectively, with a total of 0.791. The SFCs to CFP-10 regression model also had statistical significance (P < 0.001); platelet distribution width and alpha-2 globulin were its independent risk factors (all P < 0.05). Their importance levels were 0.287 and 0.247, respectively, with a total of 0.534. The quantification graph showed that quantified SFCs to ESAT-6 or CFP-10 grading had a linear correlation with risk factors. Albumin-globulin ratio, CD4+ and CD8+ were independent risk factors for false negative T-SPOT.TB (all P < 0.05). CONCLUSIONS: In T-SPOT.TB-assisted diagnosis of patients with active tuberculosis, previous treatment, decreased CD4+ and platelet count might lead to the decreased SFCs to ESAT-6, decreased alpha-2 globulin and high platelet distribution width might lead to the decreased SFCs to CFP-10, decreased albumin-globulin ratio, CD4+ and CD8+ might lead to an increase in the false negative rate of the T-SPOT.TB.
Assuntos
Antígenos de Bactérias/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose/diagnóstico , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Estudos Retrospectivos , Linfócitos T/imunologia , Tuberculose/imunologia , Tuberculose/microbiologia , Tuberculose/patologiaRESUMO
Visual working memory (VWM) is a cognitive memory buffer for temporarily processing and storing visual information. Previous studies suggest that its capacity is severely limited, and there is an ongoing debate on whether the storage capacity is object-based or feature-based in VWM. In this study, a change-detection task was employed to investigate whether and how task difficulty can affect VWM, specifically, its capacity and the unit of storage. Task difficulty was manipulated through the set size of memory items, memory fidelity required by the resolution of representation and the type of feature tested. We examined two types of stimuli: the single-feature type, where each memory item was composed of a single feature (color or shape), and the conjunctive-feature type, where each item was composed of a conjunction of two features (colored shape). Experiment 1 replicated the previous findings that memory capacity for colors was larger than shapes, and decreased with the resolution demand regardless of the type of stimuli. In Experiment 2, we analyzed and compared the results from single-feature items and conjunctive-feature items in the low- and high-resolution conditions while controlling for the number of to-be-remembered features. By directly matching the estimated capacity based on an object-unit and a feature-unit with the theoretical prediction, the results showed that the unit storage in VWM tended to be feature-based with low task difficulty, and to be object-based with high task difficulty. This suggests that VWM is dynamic and flexible, dependent on the load of the current task.
Assuntos
Percepção de Forma/fisiologia , Memória de Curto Prazo/fisiologia , Rememoração Mental/fisiologia , Percepção Visual/fisiologia , Adulto , Percepção de Cores/fisiologia , Humanos , Reconhecimento Visual de Modelos/fisiologia , Adulto JovemRESUMO
PURPOSE: The purpose of this study was to investigate the influencing factors for chest CT hysteresis and severity of coronavirus disease 2019 (COVID-19). METHODS: The chest CT data of patients with confirmed COVID-19 in 4 hospitals were retrospectively analyzed. An independent assessment was performed by one clinician using the DEXIN FACT Workstation Analysis System, and the assessment results were reviewed by another clinician. Furthermore, the mean hysteresis time was calculated according to the median time from progression to the most serious situation to improve chest CT in patients after fever relief. The optimal scaling regression analysis was performed by including variables with statistical significance in univariate analysis. In addition, a multivariate regression model was established to investigate the relationship of the percentage of lesion/total lung volume with lymphocyte and other variables. RESULTS: In the included 166 patients with COVID-19, the average value of the most serious percentage of lesion/total lung volume was 6.62, of which 90 patients with fever had an average hysteresis time of 4.5 days after symptom relief, with a similar trend observed in those without fever. Multivariate analysis revealed that lymphocyte count in peripheral blood and transcutaneous oxygen saturation decreased with the increase of the percentage of lesion/total lung volume. CONCLUSION: There is a hysteresis effect in the improvement of chest CT image relative to fever relief in patients with COVID-19. The pulmonary lesions may be related to the severity as well as decreased lymphocyte count or percutaneous oxygen saturation.
