EXPRESSION OF MULTIDRUG RESISTANCE-ASSOCIATED PROTEIN IN HUMAN GASTRIC AND RENAL CARCINOMAS

Objective The clinical signilicance of exPression of multidrug resistance- associated protein (MRP) in gastric and renal carcinoma was investigated. Methods LSAB immunohistochemistry was performed to detect eopression of MRP in the carcinoma tissues of 52 patients with gastric carcinoma and 20 cases with renal cell carcinoma. Results The positive expression rate of MRP was 38.5% (20/52) in gastric carcinoma tissues, and 60% (12/20) in renal carcinoma tissues. The expression of MRP both on cellular membrane and in cytoplasm was observed, but the expression in cytoplasm (thick granule) was more obvious. The positive expression rates of MRP in advanced gastric and renal carcinoma (Ⅲ orⅣ stage) were 60% (15/25) and 88.90% (8/9) reSPectively, which were higher than those in early lesion (Ⅰ or Ⅱ stage, 18.5% and 36.4% respectively). Furthermore, the patients with positive expression of MRP in gastric carcinoma tissues had shorter mean survival time and lower 5-year survival rate than that with negative eopression of MRP. Conclusion MRP plays an important role in the infiltration and metastasis of gastric and renal carcinoma and might contribute to the intrinsic drug - resistance in both carcinomas.

EXPRESSION AND CLINICAL SIGNIFICANCE OF MULTIDRUG RESISTANCE GENE AND MULTIDRUG RESISTANCE-ASSOCIATEDPROTEIN GENE IN ACUTE LEUKEMIA

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.

EXPRESSION OF MULTIDRUG RESISTANCE-ASSOCIATED PROTEIN (MRP) AND ITS RELATIONSHIP WITH CLINICOPATHOLOGICAL FACTORS IN NON-SMALL CELL LUNG CANCER

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.

Expression and significance of multi-drug resistance-associated protein 3 in different tumor cell lines

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.

JNK1,JNK2,and JNK3 are involved in P-glycoprotein-mediated multidrug resistance of hepatocellular carcinoma cells

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.

Expression of multidrug resistance proteins in retinoblastoma

AIM： To elucidate the mechanism of multidrug resistance in retinoblastoma, and to acquire more insights into in vivo drug resistance.METHODS： Three anticancer drug resistant Y79 human RB cells were generated against vincristine, etoposide or carboplatin, which are used for conventional chemotherapy in RB. Primary cultures from enucleated eyes after chemotherapy（PCNC） were also prepared. Their chemosensitivity to chemotherapeutic agents（vincristine, etoposide and carboplatin） were measured using MTT assay. Western blot analysis was performed to evaluate the expression of p53, Bcl-2 and various multidrug resistant proteins in retinoblastoma cells.RESULTS： Following exposure to chemotherapeutic drugs, PCNC showed less sensitivity to drugs. No significant changes observed in the p53 expression, whereas Bcl-2 expression was found to be increased in the drug resistant cells as well as in PCNC. Increased expression of P-glycoprotein（P-gp） was observed in drug resistant Y79 cells; however there was no significant change in the expression of P-gp found between primary cultures of primarily enucleated eyes and PCNC. Multidrug resistance protein 1（Mrp-1） expression was found to be elevated in the drug resistant Y79 cells as well as in PCNC. No significant change in the expression of lung resistance associatedprotein（Lrp） was observed in the drug resistant Y79 cells as well as in PCNC.CONCLUSION： Our results suggest that multidrug resistant proteins are intrinsically present in retinoblastoma which causes treatment failure in managing retinoblastoma with chemotherapy.

Effects of Hypoxia on Expression of P-gp and Mutltidrug Resistance Protein in Human Lung Adenocarcinoma A549 Cell Line

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.

Effect of Histone Deacetylase Inhibition on the Expression of Multidrug Resistance-associated Protein 2 in a Human Placental Trophoblast Cell Line

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.

