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.

Thioridazine reverses trastuzumab resistance in gastric cancer by inhibiting S-phase kinase associated protein 2-mediated aerobic glycolysis

BACKGROUND Trastuzumab constitutes the fundamental component of initial therapy for patients with advanced human epidermal growth factor receptor 2(HER-2)-positive gastric cancer(GC).However,the efficacy of this treatment is hindered by substantial challenges associated with both primary and acquired drug resistance.While S-phase kinase associated protein 2(Skp2)overexpression has been implicated in the malignant progression of GC,its role in regulating trastuzumab resistance in this context remains uncertain.Despite the numerous studies investigating Skp2 inhibitors among small molecule compounds and natural products,there has been a lack of successful commercialization of drugs specifically targeting Skp2.AIM To discover a Skp2 blocker among currently available medications and develop a therapeutic strategy for HER2-positive GC patients who have experienced progression following trastuzumab-based treatment.METHODS Skp2 exogenous overexpression plasmids and small interfering RNA vectors were utilized to investigate the correlation between Skp2 expression and trastuzumab resistance in GC cells.Q-PCR,western blot,and immunohistochemical analyses were conducted to evaluate the regulatory effect of thioridazine on Skp2 expression.A cell counting kit-8 assay,flow cytometry,a amplex red glucose/glucose oxidase assay kit,and a lactate assay kit were utilized to measure the proliferation,apoptosis,and glycolytic activity of GC cells in vitro.A xenograft model established with human GC in nude mice was used to assess thioridazine's effectiveness in vivo.RESULTS The expression of Skp2 exhibited a negative correlation with the sensitivity of HER2-positive GC cells to trastuzumab.Thioridazine demonstrated the ability to directly bind to Skp2,resulting in a reduction in Skp2 expression at both the transcriptional and translational levels.Moreover,thioridazine effectively inhibited cell proliferation,exhibited antiapoptotic properties,and decreased the glucose uptake rate and lactate production by suppressing Skp2/protein kinase B/mammalian target of rapamycin/glucose transporter type 1 signaling pathways.The combination of thioridazine with either trastuzumab or lapatinib exhibited a more pronounced anticancer effect in vivo,surpassing the efficacy of either monotherapy.CONCLUSION Thioridazine demonstrates promising outcomes in preclinical GC models and offers a novel therapeutic approach for addressing trastuzumab resistance,particularly when used in conjunction with lapatinib.This compound has potential benefits for patients with Skp2-proficient tumors.

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.

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 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.

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.

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.

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.

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。

胃、大肠癌COX-2和多药耐药相关因子表达与体外化疗药敏性的关系及意义

目的探讨胃、大肠癌细胞环氧合酶-2(COX-2)、多药耐药相关因子(P-gp、GST-π、TopoⅡα)表达与体外化疗药敏性的关系及临床意义。方法84例胃癌、大肠癌标本采用免疫组化染色法检测COX-2、P-gp、GST-π、TopoⅡα的表达,进行MTT法体外化疗药物敏感性实验,分析4种因子表达与9种化疗药物对肿瘤细胞抑制率的关系。结果肿瘤COX-2、P-gp、GST-π、TopoⅡα强表达率分别为48.8%、76.2%、78.6%、66.7%;COX-2与P-gp、COX-2与TopoⅡα之间表达具有正相关性(r=0.287、0.256,P均<0.05)。在各因子表达程度与药物对肿瘤细胞抑制率的关系中,COX-2强表达时,紫杉醇(PTX)、表阿霉素(eADM)、羟基喜树碱(OPT)对肿瘤细胞的抑制率降低(t=2.21、3.11、2.09;P均<0.05);P-gp强表达组PTX、奥沙利铂(OXA)、顺铂(DDP)对肿瘤细胞的抑制率低于弱表达组(t=2.54、2.47、2.05;P均<0.05);GST-π强表达与5-氟尿嘧啶(5-Fu)对肿瘤细胞的抑制率降低有关(t=2.13,P<0.05);TopoⅡα强表达时,长春新碱(VCR)、PTX、eADM对肿瘤细胞的抑制率升高(t=-2.29、-2.12、-2.26;P均<0.05)。结论COX-2在胃、大肠癌多药耐药中起一定的作用;COX-2、P-gp、GST-π、TopoⅡα各自表达程度仅与部分化疗药物耐药性有关;胃、大肠癌对化疗药物的耐药性与多种机制有关,仅检测部分多药耐药相关因子的表达不能准确预测化疗药敏性。