Assuntos
COVID-19 , Tomografia Computadorizada por Raios X , COVID-19/diagnóstico por imagem , Humanos , Pulmão/diagnóstico por imagem , Pulmão/fisiopatologia , Saturação de Oxigênio , Estudos Retrospectivos , SARS-CoV-2RESUMO
17beta-Estradiol (E2) induces and represses gene expression in breast cancer cells; however, the mechanisms of gene repression are not well understood. In this study, we show that E2 decreases vascular endothelial growth factor receptor 2 (VEGFR2) mRNA levels in MCF-7 cells, and this gene was used as a model for investigating pathways associated with E2-dependent gene repression. Deletion analysis of the VEGFR2 promoter indicates that the proximal GC-rich motifs at -58 and -44 are critical for the E2-dependent decreased response in MCF-7 cells. Mutation or deletion of these GC-rich elements results in loss of hormone responsiveness and shows that the -60 to -37 region of the VEGFR2 promoter is critical for both basal and hormone-dependent decreased VEGFR2 expression in MCF-7 cells. Western blot, immunofluorescent staining, RNA interference, and EMSAs support a role for Sp proteins in hormone-dependent down-regulation of VEGFR2 in MCF-7 cells, primarily through estrogen receptor (ER)alpha/Sp1 and ERalpha/Sp3 interactions with the VEGFR2 promoter. Using chromatin immuno-precipitation and transient transfection/RNA interference assays we show that the ERalpha/Sp protein-promoter interactions are accompanied by recruitment of the co-repressors SMRT (silencing mediator of retinoid and thyroid hormone receptor) and NCoR (nuclear receptor corepressor) to the promoter and that SMRT and NCoR knockdown reverse E2-mediated down-regulation of VEGFR2 expression in MCF-7 cells. This study illustrates that both SMRT and NCoR are involved in E2-dependent repression of VEGFR2 in MCF-7 cells.
Assuntos
Estradiol/farmacologia , Receptor alfa de Estrogênio/fisiologia , Fatores de Transcrição Sp/fisiologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Western Blotting , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Ensaio de Desvio de Mobilidade Eletroforética , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Imunofluorescência , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Modelos Genéticos , Regiões Promotoras Genéticas/genética , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição Sp/genética , Fatores de Transcrição Sp/metabolismo , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Fator de Transcrição Sp1/fisiologia , Fator de Transcrição Sp3/genética , Fator de Transcrição Sp3/metabolismo , Fator de Transcrição Sp3/fisiologia , TransfecçãoRESUMO
Vascular endothelial growth factor receptor-1 (VEGFR1) is expressed in cancer cell lines and tumors and, in pancreatic and colon cancer cells, activation of VEGFR1 is linked to increased tumor migration and invasiveness. Tolfenamic acid, a nonsteroidal anti-inflammatory drug, decreases Sp protein expression in Panc-1 and L3.6pl pancreatic cancer cells, and this was accompanied by decreased VEGFR1 protein and mRNA and decreased luciferase activity on cells transfected with constructs (pVEGFR1) containing VEGFR1 promoter inserts. Comparable results were obtained in pancreatic cancer cells transfected with small inhibitory RNAs for Sp1, Sp3, and Sp4 and all three proteins bound to GC-rich elements in the VEGFR1 promoter. These results show that VEGFR1 is regulated by Sp proteins and that treatment with tolfenamic acid decreases expression of this critical angiogenic factor. Moreover, in vitro studies in Panc-1 cells show that activation of VEGFR1 by VEGFB to increase mitogen-activated protein kinase 1/2 phosphorylation and cell migration on collagen-coated plates is also inhibited by tolfenamic acid. Thus, targeted degradation of Sp proteins is highly effective for inhibiting VEGFR1 and associated angiogenic responses in pancreatic cancer.
Assuntos
Neoplasias Pancreáticas/metabolismo , Fatores de Transcrição Sp/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Humanos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Invasividade Neoplásica , Neoplasias Pancreáticas/irrigação sanguínea , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fosforilação , Regiões Promotoras Genéticas , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Fator de Transcrição Sp1/metabolismo , Fator de Transcrição Sp3/metabolismo , Fator de Transcrição Sp4/metabolismo , Transfecção , Fator B de Crescimento do Endotélio Vascular/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , ortoaminobenzoatos/farmacologiaRESUMO
Bis(3'-indolyl)methane (DIM) is a metabolite of the phytochemical indole-3-carbinol, and both compounds exhibit a broad spectrum of anticancer activities. We have developed a series of synthetic symmetrical ring-substituted DIM analogues, including 5,5'-dibromoDIM, which are more potent than DIM as inhibitors of cancer cell and tumor growth. In colon cancer cells, 5,5'-dibromoDIM decreased cell proliferation and inhibited G(0)-G(1)- to S-phase progression, and this was accompanied by induction of the cyclin-dependent kinase inhibitor p21 in HT-29 and RKO colon cancer cells. Mechanistic studies showed that induction of p21 in both RKO (p53 wild-type) and HT-29 (p53 mutant) cells by 5,5'-dibromoDIM was Krüppel-like factor 4 (KLF4) dependent, and induction of p53 in RKO cells was also KLF4 dependent. Analysis of the p21 promoter in p53-dependent RKO cells showed that 5,5'-dibromoDIM activated p21 gene expression through the proximal GC-rich sites 1 and 2, and chromatin immunoprecipitation assays showed that KLF4 and p53 bound to this region of the promoter, whereas in HT-29 cells unidentified upstream cis-elements were required for induction of p21. 5,5'-DibromoDIM (30 mg/kg/d) also inhibited tumor growth and induced p21 in athymic nude mice bearing RKO cells as xenografts, showing that ring-substituted DIM such as 5,5'-dibromoDIM represent a novel class of mechanism-based drugs for clinical treatment of colon cancer.
