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1.
Homeopathy ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714214

RESUMO

BACKGROUND: Prior vaccination is often studied for its impact on individuals' post-infection prognosis. Ayurveda, Yoga, Unani, Siddha and Homeopathy (AYUSH) medicines, advised by the Government of India as prophylaxis during the first wave of the coronavirus disease 2019 (COVID-19) pandemic, were consumed by the masses in 2020. A study was therefore undertaken to observe any association between the prior usage of AYUSH prophylactic medicines and post-infection severity as reported by recovered COVID-19 individuals. METHODS: This was a retrospective, multi-centre, cohort study conducted in 21 cities of India from 5th August to 30th November 2020. Data from recovered COVID-19 patients, of either sex or any age, captured information about AYUSH prophylactic medicines intake prior to infection, disease severity, symptomatology, duration of complaints, etc. The study participants were grouped into AYUSH intake and non-intake. Primary composite outcome was the disease clinical course. Secondary clinical outcomes were the rate of and time to clinical recovery. RESULTS: Data of 5,023 persons were analysed. Ayurveda or homeopathic prophylactic medicines were consumed by more than half of the study participants: that is, 56.85% (n = 1,556) and 56.81% (n = 1,555) respectively. The overall adjusted protective effect (PE) of AYUSH prophylactic intake against moderate/severe forms of COVID-19 disease was 56.7% (95% confidence interval [CI], 48.7 to 63.50; p < 0.001). Adjusted PE for homeopathy and Siddha was 52.9% (95% CI, 42.30 to 61.50; p < 0.001) and 59.8% (95% CI, 37.80 to 74.10; p < 0.001), respectively. A statistically significant association was found between AYUSH prophylactic medicine intake and clinical recovery more frequently by the 3rd day of illness (χ2 = 9.01; p = 0.002). Time to resolution of symptoms in the AYUSH intake group was on average 0.3 days earlier than in the non-intake group (p = 0.002). CONCLUSION: AYUSH prophylactics were associated with statistically significant levels of protection against COVID-19 disease severity. Amongst these, previous intake of homeopathy or Siddha medicines was associated with some protection against moderate/severe illness and with a somewhat quicker clinical recovery. Prospective studies with experimental research design are needed to validate the findings of this study. STUDY REGISTRATION: Clinical Trials Registry-India (CTRI/2020/08/027000).

2.
Cancer Res Commun ; 2(6): 489-502, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-36923556

RESUMO

Oncology therapies targeting the immune system have improved patient outcomes across a wide range of tumor types, but resistance due to an inadequate T-cell response in a suppressive tumor microenvironment (TME) remains a significant problem. New therapies that activate an innate immune response and relieve this suppression may be beneficial to overcome this hurdle. TAK-676 is a synthetic novel stimulator of interferon genes (STING) agonist designed for intravenous administration. Here we demonstrate that TAK-676 dose-dependently triggers activation of the STING signaling pathway and activation of type I interferons. Furthermore, we show that TAK-676 is a highly potent modulator of both the innate and adaptive immune system and that it promotes the activation of dendritic cells, natural killer cells, and T cells in preclinical models. In syngeneic murine tumor models in vivo, TAK-676 induces dose-dependent cytokine responses and increases the activation and proliferation of immune cells within the TME and tumor-associated lymphoid tissue. We also demonstrate that TAK-676 dosing results in significant STING-dependent antitumor activity, including complete regressions and durable memory T-cell immunity. We show that TAK-676 is well tolerated, exhibits dose-proportional pharmacokinetics in plasma, and exhibits higher exposure in tumor. The intravenous administration of TAK-676 provides potential treatment benefit in a broad range of tumor types. Further study of TAK-676 in first-in-human phase I trials is ongoing. Significance: TAK-676 is a novel systemic STING agonist demonstrating robust activation of innate and adaptive immune activity resulting in durable antitumor responses within multiple syngeneic tumor models. Clinical investigation of TAK-676 is ongoing.


