Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 61
Filtrar
Mais filtros

Bases de dados
Tipo de documento
Intervalo de ano de publicação
2.
Proteins ; 83(5): 827-43, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25662919

RESUMO

The initiation of microtubule assembly within cells is guided by a cone shaped multi-protein complex, γ-tubulin ring complex (γTuRC) containing γ-tubulin and atleast five other γ-tubulin-complex proteins (GCPs), i.e., GCP2, GCP3, GCP4, GCP5, and GCP6. The rim of γTuRC is a ring of γ-tubulin molecules that interacts, via one of its longitudinal interfaces, with GCP2, GCP3, or GCP4 and, via other interface, with α/ß-tubulin dimers recruited for the microtubule lattice formation. These interactions however, are not well understood in the absence of crystal structure of functional reconstitution of γTuRC subunits. In this study, we elucidate the atomic interactions between γ-tubulin and GCP4 through computational techniques. We simulated two complexes of γ-tubulin-GCP4 complex (we called dimer1 and dimer2) for 25 ns to obtain a stable complex and calculated the ensemble average of binding free energies of -158.82 and -170.19 kcal/mol for dimer1 and -79.53 and -101.50 kcal/mol for dimer2 using MM-PBSA and MM-GBSA methods, respectively. These highly favourable binding free energy values points to very robust interactions between GCP4 and γ-tubulin. From the results of the free-energy decomposition and the computational alanine scanning calculation, we identified the amino acids crucial for the interaction of γ-tubulin with GCP4, called hotspots. Furthermore, in the endeavour to identify chemical leads that might interact at the interface of γ-tubulin-GCP4 complex; we found a class of compounds based on the plant alkaloid, noscapine that binds with high affinity in a cavity close to γ-tubulin-GCP4 interface compared with previously reported compounds. All noscapinoids displayed stable interaction throughout the simulation, however, most robust interaction was observed for bromo-noscapine followed by noscapine and amino-noscapine. This offers a novel chemical scaffold for γ-tubulin binding drugs near γ-tubulin-GCP4 interface.


Assuntos
Proteínas Associadas aos Microtúbulos/química , Noscapina/análogos & derivados , Noscapina/química , Tubulina (Proteína)/química , Humanos , Ligação de Hidrogênio , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Termodinâmica
3.
J Comput Aided Mol Des ; 28(9): 961-72, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25031076

RESUMO

γ-Tubulin is essential for the nucleation and organization of mitotic microtubules in dividing cells. It is localized at the microtubule organizing centers and mitotic spindle fibres. The most well accepted hypothesis for the initiation of microtubule polymerization is that α/ß-tubulin dimers add onto a γ-tubulin ring complex (γTuRC), in which adjacent γ-tubulin subunits bind to the underlying non-tubulin components of the γTuRC. This template thus determines the resulting microtubule lattice. In this study we use molecular modelling and molecular dynamics simulations, combined with computational MM-PBSA/MM-GBSA methods, to determine the extent of the lateral atomic interaction between two adjacent γ-tubulins within the γTuRC. To do this we simulated a γ-γ homodimer for 10 ns and calculated the ensemble average of binding free energies of -107.76 kcal/mol by the MM-PBSA method and of -87.12 kcal/mol by the MM-GBSA method. These highly favourable binding free energy values imply robust lateral interactions between adjacent γ-tubulin subunits in addition to their end-interactions longitudinally with other proteins of γTuRC. Although the functional reconstitution of γ-TuRC subunits and their stepwise in vitro assembly from purified components is not yet feasible, we nevertheless wanted to recognize hotspot amino acids responsible for key γ-γ interactions. Our free energy decomposition data from converting a compendium of amino acid residues identified an array of hotspot amino acids. A subset of such mutants can be expressed in vivo in living yeast. Because γTuRC is important for the growth of yeast, we could test whether this subset of the hotspot mutations support growth of yeast. Consistent with our model, γ-tubulin mutants that fall into our identified hotspot do not support yeast growth.