Assuntos
Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Indóis/farmacologia , Fatores de Transcrição Kruppel-Like/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Fator 4 Semelhante a Kruppel , Masculino , Camundongos , Camundongos Nus , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
1,1-Bis(3'-indolyl)-1-(p-substituted phenyl)methanes (C-DIMs) activate the orphan receptors peroxisome proliferator-activated receptor gamma (PPARgamma) and Nur77 and induce receptor-dependent and -independent apoptotic pathways in colon and other cancer cells. Structure-activity studies show that the p-bromo (DIM-C-pPhBr) and p-fluoro (DIM-C-pPhF) analogs, which exhibit minimal activation of Nur77 and PPARgamma, induce expression of CCAAT/enhancer-binding protein homologous protein (CHOP/GADD153) in colon cancer cells. Moreover, among a series of bromo and fluoro C-DIM analogs, their induction of CHOP was dependent on the position of the phenyl substituents (para >/= meta >/= ortho) and required a free indole group. DIM-C-pPhBr and DIM-C-pPhF not only induced CHOP but also activated death receptor 5 (CHOP dependent), cleavage of caspase 8 and poly (ADP ribose) polymerase (PARP) that is consistent with activation of the extrinsic pathway of apoptosis. These responses were associated with the activation of c-jun N-terminal kinase (JNK) pathway since inhibition of JNK inhibited induction of the extrinsic apoptotic pathway by these C-DIMs. However, in contrast to classical inducers of endoplasmic reticulum (ER) stress such as tunicamycin and thapsigargin, the C-DIM compounds did not induce glucose-related protein 78 that is a marker of ER stress. Proapoptotic and anticarcinogenic effects were also observed in athymic nude mice bearing RKO cell xenografts and treated with 30 mg/kg/day DIM-C-pPhBr and this was accompanied by increased JNK phosphorylation in the tumors. Thus, the anticarcinogenic activity of DIM-C-pPhBr in colon cancer cells and tumors is related to a novel ER stress-independent activation of JNK.
Assuntos
Antineoplásicos/farmacologia , Neoplasias do Colo/enzimologia , Ativação Enzimática/efeitos dos fármacos , Indóis/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/efeitos dos fármacos , Animais , Antineoplásicos/química , Western Blotting , Linhagem Celular Tumoral , Colágeno Tipo XI/efeitos dos fármacos , Colágeno Tipo XI/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/patologia , Humanos , Imuno-Histoquímica , Imunoprecipitação , Indóis/química , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Camundongos , Camundongos Nus , Relação Estrutura-Atividade , Fator de Transcrição CHOP/efeitos dos fármacos , Fator de Transcrição CHOP/metabolismo , Transfecção , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
1,1-Bis(3'-indolyl)-1-(p-methoxyphenyl)methane (DIM-C-pPhOCH(3)) is a methylene-substituted diindolylmethane (C-DIM) analog that activates the orphan receptor nerve growth factor-induced-Balpha (NGFI-Balpha, Nur77). RNA interference studies with small inhibitory RNA for Nur77 demonstrate that DIM-C-pPhOCH(3) induces Nur77-dependent and -independent apoptosis, and this study has focused on delineating the Nur77-independent proapoptotic pathways induced by the C-DIM analog. DIM-C-pPhOCH(3) induced caspase-dependent apoptosis in RKO colon cancer cells through decreased mitochondrial membrane potential which is accompanied by increased mitochondrial bax/bcl-2 ratios and release of cytochrome c into the cytosol. DIM-C-pPhOCH(3) also induced phosphatidylinositol-3-kinase-dependent activation of early growth response gene-1 which, in turn, induced expression of the proapoptotic nonsteroidal anti-inflammatory drug-activated gene-1 (NAG1) in RKO and SW480 colon cancer cells. Moreover, DIM-C-pPhOCH(3) also induced NAG-1 expression in colon tumors in athymic nude mice bearing RKO cells as xenografts. DIM-C-pPhOCH(3) also activated the extrinsic apoptosis pathway through increased phosphorylation of c-jun N-terminal kinase which, in turn, activated C/EBP homologous transcription factor (CHOP) and death receptor 5 (DR5). Thus, the effectiveness of DIM-C-pPhOCH(3) as a tumor growth inhibitor is through activation of Nur77-dependent and -independent pathways.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Proteínas de Ligação a DNA/fisiologia , Indóis/farmacologia , Receptores Citoplasmáticos e Nucleares/fisiologia , Receptores de Esteroides/fisiologia , Fatores de Transcrição/fisiologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Inibidores do Crescimento/farmacologia , Humanos , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores de Esteroides/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/metabolismoRESUMO
