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1.
J Hazard Mater ; 398: 122867, 2020 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-33027876

RESUMEN

Colored photonic TiO2 photoelectrodes have been prepared by a simple anodizing-annealing method. Traditionally, the photoelectrocatalytic (PEC) properties of the film are obtained by measuring the actual decomposition of organic pollutants under ultraviolet or visible light, which may take tens of minutes or even hours. Here, through the combined analysis of the apparent features and PEC properties, we found that the structure would affect the color and optical performance, and the films with different colors showed different PEC performance. Interestingly, after repeated verifications, we got a rule that the PEC performance of the TiO2 films decreased in the order with typical color of yellow, blue-green, dark yellow, blue, yellow-grey, and purple. Therefore, we provide a new idea for the visualization screening of PEC performance for the film photoelectrodes, that is, color can be used as a quick selection indicator for TiO2 films.

2.
Artículo en Inglés | MEDLINE | ID: mdl-32974825

RESUMEN

The direct discharge of urine into water bodies leads to environmental pollution, and an increase in the water treatment cost, whereas recycling of the nutrients in urine is of significant economic value. A single-compartment reactor was investigated for the recycling of phosphate and simultaneous removal of nitrogen from urine wastewater by electrochemical magnesium induction, and electrochemical oxidation for the removal of residual nitrogen from the supernatant. The results demonstrated that phosphate recovery capacity was greater than 11 mg P cm-2 h-1 at a current density of 15 m A cm-2 and anodizing time of 20 min; the removal rates of ammonium and total nitrogen in the synchronous electrochemical oxidation were 80% and 75%, respectively, at a current density of 45 m A cm-2 and anodizing time of 60 min. The anodizing time and initial pH were determined to be critical control factors in the electrochemical struvite induction and nitrogen electrochemical oxidation. The on-site electrochemical nitrogen oxidation could rapidly utilize the alkaline supernatant following phosphate recovery. Thus, the integration of the single-compartment reactor, electrochemical magnesium dosage, and simultaneous nitrogen electrochemical oxidation demonstrates potential for application to decentralized reactors to treat source-separated urine.

3.
Appl Biochem Biotechnol ; 192(2): 415-431, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32394318

RESUMEN

Three typical waste furniture boards, including fiberboard, chipboard, and blockboard, were pretreated with conventional hydrothermal method. The responses of chemical composition, physicochemical morphology, and performances of enzymatic hydrolysis were evaluated. Results indicated the almost complete hemicellulose removal at higher pretreatment temperatures, the enhanced crystallinity index, and disordered morphology of the pretreated substrates indicated that the hydrothermal pretreatment deconstructed these boards well. However, the very low enzymatic hydrolysis (< 8% after 72 h) of the pretreated substrates showed the poor biological conversion. Three hypotheses for the weakened enzymatic hydrolysis were investigated, and results indicated that the residual adhesives and their degraded fractions were mainly responsible for poor hydrolysis. When NaOH post-pretreatment was attempted, cellulose-glucose conversion of the hydrothermally pretreated fiberboard, chipboard and blockboard can be improved to 28.5%, 24.1%, and 37.5%. Herein, the process of NaOH hydrothermal pretreatment was integrated, by which the hydrolysis of pretreated fiberboard, chipboard and blockboard was greatly promoted to 47.1%, 37.3%, and 53.8%, suggesting a possible way to pretreat these unconventional recalcitrant biomasses.

4.
Bioresour Technol ; 307: 123231, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32224425

RESUMEN

Two agricultural wastes, Chinese medicinal herbal residue and spent Pleurotus ostreatus substrate, were developed to remove ammonium and phosphate from swine wastewater. These adsorbents were mesoporous materials with abundant smooth layered pores, and rough protuberances and grooves, respectively. Their adsorption capacities were 1131.65 and 1631.79 mg N g-1, and 63.41 and 62.58 mg P g-1 at pH 8.0, dosage of 0.2 g L-1 and contact time of 360 min. And kinetics data of ammonium and phosphate fitted best with the intra-particle diffusion and pseudo-second-order models, respectively. Based on the point of zero charge, FTIR and XPS analyses, ammonium was removed mainly by electrostatic attraction, ion exchange and surface precipitation, while phosphate was by ligand exchange, surface complexation and precipitation. Therefore, the two agricultural wastes have great potential to synchronously remove ammonium and phosphate from swine wastewater.


