AIM:To evaluate the role of genetic factors in the pathogenesis of idiopathic infant cholestasis.METHODS:We performed a case-control study,in-cluding 78 infants with idiopathic infant cholestasis and 113 healthy infan...AIM:To evaluate the role of genetic factors in the pathogenesis of idiopathic infant cholestasis.METHODS:We performed a case-control study,in-cluding 78 infants with idiopathic infant cholestasis and 113 healthy infants as controls.Genomic DNA was extracted from peripheral venous blood leukocytes us-ing phenol chloroform methodology.Polymerase chain reaction was used to amplify the multidrug resistance protein 3(MDR3)R652G fragment,and products were sequenced using the ABI 3100 Sequencer.RESULTS:The R652G single nucleotide polymorphism(SNP)was significantly more frequent in healthy infants(allele frequency 8.0%)than in patients(allele frequency 2.60%)(P < 0.05),odds ratio,0.29;95% confidence interval,0.12-0.84.The conjugated bilirubin in patients with the AG genotype was significantly lower than in those with the AA genotype(44.70 ± 6.15 μmol/L vs 95.52 ± 5.93 μmol/L,P < 0.05).CONCLUSION:MDR3 R652G is negatively correlated with idiopathic infant cholestasis.Children with the R652G SNP in Guangxi of China may have reduced susceptibility to infant intrahepatic cholestasis.展开更多
Multidrug resistance (MDR) is a critical problem in cancer chemotherapy. Cancer cells can develop resistance not only to a single cytotoxic drug, but also to entire classes of structurally and functionally unrelated c...Multidrug resistance (MDR) is a critical problem in cancer chemotherapy. Cancer cells can develop resistance not only to a single cytotoxic drug, but also to entire classes of structurally and functionally unrelated compounds. Several mechanisms can mediate the development of MDR, including increased drug efflux from the cells by ABC-transporters (ABCT), activation of metabolic enzymes, and defective pathways towards apoptosis. Many plant secondary metabolites (SMs) can potentially increase sensitivity of drug-resistant cancer cells to chemotherapeutical agents. The present thesis investigates the modulation of MDR by certain medicinal plants and their active compounds. The inhibition of ABCTs (P-gp/MDR1, MRP1, BCRP) and metabolic enzymes (GST and CYP3A4), and the induction of apoptosis are useful indicators of the efficacy of a potential medicinal drug. The focus of this study was the possible mechanisms of drug resistance including: expression of resistance proteins, activation of metabolic enzymes, and alteration of the apoptosis and how to overcome their resistance effect on cancer cells. The overall goal of this review was to evaluate how commonly used medicinal plants and their main active secondary metabolites modulate multidrug resistance in cancer cells in order to validate their uses as anticancer drugs, introduce new therapeutic options for resistant cancer, and facilitate the development of their anticancer strategies and/or combination therapies. In conclusion, SMs from medicinal plants exhibit multitarget activity against MDR-related proteins, metabolic enzymes, and apoptotic signaling, this may help to overcome resistance towards chemotherapeutic drugs.展开更多
目的体外HepG2细胞培养观察芒果苷(mangiferin)对多耐药相关蛋白3(multidrug resistance-associate protein 3,MRP3)和核受体孕烷X受体(pregnane X receptor,PXR)、CYP7A启动子结合因子(CYP7A promoter-binding factor,CPF)表达的影响...目的体外HepG2细胞培养观察芒果苷(mangiferin)对多耐药相关蛋白3(multidrug resistance-associate protein 3,MRP3)和核受体孕烷X受体(pregnane X receptor,PXR)、CYP7A启动子结合因子(CYP7A promoter-binding factor,CPF)表达的影响。方法用芒果苷刺激HepG2细胞72 h后,分别抽提细胞RNA、膜蛋白及核蛋白,采用半定量RT-PCR和蛋白免疫印迹检测膜转运蛋白MRP3和核受体PXR、CPF在转录与蛋白水平的表达变化。熊脱氧胆酸(ursode-oxycholic acid,UDCA)处理的HepG2细胞作为阳性对照、DMSO处理细胞为阴性对照。结果芒果苷可显著刺激HepG2细胞膜转运蛋白MRP3的mRNA(比阴性对照组高3.0倍,P<0.05)和蛋白(比阴性对照组高3.3倍,P<0.05)表达,其作用强于UDCA。芒果苷也可明显上调核受体PXR[mRNA水平增高1.7倍(P<0.05),蛋白水平增高3.7倍(P<0.01)]、CPF[mRNA水平增高2.1倍(P<0.05),蛋白水平增高4.9倍(P<0.05)]的表达。结论芒果苷刺激肝癌细胞HepG2细胞膜转运蛋白MRP3的表达上调可能与核受体PXR、CPF途径相关。展开更多