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。

葛根芩连汤有效成分对黄芩苷在Caco-2细胞模型中吸收转运的影响

目的采用LC-MS/MS法研究葛根芩连汤(葛根、黄芩、黄连、甘草)有效成分对黄芩苷在Caco-2细胞模型中吸收转运的影响。方法建立Caco-2细胞模型,采用细胞摄取实验和细胞转运实验评价多药耐药相关蛋白(MRP2)的功能。结果摄取实验中,黄芩苷的摄取量在60 min基本达到饱和[(0.68±0.07)ng/μg],加入MRP2抑制剂MK-571之后,黄芩苷的摄取量显著升高[(1.10±0.02)ng/μg,P<0.01],而P-gp转运蛋白抑制剂维拉帕米无此效果。配伍葛根素能提高黄芩苷的摄取量(P<0.05),而小檗碱、甘草苷的作用有统计学意义。细胞转运实验的结果表明,加入MRP2转运蛋白抑制剂后能增加黄芩苷从肠腔侧(AP)到基底侧(BL)侧的转运。配伍葛根素、甘草苷后能促进黄芩苷从AP到BL侧的转运,小檗碱无明显影响。结论 MRP2转运蛋白调控Caco-2细胞摄取吸收黄芩苷,推测其可能为MRP2转运蛋白的底物。葛根素可使在Caco-2细胞中黄芩苷被外排的量减少,从而增加黄芩苷的吸收量。

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。

HAPLN1通过IKK/p65信号通路诱导大肠癌HT-29细胞产生MTX耐药

目的:研究甲氨蝶呤(methotrexate,MTX)耐药前后人大肠癌(结直肠癌)HT-29细胞中透明质酸蛋白聚糖连结蛋白1(hyaluronan and proteoglycan link protein 1,HAPLN1)表达的变化及其对MTX耐药性的影响,并探究可能的分子机制。方法:采用浓度梯度递增法构建耐药细胞株HT-29/MTX;RT-PCR检测HAPLN1和多药耐药相关蛋白2(multidrug resistance-associated protein 2,MRP2)的mRNA表达水平;采用脂质体介导法将人HAPLN1和MRP2基因的干扰质粒转染HT-29/MTX细胞并筛选出稳定表达的细胞系;采用CCK-8法检测细胞活力;流式细胞术检测细胞凋亡;采用Western blot检测HAPLN1、MRP2、IκB激酶(IκB kinase,IKK)α/β、p-IKKα/β(Ser176/Ser177)、p65和p-p65(Ser536)的蛋白水平。结果:HT-29/MTX细胞中HAPLN1和MRP2的mRNA和蛋白表达水平都显著高于其亲代HT-29细胞(P<0.05),耐药倍数高达463.756。抑制HAPLN1和MRP2基因表达使MTX对HT-29/MTX细胞的IC_(50)从15.304μmol/L分别降至6.119μmol/L和7.801μmol/L,逆转倍数分别为2.501和1.962,并增强MTX诱导的细胞凋亡(P<0.05)。敲减HAPLN1基因表达和使用IKK抑制剂IKK16均可下调IKKα/β和p65蛋白磷酸化水平以及MRP2蛋白表达水平(P<0.05),但IKK16未对HAPLN1蛋白表达产生影响(P>0.05)。结论:敲减HAPLN1基因表达可在体外增强人大肠癌耐药细胞株HT-29/MTX对MTX的敏感性,这可能与其抑制IKK/p65信号通路活化,继而下调MRP2基因表达有关。

HO-1与MRP2在原发性胆囊癌组织中的表达和意义

目的:检测血红素加氧酶-1(heme oxygenase,HO-1)与多药耐药相关蛋白2(multidrug resistance-associated protein2,MRP2)在原发性胆囊癌组织中的表达,探讨其与胆囊癌发生、发展的关系。方法:采用免疫组化SP法检测67例原发性胆囊癌患者中HO-1和MRP2的表达水平。结果:原发胆囊癌组织HO-1和MRP2表达的总阳性率分别为73.1%、77.6%。其中腺癌的阳性率为76.7%和80%。依据病理分级,HO-1和MRP2表达水平由高到低分别为III级>II级>I级,且具有统计学差异(P=0.028,P=0.023);HO-1、MRP2的阳性表达与年龄、性别等临床特征无相关性;HO-1和MRP2表达之间具有良好的相关性(r=0.324,P=0.005)。结论:HO-1和MRP2在原发性胆囊癌组织高表达,对胆囊癌的发生、发展提供有利条件,二者之间表达具有良好的相关性。