Assuntos
Imunidade Inata , Neoplasias , Animais , Humanos , Camundongos , Citocinas , Interferons , Neoplasias/tratamento farmacológico , Transdução de Sinais , Microambiente Tumoral , Ensaios Clínicos Fase I como Assunto
3.
Sci Transl Med ; 13(611): eaba7791, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34524860

RESUMO

SUMOylation, the covalent conjugation of small ubiquitin-like modifier (SUMO) proteins to protein substrates, has been reported to suppress type I interferon (IFN1) responses. TAK-981, a selective small-molecule inhibitor of SUMOylation, pharmacologically reactivates IFN1 signaling and immune responses against cancers. In vivo treatment of wild-type mice with TAK-981 up-regulated IFN1 gene expression in blood cells and splenocytes. Ex vivo treatment of mouse and human dendritic cells promoted their IFN1-dependent activation, and vaccination studies in mice demonstrated stimulation of antigen cross-presentation and T cell priming in vivo. TAK-981 also directly stimulated T cell activation, driving enhanced T cell sensitivity and response to antigen ex vivo. Consistent with these observations, TAK-981 inhibited growth of syngeneic A20 and MC38 tumors in mice, dependent upon IFN1 signaling and CD8+ T cells, and associated with increased intratumoral T and natural killer cell number and activation. Combination of TAK-981 with anti-PD1 or anti-CTLA4 antibodies improved the survival of mice bearing syngeneic CT26 and MC38 tumors. In conclusion, TAK-981 is a first-in-class SUMOylation inhibitor that promotes antitumor immune responses through activation of IFN1 signaling. TAK-981 is currently being studied in phase 1 clinical trials (NCT03648372, NCT04074330, NCT04776018, and NCT04381650) for the treatment of patients with solid tumors and lymphomas.


Assuntos
Imunidade , Sumoilação
4.
Colloids Surf B Biointerfaces ; 205: 111834, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34015731

RESUMO

We developed here stimuli responsive curcumin loaded microgels based on Pluronic F-127. These microgels were prepared using coupling reaction between the amine modified Pluronic and EDTA. The microgel exhibited the affinity for hydrophobic drug, curcumin and showed pH as well as temperature-dependent release. Furthermore, the cytotoxicity study demonstrated dose-dependent inhibition of MDA-MB-231 cell growth with the most effective IC50 value (3.8 ±â€¯0.2 µg mL-1 after 24 h). Based on these findings, the fabricated curcumin loaded microgels offered additional advantages over conventional drug therapies for treatment of cancer.


Assuntos
Neoplasias da Mama , Curcumina , Microgéis , Neoplasias da Mama/tratamento farmacológico , Curcumina/farmacologia , Preparações de Ação Retardada , Feminino , Humanos , Células MCF-7 , Poloxâmero
5.
Homeopathy ; 110(1): 27-35, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32777858

RESUMO

BACKGROUND: Polar symptoms (PS)-symptoms with opposite values-are frequently used in homeopathy, but have many misleading entries in the repertory. This is caused by using absolute occurrence of symptoms, causing the same medicine to appear in both (opposite) symptom rubrics, and by lack of comparison with other medicines. Some PS, like 'aversion/desire for sweets' have a frequency distribution that is not evenly distributed around the neutral value: a desire for sweets is much more common than aversion. A desire for sweets is an indication for a specific medicine only if this desire occurs more frequently in this specific medicine population than in the remainder of the population. We need to find the best way to represent this difference. METHODS: A multi-centre, explorative, prospective, observational study was conducted by nine centres of the Central Council for Research in Homoeopathy. Two-hundred and sixteen patients were enrolled with chronic cough lasting more than 8 weeks, and received usual homeopathic care. During intake, 30 general PS, 27 polar cough symptoms and 3 non-polar cough symptoms were checked. Different ways of representing results were explored, including two quantities borrowed from mechanics: Centre of Mass (CoM) and Leverage. RESULTS: At the fourth follow-up, three medicines with more than 10 cases with good results were identified: 20 Phosphorus, 19 Pulsatilla and 13 Sulphur. The mean value of the frequency distribution of some symptoms in the whole sample was considerably different from the neutral value. Comparing a medicine population with the remainder of the respective population can give results that differ from polarity analysis. For some symptoms, the 'distance' (Leverage) between the CoMs of the medicine population and the remainder of the population was clearer than the likelihood ratio (LR). CONCLUSION: If the LR value is not clear about the prognostic value in PS, notions from mechanics such as CoM and Leverage can clarify how to interpret a polar symptom.