Asunto(s)
Compuestos de Amonio , Contaminantes Químicos del Agua , Adsorción , Animales , Concentración de Iones de Hidrógeno , Cinética , Fosfatos , Porcinos , Aguas Residuales
5.
Sci Total Environ ; 701: 134363, 2020 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-31706211

RESUMEN

Heavy metals (e.g., arsenic (As)) and tetracycline (TC) usually coexist in wastewater from livestock farm, whereas the co-adsorption behaviours and mechanisms of As(V) and TC were not well-known. This study investigated the adsorption and co-adsorption of As(V) and TC by a novel yttrium-immobilized-graphene oxide-alginate hydrogel (Y-GO-SA) to explore the adsorption behaviours and mechanisms. The adsorption of As(V) and TC was pH-dependent. The maximum adsorption capacities under the studied concentrations were 273.39 mg/g for As(V), and 477.9 mg/g for TC, respectively, which are much higher than many other reported adsorbents. Furthermore, As(V) adsorption was due to ion exchange between hydroxyl groups and H2AsO42- groups and H-bonds formed with O-containing groups on Y-GO-SA, and the adsorption of TC by Y-GO-SA was mainly ascribed to electrostatic interaction, H-bonds, π - π EDA interaction, n-π EDA interaction, and cation-bonding bridge effects. The co-adsorption of As(V) and TC in binary system indicated that the presence of TC obviously suppressed the adsorption of As(V) due to the competition for active sites, whereas the effect of presence of As(V) on adsorption of TC can be negligible due to the balance contributions from its contrary effects, i.e. enhancement (anion-π interaction) and reduction (competition for Y ions) in TC adsorption. Finally, the hydrogels performed well in the treatment of livestock farm waste water. It can be anticipated that the prepared 3D hydrogel can be used as a powerful adsorbent in the practical application of waste water treatment, owing to its easy separation, high adsorption and good reusability.


Asunto(s)
Arsénico/química , Grafito/química , Tetraciclina/química , Contaminantes Químicos del Agua/química , Adsorción , Hidrogeles , Cinética , Eliminación de Residuos Líquidos , Aguas Residuales/química
6.
J Hazard Mater ; 388: 121807, 2020 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-31831288

RESUMEN

Iron (Fe) dissimilatory reduction might impact chromium (Cr) mobility in the rice rhizosphere, but it is poorly understood. We assessed rhizosphere microbes' role in Cr immobilization and bioavailability by conducting the pot experiment to test different biochar sources (PMB - pig manure and PSB - pine sawdust) and phosphorus (P) levels impact on Cr mobility. Results showed that PMB application increased root biomass (23-65 %) and decreased root Cr concentration (46-74 %) regardless P treatment. However, P addition reduced root and shoot biomass in control and PMB treatments by 33-43 % and 25-26 %. Therefore, low P input is recommended in Cr-contaminated soil. Moreover, Geobacter was the key microbial groups which may be involved in promoting Cr release by increasing Fe dissolution. Finally, Geobacter and Fe dissimilatory reduction play a central role in Cr translocation and they should be considered in strategies to reduce rice Cr uptake by biochar application.

7.
Sci Rep ; 9(1): 15999, 2019 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-31690791

RESUMEN

As a multifunctional material, biochar is considered a potential adsorbent for removing heavy metals from wastewater. Most biochars with high adsorption capacities have been modified, but this modification is uneconomical, and modifying biochar may cause secondary pollution. Thus, it is necessary to develop an efficient biochar without modification. In this study, spent P. ostreatus substrate and spent shiitake substrate were used as the raw materials to prepare biochar. Then, the physicochemical properties of the biochars and their removal efficiencies for Pb(II) were investigated. The results showed that the physicochemical properties (e.g., large BET surface area, small pore structure and abundant functional groups) contributed to the large adsorption capacity for Pb(II); the maximum adsorption capacities were 326 mg g-1 (spent P. ostreatus substrate-derived biochar) and 398 mg g-1 (spent shiitake substrate-derived biochar), which are 1.6-10 times larger than those of other modified biochars. The Pb(II) adsorption data could be well described by the pseudo-second-order kinetic model and the Langmuir model. This study provides a new method to comprehensively utilize spent mushroom substrates for the sustainable development of the edible mushroom industry.


