FG020327逆转肿瘤多药耐药性的作用及其机制

背景与目的肿瘤细胞过量表达P鄄糖蛋白穴P-glycoprotein.P-gp雪导致多药耐药穴multidrug resistance,MDR雪是目前肿瘤化疗的一大障碍,使用多药耐药逆转剂与抗癌药物联合化疗是克服临床多药耐药的重要方法。本研究对一种新的多芳基取代咪唑化合物FG020327的体外逆转活性及其逆转机制进行了探讨。方法以MTT法检测FG020327对多药耐药肿瘤细胞MCF-7/ADR及KBv200的耐药逆转活性;以荧光分光光度计法检测FG020327对MCF-7/ADR细胞内抗癌药物阿霉素累积的影响;以罗丹明蓄积实验检测该化合物对P-gp功能的影响。结果FG020327在体外具有较强的逆转活性,在5μmol/L浓度下使多药耐药细胞KBv200对长春新碱的敏感性增加44.9倍,逆转活性是公认的强逆转剂维拉帕米的3倍熏但它对敏感株对抗癌药物的敏感性基本无影响。2.5、5和10μmol/L的FG020327使MCF-7/ADR细胞中阿霉素的累积分别增加2.3、2.7和3.7倍,但是在敏感株MCF鄄7细胞却观察不到阿霉素累积的增加。FG020327浓度依赖性增加KBv200细胞内的罗丹明蓄积,但对敏感株KB细胞内的罗丹明蓄积无影响。结论FG020327具有较强的体外逆转MDR的活性,它可能通过抑制P鄄gp功能及增加MDR细胞内抗癌药物的累积逆转MDR。     

逆转肿瘤多药耐药性的系列研究

多药耐药性（ｍｕｌｔｉｄｒｕｇ ｒｅｓｉｓｔａｎｃｅ, ＭＤＲ）是指肿瘤细胞接触一种来源于天然的抗肿瘤药物并产生耐药性的同时,对结构和作用机理不同的多种来源于天然的抗肿瘤药物产生交叉耐药性。多药耐药性是肿瘤化疗失败的主要原因。ＭＤＲ产生的原因复杂,但ｍｄｒｌ基因过度表达产生的Ｐ－糖蛋白（Ｐｅｒｍｅａｂｉｌｉｔｙ　 ｇｌｙｃｏｐｒｏｔｅｉｎ, Ｐ－ｇｐ）是 ＭＤＲ产生的最重要和最常见的原因。实际上,Ｐ－ｇｐ是一种能量依赖性药物转出泵,能将化疗药物从癌细胞内泵出细胞外,从而使药物在细胞内积蓄浓度降低,使…     

十字饱碱逆转耐药性KB细胞多药抗药性的机制

目的：研究蛋白激酶C抑制剂十字饱碱(staurosporine，ST)逆转耐长春新碱KB细胞(简称KB／VCR)的机制。方法：用MTT法比较ST作用前后KB／VCR细胞耐药性的改变，用流式细胞术观察KB／VCR药物代谢的变化，用RT—PCR法和免疫组织化学方法研究耐药膜糖蛋白(P-glycoprotein，P-gp)、耐药相关蛋白(multidrug resistance associated protein，MRP)和肺耐药蛋白(lung cancer resistance related protein，LRP)在细胞mRNA水平和蛋白水平上的表达。结果：1ng／mL ST使KB／VCR细胞耐药性下降了158倍。亲本株KB／S细胞几乎不表达P—gp，而KB／VCR细胞却近100％强表达P—gp，P=0．004；ST使KB／VCR细胞的P—gp表达强度明显降低，但阳性率未见明显改变。MRP在两种细胞的基因转录水平和蛋白水平均呈现弱表达，ST也不影响其表达。1ng／mL ST作用24h后，KB／S和KB／VCR细胞的LRP在mRNA水平及蛋白水平上表达指数均明显地高出用药前，P=0．006。结论：ST可通过降低P—gp表达强度和药物外排功能来逆转肿瘤细胞的多药抗药性，但这种作用可部分地被LRP蛋白表达增强所抵消。     