A549肺腺癌多细胞球体药敏实验、Mdr1、MRP表达以及^(99m)Tc-MIBI摄取研究

目的探讨A549肺腺癌多细胞球体的多药耐药基因(mdr1)和多药耐药相关蛋白(MRP)基因表达,甲氧基异丁基异腈(MIBI)摄取结果能否预测化疗效果。方法①血浆高峰浓度的化疗药物顺铂(DDP)、长春花碱酰胺(VDS)、氟尿嘧啶(5-氟尿嘧啶,5-FU)、羟喜树碱(HCP)、丝裂霉素(MMC)、多柔比星(阿霉素,ADM)分别进行药物敏感性实验。②单层贴壁细胞培养。96孔板1个,每组4孔,2×104细胞/孔。③MTT检测观察疗效。细胞加化疗药后培养48h,然后加MTT5mg/mL,每孔20μL,4h后用酶标仪(490nm)测量吸光度值。④RT-PCR检测A549细胞和MCF-7耐药株的mdr1和MRP表达,β2-MG作内参照。⑤96孔板内每孔一个球体,每孔掺入99mTc-MIBI9.25×104Bq(2.5μCi),分别于60和120min结束掺入并测量γ计数。结果①A549细胞药敏实验对DDP不敏感,对MMC、VDS、ADM、5-FU、HCP敏感。②MCF-7长春新碱耐药株(MCF-7/VCR)对DDP、VDS不敏感,对MMC、ADM、5-FU和HCP较敏感。③A549细胞及球体的Mdr1/β2-MG为0,MRP/β2-MG分别为0.76和0.62;MCF-7耐药细胞的mdr1/β2-MG和MRP/β2-MG分别为35和4.36。④A549多细胞球体对99mTc-MIBI120min的摄取值高于60min摄取值(P<0.05)。结论A549多细胞球体的mdr1和MRP表达水平较低以及MIBI摄取阳性提示无多药耐药性产生,与化疗药物敏感性检测结果基本一致。A549细胞对DDP耐药说明除mdr1和MRP之外,还存在与转运蛋白间接相关的其他耐药机制。

肺癌组织中耐药相关蛋白和p53 bcl-2表达及其意义

目的:探讨肺癌组织中耐药相关蛋白和p53、bcl-2表达及其意义。方法:应用免疫组化技术检测治疗前73例肺癌组织标本中P-gp、MRP、LRP、GST-π、p53和bcl-2表达。结果:非小细胞肺癌组P-gp、LRP、MRP+LRP、P-gp+p53的蛋白表达明显高于小细胞肺癌组(P<0.05)。腺癌组MRP、LRP、MRP+LRP、MRP+LRP+GST-π、MRP+LRP+P-gp+GST-π蛋白阳性表达高于鳞状细胞癌组、小细胞肺癌组(P<0.05),MRP+GST-π共表达者高于鳞状细胞癌组(P<0.01),P-gp+p53共表达者高于小细胞肺癌组(P<0.05),bcl-2蛋白阳性表达低于鳞状细胞癌组、小细胞肺癌组(P<0.05)。鳞状细胞癌组P-gp、P-gp+p53、P-gp+bcl-2的蛋白表达明显高于小细胞肺癌组(P<0.05)。P-gp与p53、bcl-2蛋白阳性表达呈正相关(P<0.05)。p53与bcl-2蛋白阳性表达呈正相关(P<0.01)。MRP与GST-π蛋白阳性表达呈正相关(P<0.05)。结论:肺癌耐药为一多途径多基因参与的过程,P-gp、LRP、MRP、GST-π、p53、bcl-2表达及其共表达可作为监测肺癌细胞原发性耐药的指标。

多药耐药相关蛋白及P-糖蛋白在胃癌组织中表达的意义

目的 :分析多药耐药相关蛋白 (multidrug resistance associated protein,MRP)、P-糖蛋白 (P- gp)在胃癌组织中表达 ,研究其与胃癌生物学行为及预后的关系。方法 :采用免疫组化法检测 5 3例胃癌组织 MRP、P- gp表达的情况 ,分析其与相关临床资料的关系。结果 :MRP、P- gp表达与临床分期、浸润深度、组织学类型无关。MRP表达与淋巴结转移显著相关 (P <0 .0 1)。 MRP、P- gp表达与 5年生存率无关。结论 :MRP在胃癌组织中的单一表达能一定程度上反映胃癌的生物学行为。 MRP、P-