目的:探讨multidrug resistance-related protein 3(MRP3)在胆囊癌中的表达及其与病理指标及预后的关系。方法:应用免疫组化SP法检测50例胆囊癌中MRP3的表达。结果:MRP3呈散在分布的淡黄色或棕褐色颗粒,主要定位于细胞浆中,散见于细胞核...目的:探讨multidrug resistance-related protein 3(MRP3)在胆囊癌中的表达及其与病理指标及预后的关系。方法:应用免疫组化SP法检测50例胆囊癌中MRP3的表达。结果:MRP3呈散在分布的淡黄色或棕褐色颗粒,主要定位于细胞浆中,散见于细胞核中,强阳性表达率为72%。随着转移程度、Nevin分级以及分化程度的增加,强阳性表达率增加,且具有统计学差异(P<0.05)。本组病人总生存期为16.42个月,强阳性表达组病人的总生存期为13.25个月,弱阳性表达组病人的总生存期为22.64个月,两者具有显著性差异(P<0.05)。单因素分析显示总生存期与MRP3的表达、Nevin分级、转移及分化程度有关(P<0.05),多因素分析显示MRP3的表达强弱以及转移是总生存期的独立预后因子(P<0.05)。结论:高表达的MRP3参与了胆囊癌的发生发展,MRP3与胆囊癌的分化、转移有关,可作为判断预后的指标。展开更多
To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hamme...To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hammerhead ribozymes inserted alternatively regularly and the plasmid of pGEM-MDR1/MRP1 used to transcribe the MDR1/MRPl（196/210） substrate containing double target sites was also constructed by DNA recombination. Endonuclease digestion analysis and DNA sequencing indicate all the recombinant plasmids were correct. The clea- vage activities were evaluated for the multi-ribozyme expression system on the MDR1/MRP1 substrate in the cell free system. The results demonstrate that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and the 72 nt of 196Rz and the 71 nt of 210Rz trans-acting hammerhead ribozymes were liberated effectively, and the trans-acting hammerhead ribozymes released were able to act on the MDR1/MRP1 double target RNA substrate and cleave the target RNA at specific sites effectively. The multi- ribozyme expression system of the [Coat＇A196Rz/Coat＇B210Rz]5 is more significantly superior to that of the [Coat＇A 196Rz/Coat＇B210Rz] 1 in cleavage of RNA substrate. The fractions cleaved by [Coat＇A 196Rz/Coat＇B210Rz]5 on the MDR1/MRP1 substrate for 8 h at observed temperatures showed no marked difference. The studies of Mg^2＋ on cleavage efficiency indicate that cleavage reaction is dependent on Mg^2＋ ions concentration. The plot of lg（kobs） vs. lgc（Mg^2＋） displays a linear relationship between 2.5 mmol/L and 20 mmol/L Mg^2＋. It suggests that Mg^2＋ ions play a crucial role in multi-ribozyme cleavage on the substrate.展开更多
基金Supported by Guangxi Scientifi c Research and Technological Development Projects Funding(Ministry Science& Technology of Guangxi,No.0816004-6)
文摘AIM:To evaluate the role of genetic factors in the pathogenesis of idiopathic infant cholestasis.METHODS:We performed a case-control study,in-cluding 78 infants with idiopathic infant cholestasis and 113 healthy infants as controls.Genomic DNA was extracted from peripheral venous blood leukocytes us-ing phenol chloroform methodology.Polymerase chain reaction was used to amplify the multidrug resistance protein 3(MDR3)R652G fragment,and products were sequenced using the ABI 3100 Sequencer.RESULTS:The R652G single nucleotide polymorphism(SNP)was significantly more frequent in healthy infants(allele frequency 8.0%)than in patients(allele frequency 2.60%)(P < 0.05),odds ratio,0.29;95% confidence interval,0.12-0.84.The conjugated bilirubin in patients with the AG genotype was significantly lower than in those with the AA genotype(44.70 ± 6.15 μmol/L vs 95.52 ± 5.93 μmol/L,P < 0.05).CONCLUSION:MDR3 R652G is negatively correlated with idiopathic infant cholestasis.Children with the R652G SNP in Guangxi of China may have reduced susceptibility to infant intrahepatic cholestasis.