非小细胞肺癌COX-2的表达与多药耐药性关系的研究

目的:探讨环氧合酶-2(COX-2)在非小细胞肺癌(NSCLC)组织中的表达,并探讨COX-2对多药耐药相关蛋白(MRP)表达的影响。方法:应用免疫组化技术检测62例非小细胞肺癌及10例正常肺组织中COX-2及MRP的表达。结果:正常肺组织未见COX-2及MRP的表达。NSCLC组织中COX-2的阳性表达率为61.3%(37/62),其阳性表达与NSCLC的组织学类型、肺癌组织不同临床分期、有无淋巴结转移、组织分化程度有关,与肺癌患者的性别无关。COX-2阳性组织中MRP的表达阳性率为89.2%(33/37),而COX-2阴性组织中MRP同时阴性率为68.0%(17/25),相关关系分析显示肺癌COX-2表达与多药耐药相关蛋白MRP表达呈显著正相关。结论:COX-2的表达参与NSCLC的发生及恶化进展,并可能调控MRP的表达。

蛇毒精氨酸酯酶Agkihpin对人鼻咽癌CNE-2细胞系MRP1表达的影响

目的探讨蛇毒精氨酸酯酶Agkihpin对人鼻咽癌CNE-2细胞系中多药耐药相关蛋白MRP1表达的影响,并试图阐明Agkihpin抑制CNE-2细胞的机制。方法用不同浓度的Agkihpin处理细胞72h后,应用免疫细胞化学、Western blot、RT-PCR法检测MRP1在CNE-2细胞中的表达。结果不同浓度Agkihpin作用CNE-2细胞72h后MRP1表达均降低,并呈现出一定的浓度依赖效应,显示Agkihpin可显著下调CNE-2细胞中MRP1表达。各加药组与不加Agkihpin组比较,差异具有统计学意义(P<0.05)。结论在人低分化鼻咽癌CNE-2细胞系中,Agkihpin能抑制MRP1的表达,并且随浓度的增大抑制作用增加,这可能是Agkihpin能降低鼻咽癌细胞活力的原因之一;Agkihpin抑制MRP1的表达提示在一定程度上可提高肿瘤细胞对化疗药物的敏感度。

Agkihpin对人肝癌SMMC-7721细胞COX-2、MRP1和E-CD表达的影响

目的探讨蛇毒精氨酸酯酶(Agkihpin)影响人肝癌SMMC-7721细胞活力、增殖和迁移的机制,为肝癌的治疗提供新的思路。方法取对数生长期SMMC-7721细胞随机分为8组,分别用质量浓度为0.207～4.130 g/mL的Agkihpin处理72 h,应用免疫细胞化学、Western blotting、RT-PCR法检测环氧合酶-2(COX-2)、表皮钙黏素(E-CD)和多药耐药相关蛋白1(MRP1)蛋白表达和基因转录水平,分析三指标之间的关系。结果与未行Agkihpin处理者比较,Agkihpin处理的SMMC-7721细胞COX-2基因转录、蛋白表达均降低(P<0.01),并呈一定的浓度依赖效应;COX-2与E-CD的表达和转录均呈负相关,MRP1与E-CD的表达和转录均呈负相关,COX-2与MRP1的表达和转录均呈正相关。结论 Agkihpin可通过下调MRP、COX-2表达及上调E-CD表达抑制人肝癌SMMC-7721细胞的活力、增殖和迁移,有望用于提高肝癌细胞对化疗药物的敏感性、逆转肝癌耐药细胞的多药耐药表型、提高肝癌患者术后生存率、抑制肝癌细胞的浸润和转移。

噻吩诺啡在Caco-2细胞上的转运特征

目的探讨噻吩诺啡在Caco-2细胞上的转运特征及其对P-糖蛋白(P-gp)功能和表达的影响。方法采用高效液相色谱-质谱-质谱法测定噻吩诺啡浓度,研究噻吩诺啡在单层细胞中的双向转运,考察时间及转运蛋白抑制剂对噻吩诺啡在Caco-2细胞上转运的影响;流式细胞仪检测胞内钙黄绿素-AM浓度,评价噻吩诺啡对P-gp的抑制作用;采用Western蛋白印迹法检测P-gp表达。结果噻吩诺啡通过Caco-2单层细胞的转运量在1.5h内随时间延长呈线性增加,表观渗透系数(Papp)2.338×10-6cm.s-1;加入P-gp及多药耐药相关蛋白2(MRP2)抑制剂环孢素A和MK571后分别提高2.8和2.3倍;在噻吩诺啡作用下,胞内钙黄绿素-AM浓度无显著变化,P-gp表达无显著增加。结论噻吩诺啡在Caco-2细胞吸收中等偏差,是P-gp和MRP2的共同底物,噻吩诺啡对P-gp无诱导或抑制作用。