Asunto(s)
Carbón Orgánico/química , Plomo/química , Pleurotus/química , Hongos Shiitake/química , Residuos/análisis , Adsorción , Cinética
8.
Polymers (Basel) ; 11(9)2019 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-31492029

RESUMEN

Although recent work has shown natural lignin products are promising to fabricate various polymer based functional composites, high-value applications were challenged by their structural complexity and inhomogeneity. This work specially assessed the potential of four technical lignins for cellulose based functional films production. These four technical lignins were obtained by emerging pretreatment systems, i.e., lactic acid-betaine deep eutectic solvent (DES), ethanol organosolv, soda/anthraquinone (Soda/AQ) and the sodium salicylate hydrotrope, and their phenolic substructures were comparatively identified by prevalent 31P NMR technique. The influence of lignin chemical structure on the antioxidant potential and UV-shielding performance of the prepared cellulose/technical lignin composite films were assessed. Results showed severe organosolv and soda/AQ pretreatment produced technical lignins with higher total phenolic hydroxyl groups (3.37 and 3.23 mmol g-1 respectively), which also exhibited higher antioxidant activities. The composite films could effectively block the ultraviolet lights especially for UVB region (ultraviolet B, 280-315 nm) at only 5 wt.% lignin content. The contribution of lignin phenolic substructures to both antioxidant activity and UV-shielding property from high to low was syringyl > guaiacyl > p-hydroxyphenyl phenolic hydroxyl groups. This work provided some useful information that could facilitate upstream lignin extraction or downstream value-added applications.

9.
J Colloid Interface Sci ; 536: 710-721, 2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-30408691

RESUMEN

In this study, a series of in situ-generated yttrium-based nanoparticle (NP)/polyethersulfone (PES) composite adsorptive membranes were prepared by the phase inversion method for the first time. The Y(NO3)3·6H2O as precursor, uniformly dispersed at the molecular level in casting solution, reacted with OH- in a coagulation bath and ambient CO2 during the phase inversion process. The Y(CO3)0.5(OH)2 NPs were formed in situ and distributed homogeneously in a PES matrix, which was confirmed by X-ray photoelectron spectroscopy (XPS) and Energy Dispersive X-Ray Spectroscopy (EDS) results. The compatibility of the nanocomposite membranes was improved by an in situ preparation method. With the increase in content of Y-based NPs in composite membranes, the surface hydrophilicity and water permeability first increased from M1 to M2, and then slightly decreased from M3 to M5, which was mainly related to membrane structure. From M1 to M5, the demixing way changed from instantaneous demixing to delayed demixing process as a result of thermodynamic enhancement and viscosity hindrance in the phase inversion process. A higher demixing rate led to a structure with large finger-like macro-voids, i.e., M1, whereas a lower demixing rate caused the suppression of finger-like macro-voids, i.e., M5. More importantly, the adsorption study indicated that the nanocomposite adsorptive membranes were stable in the treatment of fluoride-containing water, with no leakage of Y-based NPs from membrane matrix to solution. It is expected that the in situ preparation technique could be used to produce next-generation nanocomposite adsorptive membranes with improved comprehensive properties for application in water treatment.

10.
Sci Total Environ ; 634: 760-768, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29653421

RESUMEN

In order to seek a possible path for utilization bottom ash, the solid waste from biomass incineration for power generation, its basic characteristics were investigated, and removing methylene blue (MB) from aqueous solution was attempted as well. Results indicated bottom ash dominantly contained Si and Ca-related minerals with >35 mineral elements, meanwhile, it was typically characterized by alkalinity (pH of 9.5) and low specific surface area (14.5m2/g). As the only bottom ash was employed for removing MB, removal efficiency was lower than 44%, however, it was greatly improved to 100% as hydrogen peroxide was supplemented (final concentration of 4.0%). Based on the elucidated mechanisms, Fenton-like reaction was triggered by bottom ash, which was dominantly responsible for removing MB, rather than the adsorption by bottom ash. Besides, increasing reaction temperature and duration dramatically promoted MB removal by bottom ash with the aid of hydrogen peroxide (HBA). A great promotion on MB removal from 92.3mg/g to 143.9mg/g was achieved as pH was adjusted from 2.0 to 5.0, indicating MB removal was pH-dependent. The maximum removal of 260.9mg/g was achieved by HBA at a relatively high initial MB concentration of 2000.0mg/L, suggesting a great potential in treating dye wastewater by functionalizing bottom ash with the aid of hydrogen peroxide. Moreover, the released heavy metals and derived by-products from MB removal were acceptable in consideration of their potential environmental risks. Thus, the current work offers a new path to valorize the solid waste in biomass electricity generation plant.

