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1.
为观察长期药物筛选对多药抗药性模式的影响,用MDR1cDNA转染了Swiss3T3细胞.秋水仙碱选择培养两个月前后,以MTT方法测定各转化子对阿霉素,长春新碱,秋水仙碱的抗药性,以确定其多药抗药性模式.还测定了维拉帕米对各转化子的增敏效应.在非选择培养液中生长的转化子观察到基本一致的抗药性模式,即对长春新碱高度抗性,对秋水仙碱中度抗性,对阿霉素低度抗性.而在选择培养液中生长两个月后,各转化子的抗药性模式变得参差不齐.结果说明,MDR1基因表达可造成一致的抗药性模式,长期秋水仙碱孵育可改变抗药性模式的均一性.  相似文献   

2.
目的:比较轮环藤碱(Cyc)、海岛轮环藤碱(Insr)和海岛轮环藤酚碱(Insn)与维拉帕米(Ver)体外调节多药耐药性(MDR)的作用。方法:细胞毒试验采用MTT法,细胞内阿霉素(Dox)积累采用荧光分光光度法测定。结果:Cyc,Insr,Insn和Ver在分光光度法测定。结果:Cyc,Insr,Insn和Ver在MDR细胞系MCF-7/Adr和KBv200能显著调节Dox和长春新碱的耐药性具有  相似文献   

3.
比较轮环藤碱(Cyc)、海岛轮环藤碱(Insr)和海岛轮环藤酚碱(Insn)与维拉帕米(Ver)体外调节多药耐药性(MDR)的作用.方法:细胞毒试验采用MTT法,细胞内阿霉素(Dox)积累采用荧光分光光度法测定.结果:Cyc,Insr,Insn和Ver在MDR细胞系MCF7/Adr和KBv200能显著调节Dox和长春新碱的耐药性,且其作用呈剂量依赖性.Cyc,Insr,Insn和Ver均能增加MCF7/Adr细胞内Dox的积累.Cyc和Insr调节MDR作用明显优于Ver,而Insn的作用类似于Ver.结论:Cyc,Insr和Insn能通过增加MDR细胞内Dox的积累而调节MDR.  相似文献   

4.
一种新番荔枝内酯单体atemoyacin—B克服肿瘤多药抗药性   总被引:1,自引:0,他引:1  
目的 探讨atemoyacin-B(Ate)克服肿瘤多药抗药性(MDR)作用及机制。方法 Bullatacin(Bul)为阳性对照物,细胞毒测定以MTT法,Pgp功能测定以Fura2-AM法,细胞内药物积累测定以荧光分光光度计法;细胞凋亡测定以流式细胞仪法,结果:Ate对MCF-7/Dox,MCF-7,KBV200和KB细胞的IC50分别为122,120,1.34,1.27mmol.L^-1,At  相似文献   

5.
粉防己碱逆转肿瘤多药抗药性细胞的凋亡抗性作用   总被引:21,自引:3,他引:21  
目的探讨粉防己碱逆转MDR细胞凋亡抗性的作用及其机制。方法MDR细胞株MCF-7/Adr与其相应的敏感株MCF-7进行对比研究。比较粉防己碱对阿霉素(Dox)诱导MDR细胞及其相应的敏感株的凋亡作用。并比较粉防己碱对MDR细胞及其相应的敏感株的细胞bcl-2蛋白的表达的影响。细胞凋亡及bcl-2蛋白表达的测定以流式细胞仪法。结果加入Dox共同培养24h可诱导74.6%MCF-7细胞凋亡,而只引起14.3%的MCF-7/Adr细胞凋亡。只加入粉防己碱共同培养24h,未见明显增加MDR细胞及其相应敏感细胞的凋亡百分比。Dox+粉防己碱能显著地使MDR细胞的凋亡增至47.0%,与单独用Dox组相比较,差异有显著性(P<0.01),而敏感细胞株为77.8%,与单独用Dox组相比较,差异无显著性(P>0.05)。MDR细胞株与其相应的敏感株bcl-2蛋白表达水平均较低且差异无显著性。加入粉防己碱对MDR细胞株与其相应的敏感株bcl-2蛋白表达水平均未见明显影响。结论粉防己碱能逆转MDR细胞对Dox的凋亡抗性。其逆转机制可能与bcl-2蛋白表达无关。粉防己碱逆转MDR细胞MCR-7/ADR对Dox的凋亡抗性的机制有待进?  相似文献   

