Objective: To evaluate the expression and clinical significance of multidrug resistance gene (mdr1) and multidrug resistance-associated protein (MRP) gene in acute leukemia. Methods: The expression of mdr1 and MRP ass...Objective: To evaluate the expression and clinical significance of multidrug resistance gene (mdr1) and multidrug resistance-associated protein (MRP) gene in acute leukemia. Methods: The expression of mdr1 and MRP assay in 55 patients with acute leukemia (AL) by reverse transcription polymerase chain reaction (RT-PCR). Results: The mdr1 and MRP gene expression levels in the relapsed AL and the blastic plastic phases of CML were significantly higher than those in the newly diagnostic AL and controls. The mdr1 and MRP gene expression levels in the clinical drug-resistant group were significantly higher than those in the non-drug-resistant group. The complete remission (CR) rate in patients with high mdr1 expression (14.3%) was significantly lower than that with low mdr1 expression (57.5%); similarly the CR rate in patients with high MRP level was also lower than that with low MRP level. Using both high expression of mdr1 and MRP gene as the indicator for evaluating multidrug resistance (MDR), the positive predictive value and accuracy increased in comparison with single gene high expression. Conclusion: Elevated level of mdr1 or MRP gene expression might be unfavorable prognostic factors for AL patient and may be used as an important index for predicting drug-resistance and relapse in AL patient. Measuring both mdr1 and MRP gene expression would increase accuracy and sensibility of evaluating MDR in acute leukemia.展开更多
Objective: To investigate the relationship between the expression of multidrug resistance-associated protein (MRP) and clinicopathological factors and prognosis. Methods: The expression of MRP in 62 cases with non-sma...Objective: To investigate the relationship between the expression of multidrug resistance-associated protein (MRP) and clinicopathological factors and prognosis. Methods: The expression of MRP in 62 cases with non-small cell lung cancer (NSCLC) was detected using immunohistochemistry method. The expression of MRP in 30 cases of NSCLC and corresponding normal lung tissues were detected using immunohistochemistry and Western Blot. Results: this study of tumor tissues confirmed the plasma membrane and/or cytoplasm locations of MRP. There was apparent difference between normal lung tissues and NSCLC in MRP. The survival analysis of 62 NSCLC showed that the mean survival time of the patients with negative MRP expression was 69.8117.41 months and that of patients with positive MRP expression, 25.384.46 months. Log-rank test suggested that the difference between them was significant (P=0.0156). It was also found that in squamous cell lung cancer the statistically significant difference between the mean survival time of patients with positive MRP expression and those with negative MRP expression (P=0.0153). Multivariate Cox model analysis suggested that the survival time was significantly related to expression of MRP (P=0.035) and lymphatic metastasis (P=0.038). Conclusion: MRP expression in NSCLC is significantly higher compared with normal lung tissues. The mean survival time of patients with negative MRP was relative longer and expression of MRP was an independent factor for prognosis.展开更多
Objective To investigate the expression and meaning of MRP3 in different tumor cells. MethodsThe monoclonal antibody against MRP3 was used to identify the expression of MRP3 by flow cytometer in seven tumor cells and ...Objective To investigate the expression and meaning of MRP3 in different tumor cells. MethodsThe monoclonal antibody against MRP3 was used to identify the expression of MRP3 by flow cytometer in seven tumor cells and human embryo kidney cell lines 293T.And RT-PCR was used to detect the mRNA of MRP3 in eight cell lines. ResultsThe mRNA of MRP3 was expressed in three pancreatic carcinoma cell lines.MRP3 protein was observed in BxPC-3 and AsPC-1 cells. ConclusionMRP3 may express in different tumor in tissue-specific manner.BxPC-3 and AsPC-1 may serve as cellular models for in vitro studies on multidrug resistance of pancreatic carcinoma.展开更多