3-Methylcholanthrene (3MC) is an aryl hydrocarbon receptor (AhR) agonist, and it has been reported that 3MC induces estrogenic activity through AhR-estrogen receptor alpha (ER alpha) interactions. In this study, we used 3MC and 3,3',4,4',5-pentachlorobiphenyl (PCB) as prototypical AhR ligands, and both compounds activated estrogen-responsive reporter genes/gene products (cathepsin D) in MCF-7 breast cancer cells. The estrogenic responses induced by these AhR ligands were inhibited by the antiestrogen ICI 182780 and by the transfection of a small inhibitory RNA for ER alpha but were not affected by the small inhibitory RNA for AhR. These results suggest that 3MC and PCB directly activate ER alpha, and this was confirmed in a competitive ER alpha binding assay and in a fluorescence resonance energy transfer experiment in which PCB and 3MC induced CFP-ER alpha/YFP-ER alpha interactions. In a chromatin immunoprecipitation assay, PCB and 3MC enhanced ER alpha (but not AhR) association with the estrogen-responsive region of the pS2 gene promoter. Moreover, in AhR knockout mice, 3MC increased uterine weights and induced expression of cyclin D1 mRNA levels. These results show that PCB and 3MC directly activate ER alpha-dependent transactivation and extend the number of ligands that activate both AhR and ER alpha.
Assuntos
Receptor alfa de Estrogênio/metabolismo , Metilcolantreno/farmacologia , Receptores de Hidrocarboneto Arílico/agonistas , Animais , Ligação Competitiva , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Ciclina D1/biossíntese , Ciclina D1/genética , Dimerização , Estradiol/farmacologia , Receptor alfa de Estrogênio/genética , Feminino , Transferência Ressonante de Energia de Fluorescência , Humanos , Ligantes , Metilcolantreno/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Tamanho do Órgão/efeitos dos fármacos , Bifenilos Policlorados/metabolismo , Bifenilos Policlorados/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores de Hidrocarboneto Arílico/genética , Transfecção , Útero/anatomia & histologia , Útero/efeitos dos fármacosRESUMO
Betulinic acid (BA) is a phytochemical triterpenoid acid from bark extracts and is cytotoxic to cancer cells and tumors. We modified the A-ring of BA to give a 2-cyano-1-en-3-one moiety and the effects of the 2-cyano-lup-1-en-3-oxo-20-oic acid (CN-BA), 2-cyano derivative of BA, and its methyl ester (CN-BA-Me) were investigated in colon and pancreatic cancer cells. Both CN-BA and CN-BA-Me were highly cytotoxic to Panc-28 pancreatic and SW480 colon cancer cells. CN-BA and CN-BA-Me also induced differentiation in 3T3-L1 adipocytes, which exhibited a characteristic fat droplet accumulation induced by peroxisome proliferator-activated receptor gamma (PPARgamma) agonists. Based on these results, we investigated the activities of CN-BA and CN-BA-Me as PPARgamma agonists using several receptor-mediated responses including activation of transfected PPARgamma-responsive constructs, induction of p21 in Panc-28 cells and induction of caveolin-1 and Krüppel-like factor 4 in colon cancer cells. The results clearly demonstrated that both CN-BA and CN-BA-Me activated PPARgamma-dependent responses in colon (caveolin-1) and pancreatic (p21) cancer cells, whereas induction of KLF4 by these compounds in colon cancer cells was PPARgamma independent and also dependent on cell context. The PPARgamma agonist activities of CN-BA and CN-BA-Me were structure-, response/gene- and cell context-dependent suggesting that these compounds are a novel class of selective PPARgamma modulators with potential for clinical treatment of colon and pancreatic cancer.