Assuntos
Homeopatia/métodos , Funções Verossimilhança , Adulto , Humanos , Estudos Prospectivos
6.
Carbohydr Res ; 498: 108178, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33045644

RESUMO

An efficient route for the synthesis of benzimidazole nucleosides 1-8 from readily available d-glucose via 3,5-dihydroxy-1,2-O-isopropylidene-α-d-ribofuranose and 3-azido-3-deoxy-1,2-O-isopropylidene-α-d-xylofuranose intermediates has been adopted. Ribofuranosyl nucleosides 1-4 with different benzimidazole bases, and 3'-deoxy-3'-azido-ribofuranosyl nucleosides 5-8, as another series, were obtained. All these newly synthesized analogs were evaluated for anticancer activity using MDA-MB-231 cell line. Among the differently substituted derivatives, 3'-azide substituted nucleosides (5-8) are more potent compared to ribofuranosyl analogs 1-4. The C-3'-azido analog 8 having anthryl group at 2-position of nucleobase show almost similar potency as that of standard etoposide.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Benzimidazóis/química , Nucleosídeos/síntese química , Nucleosídeos/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas de Química Sintética , Humanos , Nucleosídeos/química , Relação Estrutura-Atividade
8.
Adv Pharmacol Sci ; 2019: 9080279, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30886631

RESUMO

Rapid, eco-friendly, and cost-effective one-pot synthesis of copper nanoparticles is reported here using medicinal plants like Gnidia glauca and Plumbago zeylanica. Aqueous extracts of flower, leaf, and stem of G. glauca and leaves of P. zeylanica were prepared which could effectively reduce Cu2+ ions to CuNPs within 5 h at 100°C which were further characterized using UV-visible spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive spectroscopy, dynamic light scattering, X-ray diffraction, and Fourier-transform infrared spectroscopy. Further, the CuNPs were checked for antidiabetic activity using porcine pancreatic α-amylase and α-glucosidase inhibition followed by evaluation of mechanism using circular dichroism spectroscopy. CuNPs were found to be predominantly spherical in nature with a diameter ranging from 1 to 5 nm. The phenolics and flavonoids in the extracts might play a critical role in the synthesis and stabilization process. Significant change in the peak at ∼1095 cm-1 corresponding to C-O-C bond in ether was observed. CuNPs could inhibit porcine pancreatic α-amylase up to 30% to 50%, while they exhibited a more significant inhibition of α-glucosidase from 70% to 88%. The mechanism of enzyme inhibition was attributed due to the conformational change owing to drastic alteration of secondary structure by CuNPs. This is the first study of its kind that provides a strong scientific rationale that phytogenic CuNPs synthesized using G. glauca and P. zeylanica can be considered to develop candidate antidiabetic nanomedicine.