BACKGROUND:Multidrug resistance(MDR)is extremely common in hepatocellular carcinoma(HCC)and is a major problem in cancer eradication by limiting the efficacy of chemotherapy.Modulation of c-Jun NH2-terminal kinase(JNK...BACKGROUND:Multidrug resistance(MDR)is extremely common in hepatocellular carcinoma(HCC)and is a major problem in cancer eradication by limiting the efficacy of chemotherapy.Modulation of c-Jun NH2-terminal kinase(JNK)activation could be a new method to reverse MDR.However,the relationship between JNK activity and MDR in HCC cells is unknown.This study aimed to explore the relationship between MDR and JNK in HCC cell lines with different degrees of MDR.METHODS:A MDR human HCC cell line,SMMC-7721/ ADM,was developed by exposing parental cells to gradually increasing concentrations of adriamycin.The MTT assay was used to determine drug sensitivity.Flow cytometry was used to analyze the cell cycle distribution and to measure the expression levels of P-glycoprotein(P-gp)and MDR-related protein(MRP)-1 in these cells.JNK1,JNK2 and JNK3 mRNA expression levels were quantified by real-time PCR.Expression and phosphorylation of JNK1,JNK2,and JNK3 were analyzed by Western blotting.RESULTS:The MDR of SMMC-7721/ADM cells resistant to 0.05 mg/L adriamycin was mainly attributed to the overexpression of P-gp but not MRP1.In addition,these cells had a significant increase in percentage in the S phase,accompanied by a decrease in percentage in the G0/G1 phase,which is likely associated with a reduced ability for cell proliferation and MDR generation.We found that JNK1,JNK2,and JNK3 activities were negatively correlated with the degree of MDR in HCC cells.CONCLUSION:This study suggests that JNK1,JNK2,and JNK3 activities are negatively correlated with the degree of MDR in HCC cells.展开更多
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
AIM： To study the expression and phosphorylation of extracellular signal-regulated kinase （ERK） i and ERK2 in multidrug resistant （MDR） hepatocellular carcinoma （HCC） cells.METHODS： MDR HCC cell lines, HepG2/a...AIM： To study the expression and phosphorylation of extracellular signal-regulated kinase （ERK） i and ERK2 in multidrug resistant （MDR） hepatocellular carcinoma （HCC） cells.METHODS： MDR HCC cell lines, HepG2/adriamycin （ADM） and SMMC7721/ADM, were developed by exposing parental cells to stepwise increasing concentrations of ADM. MTT assay was used to determine drug sensitivity. Flow cytometry was employed to analyze cell cycle distribution and measure cell P-glycoprotein （P-gp） and multidrug resistant protein 1 （MRP1） expression levels. ERK1 and ERK2 mRNA expression lev-ls were measured by quantitative real-time PCR （QRTPCR）. Expression and phosphorylation of ERK1 and ERK2 were analyzed by Western blot.RESULTS： MTT assay showed that HepG2/ADM andSMMC7721/ADM were resistant not only to ADM, but also to multiple anticancer drugs. The P-gp expression was over 10-fold higher in HepG2/ADM cells than in HepG2 cells （8.92% ±0.22% vs 0.88% ± 0.05%, P 〈 0.001） and over 4-fold higher in SMMC7721/ADM cells than in SMMC7721 cells （7.37% ± 0.26% vs 1.74% ± 0.25%, P 〈 0.001）. However, the MRP1 expression was not significantly higher in HepG2/ADM and SMMC7721/ADM cells than in parental cells. In addition, the percentage of MDR HepG2/ADM and SMMC7721/ADM cells was significantly decreased in the G0/G1 phase and increased in the the S phase or G2/M phase. QRT-PCR analysis demonstrated that the ERK1 and ERK2 mRNA expression increased apparently in HepG2/ADM cells and decreased significantly in SMMC7721/ADM cells. Compared with the expression of parental cells, ERK1 and ERK2 protein expressions were markedly decreased in SMMC7721/ADM cells. However, ERK2 protein expression was markedly increased while ERK1 protein expression had no significant change in HepG2/ADM cells. Phosphorylation of ERK1 and ERK2 was markedly decreased in both HepG2/ADM and SMMC7721/ADM MDR cells.CONCLUSION： ERK1 and ERK2 activities are downregulated in P-gp-mediated MDR HCC cells. ERK1 or ERK2 might be a potential drug target for circumventing MDR HCC cells,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
