Identificación de biomarcadores saturados en un carbón bituminoso tratado con ácido y un solvente no convencional / Identification of biomarkers in a bituminous coal treated with acid and an unconventional solvent / Identificação de biomarcadores saturados em carvão betuminoso tratado com ácido e solvente não convencional

Resumen Este artículo describe los biomarcadores saturados (n־alcanos, hopanos y esteranos) identificados en los extractos obtenidos de un carbón bituminoso, tratado con ácido y un solvente no convencional. Los extractos de carbones bituminosos venezolanos se obtuvieron a través de cloroformo (solvente convencional) y N,N־dimetilformamida ־DMF־ como solvente de alto poder extractivo, con y sin tratamiento ácido previo, con el fin de evaluar el rendimiento y distribución de biomarcadores característicos. El rendimiento de extracción con DMF alcanzó 44% p/p, mientras que con CHCl3, este valor no superó el 2% p/p. La desmineralización previa con HCl incrementó el rendimiento de extracción sin afectar la distribución de los biomarcadores, salvo en la relación de hidrocarburos ligeros respecto a los pesados. Se propone DMF como solvente de elección para obtener información geoquímica en carbones meteorizados.

Abstract This article describes saturated biomarkers (n־alkanes, hopanes and steranes) identified in the extracts obtained from a bituminous coal treated with acid and an unconventional solvent. Extracts of Venezuelan bituminous coals were obtained through chloroform (conventional solvent) and N,N־ dimethylformamide ־DMF־ as high extractive solvent, with and without previous acid treatment, to evaluate the performance and distribution of characteristic biomarkers. The extraction yield with DMF reached 44% w/w, while with CHCl3, this value did not exceed 2% w/w. Previous demineralization with HCl increased the extraction yield without affecting the distribution of the biomarkers, except in the ratio of light hydrocarbons to the heavy ones. DMF, therefore, is proposed as the solvent of choice to obtain geochemical information on weathered carbons.

Resumo Este artigo de pesquisa descreve os biomarcadores saturados identificados (n־alcanos, hopanos y esteranos) em extratos obtidos a partir de carvão betuminoso, tratado com ácido e um solvente não convencional. Extratos de carvão betuminoso venezuelano foram obtidos utilizando־se clorofórmio (solvente convencional) e N,N־ dimetilformamida ־DMF־ como solvente extrativo elevado, com e sem tratamento ácido prévio, com o objectivo de avaliar o rendimento e distribuição de biomarcadores característicos. O rendimento de extração com DMF atingiu 44% p/p; com CHCl3 o valor não excedeu 2% p/p. A desmineralização prévia com HCl aumentou o rendimento da extração sem afetar a distribuição dos biomarcadores, exceto na proporção de hidrocarbonetos leves e pesados. DMF é proposto como o solvente de eleição para obter informações geoquímicas sobre os carvões intemperizados.

Alyssin and Iberin in Cruciferous Vegetables Exert Anticancer Activity in HepG2 by Increasing Intracellular Reactive Oxygen Species and Tubulin Depolymerization

To determine the chemopreventive potential of alyssin and iberin, the in vitro anticancer activities and molecular targets of isothiocyanates (ITCs) were measured and compared to sulforaphane in hepatocellular carcinoma cell HepG2. The SR-FTIR spectra observed a similar pattern vis-à-vis the biomolecular alteration amongst the ITCs-treated cells suggesting a similar mode of action. All of the ITCs in this study cause cancer cell death through both apoptosis and necrosis in concentration dependent manner (20–80 μM). We found no interactions of any of the ITCs studied with DNA. Notwithstanding, all of the ITCs studied increased intracellular reactive oxygen species (ROS) and suppressed tubulin polymerization, which led to cell-cycle arrest in the S and G₂/M phase. Alyssin possessed the most potent anticancer ability; possibly due to its ability to increase intracellular ROS rather than tubulin depolymerization. Nevertheless, the structural influence of alkyl chain length on anticancer capabilities of ITCs remains inconclusive. The results of this study indicate an optional, potent ITC (viz., alyssin) because of its underlying mechanisms against hepatic cancer. As a consequence, further selection and development of effective chemotherapeutic ITCs is recommended.