P-糖蛋白、多药耐药相关蛋白在胃癌的表达与化疗敏感性的相关性研究

目的:探讨胃癌组织中P-糖蛋白(P-glycoprotein,P-gp)、多药耐药相关蛋白(multidrugresis-tance-associatedprotein,MRP)的表达及对胃癌原代细胞培养体外化疗药物敏感性的影响。方法:应用免疫组化法检测P-gp及MRP在48例胃癌及癌旁组织的表达,同时通过胃癌原代细胞培养MTT药敏试验,检测胃癌对7种临床常用化疗药物的敏感性及耐药性,进一步分析药敏试验结果与P-gp、MRP表达的相关性。结果:在48例胃癌中,P-gp及MRP阳性率分别为41.7%、29.2%,共同表达率为25.0%。癌旁组织与癌组织的P-gp、MRP阳性表达率无显著差异。在顺铂(DDP)、丝裂霉素(MMC)、阿霉素(ADM)、鬼臼乙叉甙(VP-16)、5-氟尿嘧啶(5-FU)、羟基喜树碱(HCPT)、甲氨蝶呤(MTX)中,ADM、VP-16、HCPT耐药组P-gp、MRP阳性表达及共表达率较敏感组显著升高。结论:胃癌组织P-gp、MRP表达可导致胃癌原发性耐药。P-gp、MRP介导的MDR是ADM、VP-16、HCPT耐药的重要因素。

NF-κB信号通路介导结肠癌多细胞耐药的作用研究

目的探讨NF-κB信号通路在结肠癌HT-29细胞多细胞耐药中的作用及可能机制。方法采用液体重叠培养系统和常规贴壁法对HT-29细胞进行三维(3D)和单层(2D)培养。采用倒置相差显微镜、扫描电镜观察3D培养的HT-29细胞形态,并采用免疫组化法检测增殖细胞核抗原(PCNA)的表达。电泳迁移率改变测定法(EMSA)测定3D和2D培养细胞中NF-κB的活性差异。将3D培养细胞分为两组:3D组(培养液中不加干扰因素)和3D+SN50组(培养液中加入50μg/ml SN50处理24h),采用EMSA测定两组NF-κB活性差异,TUNEL法检测细胞凋亡,Western blotting检测凋亡相关蛋白(Caspase-3、Bcl-2和Bax)的表达并对蛋白条带的光密度值进行半定量分析,外生半径测定法测定3D培养细胞对氟尿嘧啶的敏感性。结果3D培养的HT-29细胞悬浮生长,细胞相互聚集增殖形成多细胞球,中心为坏死区,周围由多层异型性细胞组成,外围细胞PCNA阳性染色明显。与2D培养细胞相比,3D细胞中NF-κB活性条带颜色较深。EMSA显示3D+SN50组NF-κB活性较3D组低,TUNEL法显示3D组细胞凋亡率(8.71%±0.73%)较3D+SN50组(15.75%±1.02%)明显降低(P<0.01)。3D+SN50组和3D组中,Caspase-3活化片段光密度值分别为126.79±13.48和87.24±10.68(P<0.01),Bax蛋白为129.73±15.28和89.26±14.31(P<0.01),Bcl-2蛋白为97.27±12.63和131.24±14.53(P<0.01)。结论NF-κB活性升高是导致结肠癌HT-29细胞多细胞耐药的重要原因之一,其机制可能与凋亡相关蛋白的表达调控有关。