Assuntos
Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Substituição de Aminoácidos , Humanos , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Mapas de Interação de Proteínas , Multimerização Proteica , Estabilidade Proteica , Schizosaccharomyces/genética , Termodinâmica , Tubulina (Proteína)/genética
4.
Int J Biol Macromol ; 254(Pt 3): 127465, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37866583

RESUMO

Rapid growth in industrialization sectors, the wastewater treatment plants become exhausted and potentially not able to give desirable discharge standards. Many industries discharge the untreated effluent into the water bodies which affects the aquatic diversity and human health. The effective disposal of industrial effluents thus has been an imperative requirement. For decades nanocellulose based materials gained immense attraction towards application in wastewater remediation and emerged out as a new biobased nanomaterial. It is light weighted, cost effective, mechanically strong and easily available. Large surface area, versatile surface functionality, biodegradability, high aspect ratio etc., make them suitable candidate in this field. Majorly cellulose based nanomaterials are used in the form of cellulose nanocrystals (CNCs), cellulose nanofibers (CNFs), or bacterial nanocellulose (BNC). This review specifically describes about a variety of extraction methods to produced nanocellulose and also discusses the modification of nanocellulose by adding functionalities in its surface chemistry. We majorly focus on the utilization of nanocellulose based materials in water remediation for the removal of different contaminants such as dyes, heavy metals, oil, microbial colony etc. This review mainly emphasizes in ray of hope towards nanocellulose materials to achieve more advancement in the water remediation fields.


Assuntos
Nanofibras , Nanopartículas , Nanoestruturas , Humanos , Água , Nanoestruturas/química , Nanopartículas/química , Nanofibras/química , Celulose/química
5.
Acta Pharmacol Sin ; 34(7): 930-8, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23708557

RESUMO

AIM: Noscapine (NOS) is a non-narcotic opium alkaloid with anti-tumor activity. The aim of this study was to investigate the effects of the combination of NOS with conventional chemotherapeutics temozolamide (TMZ), bis-chloroethylnitrosourea (BCNU), or cisplatin (CIS)on human glioblastoma cells. METHODS: U87MG human glioblastoma cells were examined. Cell proliferation was quantified using MTT assay. Western blotting and flow cytometry were used to examine apoptosis and the expression of active caspase-3 and cleaved PARP. Mouse tumor xenograft model bearing U87MG cells was treated with TMZ (2 mg·kg(-1)·d(-1), ip) or CIS (2 mg/kg, ip 3 times a week) alone or in combination with NOS (200 mg·kg(-1)·d(-1), ig) for 3 weeks. Immunohistochemistry was used to investigate the expression of active caspase-3 and Ki67 following treatment in vivo. The safety of the combined treatments was evaluated based on the body weight and histological studies of the animal's organs. RESULTS: NOS (10 or 20 mol/L) markedly increased the anti-proliferation effects of TMZ, BCNU, and CIS on U87MG cells in vitro. The calculated combination index (CI) values of NOS-CIS, NOS-TMZ, and NOS-BCNU (20 µmol/L) were 0.45, 0.51, and 0.57, respectively, demonstrating synergistic inhibition of the drug combinations. In tumor xenograft models, combined treatment with NOS robustly augmented the anti-cancer actions of TMZ and CIS, and showed no detectable toxicity. The combined treatments significantly enhanced the apoptosis, the activated caspase-3 and PARP levels in U87MG cells in vitro, and reduced Ki67 staining and increased the activated caspase-3 level in the shrinking xenografts in vivo. CONCLUSION: NOS synergistically potentiated the efficacy of FDA-approved anti-cancer drugs against human glioblastoma cells, thereby allowing them to be used at lower doses and hence minimizing their toxic side effects.


Assuntos
Antineoplásicos/administração & dosagem , Proliferação de Células/efeitos dos fármacos , Glioblastoma/patologia , Inibidores do Crescimento/administração & dosagem , Noscapina/administração & dosagem , Animais , Linhagem Celular Tumoral , Sinergismo Farmacológico , Feminino , Glioblastoma/tratamento farmacológico , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
6.
F1000Res ; 12: 1585, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38983446

RESUMO

Background: The study investigates the influence of antecedents of the theory of planned behaviour (TPB) and personality traits on entrepreneurial intention and behaviour among engineering students in an emerging economy. It employs the extension of the TPB model by focusing on the intention-behaviour gap, an under-researched area in research. Furthermore, it investigates the moderating effect of entrepreneurial motivation on the relationship between intention and behaviour to improve conceptual model predictability. Methods: A structured questionnaire was used to gather data from 1,564 engineering students, and the data were analyzed using structural equation modelling (SEM) with Amos software. Results: The results revealed that subjective norms were the strongest predictor of entrepreneurial intention and behaviour, followed by entrepreneurial alertness, perceived behavioural control, attitude towards entrepreneurship, need for achievement, and risk tolerance. Moreover, the moderation analysis showed that entrepreneurial motivation was crucial in moderating the relationship between intention and behaviour. Conclusions: The present conceptual model contributes to the existing TPB model by improving predictive power to understand the intention-behaviour relationship. The results of the study will assist policymakers, academicians of higher education institutions, and universities in developing policies, strategies, and curricula to engage more students in entrepreneurial activities.