十字饱碱逆转耐药性KB细胞多药抗药性的机制

目的:研究蛋白激酶C抑制剂十字饱碱(staurosporine,ST)逆转耐长春新碱KB细胞(简称KB/VCR)的机制。方法:用MTT法比较ST作用前后KB/VCR细胞耐药性的改变,用流式细胞术观察KB/VCR药物代谢的变化,用RTPCR法和免疫组织化学方法研究耐药膜糖蛋白(Pglycoprotein,Pgp)、耐药相关蛋白(multidrugresistanceassociatedprotein,MRP)和肺耐药蛋白(lungcancerresistancerelatedprotein,LRP)在细胞mRNA水平和蛋白水平上的表达。结果:1ng/mLST使KB/VCR细胞耐药性下降了158倍。亲本株KB/S细胞几乎不表达Pgp,而KB/VCR细胞却近100%强表达Pgp,P=0.004;ST使KB/VCR细胞的Pgp表达强度明显降低,但阳性率未见明显改变。MRP在两种细胞的基因转录水平和蛋白水平均呈现弱表达,ST也不影响其表达。1ng/mLST作用24h后,KB/S和KB/VCR细胞的LRP在mRNA水平及蛋白水平上表达指数均明显地高出用药前,P=0.006。结论:ST可通过降低Pgp表达强度和药物外排功能来逆转肿瘤细胞的多药抗药性,但这种作用可部分地被LRP蛋白表达增强所抵消。     

肿瘤多药耐药性及其逆转策略

 肿瘤细胞多药耐药性（multidrug resistance，MDR）的产生是导致肿瘤化疗失败的主要原因之一。MDR是指肿瘤细胞对一种抗肿瘤药物产生耐药性的同时，对结构和作用机制完全不同的其他抗肿瘤药物产生交叉耐药性的现象。^[1]      

肿瘤多药耐药性及其临床逆转

肿瘤多药耐药性及其临床逆转中国科学院上海药物研究所（２０００３１）马仲才，胥彬由于肿瘤细胞的多药耐药性（ｍｕｌｔｉｄｒｕｇｒｅｓｉｓｔａｎｃｅ，ＭＤＲ）越来越成为临床化疗的最大障碍之一，对ＭＤＲ的研究一直方兴未艾，在实验和临床逆转方面也做了很多尝试，...     

补骨脂素逆转人乳腺癌细胞多药耐药性的研究

目的研究中药补骨脂素对人乳腺癌细胞多耐药性的逆转作用.方法用MTT法测定药物的细胞毒性和IC50用流式细胞仪测定耐药细胞P170糖蛋白表达,并选异搏定作阳性对照,观察具有钙拮抗作用的补骨脂素对MCF-7/ADR多药耐药性的逆转作用.结果补骨脂素在非细胞毒性剂量下能使MCF-7/ADR对阿霉素的浓度升高,但对细胞表面的糖蛋白P-170却没有影响.结论补骨脂素具有逆转人乳腺癌MCF-7/ADR多药耐药性的作用.     

卵巢癌多药耐药逆转治疗研究进展

由多约耐药基因(mdrl)编码、P-糖蛋白(P-gp)介导的多药耐药性的产生是肿瘤化疗失败的重要原因。下凋mdrl基因的表达，可逆转肿瘤细胞对化疗药物的敏感性，提高化疗疗效。现综述近年来以P-gP为靶点克服卵巢癌细胞多药耐药的研究进展。     

SFRP5逆转白血病多药耐药性的研究

  目的  研究分泌型卷曲相关蛋白5(secreted frizzled related protein 5, SFRP5)对P-糖蛋白(P-glycoprotein, P-gp)介导的白血病多药耐药性的作用。  方法  采用转基因方法构建过表达SFRP5的KG1a/SFRP5细胞, real-time PCR检测MDR1 mRNA表达, Western blot检测细胞P-gp表达。免疫荧光显微镜观察细胞膜表面P-gp表达。流式细胞仪检测细胞内药物浓度。MTT方法检测细胞耐药性。  结果  与KG1a细胞及表达绿色荧光蛋白的KG1a/eGFP细胞相比, KG1a/SFRP5细胞中MDR1 mRNA水平显著下降(P < 0.01), 总P-gp表达水平亦被下调, 细胞膜表面P-gp荧光强度减弱, 细胞内的罗丹明浓度显著升高(P < 0.01), 对ADR的IC50显著降低(P < 0.01), 细胞耐药性下降。  结论  SFRP5蛋白表达可以下调MDR1转录及P-gp表达, 增加细胞内药物浓度, 逆转白血病多药耐药。      