Assuntos
Neoplasias do Colo/metabolismo , PPAR gama/agonistas , Neoplasias Pancreáticas/metabolismo , Triterpenos/farmacologia , Células 3T3-L1 , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/patologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Fator 4 Semelhante a Kruppel , Camundongos , Neoplasias Pancreáticas/patologiaRESUMO
The trifunctional carbamoylphosphate synthetase/aspartate transcarbamyltransferase/dihydroorotase (CAD) gene is hormone responsive in MCF-7 and ZR-75 breast cancer cells, and this response is inhibited by the aryl hydrocarbon receptor (AhR) agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Estrogen-dependent induction of CAD mRNA and reporter gene activity in cells transfected with constructs (pCAD) containing hormone-responsive GC-rich CAD promoter inserts involves estrogen receptor alpha (ERalpha)/Sp1 interactions with these proximal GC-rich motifs. TCDD also inhibits hormone-induced transactivation in MCF-7 and ZR-75 cells transfected with pCAD constructs. The mechanism of inhibitory AhR-ERalpha/Sp1 cross talk was further investigated by chromatin immunoprecipitation (ChIP), and the results show that ERalpha/Sp1 and the AhR are constitutively bound to the CAD gene promoter and only minor changes are observed after treatment with 17beta-estradiol, TCDD, or their combination. However, examination of interactions of these transcription factors by fluorescence resonance energy transfer shows that E2 enhances ERalpha-Sp1 interactions, whereas cotreatment with TCDD significantly decreases interaction of these proteins. These results suggest that inhibitory AhR-ERalpha/Sp1 cross talk is due, in part, to enhanced association of AhR and ERalpha (also determined by fluorescence resonance energy transfer), which coordinately dissociates ER and Sp1 and decreases ERalpha/Sp1-mediated transactivation, whereas remaining associated with the CAD promoter. This represents a novel interaction between two ligand activated receptors where one receptor inhibits activation of the second receptor.
Assuntos
Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Fator de Transcrição Sp1/metabolismo , Animais , Aspartato Carbamoiltransferase/genética , Aspartato Carbamoiltransferase/metabolismo , Neoplasias da Mama/genética , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/genética , Carbamoil Fosfato Sintase (Glutamina-Hidrolizante)/metabolismo , Linhagem Celular , Chlorocebus aethiops , Citocromo P-450 CYP1A1/genética , Di-Hidro-Orotase/genética , Di-Hidro-Orotase/metabolismo , Estradiol/farmacologia , Receptor alfa de Estrogênio/genética , Transferência Ressonante de Energia de Fluorescência , Expressão Gênica/efeitos dos fármacos , Genes Reporter/genética , Humanos , Ligantes , Mutação/genética , Dibenzodioxinas Policloradas/farmacologia , Regiões Promotoras GenéticasRESUMO
Visual working memory (VWM) is a cognitive memory buffer for temporarily holding, processing, and manipulating visual information. Previous studies have demonstrated mixed results of the effect of depth perception on VWM, with some showing a beneficial effect while others not. In this study, we employed an adapted change detection paradigm to investigate the effects of two depth cues, binocular disparity and relative size. The memory array consisted of a set of pseudo-randomly positioned colored items, and the task was to judge whether the test item was changed compared to the memory item after a retention interval. We found that presenting the items in stereoscopic depth alone hardly affected VWM performance. When combining the two coherent depth cues, a significant larger VWM capacity of the perceptually closer-in-depth items was observed than that of the farther items, but the capacity for the two-depth-planes condition was not significantly different from that for the one-plane condition. Conflicting the two depth cues resulted in cancelling the beneficial effect of presenting items at a closer depth plane. The results indicate that depth perception could affect VWM, and the visual system may have an advantage in maintaining closer-in-depth objects in working memory.
