屈洛昔芬对K562耐阿霉素细胞株耐药性的逆转作用(英文)

目的:研究屈洛昔芬(DRO)对耐阿霉素(ADR)K562细胞株(K562/A02)多药耐药性(MDR)的逆转作用及逆转机制。方法:用DRO分别处理K562/A02和K562敏感株。MTT法观察DRO影响K562/A02对ADR化学敏感性的变化。DRO 10μmol/L处理K562/A02前后,通过RT-PCR和免疫细胞化学染色,分析MDR1、GSTπ基因表达的变化,采用流式细胞技术测定细胞内ADR浓度的变化。结果:DRO显著逆转K562/A02的MDR,在20、10和5μmol/L浓度时,对ADR的化学敏感性分别增加到14、13和4倍,逆转活性与维拉帕米相当。MDR1和GSTπ的mRNA和蛋白表达在DRO 10μmol/L处理后第2天开始下降,第5天明显降低。用20、10和5μmol/L浓度的DRO处理两株细胞,K562/A02细胞内ADR积累分别增加到2.9、2.3和1.5倍。但DRO不能明显增加K562细胞内的ADR的浓度。结论:DRO对K562/A02的MDR有较强的逆转活性,逆转强度与维拉帕米相当,其逆转机制有多种不同的途径。     

双苄基异喹啉类生物碱粉防己碱与小檗胺逆转多药抗药性的比较研究

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。     

补骨脂素逆转多药耐药细胞系K562/ADR耐药性研究

目的　研究补骨脂素对白血病细胞阿霉素耐药株(K5 6 2 /ADR)多药耐药 (multidrugresistance,MDR)性的逆转作用及其机制。方法　采用MTT法检测药物细胞毒性作用 ,高效液相色谱法检测细胞内阿霉素 (ADR)的浓度 ,流式细胞术测定细胞P 糖蛋白 (P gp)的表达。 结果　补骨脂素 (1～ 2 0 μmol·L-1)能不同程度地降低ADR对K5 6 2 /ADR细胞的IC50 。 2 0 μmol·L-1能显著提高ADR在K5 6 2 /ADR细胞内的浓度 ,降低K5 6 2 /ADR细胞P gp的表达。 结论　补骨脂素能逆转K5 6 2 /ADR细胞的MDR ,其机制与抑制P gp的功能及其表达 ,增加细胞内ADR的积累有关     

一种新番荔枝内酯单体atemoyacin-B克服肿瘤多药抗药性(英文)

目的:探讨atemoyacin-B(Ate)克服肿瘤多药抗药性(MDR)作用及其机制,方法:Bullatacin(Bul)为阳性对照物,细胞毒测定以MTT法;P-gp功能测定以Fura 2-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,KBvzoo和KB细胞的IC_(50)分别为122,120,1.34,1.27 nmol·L~(-1),Ate显著增加MDR细胞内Fura-2及多柔比星(Dox)的积累,但不增加相应敏感细胞的细胞内Fura-2及Dox的积累,Ate也能诱导MDR细胞凋亡.结论:MDR细胞对Ate同样敏感,不受抗药性影响,其机制与降低P-gp功能及增加细胞内药物积累有关。     

屈洛苷芬对K562耐阿霉素细胞株耐药性的逆转作用

目的：研究屈洛昔芬（DRO）对耐阿霉素（ADR）K562细胞株（K562／A02)多药耐药性（MDR）的逆转作用及逆转机制。方法：用DRO分别处理K562／A02和K562敏感株。MTT法观察DRO影响K562／A02对ADR化学敏感性的变化。DRO 10μmol/L处理K562／A02前后,通过RT－PCR和免疫细胞化学染色,分析MDR1、GSTπ基因表达的变化,采用流式细胞技术测定细胞内ADR浓度的变化。结果：DRO显著逆转K562／A02的MDR,在20,10和5μmol/L浓度时,对ADR的化学敏感性分别增加到14、13和4倍,逆转活性与维拉帕米相当。MDR1和GSTπ的mRNA和蛋白表达在DRO 10μmol/L处理后第2天开始下降,第5天明显降低。用20、10和5μmol/L浓度的DRO处理两株细胞,K562／A02细胞内ADR积累分别增加到2．9、2．3和1．5倍。但DRO不能明显增加K562细胞内的ADR的浓度。结论：DRO对K562／A02的MDR有较强的逆转活性,逆转强度与维拉帕米相当,其逆转机制有多种不同的途径。     