9.
Blood ; 133(14): 1572-1584, 2019 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-30737236

RESUMO

Three proteasome inhibitors have garnered regulatory approvals in various multiple myeloma settings; but drug resistance is an emerging challenge, prompting interest in blocking upstream components of the ubiquitin-proteasome pathway. One such attractive target is the E1 ubiquitin-activating enzyme (UAE); we therefore evaluated the activity of TAK-243, a novel and specific UAE inhibitor. TAK-243 potently suppressed myeloma cell line growth, induced apoptosis, and activated caspases while decreasing the abundance of ubiquitin-protein conjugates. This was accompanied by stabilization of many short-lived proteins, including p53, myeloid cell leukemia 1 (MCL-1), and c-MYC, and activation of the activating transcription factor 6 (ATF-6), inositol-requiring enzyme 1 (IRE-1), and protein kinase RNA-like endoplasmic reticulum (ER) kinase (PERK) arms of the ER stress response pathway, as well as oxidative stress. UAE inhibition showed comparable activity against otherwise isogenic cell lines with wild-type (WT) or deleted p53 despite induction of TP53 signaling in WT cells. Notably, TAK-243 overcame resistance to conventional drugs and novel agents in cell-line models, including bortezomib and carfilzomib resistance, and showed activity against primary cells from relapsed/refractory myeloma patients. In addition, TAK-243 showed strong synergy with a number of antimyeloma agents, including doxorubicin, melphalan, and panobinostat as measured by low combination indices. Finally, TAK-243 was active against a number of in vivo myeloma models in association with activation of ER stress. Taken together, the data support the conclusion that UAE inhibition could be an attractive strategy to move forward to the clinic for patients with relapsed and/or refractory multiple myeloma.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Mieloma Múltiplo/tratamento farmacológico , Inibidores de Proteassoma/farmacologia , Enzimas Ativadoras de Ubiquitina/antagonistas & inibidores , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Sinergismo Farmacológico , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Humanos , Estresse Oxidativo/efeitos dos fármacos , Terapia de Salvação/métodos , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo
10.
ACS Comb Sci ; 21(3): 105-148, 2019 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-30645098

RESUMO

The Biginelli product, dihydropyrimidinone (DHPM) core, and its derivatives are of immense biological importance. There are several methods reported as modifications to the original Biginelli reaction. Among them, many involve the use of different catalysts. Also, among the advancements that have been made to the Biginelli reaction, improvements in product yields, less hazardous reaction conditions, and simplified isolation of products from the reaction predominate. Recently, solid-phase synthetic protocols have attracted the research community for improved yields, simplified product purification, recyclability of the solid support, which forms a special economic approach for Biginelli reaction. The present Review highlights the role of polymer-supported catalysts in Biginelli reaction, which may involve organic, inorganic, or hybrid polymers as support for catalysts. A few of the schemes involve magnetically recoverable catalysts where work up provides green approach relative to traditional methods. Some research groups used polymer-catalyst nanocomposites and polymer-supported ionic liquids as catalyst. Solvent-free, an ultrasound or microwave-assisted Biginelli reactions with polymer-supported catalysts are also reported.


Assuntos
Nanocompostos/química , Polímeros/química , Pirimidinonas/síntese química , Técnicas de Síntese em Fase Sólida/métodos , Catálise , Líquidos Iônicos/química , Micro-Ondas , Estrutura Molecular , Solventes/química , Propriedades de Superfície
11.
Bioorg Med Chem Lett ; 27(23): 5291-5295, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29074258

RESUMO

An efficient and practical strategy for the synthesis of unknown azetidine iminosugars (2S,3R,4S)-2-((R)-1,2-dihydroxyethyl)-3-hydroxy-4-(hydroxymethyl)azetidine 2, (2S,3r,4R)-3-hydroxy-2,4-bis(hydroxymethyl)azetidine 3 and (2S,3R,4S)-3-hydroxy-4-(hydroxymethyl)-N-methylazetidine-2-carboxylic acid 4, starting from the d-glucose has been reported. The methodology involves preparation of the 3-amino-N-benzyloxycarbonyl-3-deoxy-6-O-tert-butyldimethylsillyl-1,2-O-isopropylidene-α-d-glucofuranose 9, which was converted to the C-5-OMs derivative 11. Intramolecular nucleophilic displacement of the C-5-OMs group with in situ generated 3-amino functionality provided the required key azetidine ring skeletons 10 with additional hydroxymethyl group. Removal of 1,2-acetonide protection, followed by reduction and hydrogenolysis afforded azetidine iminosugar 2. Alternatively, removal of 1,2-acetonide group and chopping of C1-anomeric carbon gave C2-aldehyde that on reduction or oxidation followed by hydrogenolysis gave 2,4-bis(hydroxymethyl) azetidine iminosugars 3 and N-methylazetidine-2-carboxylic acid 4 respectively. The glycosidase inhibitory activity of 2-4 iminosugars was screened against various glycosidase enzymes and compared with a standard miglitol. Amongst synthesized targets, the compound 2 was found to be more potent amyloglucosidase inhibitor than miglitol. These results were supported by molecular docking studies.