汉防己甲素逆转白血病细胞株K562/ADM多药耐药性机制研究

目的 研究汉防己甲素(TTD)对慢性粒细胞白血病急性变白血病细胞株K562／ADM多药耐药(MDR)逆转的机理。方法 采用流式细胞仪检测细胞内化疗药物的浓度及细胞表面P糖蛋白(P-gp)的表达；荧光定量PCR法检测MDR1 mRNA；通过流式细胞仪检测Anexin—V判断凋亡细胞的数量。结果 10μmol/L的TTD处理K562／ADM细胞后，细胞内阿霉素(ADM)的浓度明显提高；K562／ADM细胞MDR1 mRNA／P-gp的表达下降；TTD能增强ADM致细胞凋亡的作用。结论 汉防己甲素的耐药逆转机制除了下调MDR1 mRNA／P-gp的表达引起细胞内抗癌药物的积聚外，增加抗癌药物致细胞凋亡也是耐药逆转的重要原因。．     

苄丙洛逆转肿瘤多药抗药性作用及其机理的探讨

为了探讨新的钙阻断剂苄丙洛逆转肿瘤多药抗药性的作用及其机理。方法；以Ｆｕｒａ－２／ＡＭ法测定Ｐ－糖蛋白功能，ＭＴＴ法测定细胞毒作用，细胞内阿霉素测定以荧光分光光度计法，细胞内钙离子测定用Ｆｕａ－２－ＡＭ法。结果；苄丽洛能显著增加ＤＮＲ细胞内Ｆｕｒａ－２的积累和降低ＭＣＵ－７／ＡＤＲ细胞为ＡＤＲ的ＩＣ５０，对相应的敏感细胞株ＭＣＦ－７无此作用的。     

Reversal of multidrug resistance by lipophilic drugs

The phenomenon of multidrug resistance implies that a wide spectrum of structurally and functionally unrelated chemotherapeutic drugs are recognized and processed by the molecular system which protects multidrug-resistant (MDR) cells against lipophilic cytotoxic drugs. This suggests that lipophilic agents with low toxicity may also be recognized and processed by this molecular system. At high concentrations these agents might saturate the system, thereby reversing multidrug resistance. In support of this hypothesis, 19 (73%) of 26 arbitrarily chosen lipophilic drugs were in this study found to increase the accumulation of actinomycin D in MDR WEHI 164 cells. The most potent of these drugs were also shown to sensitize these cells to the cytotoxic effect of actinomycin D and doxorubicin. There was a good correlation between the ability of the lipophilic drugs to induce an increased accumulation of actinomycin D in MDR cells and their ability to sensitize these cells to the cytotoxic effect of chemotherapeutic drugs. The ability to reverse drug resistance appeared to be additive, since increased accumulation of actinomycin D was also obtained by combining low concentrations of various lipophilic drugs. This may be a way to reduce the in vivo toxic effect of the lipophilic drugs yet still obtain a reversal of drug resistance. When MDR cells were exposed to lipophilic drugs which reversed drug resistance, the synergistic cytotoxic effect of actinomycin D and tumor necrosis factor was obtained at reduced actinomycin D concentrations.     

Reversal of multidrug resistance by surfactants.

Cremophor EL, a pharmacologically inactive solubilising agent, has been shown to reverse multidrug resistance (MDR). Using flow cytometric evaluation of equilibrium intracellular levels of daunorubicin (DNR), we found that eight other surface active agents will also reverse MDR. All the active detergents contain polyethoxylated moieties but have no similarities in their hydrophobic components. The properties of three polyethoxylated surfactants that showed the lowest toxicities, Cremophor, Tween 80 and Solutol HS15, were examined in more detail. The concentrations of Tween 80 and Solutol required to reverse DNR exclusion were 10-fold lower than for Cremophor. However while concentrations greater than or equal to 1:10(2) of the former two surfactants resulted in breakdown of cells, even 1:10 of Cremophor did not lyse cells. Studies of the effects of Cremophor on the uptake and efflux of DNR in normal and MDR cell types showed that Cremophor increases intracellular DNR primarily by locking the rapid efflux from the cells. This blockage of drug efflux may be mediated by a substantial alteration in the fluidity of cell membranes induced by Cremophor, as shown by decreased fluorescence anisotropy of a membrane probe. Consistent with these data, coinjection of adriamycin plus Cremophor into mice carrying a multidrug resistant P388 transplantable tumour significantly increased the survival time of the mice compared with adriamycin treatment alone.     