Assuntos
Empreendedorismo , Intenção , Motivação , Humanos , Masculino , Feminino , Inquéritos e Questionários , Adulto Jovem , Estudantes/psicologia , Adulto , Teoria Psicológica , Universidades , Adolescente , Teoria do Comportamento Planejado
7.
Int J Cancer ; 131(6): 1435-44, 2012 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-22052467

RESUMO

Germline mutation of the tumor suppressor gene, adenomatous polyposis coli (APC), is responsible for familial adenomatous polyposis (FAP) with nearly 100% risk for colon cancer at an early age. Although FAP is involved in only 1% of all colon cancer cases, over 80% of sporadic cancers harbor somatic mutations of APC. We show here that bromo-noscapine (EM011), a rationally designed synthetic derivative of a natural nontoxic tubulin-binding alkaloid-noscapine, that reduces the dynamics of microtubules, causes a reversible G(2) /M arrest in wild type murine embryonic fibroblasts (MEFs), but an aberrant exit from a brief mitotic block, followed by apoptosis in MEFs after APC deletion with small interfering RNA. Furthermore, both ß-catenin levels and activity fell to half the original levels with a concomitant reduction of cell proliferation-inducing cyclin D1, c-Myc, and induction of cytostatic protein p21 before caspase-3 activation. Additionally, we show a statistically significant reduction in the number of newly emerging intestinal polyps (to 35% compared with untreated mice) as well as the mean size of polyps (to 42% compared with untreated mice) in EM011-treated Apc(Min/+) mice as compared to their sham-treated control littermates. The remaining polyps in the EM011 treated group of Apc(Min/+) mice showed evidence of elevated apoptosis as revealed by immunohistochemistry. We failed to detect any evidence of histopathological and hematological toxicities following EM011 treatment. Taken together, our data are persuasive that a clinical trial of EM011 is possible for the prevention/amelioration of polyposis in FAP patients.


Assuntos
Polipose Adenomatosa do Colo/prevenção & controle , Anticarcinógenos/uso terapêutico , Dioxóis/uso terapêutico , Genes APC/fisiologia , Isoquinolinas/uso terapêutico , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/fisiologia , Feminino , Células HCT116 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Fator de Transcrição 4 , beta Catenina/fisiologia
8.
Bioorg Med Chem Lett ; 22(8): 2983-7, 2012 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-22425569

RESUMO

Facile synthesis of natural α-noscapine analogue, 9-amino-α-noscapine, a potent inhibitor of tubulin polymerization for cancer therapy, is achieved via copper(I) iodide mediated in situ aromatic azidation and reduction of 9-bromo-α-noscapine (obtained by bromination of natural α-noscapine) with NaN(3) in DMSO at 130°C in the presence of L-proline as an amino acid promoter. The protocol developed here avoided isolation of 9-azido-α-noscapine and did not cleave the sensitive C-C bond between two heterocyclic phthalide and isoquinoline units.


Assuntos
Cobre/química , Noscapina/análogos & derivados , Moduladores de Tubulina/síntese química , Catálise , Modelos Moleculares , Noscapina/síntese química , Noscapina/química , Noscapina/farmacologia , Moduladores de Tubulina/química
9.
J Comput Aided Mol Des ; 26(2): 233-47, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22170255