P-gp、MRP、LRP、P53及c-erbB-2在非小细胞肺癌中的表达

目的:探讨P糖蛋白(P-gp)、多药耐药相关蛋白(MRP)、肺耐药蛋白(LRP)、P53蛋白及c-erbB-2蛋白在术前未经治疗的非小细胞肺癌(NSCLC)中的表达及相互间的关系。方法:采用免疫组化法检测78例NSCLC癌组织及15例癌旁肺组织(距癌灶5 cm)中P-gp、MRP、LRP、P53及c-erbB-2的蛋白表达情况。结果:免疫组化显示P-gp、MRP、LRP、P53及c-erbB-2在肺癌组织中的阳性表达率分别是65.4%(51/78)、39.7%(31/78)、56.4%(44/78)、53.8%(42/78)及43.6%(34/78),均显著高于癌旁肺组织中的表达水平(P<0.05);MRP和LRP蛋白表达在不同病理类型(腺癌、鳞癌及大细胞癌)之间比较均具有显著性差异(P分别为0.008和<0.001),LRP及P53蛋白表达在不同病理分化程度之间具有显著性差异(P分别为0.025和0.026);c-erbB-2表达与P-gp、MRP、LRP、P53均有相关性(Spearman相关系数分别为0.317、0.401、0.519和0.341,P值分别为0.005、<0.001、<0.001和0.002),P53与MRP之间(Spearman相关系数为=0.260,P=0.022)以及LRP与MRP之间(Spearman相关系数为0.371,P=0.001)有相关性。结论:P-gp、MRP、LRP、P53及c-erbB-2这些蛋白的表达在NSCLC的多药耐药形成及肿瘤的发生发展中可能具有一定的协同作用。

食管、贲门癌组织中P-糖蛋白与多药耐药相关蛋白的表达

目的:检测食管癌、贲门癌组织中P-糖蛋白(P-gp)和多药耐药相关蛋白(MRP)的表达。方法:应用免疫组化方法检测50例食管癌、50例贲门癌及各自相应癌旁正常组织中P-gp和MRP的表达。结果:食管癌与相应癌旁正常组织中P-gp的阳性表达率分别为2%,2%,而MRP为76%和42%;贲门癌与相应癌旁正常组织中P-gp的阳性表达率为54%,30%,而MRP为42%与20%。食管癌组织中MRP的表达、贲门癌组织中P-gp和MRP的表达均高于相应癌旁组织(P<0.05)。MRP与食管癌的分化程度有关,P-gp与MRP与贲门癌的分化程度有关(P均<0.05)。2者与食管癌或贲门癌的浸润深度、淋巴结转移均无关(P>0.05)。食管贲门癌组织中MRP与P-gp的表达无相关性(rs=0.173,P>0.05)。结论:食管癌的多药耐药与MRP有关;而贲门癌的多药耐药则为P-gp和MRP共同参与。P-gp和MRP可反映食管贲门癌的分化程度,但不能反映其浸润和转移等生物学特征。

多药耐药相关蛋白在阿霉素诱导人肝癌细胞SMMC-7721耐药性产生中的作用及机理

目的 动态观察阿霉素 (ADM )诱导肝癌细胞SMMC 772 1耐药性的产生 ,了解多药耐药相关蛋白 (MRP)在其耐药机理中的作用。方法 分别用逐步提高培养基中ADM的浓度诱导SMMC 772 1细胞和用含不同ADM浓度的培养基直接短期培养SMMC 772 1细胞的方法 ,诱导细胞产生耐药性 ,绘制剂量反应曲线 ,确定细胞耐药倍数 ,RT PCR法测定细胞MRPmRNA的表达水平 ,流式细胞仪检测细胞内柔红霉素 (DNR)的浓度。结果 随着培养基中ADM浓度的逐步提高 ,MRPmRNA的表达也逐渐增强 ,细胞内DNR浓度明显下降 ,SMMC 772 1细胞的耐药性逐渐增加 ;用含不同ADM浓度的培养基直接培养亲代细胞后 ,虽然MRPmRNA表达明显升高 ,但细胞内DNR浓度仍维持较高水平 ,并且绝大部分细胞短期内死亡。结论 ADM可以逐步诱导肝癌细胞产生耐药性 ,其机理主要是由于MRP基因过度表达 ,其蛋白产物能明显降低细胞内化疗药物浓度 ,从而细胞获得耐药性。