6.
目的:研究维生素K3(Men)降低EAC/Dox细胞对阿霉素(Dox)的抗药性.方法:测定谷胱甘肽(GSH),细胞膜流动性及谷胱甘肽S转移酶(GST)活性.细胞存活力以甲基四唑蓝法测定.结果:EAC/Dox细胞GSH,GST及膜流动性均较EAC细胞增加(P<001).Dox对EAC/Dox细胞IC50为223(158-288)mg·L-1.Men5或10mg·L-1可降低EAC/Dox细胞GSH(P<001),1mg·L-1对GSH无影响(P>005),但可降低细胞膜流动性(P<005).Men1,5或10mg·L-1可使DoxIC50降低到9.6(78-113),60(28-92),或53(39-67)mg·L-1(P<001).结论:Men在体外降低EAC/Dox细胞对Dox抗药性与对GSH的耗竭有关.  相似文献   

7.
本文用单克隆抗荧光偏振免疫分析法(MAb-FPLA)与多克隆FPLA法(PC-FPIA)测定肾移植病环孢素(CsA)的全血浓度并进行了比较。49例肾移植术后病人口服不同剂量CsA期间,共监测CsA全血谷浓度65例次。结果表明:表MAb-FPIA法观察浓度40~600ng/ml的范围内,PC-FPIA法的测定结果为110~1700ng/ml,是MAb-FPIA法的1.7~3.9倍。两种方法之间有良好  相似文献   

8.
7-甲氧基-3-苯基香豆素的合成季小慎,严久凤,王雪峰(解放军药物化学研究所,北京102205;中国医药研究开发中心,北京100083)SYNTHESISOF7-METHOXY-3-PHENYLCOUMARIN¥JIXiao-Shen;YANJiu-...  相似文献   

9.
吗丙嗪逆转多药抗药性作用及其分子机制的探讨   总被引:3,自引:0,他引:3  
目的:探讨吗丙嗪逆转肿瘤多药抗药性(MDR)的作用及其机制。方法:以MTT与Fura-2-AM法进行吗丙嗪逆转MDR活性测定;以DPH荧光测定法探讨吗丙嗪对膜脂流动性的影响;以荧光分光光度计法测定吗丙嗪与高钙或低钙对细胞内阿霉素(Dox)积累的影响及Fura-2-AM法测定吗丙嗪对细胞内游离钙离子浓度的影响。结果:在浓度2.5μmol·L-1时,吗丙嗪能显著增加MCF-7/ADR细胞内Fura-2的积累和降低MCF-7/ADR对Dox的IC50而对敏感株MCF-7无明显影响,表明吗丙嗪具有逆转MDR的作用。吗丙嗪能显著增加MDR细胞内Dox积累和降低MDR细胞的膜脂流动性。高钙或低钙对MDR细胞内Dox积累无影响,吗丙嗪也不能改变1997-04-11收稿1中山医科大学中心实验室,广州510089作者简介:符立梧,男,32岁,博士,讲师,主要从事逆转多药抗药性的研究;潘启超,男,67岁,教授,博士生导师,主要从事肿瘤药理与化疗方面的研究MDR细胞内游离钙离子浓度。结论:吗丙嗪有逆转MDR作用。其逆转机制与降低膜脂流动性增加细胞内DOX积累有关,与钙离子浓度无关  相似文献   