Assuntos
Inibidores Enzimáticos/farmacologia , Glicosídeo Hidrolases/antagonistas & inibidores , Imino Açúcares/farmacologia , Simulação de Acoplamento Molecular , Aspergillus niger/enzimologia , Canavalia/enzimologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Escherichia coli/enzimologia , Glicosídeo Hidrolases/metabolismo , Hidroxilação , Imino Açúcares/síntese química , Imino Açúcares/química , Estrutura Molecular , Relação Estrutura-Atividade , alfa-Galactosidase/antagonistas & inibidores , alfa-Galactosidase/metabolismo , alfa-Manosidase/antagonistas & inibidores , alfa-Manosidase/metabolismo
12.
Org Biomol Chem ; 14(17): 4136-45, 2016 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-27074628

RESUMO

An efficient route was developed for synthesis of bicyclic benzimidazole nucleosides from readily available d-glucose. The key reactions were Vörbruggen glycosylation and ring closing metathesis (RCM). Primarily, to understand the mode of DNA binding, we performed a molecular docking study and the binding was found to be in the minor groove region. Based on the proposed binding model, UV-visible and fluorescence spectroscopic techniques using calf thymus DNA (CT-DNA) demonstrated a non-intercalative mode of binding. Antiproliferative activity of nucleosides was tested against MCF-7 and MDA-MB-231 breast cancer cell lines and found to be active at low micromolar concentrations. Compounds and displayed significant antiproliferative activity as compared to and with the reference anticancer drug, doxorubicin. Cell cycle analysis showed that nucleoside induced cell cycle arrest at the S-phase. Confocal microscopy has been performed to validate the induction of cellular apoptosis. Based on these findings, such modified bicyclic benzimidazole nucleosides will make a significant contribution to the development of anticancer drugs.


Assuntos
Antineoplásicos/farmacologia , Benzimidazóis/farmacologia , DNA de Neoplasias/efeitos dos fármacos , Nucleosídeos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Benzimidazóis/síntese química , Benzimidazóis/química , Sítios de Ligação/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Conformação Molecular , Simulação de Acoplamento Molecular , Nucleosídeos/síntese química , Nucleosídeos/química , Relação Estrutura-Atividade
13.
Chemistry ; 22(23): 7917-23, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27113075

RESUMO

The base-pairing properties of 5-mercuricytosine have been explored at the monomer level by NMR titrations and at the oligonucleotide level by melting temperature measurements. The NMR studies revealed a relatively high affinity for guanine, hypoxanthine, and uridine, that is, bases that are deprotonated upon coordination of Hg(II) . Within an oligonucleotide duplex, 5-mercuricytosine formed Hg(II) -mediated base pairs with thymine and guanine. In the former case, the duplex formed was as stable as the respective duplex comprising solely Watson-Crick base pairs. Based on detailed thermodynamic analysis of the melting curves, the stabilization by the Hg(II) -mediated base pairs may be attributed to a comparatively low entropic penalty of hybridization.


Assuntos
Pareamento de Bases , Citosina/análogos & derivados , Mercúrio/química , Oligonucleotídeos/química , Guanina/química , Conformação de Ácido Nucleico , Hibridização de Ácido Nucleico , Termodinâmica , Timina/química
14.
Colloids Surf B Biointerfaces ; 143: 352-358, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27022876