环氧化酶-2选择性抑制剂逆转MCF-7/ADR细胞多药耐药的实验研究

目的 研究环氧化酶-2(COX-2)选择性抑制剂Celecoxib对人乳腺癌细胞系MCF-7/ADR的多药耐药(MDR)逆转作用.方法 采用四甲基偶氮唑蓝(MTT)法测定Celecoxib对MCF-7/ADR细胞的无毒剂量,并检测在此剂量下的耐药细胞逆转倍数;荧光分光光度法测定Celecoxib对细胞内阿霉素(ADM)荧光强度的影响.结果 无毒剂量的Celecoxib(1×10-3 μmol/L)可显著降低ADM对MCF-7/ADR的半数抑制浓度(IC50),逆转耐药倍数为1.91倍.Celecoxib能够提高MDR细胞内ADM荧光强度.结论 Celecoxib具有逆转人乳腺癌MCF-7/ADR多药耐药性的作用,可能与增加MDR细胞内化疗药物聚集量有关.     

Bullatacin克服肿瘤多药抗药性作用及其机理

目的：探讨bullatacin克服肿瘤多药抗药性(MDR)的作用及其机制。方法：以两对MDR细胞株及其相应的敏感株进行对比,比较两种细胞株的细胞毒、Fura-2及阿霉素细胞内积累。结果：bullatacin不仅对敏感细胞株具有很强的细胞毒活性,而且对MDR细胞株也同样具有很强的细胞毒活性,不受抗药性的影响。bullatacin能使MDR细胞内Fura-2的积累增加;也能增加MDR细胞内阿霉素的积累。结论：bullatacin具有克服MDR的作用,其作用机理与bullatacin影响MDR细胞P-gp的功能,使MDR细胞内抗癌药物积累增加有关。     

单抗导向阿霉素免疫毫微粒抗肝癌作用的机制

目的　研究抗人肝癌单克隆抗体HAb18为导向载体的阿霉素 (ADR )人体白蛋白 (HSA)免疫毫微粒HAb18 ADR HSA NP抗肝癌作用的机制。方法　利用激光共聚焦仪和透射电镜观察HAb18 ADR HSA NP在人肝癌细胞SMMC 772 1中的内化作用 ,通过扫描电镜和透射电镜观察HAb18 ADR HSA NP对SMMC 772 1多药耐药株 (SMMC 772 1/MDR+ )的结合和内化现象 ,采用四甲基偶氮唑蓝比色法测定HAb18 ADR HSA NP对SMMC 772 1及其耐药细胞的杀伤作用。结果　HAb18 ADR HSA NP在SMMC 772 1细胞中存在内化现象 ,且该内化与温度有关 ,具抗体特异性。同时 ,HAb18 ADR HSA NP在SMMC 772 1/MDR+ 表面结合 ,并能内化 ;且其能增强SMMC 772 1/MDR+ 对ADR杀伤的敏感性。结论　HAb18 ADR HSA NP抗肝癌作用的机制是其内化释药杀伤机制     