To study the effects of hypoxia on the expression of P-gp and mutltidrug resistance protein in human lung adenocarcinoma A549 cell line, and to explore the probable mechanism of hypoxia in tumor cell of MDR. The expre...To study the effects of hypoxia on the expression of P-gp and mutltidrug resistance protein in human lung adenocarcinoma A549 cell line, and to explore the probable mechanism of hypoxia in tumor cell of MDR. The expression of hypoxia inducible factor-1α, P-gp and mutltidrug resistance protein was immunohistochemically detected by culturing human lung adenocarcinoma A549 cell under hypoxia (2 % O_2) for 24 h. After interaction with adriamycin or cisplatin under hypoxia (2 % O_2) for 24 h, the cell survival rate was detected by MTT. Our results showed that the expression of hypoxia inducible factor-1α, P-gp and mutltidrug resistance protein under hypoxia were higher than the expression under normoxia, and correlations between the expression of HIF-1α and P-gp or multidrug resistance-associated protein was observed (P<0.05). The resistance of adriamycin of A549 cell was enhanced under hypoxia. It is concluded that the resistance of tumor chemotherapy is enhanced in hypoxia. The expression of HIF-1α is obviously correlated with the expression of P-gp and mutltidrug resistance protein.展开更多
Multidrug resistance-associated proteins （MRPs） can effiux structurally diverse drugs, drug conjugates, drug metabolites, as well as other small molecules out of the cells, and this is the main cause of producing mu...Multidrug resistance-associated proteins （MRPs） can effiux structurally diverse drugs, drug conjugates, drug metabolites, as well as other small molecules out of the cells, and this is the main cause of producing multidrug resistance （MDR） of some anticaneer drugs. Therefore, it is crucial to uncover the molecular features of MRPs substrates in developing anti-MDR cancer therapy. In the present study, common feature pharmacophore models were developed by employing CATALYST Pharmacophore Modeling and Analysis tools using substrates of MRPs, including MRP1, -2, -3, -4, -5, -6, -8 and MRPs family, respectively. The models were validated using independent decoy sets generated in DUD-E, and the ones with best A UC （area under the curve） scores were chosen to predict endogenous substrates by screening the Human Metabolome Database （HMDB）. A number of molecules obtained by pharmacophore screening have been validated in the literatures. By comparing physical properties （ALOGP, Molecular_PolarSurfaceArea, Molecular_Volume, Molecular_Weight, Num H Acceptors, Num H Donors） and scaffold features of the screened candidates with the known substrates, we found that： 1） The two sets have consistent ALOGP, Molecule_Volume and Molecule_Weight distribution trend; 2） Substrates of MRP1 have a better lipophilicity than the other subtypes, which is consistent with the two hydrophobic centers on the MRP1 pharmacophore; 3） In the aspect of the scaffold structures, they have the identical or similar backbone fragments.展开更多
Background： Placental multidrug resistance-associated protein 2 （MRP2）, encoded by ABCC2 gene in human, plays a significant role in regulating drugs＇ transplacental transfer rates. Studies o11 placental MRP2 regul...Background： Placental multidrug resistance-associated protein 2 （MRP2）, encoded by ABCC2 gene in human, plays a significant role in regulating drugs＇ transplacental transfer rates. Studies o11 placental MRP2 regulation could provide more therapeutic targets for individualized and safe pharmacotherapy during pregnancy. Currently, the roles of epigenetic mechanisms in regulating placental drug transporters are still unclear. This study aimed to investigate the effect of histone deacetylases （HDACs） inhibition on MRP2 expression in the placental trophoblast cell line and to explore whether HDAC 1/2/3 are preliminarily involved in this process. Methods： The human choriocarcinoma-derived trophoblast cell line （Bewo cells） was treated with the HDAC inhibitors-trichostatin A （TSA） at different concentration gradients of 0.5, 1.0, 3.0, and 5.0 μmol/L. Cells were harvested after 24 and 48 h treatment. Small interfering RNA （siRNA） specific for HDACI/HDAC2/HDAC3 or control siRNA was transfected into cells. Total HDAC activity was detected by colorimetric assay kits. HDAC 1/2/3/ABCC2 messenger RNA （mRNA） and protein expressions were determined by real-time quantitative polymerase chain reaction and Western-blot analysis, respectively. Immunofluorescence for MRP2 protein expression was visualized and assessed using an immunofluorescence microscopy and ImageJ software, respectively. Results： TSA could inhibit total HDAC activity and HDAC 1/2/3 expression in company with increase ofM RP2 expression in Bewo cells. Reduction of HDAC 1 protein level was noted after 24 h of TSA incubation at 1.0, 3.0, and 5.0 μmol/L （vs. vehicle group, all