11.
Oncotarget ; 8(24): 39154-39166, 2017 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-28388577

RESUMEN

Enhanced chemoresistance is, among other factors, believed to be responsible for treatment failure and tumor relapse in patients with epithelial ovarian cancer (EOC). Here, we exposed EOC cells to interleukin-6 (IL-6) to activate oncogenic STAT3, which directly repressed miR-204 via a conserved STAT3-binding site near the TRPM3 promoter region upstream of miR-204. Repression of miR-204 was required for IL-6-induced cisplatin (cDDP) resistance. Furthermore, we identified the IL-6 receptor (IL-6R), which mediates IL-6-dependent STAT3 activation, as a direct miR-204 target. Importantly, the resulting IL-6R/STAT3/miR-204 feedback loop was identified in patients with EOC, and its activity correlated with chemosensitivity. Moreover, exogenous miR-204 blocked this circuit and enhanced cDDP sensitivity both in vitro and in vivo by inactivating IL-6R/STAT3 signaling and subsequently decreasing the expression of anti-apoptotic proteins. Our findings illustrate the function of this feedback loop in cDDP-based therapy and may offer a broadly useful approach to improve EOC therapy.


Asunto(s)
Cisplatino/farmacología , Resistencia a Antineoplásicos , Retroalimentación Fisiológica , MicroARNs/genética , Neoplasias Glandulares y Epiteliales/patología , Neoplasias Ováricas/patología , Receptores de Interleucina-6/metabolismo , Factor de Transcripción STAT3/metabolismo , Animales , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinoma Epitelial de Ovario , Proliferación Celular/efectos de los fármacos , Cistadenocarcinoma Seroso/tratamiento farmacológico , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/metabolismo , Cistadenocarcinoma Seroso/patología , Femenino , Estudios de Seguimiento , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Neoplasias Glandulares y Epiteliales/tratamiento farmacológico , Neoplasias Glandulares y Epiteliales/genética , Neoplasias Glandulares y Epiteliales/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Pronóstico , Receptores de Interleucina-6/genética , Factor de Transcripción STAT3/genética , Transducción de Señal/efectos de los fármacos , Tasa de Supervivencia , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
12.
ACS Appl Mater Interfaces ; 6(19): 16712-20, 2014 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-25188022

RESUMEN

Doped TiO2 with metal, nonmetal, and rare earth elements has shown a great potential in energy and environmental applications, but it is difficult to dope well-defined TiO2 single crystals (SCs) with {001} exposed facet due to their high crystallinity. In this work, we developed a green and general approach to prepare the {001}-exposed TiO2 SCs doped with various elements, on the basis of recycling the wasted ethylene glycol electrolyte from the anodic oxidation for TiO2 nanotube preparation. All six representative elements (i.e., metal, nonmetal, and rare earth types) could be successfully doped into the TiO2 SCs without breaking their single-crystalline structure and exposed high-energy facet. The electronic properties of the doped TiO2 SCs were significantly improved. All the doped TiO2 SCs exhibited a superior photoactivity under visible-light irradiation for degrading rhodamine B, a typical organic pollutant. The prepared doped TiO2 SCs have a promising potential in environmental and energy applications.

13.
Water Res ; 66: 273-282, 2014 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-25222331

RESUMEN

Anodic material plays a vital role in electrochemical water treatment. Titanium dioxide (TiO2) has been widely recognized as an excellent semiconductor photocatalyst, rather than an efficient electrocatalyst, due to its relatively low electric conductivity and poor electrochemical activity. In this work, it is found that TiO2 can actually become a superior electrocatalyst when its crystal shape and exposed facet are finely tuned. The shape-engineered TiO2 single crystals with {001} facets exhibit an excellent electro-catalytic activity and stability for degrading typical organic pollutants such as rhodamine B and bisphenol A, and treating complex landfill leachate. Its electro-catalytic superiority is mainly attributed to the single-crystalline structure and exposed polar {001} facet. Our findings could provide new possibility of utilizing TiO2 for efficient electrochemical water treatment because of its high activity, great stability, low cost and no toxicity.