三氧化二砷对胃癌细胞SGC7901/ADR GST-π和TopoⅡ表达的影响

目的探讨三氧化二砷(As2O3)对胃癌细胞SGC7901/ADR阿霉素(ADM)耐药性的逆转作用和对GSTπ和TopoⅡ表达的影响。方法用MTT法检测As2O3的非细胞毒性浓度和SGC7901/ADR细胞对ADM的敏感性,用流式细胞仪检测细胞内药物浓度及用免疫组织化学法检测细胞GSTπ和TopoⅡ的表达。结果与结论0.4~0.8μmol.L-1As2O3对耐药细胞SGC7901/ADR无明显毒性(P<0.01),As2O3可下调GSTπ表达,提高SGC7901/ADR细胞内ADM浓度,部分逆转SGC7901/ADR细胞对ADM的耐药性。     

冬凌草甲素逆转SGC7901/ADR细胞的多药耐药性及其机制

目的 观察冬凌草甲素(Ori)对胃癌细胞株SGC7901/ADR多药耐药性的逆转及其作用机制.方法 用MTT法检测Ori的非细胞毒浓度及对SGC7901/ADR细胞株阿霉素敏感性的影响;免疫荧光法检测Ori对SGC7901/ADR细胞p-糖蛋白(P-gp)活性及表达的影响;RT-PCR法检测Ori对细胞MDR1基因转录的影响.结果 用Ori无毒剂量处理细胞后,细胞对阿霉素的逆转倍数为4.53,MDR1基因的转录降低了0.78,P-gp的表达率降低了18.83％.结论 Ori能逆转SGC7901/ADR细胞的多药耐药性,其机制为降低MDR1基因的转录和下调P-gp的表达.     

他莫昔芬体外降低EAC/ADR细胞对阿霉素的耐药性

目的研究他莫昔芬体外降低EAC／ADR细胞对阿霉素耐药性的作用及耐药性与细胞膜流动性的相关性。方法细胞内谷胱甘肽含量及细胞膜流动性分别以荧光分光光度法及荧光偏振法测定，细胞存活力以甲基四唑蓝法测定。结果EAC／ADR细胞膜流动性及谷胱甘肽含量均比敏感EAC细胞明显提高。他莫昔芬2mg·L-1及5mg·L-1不影响EAC／ADR细胞谷胱甘肽含量（P＞0.05），但可明显降低其细胞膜流动性（P＜0.05）。他莫昔芬2mg·L-1或5mg·L-1与阿霉素体外合用于EAC／ADR细胞可降低其对阿霉素的耐药性，同时发现他莫昔芬不影响阿霉素对敏感EAC细胞的毒性。结论EAC／ADR细胞膜流动性增加与其对阿霉素的耐药性有着密切关系，他莫昔芬在降低EAC／ADR细胞膜流动性的同时降低细胞对阿霉素的耐药性。     

胡桃醌对肿瘤细胞的增殖抑制作用和抗菌作用

本文主要探讨胡桃醌对部分移植性肿瘤细胞增殖作用的影响。经72h的作用结果表明,胡桃醌对不同肿瘤细胞的增殖抑制浓度分别为:HeLa Cell IC_(50) 13.8μg/ml,P388 CellIC_(50) 9.8μg/ml,P388/ADR Cell IC_(50) 7.1μg/ml,S180 Cell IC_(50) 11.6μg/ml. 从胡桃醌对S_(180)细胞的增殖抑制作用,可以得出该化合物的作用方式有,杀伤细胞与浓度的依赖关系。     

干扰素与维拉帕米逆转乳腺癌细胞耐药作用的研究

目的:研究α-干扰素与维拉帕米对体外培养的乳腺癌细胞多药耐药(MDR)的逆转作用。方法:以对药物敏感的人乳腺癌细胞系MCF-7和经阿霉素(ADM)诱导具有MDR表型的人乳腺癌耐药细胞系MCF-7/ADR为体外试验模型,分别单用及联用α-干扰素与维拉帕米对细胞系进行处理,MTT法检测各组细胞存活率,计算半数抑制浓度(IC50)、耐药倍数和逆转倍数;流式细胞术定量检测细胞表面P-170的表达。结果:α-干扰素与维拉帕米联用后使乳腺癌细胞耐ADM的IC50降低为0.32μmol·L-1,优于二者单用(2.29、1.23μmol·L-1),逆转倍数升高到51.88(二者单用为7.25、13.49),P-170表达低于二者单用。结论:单独应用α-干扰素、维拉帕米均可达到部分逆转MCF-7/ADR对ADM的耐药作用,但二者联用效果更强。     