P 〈 0.001 ）, accompanied with dose-dependent induction of MRP2 expression （P = 0.045 for 1.0 μmol/L, P = 0.001 for 3.0 μmol/L, and P 〈 0.001 for 5.0 μmol/L）, whereas no significant diferences in MRP2 expression were noted after HDAC2/3 silencing. Fluorescent micrograph images of MRP2 protein were expressed on the cell membrane. The fluorescent intensities of MRP2 in the control, HDAC2, and HDAC3 siRNA-transfected cells weir week, and no significant differences were noticed among these three groups （all P 〉 0.05）. However, MRP2 expression was remarkably elevated in H DAC1 siRNA-transfected cells, which displayed an almost 3.19-fold changes in comparison with the control siRNA-transfected cells （P 〈 0.001 ）. Conclusions： HDACs inhibition could up-regulate placental MRP2 expression in ritzy, and HDAC 1 was probably to be involved in this process.展开更多
文摘Objective: To evaluate the expression and clinical significance of multidrug resistance gene (mdr1) and multidrug resistance-associated protein (MRP) gene in acute leukemia. Methods: The expression of mdr1 and MRP assay in 55 patients with acute leukemia (AL) by reverse transcription polymerase chain reaction (RT-PCR). Results: The mdr1 and MRP gene expression levels in the relapsed AL and the blastic plastic phases of CML were significantly higher than those in the newly diagnostic AL and controls. The mdr1 and MRP gene expression levels in the clinical drug-resistant group were significantly higher than those in the non-drug-resistant group. The complete remission (CR) rate in patients with high mdr1 expression (14.3%) was significantly lower than that with low mdr1 expression (57.5%); similarly the CR rate in patients with high MRP level was also lower than that with low MRP level. Using both high expression of mdr1 and MRP gene as the indicator for evaluating multidrug resistance (MDR), the positive predictive value and accuracy increased in comparison with single gene high expression. Conclusion: Elevated level of mdr1 or MRP gene expression might be unfavorable prognostic factors for AL patient and may be used as an important index for predicting drug-resistance and relapse in AL patient. Measuring both mdr1 and MRP gene expression would increase accuracy and sensibility of evaluating MDR in acute leukemia.
文摘Objective: To investigate the relationship between the expression of multidrug resistance-associated protein (MRP) and clinicopathological factors and prognosis. Methods: The expression of MRP in 62 cases with non-small cell lung cancer (NSCLC) was detected using immunohistochemistry method. The expression of MRP in 30 cases of NSCLC and corresponding normal lung tissues were detected using immunohistochemistry and Western Blot. Results: this study of tumor tissues confirmed the plasma membrane and/or cytoplasm locations of MRP. There was apparent difference between normal lung tissues and NSCLC in MRP. The survival analysis of 62 NSCLC showed that the mean survival time of the patients with negative MRP expression was 69.8117.41 months and that of patients with positive MRP expression, 25.384.46 months. Log-rank test suggested that the difference between them was significant (P=0.0156). It was also found that in squamous cell lung cancer the statistically significant difference between the mean survival time of patients with positive MRP expression and those with negative MRP expression (P=0.0153). Multivariate Cox model analysis suggested that the survival time was significantly related to expression of MRP (P=0.035) and lymphatic metastasis (P=0.038). Conclusion: MRP expression in NSCLC is significantly higher compared with normal lung tissues. The mean survival time of patients with negative MRP was relative longer and expression of MRP was an independent factor for prognosis.
文摘Objective To investigate the expression and meaning of MRP3 in different tumor cells. MethodsThe monoclonal antibody against MRP3 was used to identify the expression of MRP3 by flow cytometer in seven tumor cells and human embryo kidney cell lines 293T.And RT-PCR was used to detect the mRNA of MRP3 in eight cell lines. ResultsThe mRNA of MRP3 was expressed in three pancreatic carcinoma cell lines.MRP3 protein was observed in BxPC-3 and AsPC-1 cells. ConclusionMRP3 may express in different tumor in tissue-specific manner.BxPC-3 and AsPC-1 may serve as cellular models for in vitro studies on multidrug resistance of pancreatic carcinoma.