RESUMO

Biocompatible nanogels were prepared using thiol modified hyaluronic acid and diacrylated pluronic F127 polymer. A simple Michael type addition reaction of activated thiol groups on acrylate moiety lead to the formation of these nanogels, which were further effectively fabricated with an anticancer drug for evaluating sustained drug release approach. Nanogels prepared were of 150nm in diameter with a narrow size distribution pattern. DOX released from these nanogels showed a slow and sustained release at acidic pH 5.0 as compared to minimal release at physiological pH 7.4. Cytotoxicity data revealed the higher efficiency of DOX loaded nanogels as compared to free DOX in Hela cell lines. Cellular uptake images supported the cytotoxicity data and displayed DOX intercalation at nuclear level of cells. The sustained drug delivery system showed DOX release after 24h and continued thereafter without affecting normal cells. Based on these findings, such nanogel system may be useful for delivering anticancer drug without hampering their toxicity value over longer durations and reducing the total dose amount in anticancer therapy.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Preparações de Ação Retardada/síntese química , Doxorrubicina/farmacologia , Portadores de Fármacos/síntese química , Ácido Hialurônico/química , Nanoestruturas/química , Acrilatos/química , Antibióticos Antineoplásicos/química , Sequência de Carboidratos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Portadores de Fármacos/farmacologia , Liberação Controlada de Fármacos , Géis , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Metaloproteinase 2 da Matriz/metabolismo , Polietilenos/química , Polipropilenos/química
15.
PLoS One ; 10(4): e0123882, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25860128

RESUMO

SUMOylation is a post-translational ubiquitin-like protein modification pathway that regulates important cellular processes including chromosome structure, kinetochore function, chromosome segregation, nuclear and sub-nuclear organization, transcription and DNA damage repair. There is increasing evidence that the SUMO pathway is dysregulated in cancer, raising the possibility that modulation of this pathway may have therapeutic potential. To investigate the importance of the SUMO pathway in the context of cancer cell proliferation and tumor growth, we applied lentivirus-based short hairpin RNAs (shRNA) to knockdown SUMO pathway genes in human cancer cells. shRNAs for SAE2 and UBC9 reduced SUMO conjugation activity and inhibited proliferation of human cancer cells. To expand upon these observations, we generated doxycycline inducible conditional shRNA cell lines for SAE2 to achieve acute and reversible SAE2 knockdown. Conditional SAE2 knockdown in U2OS and HCT116 cells slowed cell growth in vitro, and SAE2 knockdown induced multiple terminal outcomes including apoptosis, endoreduplication and senescence. Multinucleated cells became senescent and stained positive for the senescence marker, SA-ß Gal, and displayed elevated levels of p53 and p21. In an attempt to explain these phenotypes, we confirmed that loss of SUMO pathway activity leads to a loss of SUMOylated Topoisomerase IIα and the appearance of chromatin bridges which can impair proper cytokinesis and lead to multinucleation. Furthermore, knockdown of SAE2 induces disruption of PML nuclear bodies which may further promote apoptosis or senescence. In an in vivo HCT116 xenograft tumor model, conditional SAE2 knockdown strongly impaired tumor growth. These data demonstrate that the SUMO pathway is required for cancer cell proliferation in vitro and tumor growth in vivo, implicating the SUMO pathway as a potential cancer therapeutic target.


Assuntos
Neoplasias/metabolismo , Neoplasias/patologia , Transdução de Sinais , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Animais , Apoptose/genética , Ciclo Celular/genética , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células , Senescência Celular/genética , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Xenoenxertos , Humanos , Neoplasias/genética , Fenótipo , Interferência de RNA , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética , Sumoilação , Carga Tumoral/genética
16.
PLoS One ; 9(11): e111060, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25365521