Effect of ADAM17-shRNA on proliferation of human breast cancer cell line MCF-7 in hypoxia / 重庆医学

Objective To investigate the effects of shRNA targeting a disintegrin and metalloproteinases 17(ADAM17)on the proliferation of human breast cancer MCF-7 cells in hypoxia environment.Methods The four specific ADAM17-shRNA se-quences aiming at ADAM17 were designed,transfected into MCF-7 cells by electroporation,and cultured in hypoxia environment. The experiment was divided into the control group (blank phosphate buffer solution,PBS),nonsense sequence group (transfected with ADAM17-shNC)and shRNA transfection group (transfected with ADAM17-shRNA,the highest silencing efficiency of shR-NA was selected for following experiments).Real-time PCR was used to detect the expression of ADAM17 mRNA.The prolifera-tion ability and cell cycle change of MCF-7 cells were detected by iCELLigence and flow cytometry (FCM),respectively.Results Compared with control group and nonsense sequence group,the four ADAM17-shRNA transfection groups all had the silence effect on ADAM17 gene expression (P <0.05 ),the difference was statistically significant(P <0.05 ),particularly shRNA1219 had the highest inhibitory rate (F =5.11,P <0.01 ).The cellular proliferation ability and cell growth speed in the shRNA transfection group were significantly decreased compared with the control group and nonsense sequence group (P <0.05).Most cells of shRNA transfection group remained in the G0/G1 phase (73.35 ± 2.45 ),which in the control group and nonsense sequence group was (62.56±2.35)and (62.68 ±1.20)respectively,the difference was statistically significant(P <0.05).The cell cycle progression was significantly delayed.Conclusion ADAM17-shRNA inhibits the proliferation of MCF-7 cells under hypoxic environment.

Mild-acid hydrolysis of a native polysulfated fraction from Acanthophora muscoides generates sulfated oligosaccharides displaying in vitro thrombin generation inhibition / Hidrólise ácida branda de uma fração polissulfatada de Acanthophora muscoides gera oligossacarídeos sulfatados mostrando inibição de geração de trombina in vitro

A. muscoides (Rhodophyta) has three polysulfated fractions (-1, -2 and Am-3). Am-2 displayed anti -inflammation and serpin-independent anticoagulation effects; however, no effect of oligomers on thrombin-generation (TG) has been demonstrated. This study employed mild-acid hydrolysis to obtain low-molecular-size derivatives from Am-2 and compared in vitro inhibitory effects between intact Am-2 and its hydrolysates on a TG assay. The polysaccharidic extract was fractionated by DEAE-cellulose that revealed Am-2 eluted with 0.75-M NaCl containing sulfate (23%), hexoses (51%) and absence of proteins, and indicating, by one-dimension nuclear magnetic resonance, structure of galactan similar to that of the extract. The depolymerization with HCl (0.02 or 0.04-M, 60°C) for different times progressively reduced the charge density and the molecular-size of Am-2 based on electrophoresis in agarose and polyacrylamide gels, respectively, where at higher acid concentration and critical time up to 5h yielded fragment of Ì´14-kDa similar to that of unfractionated heparin (UHEP). Regarding the TG assay, intact Am-2 inhibited concentration- dependent intrinsic pathway, whereas its hydrolysates abolished it like UHEP, except the analog fragment (92.87% inhibition), when in 60-fold diluted human plasma using chromogenic method in a continuous system. The results reveal an alternative approach for the production of oligosaccharides from A. muscoides with TG inhibition.

A rodofícea A. muscoides possui três frações polissulfatadas (-1, -2 e Am-3). Am-2 mostrou efeito anti-inflamação e anticoagulação independente de serpina. Entretanto, não se demonstrou efeito de oligômeros sobre ensaio de geração de trombina (GT) . Este estudo empregou hidrólise ácida branda para obter derivados de tamanho molecular baixo de Am -2 e os efeitos inibitórios in vitro entre Am-2 intacta e hidrolisados comparados sobre um ensaio de GT. O extrato polissacarídico, fracionado por DEAE-celulose, revelou Am-2 eluída com NaCl-0,75M contendo sulfato (23%), hexoses (51%) e destituída de proteínas. E, ainda, por ressonância magnética nuclear-unidimensional, indicando galactana semelhante a do extrato. A depolimerização com HCl (0,02 ou 0,04-M; 60°C) reduziu, progressivamente durante tempos diferentes, a densidade de carga e o tamanho molecular de Am-2 baseada nas eletroforeses em géis de agarose e de poliacrilamida, respectivamente, em que, concentração ácida elevada e tempo crítico de até 5h renderam fragmento de Ì´14-kDa semelhante ao da heparina não fracionada (HEPNF). Já no ensaio de GT, Am-2 intacta, quando em plasma humano diluído 60 vezes, usando método cromogênico por meio de sistema contínuo, quem inibiu a via intrínseca dependente de concentração, ao passo que seus hidrolisados aboliram como HEPNF, exceto fragmento análogo (inibição 92,87%). Os resultados revelam uma abordagem alternativa para produzir oligossacarídeos de A. muscoides com inibição de GT.