Asunto(s)
Electroquímica/métodos , Oxígeno/química , Titanio/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Carbono/química , Catálisis , Electrodos , Concentración de Iones de Hidrógeno , Rodaminas/análisis , Espectrofotometría Ultravioleta , Temperatura
15.
Acta Biochim Biophys Sin (Shanghai) ; 45(11): 963-72, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24108762

RESUMEN

Recent studies have shown that microRNA-106a (miR-106a) is overexpressed in gastric cancer and contributes to tumor growth. In this study, we investigated whether miR-106a mediated resistance of the gastric cancer cell line SGC7901 to the chemotherapeutic agent cisplatin (DDP). MiR-106a expression was up-regulated in the DDP resistant cell line SGC7901/DDP compared with its parental line SGC7901. Transfection of miR-106a induced DDP resistance in SGC7901, while suppression of miR-106a in SGC7901/DDP led to enhanced DDP cytotoxicity. Further study indicated that the mechanism of miR-106a-induced DDP resistance involved the expression of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) protein and its downstream phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) pathway. This study provides a novel mechanism of DDP resistance in gastric cancer.


Asunto(s)
Antineoplásicos/farmacología , Cisplatino/farmacología , MicroARNs/fisiología , Fosfohidrolasa PTEN/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Neoplasias Gástricas/tratamiento farmacológico , Secuencia de Bases , Western Blotting , Línea Celular Tumoral , Cartilla de ADN , Humanos , Neoplasias Gástricas/enzimología , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patología , Regulación hacia Arriba
16.
Chem Commun (Camb) ; 49(54): 6075-7, 2013 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-23727818

RESUMEN

Novel TiO2 mesocrystalline microrods with unique hexagonal structure were prepared via a facial thermal method. Their photocatalytic performance under UV irradiation was much higher than that of the Degussa P25 benchmark, one of the best commercial polycrystalline TiO2 photocatalyst. The hexagonal microrods were formed through self-directed self-assembly within intermediate scaffolds.

17.
FEBS Lett ; 587(1): 73-81, 2013 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-23178712

RESUMEN

MicroRNAs (miRNA) have emerged as key players in carcinogenesis. Here, we investigated the role of miR-137 in the pathogenesis of lung cancer. The downregulation of miR-137 in lung cancer cells could be rescued following inhibition of DNA methylation. Ectopic expression of miR-137 in lung cancer cells significantly downregulated Cdc42, Cdk6 and induced G1 cell cycle arrest, leading to a significant decrease in cell growth in vivo and in vitro. Further, both Cdc42 and Cdk6 were confirmed as targets of miR-137.


Asunto(s)
Quinasa 6 Dependiente de la Ciclina/antagonistas & inhibidores , Regulación hacia Abajo , Neoplasias Pulmonares/metabolismo , Pulmón/metabolismo , MicroARNs/metabolismo , Proteína de Unión al GTP cdc42/antagonistas & inhibidores , Animales , Antineoplásicos/farmacología , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/terapia , Línea Celular Tumoral , Proliferación Celular , Quinasa 6 Dependiente de la Ciclina/genética , Quinasa 6 Dependiente de la Ciclina/metabolismo , Metilasas de Modificación del ADN/antagonistas & inhibidores , Fase G1/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica , Silenciador del Gen , Técnicas de Transferencia de Gen , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Pulmón/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/terapia , Ratones , MicroARNs/genética , Ensayos Antitumor por Modelo de Xenoinjerto , Proteína de Unión al GTP cdc42/genética , Proteína de Unión al GTP cdc42/metabolismo
18.
Acta Biochim Biophys Sin (Shanghai) ; 45(2): 80-6, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23178914

RESUMEN

Multidrug resistance (MDR) to chemotherapeutic agents is a major obstacle to successful treatment in breast cancer patients. The aims of this study were to investigate whether miR-137 was involved in the regulation of MDR, and to explore the mechanism of miR-137 on the sensitivity of MCF-7/ADM cells. miR-137 was downregulated in MCF-7/ADM cells, and its expression was found to inversely correlate with Y-box binding protein-1 (YB-1) and P-glycoprotein (P-gp) levels in breast cancer cells. Furthermore, YB-1 was confirmed as a target of miR-137 by luciferase reporter assay and western blot analysis. Moreover, elevated expression of miR-137 reduced the protein expression levels of YB-1 and P-gp, mimicking the effect of YB-1 knockdown in the sensitivity of MCF-7/ADM cells to anticancer agents, whereas restoration of YB-1 diminished this effect. In conclusion, our results demonstrated that miR-137 was involved in MDR in cancer through modulation of P-gp by targeting YB-1, suggesting that miR-137 might be a potential target for preventing and reversing MDR in tumor cells.