Inhibition of P-glycoprotein by natural products in human breast cancer cells

Multidrug resistance (MDR) is one of the most significant obstacles in cancer chemotherapy. One of the mechanisms involved in the development of MDR is the over-expression of P-glycoprotein (P-gp). It is widely known that natural compounds found in vegetables, fruits, plant-derived beverages and herbal dietary supplements not only have anticancer properties, but may also modulate P-gp activity. Therefore, the purpose of this investigation was to examine the effects of naturally occurring products on P-gp function in human breast cancer cell lines, MCF-7 (sensitive) and MCF-7/ADR (resistant). The accumulation of daunomycin (DNM), a P-gp substrate, was greater in the sensitive cells compared to the resistant cells, while the efflux of DNM was higher in the resistant cells compared to the sensitive cells over a period of 2 h. The IC50 value of DNM in the resistant cells was about 22 times higher than that in the sensitive cells, indicating an over-expression of P-gp in the resistant cells, MCF-7/ADR. All of the compounds tested, with the exception of fisetin, significantly decreased the IC50 value of DNM. Biochanin A showed the greatest increase in [3H]-DNM accumulation, increasing by 454.3 +/- 19.5% in the resistant cells, whereas verapamil, the positive control, increased the accumulation by 229.4 +/- 17.6%. Also, the accumulation of [3H]-DNM was increased substantially by quercetin and silymarin while it was reduced by fisetin. Moreover, biochanin A, silymarin, and naringenin significantly decreased DNM efflux from MCF-7/ADR cells compared with the control. These results suggest that some flavonoids such as biochanin A and silymarin may reverse MDR by inhibiting the P-gp function.     

阿霉素对艾氏腹水癌细胞产生多药抗药性的研究

用对阿霉素较为敏感的艾氏腹水癌在小鼠体内用阿霉素进行长达50 wk的治疗,致使EAC细胞对阿霉素产生抗药性.抗药性细胞的生长比敏感株缓慢,每只小鼠体内总的瘤细胞体积,细胞计数,及平均单一细胞体积均比敏感株明显为小,同时还发现染色体匀染及双微体结构.该模型对长春新碱,放线菌素D.及丝裂霉素C均产生交叉抗药性,对VP-16产生部分交叉抗药性.而对冬凌草甲素则无交叉抗药性.     

维生素K3体外降低Ehrlich腹水癌细胞对阿霉素的抗药性

AIM: To study the effect of menadione (Men) reducing doxorubicin (Dox) resistance in Ehrlich ascites carcinoma (EAC) cells resistant to Dox (EAC/Dox cells). METHODS: Glutathione (GSH) content and membrane fluidity were measured by fluorometric assay and fluorescence depolarization assay, respectively. Glutathione S-transferase (GST) activity was measured with 1-chloro-2,4-dinitrobenzene as the substrate. Cell viability was determined by 3-(4, 5-dimethylthiazol)-2, 5-diphenyltetrazolium bromide assay. RESULTS: GSH content, GST activity, and membrane fluidity in EAC/Dox cells were higher than those in EAC cells (P < 0.01). The IC50 (95% confidence limits) for Dox on EAC/Dox cell was 22.3 (15.8-28.8) mg.L-1. Relative resistance of Dox in EAC/Dox cells was 42-fold. Pretreatment of EAC/Dox cells with Men 5 or 10 mg.L-1 decreased intracellular GSH content (P < 0.01). Men 1 mg.L-1 had no obvious effect on GSH content in EAC/Dox cells (P > 0.05), but decreased the elevated membrane fluidity efficiently (P < 0.05). Men had no obvious effect on GST activity in EAC/Dox cells (P > 0.05). IC50 of Dox was reduced to 9.6 (7.8-11.3), 6.0 (2.8-9.2), or 5.3 (3.9-6.7) mg.L-1 in EAC/Dox cells pretreated with Men 1, 5, or 10 mg.L-1. CONCLUSION: Men reduced Dox resistance effectively due in part to its depletion of GSH content in EAC/Dox cells.     