RESUMO

Our screen for tubulin-binding small molecules that do not depolymerize bulk cellular microtubules, but based upon structural features of well known microtubule-depolymerizing colchicine and podophyllotoxin, revealed tubulin binding anti-cancer property of noscapine (Ye et al. in Proc Natl Acad Sci USA 95:2280-2286, 1998). Guided by molecular modelling calculations and structure-activity relationships we conjugated at C9 of noscapine, a folate group-a ligand for cellular folate receptor alpha (FRα). FRα is over-expressed on some solid tumours such as ovarian epithelial cancers. Molecular docking experiments predicted that a folate conjugated noscapine (Targetin) accommodated well inside the binding cavity (docking score -11.295 kcal/mol) at the interface between α- and ß-tubulin. The bulky folate moiety of Targetin is extended toward lumen of microtubules. The binding free energy (ΔG (bind)) computed based on molecular mechanics energy minimization was -221.01 kcal/mol that revealed favourable interaction of Targetin with the receptor. Chemical synthesis, tubulin-binding experiments, and anti-cancer activity in vitro corroborate fully well with the molecular modelling experiments. Targetin binds tubulin with a dissociation constant (K (d) value) of 149 ± 3.0 µM and decreases the transition frequencies between growth and shortening phases of microtubule assembly dynamics at concentrations that do not alter the total polymer mass. Cancer cells in general were more sensitive to Targetin compared with the founding compound noscapine (IC(50) in the range of 15-40 µM). Quite strikingly, ovarian cancer cells (SKOV3 and A2780), known to overexpress FRα, were much more sensitive to targetin (IC(50) in the range of 0.3-1.5 µM).


Assuntos
Anticarcinógenos/química , Anticarcinógenos/farmacologia , Ácido Fólico/química , Noscapina/química , Noscapina/farmacologia , Tubulina (Proteína)/metabolismo , Anticarcinógenos/síntese química , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Simulação por Computador , Receptor 1 de Folato/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Ligantes , Microtúbulos/química , Microtúbulos/efeitos dos fármacos , Modelos Moleculares , Neoplasias/tratamento farmacológico , Noscapina/síntese química , Ligação Proteica/efeitos dos fármacos , Conformação Proteica , Relação Estrutura-Atividade , Tubulina (Proteína)/química , Tubulina (Proteína)/efeitos dos fármacos
10.
SAGE Open Med ; 10: 20503121221137005, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36385790

RESUMO

Objectives: The underlying molecular mechanisms of diabetic nephropathy have yet not been investigated clearly. In this investigation, we aimed to identify key genes involved in the pathogenesis and prognosis of diabetic nephropathy. Methods: We downloaded next-generation sequencing data set GSE142025 from Gene Expression Omnibus database having 28 diabetic nephropathy samples and nine normal control samples. The differentially expressed genes between diabetic nephropathy and normal control samples were analyzed. Biological function analysis of the differentially expressed genes was enriched by Gene Ontology and REACTOME pathways. Then, we established the protein-protein interaction network, modules, miRNA-differentially expressed gene regulatory network and transcription factor-differentially expressed gene regulatory network. Hub genes were validated by using receiver operating characteristic curve analysis. Results: A total of 549 differentially expressed genes were detected including 275 upregulated and 274 downregulated genes. The biological process analysis of functional enrichment showed that these differentially expressed genes were mainly enriched in cell activation, integral component of plasma membrane, lipid binding, and biological oxidations. Analyzing the protein-protein interaction network, miRNA-differentially expressed gene regulatory network and transcription factor-differentially expressed gene regulatory network, we screened hub genes MDFI, LCK, BTK, IRF4, PRKCB, EGR1, JUN, FOS, ALB, and NR4A1 by the Cytoscape software. The receiver operating characteristic curve analysis confirmed that hub genes were of diagnostic value. Conclusions: Taken above, using integrated bioinformatics analysis, we have identified key genes and pathways in diabetic nephropathy, which could improve our understanding of the cause and underlying molecular events, and these key genes and pathways might be therapeutic targets for diabetic nephropathy.

11.
Heliyon ; 8(4): e09209, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35399375

RESUMO

Highly efficient and durable, silver nanoparticles doped Active Carbon Spheres ACS(Ag) were synthesized by carbonization and activation of silver exchanged resins. The silver exchanged resins were prepared by exchanging H+ ions of polystyrene sulphonate resin with Ag+ ions of silver nitrate (AgNO3). The quantity of Ag+ in the spheres was controlled by varying the concentration of AgNO3, from 0.0125 to 0.1 M. With increasing molar concentration of AgNO3, the effective intake of Ag+ by the sphere increases from 1.1 to 8.1 weight percent (wt %). For activation, the spheres were incubated in the CO2 atmosphere for 6 h at fixed soaking temperature i.e. 1123 K. The characterization of synthesized silver doped ACS was performed by using different sophisticated instrumental techniques. The antimicrobial activity of silver doped ACS was studied against different bacterial strains like, E. coli, B. subtilis and Staphylococcus aureus. The study demonstrated that the zone of inhibition for E. coli was 16.9 ± 0.7 mm while for B. subtilis it was 17.1 ± 0.3 mm at a concentration of 8 mg of synthesized material. In addition, satisfactory results were obtained in shake flask and filtration test experiments also, even at a low concentration of 2 mg, showing growth inhibition of 94% for E. coli and 93% for B. subtilis. When the concentration of silver doped ACS was increased to 8 mg, complete removal of both the bacteria was observed after 24 h (100 % reduction for E. coli and B. subtilis). Furthermore, when silver doped ACS was tested against Staphylococcus aureus according to ASTM:E 2149-01 method, biocidal activity of up to 73% was observed. Therefore, the silver doped ACS can be considered as a potential biocidal material for the studied bacterial strains and hence find suitable application for decontamination of water.