Assuntos
Memória de Curto Prazo , Percepção Visual , Adulto , Humanos , Experimentação Humana não Terapêutica , Estimulação Luminosa/instrumentação , Estimulação Luminosa/métodosRESUMO
Vascular endothelial growth factor receptor-2 kinase insert domain receptor (VEGFR2/KDR) is critical for angiogenesis, and VEGFR2 mRNA and protein are expressed in ZR-75 breast cancer cells and induced by 17beta-estradiol (E2). Deletion analysis of the VEGFR2 promoter indicates that the proximal GC-rich region is required for both basal and hormone-induced transactivation, and mutation of one or both of the GC-rich motifs at -58 and -44 results in loss of transactivation. Electrophoretic mobility shift and chromatin immunoprecipitation assays show that Sp1, Sp3, and Sp4 proteins bind the GC-rich region of the VEGFR2 promoter. Results of the chromatin immunoprecipitation assay also demonstrate that ERalpha is constitutively bound to the VEGFR2 promoter and that these interactions are not enhanced after treatment with E2, whereas ERalpha binding to the region of the pS2 promoter containing an estrogen-responsive element is enhanced by E2. RNA interference studies show that hormone-induced activation of the VEGFR2 promoter constructs requires Sp3 and Sp4 but not Sp1, demonstrating that hormonal activation of VEGFR2 involves a nonclassical mechanism in which ERalpha/Sp3 and ERalpha/Sp4 complexes activate GC-rich sites where Sp proteins but not ERalpha bind DNA. These results show for the first time that Sp3 and Sp4 cooperatively interact with ERalpha to activate VEGFR2 and are in contrast to previous results showing that several hormone-responsive genes are activated by ERalpha/Sp1 in breast cancer cell lines.
Assuntos
Neoplasias da Mama/metabolismo , Estradiol/fisiologia , Receptor alfa de Estrogênio/metabolismo , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição Sp/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Sequência de Bases , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Estradiol/metabolismo , Humanos , Dados de Sequência Molecular , Neovascularização Patológica , Regiões Promotoras GenéticasRESUMO
Replicative senescence/crisis is thought to act as a tumor suppressor mechanism. Although recent data indicate that normal human cells cannot be converted into cancer cells without telomerase, the original concept of senescence as a tumor suppressor mechanism is that senescence/crisis would act to limit the growth of telomerase-negative tumors. We show here that this concept is valid when oncogene-expressing human and bovine cells are introduced into immunodeficient mice using tissue reconstruction techniques, as opposed to conventional subcutaneous injection. Primary human and bovine adrenocortical cells were transduced with retroviruses encoding Ha-Ras(G12V) and SV40 large T antigen and transplanted in immunodeficient mice using tissue reconstruction techniques. Transduced cells were fully malignant (invasive and metastatic) in this model. They had negligible telomerase activity both before transplantation and when recovered from tumors. When serially transplanted, tumors showed progressively slower growth, decreased invasion and metastasis, shortened telomeres, and morphological features of crisis. Whereas telomerase was not essential for malignant behavior, expression of human telomerase reverse transcriptase enabled cells from serially transplanted tumors that had ceased growth to reacquire tumorigenicity. Moreover, telomerase-negative oncogene-expressing cells were tumorigenic only when transplanted using tissue reconstruction techniques; human telomerase reverse transcriptase was required for cells to form tumors when cells were injected subcutaneously. This work provides a new model to study crisis in an in vivo setting and its effects on malignancy; despite having invasive and metastatic properties, cells are eventually driven into crisis by proliferation in the absence of a telomere maintenance mechanism.
Assuntos
Neoplasias do Córtex Suprarrenal/enzimologia , Neoplasias do Córtex Suprarrenal/patologia , Córtex Suprarrenal/enzimologia , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Telomerase/deficiência , Telomerase/metabolismo , Córtex Suprarrenal/patologia , Córtex Suprarrenal/fisiologia , Neoplasias do Córtex Suprarrenal/genética , Animais , Antígenos Transformantes de Poliomavirus/fisiologia , Bovinos , Divisão Celular/fisiologia , Transformação Celular Neoplásica/genética , Proteínas de Ligação a DNA , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos SCID , Transplante de Neoplasias , Telomerase/genética , Telômero/fisiologia , Transdução Genética , Transplante Heterólogo , Proteínas ras/fisiologiaRESUMO
It is known that the perceived size of an afterimage is modulated by the perceived distance between the observer and the depth plane on which the afterimage is projected (Emmert's law). Illusions like Ponzo demonstrate that illusory distance induced by depth cues can also affect the perceived size of an object. In this study, we report that the illusory distance not only modulates the perceived size of object's afterimage during the presence of the depth cues, but the modulation persists after the disappearance of the depth cues. We used an adapted version of the classic Ponzo illusion. Illusory depth perception was induced by linear perspective cues with two tilted lines converging at the upper boundary of the display. Two horizontal bars were placed between the two lines, resulting in a percept of the upper bar to be farther away than the lower bar. Observers were instructed to make judgment about the relative size of the afterimage of the lower and the upper bars after adaptation. When the perspective cues and the bars were static, the illusory effect of the Ponzo afterimage is consistent with that of the traditional size-distance illusion. When the perspective cues were flickering and the bars were static, only the afterimage of the latter was perceived, yet still a considerable amount of the illusory effect was perceived. The results could not be explained by memory of a prejudgment of the bar length during the adaptation phase. The findings suggest that cooccurrences of depth cues and object may link a depth marker for the object, so that the perceived size of the object or its afterimage is modulated by feedback of depth information from higher-level visual cortex even when there is no depth cues directly available on the retinal level.