基金supported by grants from the Medical Innovation Fundation of Fujian Province(No.2007-CXB-7)the Natural Science Foundation of Fujian Province(No.2009D010)
文摘BACKGROUND:Multidrug resistance(MDR)is extremely common in hepatocellular carcinoma(HCC)and is a major problem in cancer eradication by limiting the efficacy of chemotherapy.Modulation of c-Jun NH2-terminal kinase(JNK)activation could be a new method to reverse MDR.However,the relationship between JNK activity and MDR in HCC cells is unknown.This study aimed to explore the relationship between MDR and JNK in HCC cell lines with different degrees of MDR.METHODS:A MDR human HCC cell line,SMMC-7721/ ADM,was developed by exposing parental cells to gradually increasing concentrations of adriamycin.The MTT assay was used to determine drug sensitivity.Flow cytometry was used to analyze the cell cycle distribution and to measure the expression levels of P-glycoprotein(P-gp)and MDR-related protein(MRP)-1 in these cells.JNK1,JNK2 and JNK3 mRNA expression levels were quantified by real-time PCR.Expression and phosphorylation of JNK1,JNK2,and JNK3 were analyzed by Western blotting.RESULTS:The MDR of SMMC-7721/ADM cells resistant to 0.05 mg/L adriamycin was mainly attributed to the overexpression of P-gp but not MRP1.In addition,these cells had a significant increase in percentage in the S phase,accompanied by a decrease in percentage in the G0/G1 phase,which is likely associated with a reduced ability for cell proliferation and MDR generation.We found that JNK1,JNK2,and JNK3 activities were negatively correlated with the degree of MDR in HCC cells.CONCLUSION:This study suggests that JNK1,JNK2,and JNK3 activities are negatively correlated with the degree of MDR in HCC cells.
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.
基金Supported by Innovation Fund of Fujian Province,No.2007-CXB-7Key Science and Technology Project of Xiamen,No.3502Z20077045
文摘AIM： To study the expression and phosphorylation of extracellular signal-regulated kinase （ERK） i and ERK2 in multidrug resistant （MDR） hepatocellular carcinoma （HCC） cells.METHODS： MDR HCC cell lines, HepG2/adriamycin （ADM） and SMMC7721/ADM, were developed by exposing parental cells to stepwise increasing concentrations of ADM. MTT assay was used to determine drug sensitivity. Flow cytometry was employed to analyze cell cycle distribution and measure cell P-glycoprotein （P-gp） and multidrug resistant protein 1 （MRP1） expression levels. ERK1 and ERK2 mRNA expression lev-ls were measured by quantitative real-time PCR （QRTPCR）. Expression and phosphorylation of ERK1 and ERK2 were analyzed by Western blot.RESULTS： MTT assay showed that HepG2/ADM andSMMC7721/ADM were resistant not only to ADM, but also to multiple anticancer drugs. The P-gp expression was over 10-fold higher in HepG2/ADM cells than in HepG2 cells （8.92% ±0.22% vs 0.88% ± 0.05%, P 〈 0.001） and over 4-fold higher in SMMC7721/ADM cells than in SMMC7721 cells （7.37% ± 0.26% vs 1.74% ± 0.25%, P 〈 0.001）. However, the MRP1 expression was not significantly higher in HepG2/ADM and SMMC7721/ADM cells than in parental cells. In addition, the percentage of MDR HepG2/ADM and SMMC7721/ADM cells was significantly decreased in the G0/G1 phase and increased in the the S phase or G2/M phase. QRT-PCR analysis demonstrated that the ERK1 and ERK2 mRNA expression increased apparently in HepG2/ADM cells and decreased significantly in SMMC7721/ADM cells. Compared with the expression of parental cells, ERK1 and ERK2 protein expressions were markedly decreased in SMMC7721/ADM cells. However, ERK2 protein expression was markedly increased while ERK1 protein expression had no significant change in HepG2/ADM cells. Phosphorylation of ERK1 and ERK2 was markedly decreased in both HepG2/ADM and SMMC7721/ADM MDR cells.CONCLUSION： ERK1 and ERK2 activities are downregulated in P-gp-mediated MDR HCC cells. ERK1 or ERK2 might be a potential drug target for circumventing MDR HCC cells,
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To study the effects of hypoxia on the expression of P-gp and mutltidrug resistance protein in human lung adenocarcinoma A549 cell line, and to explore the probable mechanism of hypoxia in tumor cell of MDR. The expression of hypoxia inducible factor-1α, P-gp and mutltidrug resistance protein was immunohistochemically detected by culturing human lung adenocarcinoma A549 cell under hypoxia (2 % O_2) for 24 h. After interaction with adriamycin or cisplatin under hypoxia (2 % O_2) for 24 h, the cell survival rate was detected by MTT. Our results showed that the expression of hypoxia inducible factor-1α, P-gp and mutltidrug resistance protein under hypoxia were higher than the expression under normoxia, and correlations between the expression of HIF-1α and P-gp or multidrug resistance-associated protein was observed (P<0.05). The resistance of adriamycin of A549 cell was enhanced under hypoxia. It is concluded that the resistance of tumor chemotherapy is enhanced in hypoxia. The expression of HIF-1α is obviously correlated with the expression of P-gp and mutltidrug resistance protein.