10.
用[3H]胸腺嘧啶核苷([3H]TdR)参入法,电镜,免疫组化,原位杂交方法,在自发性高血压大鼠(SHR)观察了粉防己碱(Tet,0.03μmol·kg-1·d-1×8周ig)对血管平滑肌细胞(VSMC)增殖的作用及对生长因子PDGF-B,bFGF的抗原表达及其相关癌基因c-sis,c-mycmRNA表达的影响.结果发现:Tet在降低SHR血压(P<0.01)同时,能减少VSMC的线粒体,粗面内质网和[3H]TdR参入量(P<0.01),并能逆转VSMC增殖时PDGF-B,bFGF抗原(P<0.05)及c-sis,c-mycmRNA的表达增强.提示:Tet抑制SHR的VSMC增殖与生长因子及癌基因调控的分子生物学机制有关  相似文献   

11.
阿霉素和紫杉醇诱发的人乳腺癌耐药细胞株的比较研究   总被引:1,自引:3,他引:1  
目的通过比较研究乳腺癌耐药细胞株的细胞生物学特性,探讨不同化疗药物诱发的多药耐药细胞模型的共性。方法以人乳腺癌细胞株MCF-7为亲本细胞,采用阿霉素(Adriamycin,Adr)及紫杉醇(Taxol,Tax)低浓度持续加量诱导法建立了多药耐药的人乳腺癌细胞株MCF-7Adr及MCF-7Tax。SRB法测定细胞生长曲线、半数致死浓度(IC50)、耐药指数(RF)和耐药谱;显微镜观察细胞形态,FCM分析细胞动力学周期,免疫组化检测细胞表型变化;Hoechst33342染色分析侧群细胞(side population,sp)比例。结果MCF-7Adr及MCF-7Tax细胞较MCF-7亲本细胞对相应药物的IC50提高500倍,撤药培养100 d后RF仍维持在150倍以上,并对多种化疗药物产生交叉耐药性;耐药细胞分化程度低于同步传代的亲本细胞,细胞倍增时间与亲本细胞接近,但S期细胞明显增加,G1期细胞减少,且随着撤药时间的延长,耐药细胞的增殖速度加快;耐药细胞P-gP、LRP和GSTπ的表达水平较亲本细胞有明显增加,ER阳性表达丢失;耐药细胞中SP细胞比例明显增高。结论MCF-7Adr和MCF-7Tax具有多药耐药细胞的基本生物学共性,两者均可作为研究MDR机制的耐药细胞模型。  相似文献   

12.
为观察长期药物筛选对多药抗药性模式的影响,用MDR1 cDNA转染了Swiss 3T3细胞. 秋水仙碱选择培养两个月前后,以MTT方法测定各转化子对阿霉素,长春新碱,秋水仙碱的抗药性,以确定其多药抗药性模式. 还测定了维拉帕米对各转化子的增敏效应. 在非选择培养液中生长的转化子观察到基本一致的抗药性模式,即对长春新碱高度抗性,对秋水仙碱中度抗性,对阿霉素低度抗性. 而在选择培养液中生长两个月后,各转化子的抗药性模式变得参差不齐. 结果说明,MDR1基因表达可造成一致的抗药性模式,长期秋水仙碱孵育可改变抗药性模式的均一性.  相似文献   

13.
1.?The expression and function of P-glycoprotein (P-gp) is associated with the phenotype of multidrug resistance (MDR). Saikosaponin A (SSA) is a triterpenoid saponin isolated from Radix Bupleuri. This study was mainly designed to understand effects of SSA on MDR in MCF-7/ADR and HepG2/ADM cells.

2.?MDR reversal was examined as the alteration of cytotoxic drugs IC50 in resistant cells in the presence of SSA by MTT assay, and was compared with the non-resistant cells. Apoptosis and uptake of P-gp substrates in the tumor cells were detected by flow cytometry. Western blot was performed to assay the expression of P-gp.

3.?Our results demonstrate SSA could increase the chemosensitivity of P-gp overexpressing HepG2/ADM and MCF-7/ADR cells to doxorubicin (DOX), vincristine (VCR) and paclitaxel. SSA promoted apoptosis of MCF-7/ADR cells in the presence of DOX. Moreover, it could also increase the retention of P-gp substrates DOX and rhodamine 123 in MCF-7/ADR cells, and decrease digoxin efflux ratio in Caco-2 cell monolayer. Finally, a mechanistic study showed that SSA reduced P-gp expression without affecting hydrolytic activity of P-gp.