12.
J Comput Aided Mol Des ; 25(5): 443-54, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21544622

RESUMO

Noscapine and its derivatives are important microtubule-interfering agents shown to have potent anti-tumor activity. The binding free energies (ΔG (bind)) of noscapinoids computed using linear interaction energy (LIE) method with a surface generalized Born (SGB) continuum solvation model were in agreement with the experimental ΔG (bind) with average root mean square error of 0.082 kcal/mol. This LIE-SGB model guided us in designing a novel derivative of noscapine, amino-noscapine [(S)-3-((R)-9-amino-4-methoxy-6-methyl-5,6,7,8-tetrahydro [1, 3] dioxolo[4,5-g]isoquinolin-5-yl)-6,7-dimethoxy isobenzo-furan-1(3H)-one] that has higher tubulin binding activity (predicted ΔG (bind) = -6.438 kcal/mol and experimental ΔG (bind) = -6.628 kcal/mol) than noscapine, but does not significantly change the total extent of the tubulin subunit/polymer ratio. The modes of interaction of amino-noscapine with the binding pocket of tubulin involved three hydrogen bonds and are distinct compared to noscapine which involved only one hydrogen bond. Also the patterns of non-bonded interactions are albeit different between both the lignads. The 'blind docking' approach (docking of ligand with different binding sites of a protein and their evaluations) as well as the reasonable accuracy of calculating ΔG (bind) using LIE-SGB model constitutes the first evidence that this class of compounds binds to tubulin at a site overlapping with colchicine-binding site or close to it. Our results revealed that amino-noscapine has better anti-tumor activity than noscapine.


Assuntos
Antineoplásicos/química , Colchicina/química , Noscapina/análogos & derivados , Noscapina/química , Tubulina (Proteína)/química , Antitussígenos , Sítios de Ligação , Desenho de Fármacos , Ligação de Hidrogênio , Ligantes , Microtúbulos/química , Microtúbulos/metabolismo , Modelos Químicos , Estrutura Molecular , Noscapina/síntese química , Polimerização , Ligação Proteica , Termodinâmica , Tubulina (Proteína)/metabolismo
13.
J Soc Econ Dev ; 23(Suppl 1): 113-130, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720481

RESUMO

Based on primary data collected from the households of Dangs district in South Gujarat, India, the paper shows that every year a third of young adults migrate to Surat district and neighbouring areas for half a year to work as sugarcane harvesters. The data show that they live in temporary shelters in harsh conditions with bare minimum necessities and amenities. A large share of their earnings, much lower than the minimum wage rate for agricultural labour, is used to pay the labour contractors who provide cash advances during the lean post-monsoon months. Paying back the principal amount with hefty interest on it traps generations of migrant workers in the vicious cycle of poverty and indebtedness.

14.
Front Endocrinol (Lausanne) ; 12: 628907, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34248836

RESUMO

Obesity is an excess accumulation of body fat. Its progression rate has remained high in recent years. Therefore, the aim of this study was to diagnose important differentially expressed genes (DEGs) associated in its development, which may be used as novel biomarkers or potential therapeutic targets for obesity. The gene expression profile of E-MTAB-6728 was downloaded from the database. After screening DEGs in each ArrayExpress dataset, we further used the robust rank aggregation method to diagnose 876 significant DEGs including 438 up regulated and 438 down regulated genes. Functional enrichment analysis was performed. These DEGs were shown to be significantly enriched in different obesity related pathways and GO functions. Then protein-protein interaction network, target genes - miRNA regulatory network and target genes - TF regulatory network were constructed and analyzed. The module analysis was performed based on the whole PPI network. We finally filtered out STAT3, CORO1C, SERPINH1, MVP, ITGB5, PCM1, SIRT1, EEF1G, PTEN and RPS2 hub genes. Hub genes were validated by ICH analysis, receiver operating curve (ROC) analysis and RT-PCR. Finally a molecular docking study was performed to find small drug molecules. The robust DEGs linked with the development of obesity were screened through the expression profile, and integrated bioinformatics analysis was conducted. Our study provides reliable molecular biomarkers for screening and diagnosis, prognosis as well as novel therapeutic targets for obesity.