Assuntos
Pós-Imagem/fisiologia , Sinais (Psicologia) , Percepção de Profundidade/fisiologia , Percepção de Distância/fisiologia , Feminino , Humanos , Masculino , Ilusões Ópticas/fisiologia , Percepção de Tamanho/fisiologiaRESUMO
BACKGROUND: Recent achievement in genetics and epigenetics has led to the exploration of the pathogenesis of systemic lupus erythematosus (SLE). Identification of differentially expressed genes and their regulatory mechanism(s) at whole-genome level will provide a comprehensive understanding of the development of SLE and its devastating complications, lupus nephritis (LN). METHODS: We performed whole-genome transcription and DNA methylation analysis in PBMC of 30 SLE patients, including 15 with LN (SLE LN(+)) and 15 without LN (SLE LN(-)), and 25 normal controls (NC) using HumanHT-12 Beadchips and Illumina Human Methy450 chips. The serum proinflammatory cytokines were quantified using Bio-plex Human Cytokine 27-plex assay. Differentially expressed genes and differentially methylated CpG were analyzed with GenomeStudio, R, and SAM software. The association between DNA methylation and gene expression were tested. Gene interaction pathways of the differentially expressed genes were analyzed by IPA software. RESULTS: We identified 552 upregulated genes and 550 downregulated genes in PBMC of SLE. Integration of DNA methylation and gene expression profiling showed that 334 upregulated genes were hypomethylated, and 479 downregulated genes were hypermethylated. Pathway analysis on the differential genes in SLE revealed significant enrichment in interferon (IFN) signaling and toll-like receptor (TLR) signaling pathways. Nine IFN- and seven TLR-related genes were identified and displayed step-wise increase in SLE LN(-) and SLE LN(+). Hypomethylated CpG sites were detected on these genes. The gene expressions for MX1, GPR84, and E2F2 were increased in SLE LN(+) as compared to SLE LN(-) patients. The serum levels of inflammatory cytokines, including IL17A, IP-10, bFGF, TNF-α, IL-6, IL-15, GM-CSF, IL-1RA, IL-5, and IL-12p70, were significantly elevated in SLE compared with NC. The levels of IL-15 and IL1RA correlated with their mRNA expression. The upregulation of IL-15 may be regulated by hypomethylated CpG sites in the promotor region of the gene. CONCLUSIONS: Our study has demonstrated that significant number of differential genes in SLE were involved in IFN, TLR signaling pathways, and inflammatory cytokines. The enrichment of differential genes has been associated with aberrant DNA methylation, which may be relevant to the pathogenesis of SLE. Our observations have laid the groundwork for further diagnostic and mechanistic studies of SLE and LN.
Assuntos
Metilação de DNA/genética , Regulação da Expressão Gênica/imunologia , Leucócitos Mononucleares , Lúpus Eritematoso Sistêmico/genética , Adulto , Feminino , Estudo de Associação Genômica Ampla , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase em Tempo RealRESUMO
1,1-Bis(3'-indolyl)-1-(p-trifluoromethylphenyl)methane (DIM-C-pPhCF3) and troglitazone activate peroxisome proliferator-activated receptor gamma (PPARgamma) in Panc-28 pancreatic cancer cells and also inhibit cell proliferation. DIM-C-pPhCF3 was more active than troglitazone and was used as a model to investigate the mechanism of PPARgamma-dependent inhibition of Panc-28 cell growth. DIM-C-pPhCF3 significantly inhibited G0/G1-->S phase progression, as determined by FACS analysis, and this was associated with decreased retinoblastoma protein phosphorylation and increased p21 protein and mRNA expression, but no change in p27 or cyclin D1. PPARgamma antagonists blocked DIM-C-pPhCF3-induced growth inhibition and induction of p21 protein, and similar inhibitory effects were observed in Panc-28 cells transfected with a construct (pWWP) containing a -2325 to +8 p21 promoter insert. Deletion analysis of the p21 promoter indicated that PPARgamma-dependent activation of p21 promoter constructs by DIM-C-pPhCF3 required GC-rich sites 3 and 4 in the proximal region (-124 to -60) of the p21 promoter. The results of RNA interference and protein expression/DNA binding assays suggest that DIM-C-pPhCF3 induced p21 expression through a novel mechanism that involves PPARgamma interactions with both Sp1 and Sp4 proteins bound to the proximal GC-rich region of the p21 promoter.