基金The National Natural Science Foundation of China(Grant No.21272017 and 21572010)
文摘Multidrug resistance-associated proteins （MRPs） can effiux structurally diverse drugs, drug conjugates, drug metabolites, as well as other small molecules out of the cells, and this is the main cause of producing multidrug resistance （MDR） of some anticaneer drugs. Therefore, it is crucial to uncover the molecular features of MRPs substrates in developing anti-MDR cancer therapy. In the present study, common feature pharmacophore models were developed by employing CATALYST Pharmacophore Modeling and Analysis tools using substrates of MRPs, including MRP1, -2, -3, -4, -5, -6, -8 and MRPs family, respectively. The models were validated using independent decoy sets generated in DUD-E, and the ones with best A UC （area under the curve） scores were chosen to predict endogenous substrates by screening the Human Metabolome Database （HMDB）. A number of molecules obtained by pharmacophore screening have been validated in the literatures. By comparing physical properties （ALOGP, Molecular_PolarSurfaceArea, Molecular_Volume, Molecular_Weight, Num H Acceptors, Num H Donors） and scaffold features of the screened candidates with the known substrates, we found that： 1） The two sets have consistent ALOGP, Molecule_Volume and Molecule_Weight distribution trend; 2） Substrates of MRP1 have a better lipophilicity than the other subtypes, which is consistent with the two hydrophobic centers on the MRP1 pharmacophore; 3） In the aspect of the scaffold structures, they have the identical or similar backbone fragments.
文摘Background： Placental multidrug resistance-associated protein 2 （MRP2）, encoded by ABCC2 gene in human, plays a significant role in regulating drugs＇ transplacental transfer rates. Studies o11 placental MRP2 regulation could provide more therapeutic targets for individualized and safe pharmacotherapy during pregnancy. Currently, the roles of epigenetic mechanisms in regulating placental drug transporters are still unclear. This study aimed to investigate the effect of histone deacetylases （HDACs） inhibition on MRP2 expression in the placental trophoblast cell line and to explore whether HDAC 1/2/3 are preliminarily involved in this process. Methods： The human choriocarcinoma-derived trophoblast cell line （Bewo cells） was treated with the HDAC inhibitors-trichostatin A （TSA） at different concentration gradients of 0.5, 1.0, 3.0, and 5.0 μmol/L. Cells were harvested after 24 and 48 h treatment. Small interfering RNA （siRNA） specific for HDACI/HDAC2/HDAC3 or control siRNA was transfected into cells. Total HDAC activity was detected by colorimetric assay kits. HDAC 1/2/3/ABCC2 messenger RNA （mRNA） and protein expressions were determined by real-time quantitative polymerase chain reaction and Western-blot analysis, respectively. Immunofluorescence for MRP2 protein expression was visualized and assessed using an immunofluorescence microscopy and ImageJ software, respectively. Results： TSA could inhibit total HDAC activity and HDAC 1/2/3 expression in company with increase ofM RP2 expression in Bewo cells. Reduction of HDAC 1 protein level was noted after 24 h of TSA incubation at 1.0, 3.0, and 5.0 μmol/L （vs. vehicle group, all P 〈 0.001 ）, accompanied with dose-dependent induction of MRP2 expression （P = 0.045 for 1.0 μmol/L, P = 0.001 for 3.0 μmol/L, and P 〈 0.001 for 5.0 μmol/L）, whereas no significant diferences in MRP2 expression were noted after HDAC2/3 silencing. Fluorescent micrograph images of MRP2 protein were expressed on the cell membrane. The fluorescent intensities of MRP2 in the control, HDAC2, and HDAC3 siRNA-transfected cells weir week, and no significant differences were noticed among these three groups （all P 〉 0.05）. However, MRP2 expression was remarkably elevated in H DAC1 siRNA-transfected cells, which displayed an almost 3.19-fold changes in comparison with the control siRNA-transfected cells （P 〈 0.001 ）. Conclusions： HDACs inhibition could up-regulate placental MRP2 expression in ritzy, and HDAC 1 was probably to be involved in this process.