Reversal of multidrug resistance by derivatives of acrivastine

A major obstacle to successful cancer chemotherapy is the development of multidrug resistance (MDR) characterized by the overexpression of the drug transporter P-glycoprotein and the enhanced cellular efflux of many anticancer drugs. The identification and use of agents that reverse the MDR phenotype or drug-resistant tumors could provide an adjuvant to conventional cancer chemotherapy that would significantly enhance treatment efficacy. Several derivatives of acrivastine and a structurally-related benzyl piperazine were used in the present study to establish the utility of structure-activity and in vitro analyses to identify compounds that are effective at sensitizing MDR tumors in vivo. Of the seven compounds evaluated, 5 were identified by structure-activity analyses as inhibitors of P-glycoprotein, 1 was identified as a possible inhibitor, and 1 was deemed a non-interactor. In vitro analyses indicated that all seven compounds could inhibit P-glycoprotein; however, the compound identified by structure-activity analyses as a non-interactor was least potent. In vivo experimentation revealed that the more potent P-glycoprotein inhibitors, as determined by either structure-activity analyses or in vitro testing, also sensitized multidrug-resistant tumor masses implanted into athymic nude mice to treatment with vinblastine; though, efficacy was limited by host toxicity. Results from this study corroborate previously-established relationships between chemical structure and P-glycoprotein inhibition. Results further demonstrate that P-glycoprotein inhibitory potency, as established by structure-activity or in vitro analyses, provides insight into the ability of the agent to sensitize drug-resistant tumors in vivo.     

Reversal of multidrug resistance by phenothiazines and structurally related compounds

Summary The multidrug-resistance (MDR)-reversal activity of 232 phenothiazines and structurally related compounds was tested in MDR P388 cells. Such activity was found among compounds exhibiting two ring structures (phenyl, cyclopentyl, cyclohexyl, thienyl or 5-norbornen-2-yl but not pyridinyl) linked by a variety of bridge types and possessing a secondary or tertiary amine group. Among 192 such compounds, 31.8% displayed good activity (MDR-reversal ratio, 10) and 8.3%, outstanding activity (MDR-reversal ratio, 30). In a subgroup comprising 56 compounds with a carbonyl residue, 4 with sulfuryl residue and 1 with thienyl residue, 42.7% showed good activity and 18%, outstanding activity. The contribution of these residues to the MDR-reversal activity was particularly evident among compounds containing a cyclic tertiary amine. Among 49 such compounds, 51% displayed good activity and 20.4%, outstanding activity, whereas among the 85 compounds lacking such groups, only 31.8% showed good activity and 4.7%, outstanding activity. Enhancement of this activity by the carbonyl group is also obtained when the latter is part of an amide bond of a tertiary amine. As compounds with a carbonyl group located on the rings, on the bridge to the amine group or beyond the amine are efficient MDR reversers, it seems that the cxact molecular location of the carbonyl group is not critical for the elicitation of this activity.Abbreviations ADR Adriamycin - MDR multidrug resistance - P388/ADR multidrug-resistant P388 cells     

肿瘤细胞多药耐药逆转的研究进展

肿瘤细胞对抗癌药物的多药耐药（MDR）是导致肿瘤化学治疗失败的主要原因,寻找适用于临床的高效、低毒的多药耐药逆转方法是当前本研究领域的共同目标。随着分子生物学技术和现代医药技术的发展,有关肿瘤细胞多药耐药逆转的研究也取得了一定的进展。     

Reversal of multidrug resistance by two novel indole derivatives.

Two new fused indoles were found to overcome multidrug resistance in P388/Adr cells in vitro. These agents potentiated the cytotoxicity of the antitumor drugs Adriamycin, vinblastine, and vincristine in multidrug-resistant cells with no effect on drug-sensitive parent P388 cells. They significantly increased the ATP-dependent accumulation of [3H]-vinblastine and inhibited efflux of the labeled drug from resistant cells. These compounds also inhibited photoaffinity labeling of P-glycoprotein by [3H]azidopine in P388/Adr cells and membranes isolated from these cells. In addition, the calcium antagonist activity of these compounds was very weak compared with that of verapamil. These data suggest that the compounds reported here may specifically overcome multidrug resistance without the serious hypotensive effects associated with calcium antagonists and that this activity may be independent of their ability to block calcium transport.