急性髓性白血病的多药耐药基因-1 C3435T基因多态性与P-gp表达的相关性研究

目的:研究急性髓性白血病(acute myeloid leukaemia,AML)患者的多药耐药基因(multidrug resistance,MDR)-1C3435T基因多态性和P-gp(permeability-glycoprotein)蛋白表达的相关性。方法:采用流式细胞仪测定P-gp表达水平,限制性内切酶多型性—聚合酶链反应测定MDR-1C3435T多态性,并统计其相关性。结果:中国AML患者中MDR-13435基因座上的多态性有自己的分布特点,MDR-13435TT和低P-gp表达显著相关。结论:黄种人AML患者中MDR-13435基因座上的多态性有与白种人不同的分布特点,可能为不同种族的AML患者对相同的化疗药物有效率却不同的原因之一;MDR-13435TT有望预测AML患者化疗敏感程度较其他携带者高,可能可以作为良性预后因素之一。

汉防己甲素与5-溴汉防己甲素逆转耐药机制与降低MRP7表达水平有关(英文)

本研究的目的是探索汉防己甲素(Tet)与5-溴汉防己甲素(BrTet)逆转耐药的机制是否与调节多药耐药相关蛋白7(MRP7)表达水平有关。采用MTT法检测柔红霉素(DNR)对人白血病敏感细胞株K562与人白血病耐药细胞株K562/A02细胞增殖的抑制作用,计算半数抑制浓度(IC50)及耐药倍数。将细胞分组,加入BrTet、Tet,用实时PCR法检测细胞MRP7 mRNA表达,Western bolt法检测细胞MRP7蛋白和P-糖蛋白(P-gp)的表达,流式细胞术检测细胞内DNR蓄积。结果表明:K562/A02对DNR的耐药倍数为23.65倍。分别加入1μmol/L Tet与2.0μmol/L BrTet后,K562/A02细胞的MRP7 mRNA相对表达水平分别降低至2%和12%,MRP7蛋白表达降低了53.2%与83.7%,P-gp表达分别下调58.47%与52.20%;1.0μmol/L Tet与2.0μmol/L BrTet分别使K562/A02细胞内DNR提高了94.32%与271%。结论:BrTet与Tet均可逆转耐药,其逆转机制除了抑制P-gp的表达之外,还可能与抑制MRP7的表达,增加肿瘤细胞内抗肿瘤药物浓度有关。在相同摩尔浓度下,Tet与BrTet对MRP7表达的下调作用无显著性差异。

非小细胞肺癌组织中MRP1 mRNA和GST-π mRNA的表达及意义

目的:探讨多药耐药相关蛋白MRP1和谷胱甘肽-S-转移酶(GST-π)在非小细胞肺癌(Non-small cell lung cancer,NSCLC)组织中的表达水平以及与肺癌生物学特性的关系。方法:RT-PCR、凝胶电泳-积分光密度IOD比值半定量法检测MRP1 mRNA和GST-π mRNA在36例NSCLC组织和12例癌旁组织中的表达,并分析它们在TNM分期中的表达情况。结果:MRP1和GST-π在NSCLC(83·3%、88·9%)和癌旁组织中(75·0%、83·3%)表达阳性率均差异无统计学意义,P值分别为0·135和0·413;MRP1 mRNA和GST-π mRNA在NSCLC组织中的表达(IOD比值分别为0·7403、1·2679)明显高于在癌旁组织(IOD比值分别为0·2013、0·4217),均P=0·000;二者在各T分期中的表达均差异无统计学意义,P值均>0·05;二者在有淋巴结转移组(IOD比值分别为0·8496、1·3874)和有远端转移组中的表达(IOD比值分别为0·9583、1·5790)均明显高于无淋巴结转移组(IOD比值=分别为0·6591、1·0571)和无远处转移组(IOD比值分别为0·6553、1·1109),P值分别为0·047、0·021、0·042和0·015。结论:对MRP1和GST-π mRNA的联合检测有助于临床预测预后及指导化疗的个体化用药。