Assuntos
Biologia Computacional , Redes Reguladoras de Genes , Simulação de Acoplamento Molecular , Obesidade/genética , Transdução de Sinais/genética , Regulação para Baixo/genética , Ontologia Genética , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Mapas de Interação de Proteínas/genética , Curva ROC , Reprodutibilidade dos Testes , Magreza/genética , Fatores de Transcrição/metabolismo , Transcriptoma , Regulação para Cima/genética
15.
Int J Cancer ; 126(1): 256-65, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19626589

RESUMO

(S)-3-((R)-9-bromo-4-methoxy-6-methyl-5,6,7,8-tetrahydro-[1,3]dioxolo[4,5-g]isoquino-lin-5-yl)-6,7-dimethoxyisobenzofuran-1(3H)-one (EM011) is a tubulin-binding agent with significant anticancer activity. Here we show that EM011 modulates microtubule dynamics at concentrations that do not alter the total polymer mass of tubulin. In particular, EM011 decreases the transition frequencies between growth and shortening phases and increases the duration microtubules spend in an idle 'pause' state. Using B16LS9 murine melanoma cells, we show that EM011 briefly arrests cell-cycle progression at the G2/M phase by formation of multiple aster spindles. An aberrant mitotic exit without cytokinesis then occurs, leading to the accumulation of abnormal multinucleated cells prior to apoptosis. Our pharmacokinetic studies conformed to a linear dose-response relationship upto 150 mg/kg. However, non-linearity was observed at 300 mg/kg. In a syngeneic murine model of subcutaneous melanoma, better antitumor responses were seen at 150 mg/kg compared to 300 mg/kg of EM011. Unlike currently available chemotherapeutics, EM011 is non-toxic to normal tissues and most importantly, does not cause any immunosuppression and neurotoxicity. Our data thus warrant a clinical evaluation of EM011 for melanoma therapy.


Assuntos
Antineoplásicos/uso terapêutico , Dioxóis/metabolismo , Isoquinolinas/metabolismo , Melanoma Experimental/tratamento farmacológico , Tubulina (Proteína)/metabolismo , Animais , Antineoplásicos/metabolismo , Feminino , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL
16.
J Exp Clin Cancer Res ; 39(1): 52, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32197643

RESUMO

BACKGROUND: Runt-related transcription factor 1 (RUNX1) is a heterodimeric transcription factor that binds to the core element of many enhancers and promoters and can accelerate apoptosis in various tumors. However, the regulatory mechanisms underlying RUNX1 expression in neuroblastoma (NB), a highly malignant tumor in childhood, remain largely unclear. In this study, we aimed to assess the role of RUNX1 in NB and to reveal the underlying mechanisms that may contribute to finding a potential therapeutics strategy against NB. METHODS: Growth, invasion, metastasis and angiogenesis were assessed using Cell Counting Kit-8 (CCK-8) immunocytochemistry, and studies involving soft agar, cell invasion, tube formation and whole animals. The levels of expression were measured using real-time quantitative PCR for RNA, Western blot and immunostaining analyses for proteins. Luciferase reporter and chromatin immunoprecipitation assays indicated that RUNX1 directly binds within the BIRC5, CSF2RB and NFKBIA promoter regions to facilitate transcription. The level of apoptosis was assessed by determining mitochondrial membrane potential and flow cytometry. RESULTS: RUNX1 was highly expressed in ganglioneuroma (GN) and well-differentiated (WD) tissues relative to the poorly differentiated (PD) and undifferentiated (UD) ones. Moreover, RUNX1 effectively reduced cell viability, invasion, metastasis, angiogenesis, and promoted apoptosis in vitro and in vivo. RUNX1 reduced BIRC5 transcription and increased CSF2RB and NFKBIA transcription by directly binding BIRC5, CSF2RB and NFKBIA promoters. In addition, cytotoxic drugs, especially cisplatin, significantly increased RUNX1 expression in NB cells and promoted apoptosis. CONCLUSIONS: These data show that RUNX1 is an independent surrogate marker for the progression of NB and it can be used for monitoring NB prognosis during therapy.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Neuroblastoma/genética , Animais , Apoptose/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Subunidade alfa 2 de Fator de Ligação ao Core/biossíntese , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Progressão da Doença , Feminino , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Neuroblastoma/irrigação sanguínea , Neuroblastoma/metabolismo , Neuroblastoma/patologia
17.
J Cell Biochem ; 106(6): 1146-56, 2009 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-19229861