Assuntos
Carcinoma Ductal Pancreático , Proteínas de Ciclo Celular/genética , PPAR gama/metabolismo , Neoplasias Pancreáticas , Fator de Transcrição Sp1/metabolismo , Fatores de Transcrição/metabolismo , Anticarcinógenos/farmacologia , Proteínas de Ciclo Celular/metabolismo , Divisão Celular/fisiologia , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21 , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Indóis/farmacologia , Regiões Promotoras Genéticas/fisiologia , Fator de Transcrição Sp4Assuntos
Testes Diagnósticos de Rotina/métodos , Testes Hematológicos/métodos , Modelos Estatísticos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/diagnóstico , Adulto , Idoso , China/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Tuberculose/epidemiologia , Tuberculose/microbiologiaRESUMO
1,1-Bis(3'-indolyl)-1-(p-anisyl)methane (DIM-C-pPhOCH3) activates the orphan receptor nerve growth factor-induced Balpha (Nur77) in cancer cells, and in this study, DIM-C-pPhOCH3 decreased Panc1 pancreatic cancer cell survival and arrested cells in G0-G1. These responses were accompanied by induction of the cyclin-dependent kinase inhibitor p21 in pancreatic cancer cells. Mechanistic studies showed that induction of p21 mRNA and protein by DIM-C-pPhOCH3 was Nur77 dependent but did not depend on Krüppel-like factor 4, which was also induced by DIM-C-pPhOCH3. Activation of p21 promoter constructs by DIM-C-pPhOCH3 required the GC-rich proximal region of the promoter, and results of RNA interference studies showed that Nur77-dependent activation of the p21 promoter involved interactions with Sp1 and Sp4 but not Sp3. Interactions of Nur77 with the p21 promoter in Panc1 cells treated with DIM-C-pPhOCH3 were also confirmed in chromatin immunoprecipitation assays. These data show that activation of nuclear Nur77 results in a novel pathway for induction of p21, which is independent of Nur77 response elements but dependent on Sp proteins bound to the GC-rich proximal region of the p21 promoter.
Assuntos
Anisóis/farmacologia , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Indóis/farmacologia , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Neoplasias Pancreáticas/metabolismo , Apoptose/fisiologia , Processos de Crescimento Celular/fisiologia , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Interpretação Estatística de Dados , Regulação Neoplásica da Expressão Gênica , Humanos , Indóis/metabolismo , Substâncias Intercalantes/metabolismo , Fator 4 Semelhante a Kruppel , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/biossíntese , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Regiões Promotoras GenéticasRESUMO
Deletion analysis of several 17beta-estradiol (E(2))-responsive genes have identified GC-rich sites that are associated with hormone-induced transactivation in MCF-7 breast cancer cells. However, the role of individual specificity proteins (Sps) in mediating hormone-induced gene expression has not been unequivocally determined. In transient transfection studies using E(2)-responsive GC-rich promoters from the E(2)F1, carbamoylphosphate synthetase/aspartate transcarbamylase/dihydroorotase (CAD), and retinoic acid receptor alpha (RAR alpha) genes, RNA interference using small inhibitory RNAs for Sp1 (iSp1), Sp3 (iSp3), and Sp4 (iSp4) decreased both basal and E(2)-induced transactivation. The contributions of individual Sp proteins to basal and E(2)-induced activity were promoter dependent. iSp1, iSp3, and iSp4 also significantly inhibited hormonal induction of E(2)F1, CAD, and RAR alpha mRNA levels; however, the enhanced inhibitory effects of the latter two small inhibitory RNAs suggest that Sp3 and Sp4 play a major role in estrogen receptor alpha/Sp-mediated gene expression in MCF-7 cells.