4.?In conclusion, our findings suggest that SSA could be further developed for sensitizing resistant cancer cells and used as an adjuvant therapy together with anticancer drugs to improve their therapeutic efficacies.  相似文献   

14.
Doxorubicin (adriamycin) preconditioned S180 cells were more resistant to doxorubicin. The resistance was detected by three different methods (short-term test, colony assay, tissue culture assay). The doxorubicin-resistant S180 cells express the pleitrop drug resistance phenotype. There exists a multidrug resistance to doxorubicin, dactinomycin (actinomycin D), vincristine and colchicine. In addition, collateral sensitivity was found to fluorouracil (5-fluorouracil) and methotrexate. This multidrug phenotype is in accordance with the pleiotropic phenotype of colchicine-resistant CHO cells. Resistant S180 cells express a glycoprotein of Mr 170 kd determined by indirect immunofluorescence using a monoclonal antibody (Mab 265/F4) to the P-glycoprotein of colchicine-resistant CHO-cells. The P-glycoprotein could be an important prognostic factors for tumors with multidrug resistance.  相似文献   

15.
目的:评价市售阿霉素脂质体体外逆转肿瘤多药耐药(MDR)的作用。方法:MTT法比较阿霉素和阿霉素脂质体体外对敏感和耐药细胞的细胞毒作用;荧光显微镜观察2组药物对敏感和耐药细胞的影响;流式细胞仪检测2组分别在细胞内的积累和外排情况。结果:细胞毒性试验结果显示,尽管在敏感细胞中,阿霉素脂质体IC50远高于阿霉素溶液组,对于耐药细胞株,阿霉素脂质体的IC50与游离阿霉素无显著性差异(P>0.05);细胞荧光染色显示,阿霉素脂质体较溶液在耐药细胞核中有更强的红染;细胞摄取试验显示,相同浓度下,阿霉素脂质体较溶液组在耐药细胞中积累量差异无显著性(P>0.05),但外排试验显示,在耐药细胞KBv200中,相同浓度下的脂质体较溶液具有更强的细胞滞留能力(P<0.05)。结论:阿霉素脂质体较阿霉素溶液在体外能更多进入耐药细胞核,并表现出更强的药物滞留能力,可部分克服多药耐药。  相似文献   

16.
Summary Purpose: DDB (dimethyl-4,4′-dimethoxy-5,6,5′6′-dimethylene dioxybiphenyl-2,2′-dicarboxylate) is a synthetic hepatoprotectant which has been widely used to treat chronic viral hepatitis B patients in China for more than 20 years. In this study, we evaluated DDB as a multidrug resistance (MDR) chemosensitizing agent. Methods: A panel of sensitive and resistant cancer cell lines were treated with various concentration of DDB, and the effect on chemosensitivity and accumulation of anticancer drugs; promotion of apoptosis and P-glycoprotein (P-gp) expression were determined by MTT (Dimethyl thiazolyl-2,5-diphenyltetrazolium bromide) assay, fluorospectrometry and flow cytometry respectively. Drug resistance reversal activity of DDB was also examined in BALB/c nude mice bearing both acquired MDR human nasopharyngeal carcinoma KBv200 and parental KB xenografts. The effect of DDB on the pharmacokinetics of Dox and hematological toxicity induced by Dox was measured in ICR and C57/BL mice, respectively. Results: DDB at nontoxic concentrations of 12.5, 25 and 50 μM partly reversed the resistance to vincristine, doxorubicin, paclitaxel in acquired MDR breast carcinoma MCF-7/Adr cells, KBv200 and intrinsic MDR human hepatocarcinoma Bel7402 cells, whereas no chemosensitizing effect of DDB was observed in sensitive KB and MCF-7 cells. DDB increased the intracellular accumulation of doxorubicin and inhibited surface P-gp expression in MCF-7/Adr cells. Furthermore, it was found that DDB promoted doxorubicin-induced apoptosis of Bel7402 cells through enhanced caspase-3 activation. Co-administration of DDB at 300 and 500 mg/kg orally to nude mice increased the antitumor activity of vincristine to KBv200 xenografts without a significant increase in toxicity. In contrast, Co-administration of DDB did not inhibit the growth of KB xenografts. DDB also markedly reduced the decrease of leukocytes in doxorubicin-treated C57/BL mice. Co-administration of DDB increased Dox concentration in ICR mice bearing S180 sarcoma, but no pharmacokinetical interaction with Dox was observed. Conclusion: These results indicate that DDB has MDR reversal activity by inhibiting P-gp and when used in combination with anti-cancer drugs, it could potentially be used as a clinical treatment for P-gp-mediated MDR cancers.  相似文献   

17.
Overexpression of P-glycoprotein (P-gp) by tumours results in multidrug resistance (MDR) to structurally and functionally unrelated chemotherapeutic drugs. Combined therapy with MDR-related cytotoxins and MDR modulators is a promising strategy to overcome clinical MDR. This study was performed to explore the MDR reversal activity of a novel compound 2-[4-(2-pyridin-2-yl-vinyl) phenyl]-4,5-bis-(4-N,N-diethylaminophenyl)-1(H)-imidazole (FG020318) in-vitro and in-vivo. Tetrazolium (MTT) assay was used to evaluate the ability of FG020318 to reverse drug resistance in two P-gp-expressing tumour cell lines, KBv200 and MCF-7/adr. Intracellular doxorubicin accumulation was determined by fluorescence spectrophotometry in MCF-7/adr cell line. The effect of FG020318 on P-gp function was demonstrated by rhodamine 123 (Rh123) accumulation in KBv200 cells. KBv200 cell xenograft models were established to study the in-vivo effect of FG020318 on reversing MDR. FG020318 was not cytotoxic by itself against P-gp expressing KBv200 cells and MCF-7/adr cells and their parental drug-sensitive KB cells and MCF-7 cells. FG020318 could significantly increase the sensitivity of MDR cells to antitumour drugs including doxorubicin and vincristine in MCF-7/adr cells and KBv200 cells, respectively. It was much stronger than the positive control verapamil in reversal of MDR. FG020318 also increased the intracellular accumulation of doxorubicin in a concentration-dependent manner in MCF-7/adr cells, but did not affect the accumulation of doxorubicin in drug-sensitive MCF-7 cells. The Rh123 accumulation in resistant KBv200 cells was also increased by the addition of FG020318, but Rh123 accumulation was not affected by FG020318 in drug-sensitive KB cells. FG020318 potentiated the antitumour activity of vincristine to KBv200 xenografts and was an efficacious modulator in-vivo. Our results suggested that FG020318 was a highly potent, efficacious MDR modulator not only in-vitro but also in-vivo. The reversal of drug resistance by FG020318 was probably related to the increased anticancer drug accumulation and its inhibition of P-gp function of MDR tumour cells.  相似文献   

18.
田晖  潘启超 《药学学报》1997,32(4):245-250
比较了2种结构相近的双苄基异喹啉(BBI)生物碱粉防己碱(TTD)、小檗胺(BBM)与维拉帕米(VRP)逆转多药抗药性的作用。结果,TTD,BBM和VRP在多药抗药的MCF-7/Adr和KBv200细胞对ADR和VCR均有明显增敏作用,且作用呈剂量依赖性。其中10μmol·L-1TTD能完全逆转MCF-7/Adr细胞对ADR的抗药性。TTD,BBM和VRP均有增加MCF-7/Adr细胞内阿霉素积累的作用。TTD和BBM在结构上仅有微小差别,但TTD的逆转MDR作用优于VRP10倍,而BBM的作用与VRP相仿。TTD在裸鼠体内MCF-7/Adr实体瘤模型上也证实有明显逆转ADR抗药性的作用。  相似文献   

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