RESUMO

Plk1 is a checkpoint protein whose role spans all of mitosis and includes DNA repair, and is highly conserved in eukaryotes from yeast to man. Consistent with this wide array of functions for Plk1, the cellular consequences of Plk1 disruption are diverse, spanning delays in mitotic entry, mitotic spindle abnormalities, and transient mitotic arrest leading to mitotic slippage and failures in cytokinesis. In this work, we present the in vitro and in vivo consequences of Plk1 inhibition in cancer cells using potent, selective small-molecule Plk1 inhibitors and Plk1 genetic knock-down approaches. We demonstrate for the first time that cellular senescence is the predominant outcome of Plk1 inhibition in some cancer cell lines, whereas in other cancer cell lines the dominant outcome appears to be apoptosis, as has been reported in the literature. We also demonstrate strong induction of DNA double-strand breaks in all six lines examined (as assayed by γH2AX), which occurs either during mitotic arrest or mitotic-exit, and may be linked to the downstream induction of senescence. Taken together, our findings expand the view of Plk1 inhibition, demonstrating the occurrence of a non-apoptotic outcome in some settings. Our findings are also consistent with the possibility that mitotic arrest observed as a result of Plk1 inhibition is at least partially due to the presence of unrepaired double-strand breaks in mitosis. These novel findings may lead to alternative strategies for the development of novel therapeutic agents targeting Plk1, in the selection of biomarkers, patient populations, combination partners and dosing regimens.


Assuntos
Proteínas de Ciclo Celular/antagonistas & inibidores , Senescência Celular/efeitos dos fármacos , Senescência Celular/genética , Dano ao DNA/efeitos dos fármacos , Mitose/genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Humanos , Mitose/efeitos dos fármacos , Interferência de RNA , RNA Interferente Pequeno/genética , Quinase 1 Polo-Like
17.
PLoS One ; 9(9): e106039, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25216353

RESUMO

Diabetes mellitus is a multifactorial metabolic disease characterized by post-prandial hyperglycemia (PPHG). α-amylase and α-glucosidase inhibitors aim to explore novel therapeutic agents. Herein we report the promises of Dioscorea bulbifera and its bioactive principle, diosgenin as novel α-amylase and α-glucosidase inhibitor. Among petroleum ether, ethyl acetate, methanol and 70% ethanol (v/v) extracts of bulbs of D. bulbifera, ethyl acetate extract showed highest inhibition upto 72.06 ± 0.51% and 82.64 ± 2.32% against α-amylase and α-glucosidase respectively. GC-TOF-MS analysis of ethyl acetate extract indicated presence of high diosgenin content. Diosgenin was isolated and identified by FTIR, 1H NMR and 13C NMR and confirmed by HPLC which showed an α-amylase and α-glucosidase inhibition upto 70.94 ± 1.24% and 81.71 ± 3.39%, respectively. Kinetic studies confirmed the uncompetitive mode of binding of diosgenin to α-amylase indicated by lowering of both Km and Vm. Interaction studies revealed the quenching of intrinsic fluorescence of α-amylase in presence of diosgenin. Similarly, circular dichroism spectrometry showed diminished negative humped peaks at 208 nm and 222 nm. Molecular docking indicated hydrogen bonding between carboxyl group of Asp300, while hydrophobic interactions between Tyr62, Trp58, Trp59, Val163, His305 and Gln63 residues of α-amylase. Diosgenin interacted with two catalytic residues (Asp352 and Glu411) from α-glucosidase. This is the first report of its kind that provides an intense scientific rationale for use of diosgenin as novel drug candidate for type II diabetes mellitus.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/enzimologia , Dioscorea/química , Diosgenina/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/metabolismo , Animais , Domínio Catalítico , Dicroísmo Circular , Diabetes Mellitus Experimental/patologia , Diosgenina/química , Diosgenina/farmacologia , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Intestinos/enzimologia , Cinética , Camundongos , Simulação de Acoplamento Molecular , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Ligação Proteica/efeitos dos fármacos , Espectrometria de Fluorescência , Sus scrofa , alfa-Amilases/metabolismo
18.
Mol Cancer Ther ; 13(9): 2170-83, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24980948

RESUMO

Aurora A kinase orchestrates multiple key activities, allowing cells to transit successfully into and through mitosis. MLN8237 (alisertib) is a selective Aurora A inhibitor that is being evaluated as an anticancer agent in multiple solid tumors and heme-lymphatic malignancies. The antitumor activity of MLN8237 when combined with docetaxel or paclitaxel was evaluated in in vivo models of triple-negative breast cancer grown in immunocompromised mice. Additive and synergistic antitumor activity occurred at multiple doses of MLN8237 and taxanes. Moreover, significant tumor growth delay relative to the single agents was achieved after discontinuing treatment; notably, durable complete responses were observed in some mice. The tumor growth inhibition data generated with multiple dose levels of MLN8237 and paclitaxel were used to generate an exposure-efficacy model. Exposures of MLN8237 and paclitaxel achieved in patients were mapped onto the model after correcting for mouse-to-human variation in plasma protein binding and maximum tolerated exposures. This allowed rank ordering of various combination doses of MLN8237 and paclitaxel to predict which pair would lead to the greatest antitumor activity in clinical studies. The model predicted that 60 and 80 mg/m(2) of paclitaxel (every week) in patients lead to similar levels of efficacy, consistent with clinical observations in some cancer indications. The model also supported using the highest dose of MLN8237 that can be achieved, regardless of whether it is combined with 60 or 80 mg/m(2) of paciltaxel. The modeling approaches applied in these studies can be used to guide dose-schedule optimization for combination therapies using other therapeutic agents.


Assuntos
Aurora Quinase A/antagonistas & inibidores , Azepinas/administração & dosagem , Neoplasias Experimentais/tratamento farmacológico , Pirimidinas/administração & dosagem , Taxoides/administração & dosagem , Animais , Antineoplásicos/administração & dosagem , Área Sob a Curva , Linhagem Celular Tumoral , Docetaxel , Esquema de Medicação , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Transplante de Neoplasias , Paclitaxel/administração & dosagem , Pesquisa Translacional Biomédica
19.
Mol Cancer Ther ; 13(1): 122-33, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24222664

RESUMO

The high prevalence of KRAS mutations and importance of the RalGEF-Ral pathway downstream of activated K-ras in pancreatic ductal adenocarcinoma (PDAC) emphasize the importance of identifying novel methods by which to therapeutically target these pathways. It was recently demonstrated that phosphorylation of RalA S194 by Aurora A kinase (AAK) is critical for PDAC tumorigenesis. We sought to evaluate the AAK-selective inhibitor MLN8237 as a potential indirect anti-RalA-targeted therapy for PDAC. We used a site-specific phospho-S194 RalA antibody and determined that RalA S194 phosphorylation levels were elevated in a subset of PDAC cell lines and human tumors relative to unmatched normal controls. Effects of MLN8237 on anchorage-independent growth in PDAC cell lines and growth of patient-derived xenografts (PDX) were variable, with a subset of cell lines and PDX showing sensitivity. Surprisingly, RalA S194 phosphorylation levels in PDAC cell lines or PDX tumors did not correlate with MLN8237 responsiveness. However, we identified Ki67 as a possible early predictive biomarker for response to MLN8237 in PDAC. These results indicate that MLN8237 treatment may be effective for a subset of patients with PDAC independent of RalA S194 phosphorylation. Ki67 may be an effective pharmacodynamic biomarker to identify response early in the course of treatment.


Assuntos
Azepinas/administração & dosagem , Carcinogênese/efeitos dos fármacos , Carcinoma Ductal Pancreático/tratamento farmacológico , Antígeno Ki-67/genética , Pirimidinas/administração & dosagem , Proteínas ral de Ligação ao GTP/genética , Aurora Quinase A/metabolismo , Biomarcadores Tumorais/genética , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Humanos , Mutação , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras) , Proteínas ral de Ligação ao GTP/metabolismo , Proteínas ras/genética
20.
PLoS One ; 8(12): e82529, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24367520

RESUMO

Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS(•+) and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS(•+) radical with a second order rate constant of 2.33 × 10(6) and 1.72 × 10(6), respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48 × 10(6) and 4.46 × 10(6) were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C27H42O3) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants.


Assuntos
Antioxidantes/química , Dioscorea/química , Sequestradores de Radicais Livres/química , Extratos Vegetais/química , Plantas Medicinais/química , Cromatografia Líquida de Alta Pressão , Flavonas/química , Fenol/química , Análise de Componente Principal
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