Generación de monómeros aromáticos por Aspergillus y Penicillum spp a partir de lignina residual de paja de trigo / Aromatic monomers generation by Aspergillus and Penicillium spp from residual wheat straw lignin

Antecedentes: La paja de trigo es un residuo agrícola con un 17% de lignina, un polímero recalcitrante con potencial biotecnológico si se despolimeriza en aromáticos de interés para la industria; lo que es posible por métodos químicos, pero que son costosos y contaminantes. Una alternativa es su despolimerización biológica por hongos mitospóricos ligninolíticos como Aspergillus y Penicillium spp. Sin embargo existen pocos reportes del uso de hongos en la generación de aromáticos por despolimerización de la lignina de residuos agrícolas. Objetivo: Determinar la generación de aromáticos utilizando los hongos Aspergillus y Penicillium por despolimerización de la lignina residual de paja de trigo semipurificada. Métodos: Para ello los hongos se cultivaron en lignina residual de paja de trigo por 28 días, que por despolimerización generaron aromáticos que se identificaron en cromatografía de gases. Resultados: Los resultados mostraron que ambos hongos generan aromáticos como: guayacol 3,5, vainillina 3,3, ácidos hidroxibenzoico 3,2, vainillinico 3,3, siringico 10,1 y ferúlico 21,9 mg mL-1. Conclusiones: Aspergillus y Penicillium son una opción ecológica en el aprovechamiento de la lignina residual de paja de trigo semipurificada para la generación de aromáticos de interés industrial, en un tiempo relativamente corto a partir de un residuo abundante y barato.

Background: Wheat straw is an agricultural waste, which contains 17% of lignin, a recalcitrant polymer with biotechnological potential provided it is depolymerized. Lignin depolymerization has attracted interest because it yields aromatics of industrial interest; chemical and physical methods are available but entail economic and environmental constraints. An alternative is to exploit the ligninolytic capacity of mitosporic fungi, such as Aspergillus and Penicillium spp. There are few reports on the use of these funguses in the generation of aromatics by lignin depolymerization. Objetives: To use Aspergillus and Penicillium spp in the biological generation of aromatics from semipurified residual wheat straw lignin. Methods: Funguses were grown in semipurified residual wheat straw lignin for 28 days; produced aromatics were followed using gas chromatography. Results: Obtained results indicate a range of aromatics produced, i.e. 3,5 mg mL-1 guaiacol, 3,3 vanillin, 3,2 hydroxybenzoic acid, 3,3 vanillinic, 10,1 syringic and 21,9 ferulic. Conclusions: Aspergillus and Penicillium represent an ecological option in the exploit of semi-purified residual lignin from wheat straw to generate aromatics in a shorter period from an abundant and cheap residue.

Research progress of microtubule inhibitor-induced tumor cell mitotic catastrophe / 中国药理学通报

Microtubule inhibitor has been a hot area of anticancer drugs research.Microtubule inhibitor exert an anti-tumor effect by promoting or inhibiting the microtubule aggregation to break the dynamic balance of microtubule,hindering the spindle forma-tion of tumor cells,and then blocking the process of cell divi-sion.Mitotic catastrophe is a cell death phenomenon that is caused by abnormal cell division and damage of spindle structure in cell mitosis phase.In recent years more and more attention has been paid to mitotic catastrophe cell death because it has been confirmed clinically that microtubule inhibitors can induce mitotic catastrophe death of tumor cells.This paper reviews the latest research progress of microtubule inhibitors,and discusses the molecular mechanisms of mitotic catastrophe cell death tumor cells induced by microtubule inhibitors.

Microtubule-destabilizing protein stathmin—a new target for gene therapy of cancer / 中国癌症杂志

Stathmin is a novel member of microtubule-destabilizing proteins that play a critical role in the regulation of the dynamic equilibrium of microtubules during different phases of the cell cycle.The overexpression of stathmin was found in different type of cancer.Inhibition of stathmin expression in malignant cells may interfere with their orderly progression through the cell cycle.Overexpression of stathmin can affect the action of antimicrotuble drugs by markedly decreasing binding of paclitaxel,and increasing binding of Vinca alkaloids.In addition,stathmin provides an attractive molecular target for cancer therapy.It may be possible to combine adenovirus-mediated anti-stathmin ribozyme therapy with a chemotherapeutic agent such as taxol to obtain a more potent antiproliferative and antitumor effect.