Asunto(s)
Antineoplásicos/uso terapéutico , MicroARNs/metabolismo , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/metabolismo , Proteína 1 de Unión a la Caja Y/antagonistas & inhibidores , Proteína 1 de Unión a la Caja Y/metabolismo , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos , Humanos , Células MCF-7 , Neoplasias Experimentales/patología , Resultado del Tratamiento
19.
Pharm Biol ; 50(10): 1233-40, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22957792

RESUMEN

CONTEXT: Multidrug-resistance is a serious obstacle encountered in leukemia treatment. Recent studies have shown microRNA-21 (miR-21) is overexpressed in several types of cancer and contributes to tumor resistance to chemotherapy. In our previous studies, we found triptolide (TPL) could enhance adriamycin-induced cytotoxicity and apoptosis in K562/A02 cells. OBJECTIVE: In the present study, we investigated the mechanism of TPL on the sensitivity of K562/A02 cells to adriamycin. MATERIALS AND METHODS: Cell viability was assessed by methyl thiazolyl tetrazolium (MTT) assay. Expression of mature miR-21 was determined by SYBER green PCR. The miR-21 mimics and inhibitors were chemically synthesized and transfected into K562 cells or K562/A02 cells. PTEN protein levels was determined by western blots. PTEN promoter activity was measured by luciferase assays. RESULTS: TPL (5 nmol/L) increased the sensitivity of K562/A02 to adriamycin. When adriamycin was combined with 5 nmol/L TPL, the mean apoptotic population of K562/A02 cells was increased from 4.3 to 18.5%, respectively. K562/A02 cells showed a significant reduction in miR-21 and phosphatase and tensin homolog deleted on chromosome ten (PTEN) expressions after TPL treatment. K562/A02 cells that were transfected with the miR-21 inhibitor had a significantly higher PTEN protein level than the control. K562 cells that were pre-treated with PTEN siRNA had increased survival rate compared to the control group. DISCUSSION AND CONCLUSION: Our findings indicated that triptolide modulates the sensitivity of K562/A02 cells to adriamycin by regulating miR-21 expression. Triptolide inhibited miR-21 expression and enhanced PTEN levels in K562/A02 cells.


Asunto(s)
Diterpenos/farmacología , Doxorrubicina/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , MicroARNs/genética , Fenantrenos/farmacología , Antibióticos Antineoplásicos/farmacología , Antineoplásicos Alquilantes/farmacología , Apoptosis/efectos de los fármacos , Western Blotting , Supervivencia Celular/efectos de los fármacos , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Compuestos Epoxi/farmacología , Humanos , Células K562 , Fosfohidrolasa PTEN/genética , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas
20.
Oncol Lett ; 3(2): 485-489, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22740937

RESUMEN

Multidrug resistance is a serious obstacle encountered in leukemia treatment. Previous studies have found drug resistance in human leukemia is mainly associated with overexpression of the multidrug resistance gene 1 (MDR1). The aim of the present study was to investigate the modulation of P-glycoprotein expression by triptolide in adriamycin-resistant K562/A02 cells. The reverse effects of triptolide on drug resistance in K562/A02 cells were assessed by 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide (MTT) assay. The percentage of apoptotic cells was obtained from annexin V/fluorescein isothiocyanate (FITC) and propridium iodide (PI) double-staining. The effects of triptolide on P-glycoprotein activity were evaluated by measuring intracellular adriamycin accumulation. The expression of P-glycoprotein was determined by flow cytometry. A luciferase reporter gene assay was used to detect the transcriptional activity of the MDR1 promoter. Results revealed that triptolide decreased the degree of resistance of K562/A02 cells, and significantly inhibited P-glycoprotein expression and drug-transport function, and increased the accumulation of adriamycin in K562/A02 cells as measured by flow cytometry. A luciferase reporter gene assay demonstrated that triptolide was capable of inhibiting the transcriptional activity of the MDR1 promoter. Triptolide may effectively reverse the adriamycin resistance in K562/A02 cells via modulation of the P-glycoprotein expression and by increasing intracellular adriamycin accumulation.

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