RESUMO

In the present investigation, we determined the chemotherapeutic efficacy of 9-bromonoscapine (Br-Nos), a more potent noscapine analog, on MCF10A, spontaneously immortalized human normal breast epithelial cells and MCF10A-CSC3, cigarette smoke condensate (CSC)-transformed cells. The results from cytogenetic analysis showed that Br-Nos induced polyploidy and telomeric association in MCF10A-CSC3 cells, while MCF10A cells remained unaffected. Our immunofluorescence data further demonstrated that MCF10A-CSC3 cells were susceptible to mitotic catastrophe on exposure to Br-Nos and failed to recover after drug withdrawal. MCF10A-CSC3 cells exhibited Br-Nos-induced aberrant multipolar spindle formation, which irreversibly impaired the alignment of replicated chromosome to the equatorial plane and finally culminated in cell death. Although MCF10A cells upon Br-Nos treatment showed bipolar spindles with some uncongressed chromosomes, these cells recovered fairly well after drug withdrawal. Our flow-cytometry analysis data reconfirmed that MCF10A-CSC3 cells were more susceptible to cell death compared to MCF10A cells. Furthermore, our results suggest that decreased levels of cdc2/cyclin B1 and cdc2 kinase activity are responsible for Br-Nos-induced mitotic cell arrest leading to cell death in MCF10A-CSC3 cells. This study thus explores the underlying mechanism of Br-Nos-induced mitotic catastrophe in CSC-transformed MCF10A-CSC3 cells and its potential usefulness as a chemotherapeutic agent for prevention of cigarette smoke-induced breast cancer growth.


Assuntos
Neoplasias da Mama/metabolismo , Transformação Celular Neoplásica/induzido quimicamente , Células Epiteliais , Mitose/efeitos dos fármacos , Nicotiana/química , Noscapina , Fumaça , Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Proteína Quinase CDC2/metabolismo , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Ciclina B , Ciclina B1 , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/fisiologia , Feminino , Humanos , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/efeitos dos fármacos , Glândulas Mamárias Humanas/metabolismo , Noscapina/análogos & derivados , Noscapina/farmacologia , Fuso Acromático/efeitos dos fármacos
18.
Cancer Res ; 67(8): 3862-70, 2007 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-17440101

RESUMO

We have previously discovered the naturally occurring antitussive alkaloid noscapine as a tubulin-binding agent that attenuates microtubule dynamics and arrests mammalian cells at mitosis via activation of the c-Jun NH(2)-terminal kinase pathway. It is well established that the p53 protein plays a crucial role in the control of tumor cell response to chemotherapeutic agents and DNA-damaging agents; however, the relationship between p53-driven genes and drug sensitivity remains controversial. In this study, we compared chemosensitivity, cell cycle distribution, and apoptosis on noscapine treatment in four cell lines derived from the colorectal carcinoma HCT116 cells: p53(+/+) (p53-wt), p53(-/-) (p53-null), p21(-/-) (p21-null), and BAX(-/-) (BAX-null). Using these isogenic variants, we investigated the roles of p53, BAX, and p21 in the cellular response to treatment with noscapine. Our results show that noscapine treatment increases the expression of p53 over time in cells with wild-type p53 status. This increase in p53 is associated with an increased apoptotic BAX/Bcl-2 ratio consistent with increased sensitivity of these cells to apoptotic stimuli. Conversely, loss of p53 and p21 alleles had a counter effect on both BAX and Bcl-2 expression and the p53-null and p21-null cells were significantly resistant to the antiproliferative and apoptotic effects of noscapine. All but the p53-null cells displayed p53 protein accumulation in a time-dependent manner on noscapine treatment. Interestingly, despite increased levels of p53, p21-null cells were resistant to apoptosis, suggesting a proapoptotic role of p21 and implying that p53 is a necessary but not sufficient condition for noscapine-mediated apoptosis.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Noscapina/farmacologia , Proteína Supressora de Tumor p53/biossíntese , Alelos , Apoptose/fisiologia , Divisão Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Inibidor de Quinase Dependente de Ciclina p21/deficiência , Inibidor de Quinase Dependente de Ciclina p21/genética , Fase G2/efeitos dos fármacos , Células HCT116 , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína Supressora de Tumor p53/deficiência , Proteína Supressora de Tumor p53/genética , Proteína X Associada a bcl-2/metabolismo
19.
J Mol Neurosci ; 68(4): 565-589, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30982163