文摘Multidrug resistance (MDR) is a critical problem in cancer chemotherapy. Cancer cells can develop resistance not only to a single cytotoxic drug, but also to entire classes of structurally and functionally unrelated compounds. Several mechanisms can mediate the development of MDR, including increased drug efflux from the cells by ABC-transporters (ABCT), activation of metabolic enzymes, and defective pathways towards apoptosis. Many plant secondary metabolites (SMs) can potentially increase sensitivity of drug-resistant cancer cells to chemotherapeutical agents. The present thesis investigates the modulation of MDR by certain medicinal plants and their active compounds. The inhibition of ABCTs (P-gp/MDR1, MRP1, BCRP) and metabolic enzymes (GST and CYP3A4), and the induction of apoptosis are useful indicators of the efficacy of a potential medicinal drug. The focus of this study was the possible mechanisms of drug resistance including: expression of resistance proteins, activation of metabolic enzymes, and alteration of the apoptosis and how to overcome their resistance effect on cancer cells. The overall goal of this review was to evaluate how commonly used medicinal plants and their main active secondary metabolites modulate multidrug resistance in cancer cells in order to validate their uses as anticancer drugs, introduce new therapeutic options for resistant cancer, and facilitate the development of their anticancer strategies and/or combination therapies. In conclusion, SMs from medicinal plants exhibit multitarget activity against MDR-related proteins, metabolic enzymes, and apoptotic signaling, this may help to overcome resistance towards chemotherapeutic drugs.
文摘目的体外HepG2细胞培养观察芒果苷(mangiferin)对多耐药相关蛋白3(multidrug resistance-associate protein 3,MRP3)和核受体孕烷X受体(pregnane X receptor,PXR)、CYP7A启动子结合因子(CYP7A promoter-binding factor,CPF)表达的影响。方法用芒果苷刺激HepG2细胞72 h后,分别抽提细胞RNA、膜蛋白及核蛋白,采用半定量RT-PCR和蛋白免疫印迹检测膜转运蛋白MRP3和核受体PXR、CPF在转录与蛋白水平的表达变化。熊脱氧胆酸(ursode-oxycholic acid,UDCA)处理的HepG2细胞作为阳性对照、DMSO处理细胞为阴性对照。结果芒果苷可显著刺激HepG2细胞膜转运蛋白MRP3的mRNA(比阴性对照组高3.0倍,P<0.05)和蛋白(比阴性对照组高3.3倍,P<0.05)表达,其作用强于UDCA。芒果苷也可明显上调核受体PXR[mRNA水平增高1.7倍(P<0.05),蛋白水平增高3.7倍(P<0.01)]、CPF[mRNA水平增高2.1倍(P<0.05),蛋白水平增高4.9倍(P<0.05)]的表达。结论芒果苷刺激肝癌细胞HepG2细胞膜转运蛋白MRP3的表达上调可能与核受体PXR、CPF途径相关。
文摘目的:探讨multidrug resistance-related protein 3(MRP3)在胆囊癌中的表达及其与病理指标及预后的关系。方法:应用免疫组化SP法检测50例胆囊癌中MRP3的表达。结果:MRP3呈散在分布的淡黄色或棕褐色颗粒,主要定位于细胞浆中,散见于细胞核中,强阳性表达率为72%。随着转移程度、Nevin分级以及分化程度的增加,强阳性表达率增加,且具有统计学差异(P<0.05)。本组病人总生存期为16.42个月,强阳性表达组病人的总生存期为13.25个月,弱阳性表达组病人的总生存期为22.64个月,两者具有显著性差异(P<0.05)。单因素分析显示总生存期与MRP3的表达、Nevin分级、转移及分化程度有关(P<0.05),多因素分析显示MRP3的表达强弱以及转移是总生存期的独立预后因子(P<0.05)。结论:高表达的MRP3参与了胆囊癌的发生发展,MRP3与胆囊癌的分化、转移有关,可作为判断预后的指标。
基金Supported by Fund of Shenzhen Bureau of Science and Technology, China(No.20008).
文摘To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hammerhead ribozymes inserted alternatively regularly and the plasmid of pGEM-MDR1/MRP1 used to transcribe the MDR1/MRPl（196/210） substrate containing double target sites was also constructed by DNA recombination. Endonuclease digestion analysis and DNA sequencing indicate all the recombinant plasmids were correct. The clea- vage activities were evaluated for the multi-ribozyme expression system on the MDR1/MRP1 substrate in the cell free system. The results demonstrate that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and the 72 nt of 196Rz and the 71 nt of 210Rz trans-acting hammerhead ribozymes were liberated effectively, and the trans-acting hammerhead ribozymes released were able to act on the MDR1/MRP1 double target RNA substrate and cleave the target RNA at specific sites effectively. The multi- ribozyme expression system of the [Coat＇A196Rz/Coat＇B210Rz]5 is more significantly superior to that of the [Coat＇A 196Rz/Coat＇B210Rz] 1 in cleavage of RNA substrate. The fractions cleaved by [Coat＇A 196Rz/Coat＇B210Rz]5 on the MDR1/MRP1 substrate for 8 h at observed temperatures showed no marked difference. The studies of Mg^2＋ on cleavage efficiency indicate that cleavage reaction is dependent on Mg^2＋ ions concentration. The plot of lg（kobs） vs. lgc（Mg^2＋） displays a linear relationship between 2.5 mmol/L and 20 mmol/L Mg^2＋. It suggests that Mg^2＋ ions play a crucial role in multi-ribozyme cleavage on the substrate.