盐酸千金藤素逆转EAC/ADR细胞多药耐药性的作用及其机制

目的研究盐酸千金藤素对艾氏腹水癌耐药细胞株EAC/ADR多药耐药性的逆转作用及其与核因子κB(NF-κB)的关系，探讨其作用机制。方法MTT法、小鼠移植瘤模型实验观察盐酸千金藤素体外和体内逆转细胞多药耐药性的作用; Dot-ELISA法检测细胞核NF-κB水平及药物作用后的变化。结果盐酸千金藤素体外能逆转EAC/ADR细胞的耐药性，逆转倍数为13倍；体内能延长荷瘤小鼠的生存时间，生命延长率为75.37%；并能降低EAC/ADR细胞中NF-κB的持续性活性及化疗药物对其的激活。结论盐酸千金藤素具有逆转多药耐药性的作用，其机制可能与抑制NF-κB的活性有关。     

Role of differential drug uptake, efflux, and binding of etoposide in sensitive and resistant human tumor cell lines: implications for the mechanisms of drug resistance

In order to study the mechanism of etoposide (VP-16) resistance in human tumor cells and to assess the role of P-170 glycoprotein in VP-16 accumulation, we have examined the uptake and efflux of VP-16 in both sensitive and multidrug-resistant MCF-7 human breast and HL60 human promyelocytic leukemia cells. The drug-resistant cells, MCF-7/ADR and HL60/ADR, were selected for resistance to adriamycin and were 200- to 250-fold resistant to VP-16. Whereas MCF-7/ADR cells overexpress the P-170 glycoprotein and show the multidrug-resistant phenotype, HL60/ADR cells do not overexpress the P-170 glycoprotein. Although there was a 2-fold decrease in accumulation of VP-16 in MCF-7/ADR cells, this decrease did not correlate with a 250-fold resistance to the drug. VP-16 efflux was rapid and almost complete from MCF-7 cell lines and it was decreased at 4 degrees. Further, there was a significant increase in VP-16 accumulation in the MCF-7/ADR cells in the presence of glucose-free medium supplemented with sodium azide. However, no change in the pattern of VP-16 efflux was observed. Under these conditions, addition of glucose caused release of VP-16 from MCF-7/ADR cells, suggesting energy-dependent modifications in the drug binding. Coincubation of vincristine with VP-16 also increased the drug accumulation and decreased the rate of efflux of VP-16 in both sensitive and resistant MCF-7 cells, suggesting that vincristine and VP-16 may compete for similar binding and efflux mechanisms in these cell lines. In contrast, daunorubicin increased VP-16 accumulation only in the sensitive MCF-7 cell line, whereas the efflux rate of VP-16 was not significantly changed in either cell line. HL60 sensitive cells accumulated 4- to 5-fold more VP-16 than the resistant subline. Both sensitive and resistant cells showed an important noneffluxable pool of the drug, 3-fold larger for sensitive cells (79 +/- 12 versus 25 +/- 2 pmol of VP-16/mg of protein, for sensitive and resistant cells, respectively). The efflux of VP-16 was temperature dependent only in sensitive cells. VP-16 accumulation in HL60/ADR cells was increased in glucose-free medium supplemented with sodium azide; however, the noneffluxable pool of VP-16 was not significantly changed. In contrast, although these conditions had no effect on the drug accumulation in the parental line, they caused a decrease in the noneffluxable pool of VP-16, suggesting an energy-dependent binding and retention of VP-16.(ABSTRACT TRUNCATED AT 400 WORDS)