RESUMO

Non-functioning pituitary adenomas (NFPAs) are locally invasive with high morbidity. The objective of this study was to diagnose important genes and pathways related to the invasiveness of NFPAs and gain more insights into the underlying molecular mechanisms of NFPAs. The gene expression profiles of GSE51618 were downloaded from the Gene Expression Omnibus database with 4 non-invasive NFPA samples, 3 invasive NFPA samples, and 3 normal pituitary gland samples. Differentially expressed genes (DEGs) are screened between invasive NFPA samples and normal pituitary gland samples, followed by pathway and ontology (GO) enrichment analyses. Subsequently, a protein-protein interaction (PPI) network was constructed and analyzed for these DEGs, and module analysis was performed. In addition, a target gene-miRNA network and target gene-TF (transcription factor) network were analyzed for these DEGs. A total of 879 DEGs were obtained. Among them, 439 genes were upregulated and 440 genes were downregulated. Pathway enrichment analysis indicated that the upregulated genes were significantly enriched in cysteine biosynthesis/homocysteine degradation (trans-sulfuration) and PI3K-Akt signaling pathway, while the downregulated genes were mainly associated with docosahexaenoate biosynthesis III (mammals) and chemokine signaling pathway. GO enrichment analysis indicated that the upregulated genes were significantly enriched in animal organ morphogenesis, extracellular matrix, and hormone activity, while the downregulated genes were mainly associated with leukocyte chemotaxis, dendrites, and RAGE receptor binding. Subsequently, ESR1, SOX2, TTN, GFAP, WIF1, TTR, XIST, SPAG5, PPBP, AR, IL1R2, and HIST1H1C were diagnosed as the top hub genes in the upregulated and downregulated PPI networks and modules. In addition, HS3ST1, GPC4, CCND2, and SCD were diagnosed as the top hub genes in the upregulated and downregulated target gene-miRNA networks, while CISH, ISLR, UBE2E3, and CCNG2 were diagnosed as the top hub genes in the upregulated and downregulated target gene-TF networks. The new important DEGs and pathways diagnosed in this study may serve key roles in the invasiveness of NFPAs and indicate more molecular targets for the treatment of NFPAs.


Assuntos
Adenoma/genética , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Invasividade Neoplásica/genética , Neoplasias Hipofisárias/genética , Adenoma/patologia , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias Hipofisárias/patologia
20.
Sci Rep ; 9(1): 11384, 2019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31388042

RESUMO

The present study investigates the hydrothermal liquefaction (HTL) of harmful green macroalgal blooms at a temperature of 270 °C with, and without a catalyst with a holding time of 45 min. The effect of different catalysts on the HTL product yield was also studied. Two separation methods were used for recovering the biocrude oil yield from the solid phase. On comparision with other catalyst, Na2CO3 was found to produce higher yiled of bio-oil. The total bio-oil yield was 20.10% with Na2CO3, 18.74% with TiO2, 17.37% with CaO, and 14.6% without a catalyst. The aqueous phase was analyzed for TOC, COD, TN, and TP to determine the nutrient enrichment of water phase for microalgae cultivation. Growth of four microalgae strains viz., Chlorella Minutissima, Chlorella sorokiniana UUIND6, Chlorella singularis UUIND5 and Scenedesmus abundans in the aqueous phase were studied, and compared with a standard growth medium. The results indicate that harmful macroalgal blooms are a suitable feedstock for HTL, and its aqueous phase offers a promising nutrient source for microalgae.


Assuntos
Biocombustíveis , Carbonatos/química , Proliferação Nociva de Algas , Microbiologia Industrial/métodos , Microalgas/metabolismo , Biomassa , Catálise , Temperatura Alta , Nutrientes/metabolismo , Microbiologia da Água
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA