临床药师对外科723份运行病历的干预研究

目的通过临床药师对外科运行病历的干预,提高了外科医生合理、安全、有效使用药物的水平。方法2006年3月至2009年6月每周对外科运行病历随机抽查10～15份,根据2005年版《中国药典》、《新编药物学》16版、《抗菌药物临床应用指导原则》、《卫生部办公厅关于抗菌药物临床应用管理有关问题的通知》、麻醉药品及第一类精神药品管理办法等参考资料,对每份运行病历进行认真查阅和分析,发现问题及时与医生探讨和协商并提出书面整改建议。结果经过几年的运行干预723份病历,提出建议的174例占24.1%,此方法对外科合理、安全、有效的用药起到了保障作用。结论临床药师以干预运行病历方式工作,方法切实可行,值得推广。     

三氧化二砷对人肺腺癌A549/R细胞多药耐药相关蛋白表达的影响

目的探讨三氧化二砷(As2O3)对人肺腺癌A549/R细胞耐药性的逆转作用及对多药耐药相关蛋白（MRP）表达的影响。方法以荧光分光光度计测定细胞内药物浓度的改变，采用半定量逆转录聚合酶联反应(RT PCR) 技术检测As2O3处理后A549/R MRP基因表达的变化。结果As2O3的非细胞毒性剂量可增加A549/R细胞内多柔比星(ADM)浓度，降低其IC50。A549/R细胞中MRP呈过表达状态，不同浓度的As2O3处理A549/R后MRP表达水平明显降低。结论As2O3可部分逆转A549/R细胞对ADM的耐药性，其逆转机制与改变MRP基因表达有关。     

Src激酶抑制剂对人肺癌顺铂耐药细胞A549/DDP多药耐药性的影响及机制

目的研究Src激酶抑制剂PP2对人肺癌顺铂耐药细胞A549/DDP多药耐药性的影响及机制。方法以5和10μmol.L-1Src激酶抑制剂PP2作用A549/DDP细胞24h后,应用Western blot考察肿瘤细胞Src磷酸化表达的变化,MTT法检测细胞的药物敏感性,流式细胞仪考察细胞P-gp表达的变化,Western blot及Real-time PCR考察肿瘤细胞MDR1蛋白及mRNA表达的变化。结果 Src激酶抑制剂PP2可下调A549/DDP细胞Src磷酸化表达,5和10μmol.L-1 Src激酶抑制剂PP2作用后,顺铂对A549/DDP细胞的药物敏感性分别提高了1.37和2.47倍,细胞P-gp表达分别为对照组的65.2%和46.4%,MDR1在蛋白水平表达显著降低,MDR1在mRNA水平的表达分别为对照组的50.24%(P<0.05)和37.6%(P<0.05)。结论 Src激酶抑制剂PP2可逆转A549/DDP细胞多药耐药性,其机制可能与降低细胞MDR1表达水平有关。     

雷公藤甲素对肺癌A549/DDP细胞多药耐药的逆转作用及机制

【】 目的：探讨雷公藤甲素对肺癌A549/DDP多药耐药的逆转作用及机制。方法：雷公藤甲素作用于肺癌A549/DDP细胞后,应用MTS法检测细胞生长抑制率,流式细胞术检测细胞内罗丹明-123(Rhodamine-123,Rh-123)及细胞表面P-糖蛋白(P-glycoprotein,P-gp)表达,应用Western blot法和real time PCR检测肿瘤细胞多药耐药蛋白 (MDR1)和肺耐药相关蛋白(LRP)表达变化,应用报告基因技术检测细胞NF-κB启动子活性,应用Western blot法检测肿瘤细胞Akt磷酸化。结果：雷公藤甲素可提高肺癌A549/DDP细胞药物敏感性,经2μM和10μM雷公藤甲素作用后,顺铂逆转倍数(RF)分别为2.09倍和2.93倍,肿瘤细胞中Rh-123含量分别提高了1.38倍和2.88倍,P-gp表达分别是对照组的57.1%和32.1%,MDR1和LRP蛋白表达水平显著下降,MDR1 mRNA表达分别是对照组的64.2%和22.6%,LRP mRNA表达分别是对照组的54.8%和34.7%, NF-κB启动子活性分别是对照组的55.6%和23.6%,Akt磷酸化水平显著下降。结论：雷公藤甲素可逆转肺癌A549/DDP细胞多药耐药性,提高肿瘤细胞药物敏感性,抑制药物外排,降低细胞MDR1和LRP表达,其机制可能与抑制Akt磷酸化水平,下调NF-κB启动子活性有关。     

人单核细胞白血病细胞系SHI-1的多药耐药和耐药蛋白的表达

目的 探讨人单核细胞白血病细胞系SHI-1多药耐药谱及其机制.方法 噻唑蓝(MTT)检测SHI-1细胞对柔红霉素、鬼臼乙叉甙、高三尖杉酯碱、紫杉醇和长春新碱的敏感性;流式细胞术(FCM)检测SHI-1细胞中P糖蛋白(P-gp)、多药耐药相关蛋白(MRP)、肺耐药相关蛋白(LRP)、乳腺癌耐药蛋白(BCRP)、谷胱甘肽-S-转移酶-π(GST-π)等耐药蛋白的表达.结果 MTT药敏实验结果显示SHI-1细胞存在着多药耐药,尤其对VP-16最为明显.FCM检测显示SHI-1细胞中P-gp阳性比例10.78%,相对荧光强度(RFI)为1.02;GST-π阳性率93.52%,RFI 6.91;LRP阳性率92.86%,RFI 8.00;MRP阳性率4.54%,RFI 1.38;BCRP阳性率3.84%,RFI 1.06.结论 SHI-1细胞存在多药耐药,以对VP-16最为明显,其耐药机制可能与LRP和GST-π的高表达有关.     

槲皮素对胃癌细胞多药耐药的逆转作用

目的 了解槲皮素对胃癌组织P-糖蛋白(P-gp)和多药耐药相关蛋白1(MRP1)的逆转作用。方法 取27例胃癌手术标本,采用体外细胞培养,测定槲皮素对肿瘤细胞化疗药物敏感性的影响(H^3-TDR法),并分析肿瘤组织P-gp、MRP1表达的关系。结果 P-gp阴性细胞5种化疗药物的敏感性均高于P-gp阳性,其中ADM组差别有显性。而槲皮素可随剂量增加,使P-gp阳性细胞化疗药物敏感性增加,其中MTX、VP-16及ADM组有显性差别。MRP1阴性细胞对5种化疗药物的敏感性均高于MRP1阳性,其中MTX、MMC和5-FU组差别有显性。槲皮素不能使两组细胞化疗敏感性有明显改变。结论 槲皮素能逆转P-gp的多药耐药,特别是对MTX、VP-16及ADM的耐药。但对MRP1引起的耐药,逆转效果不明显。     

P-糖蛋白与肿瘤多药耐药的关系及环孢素对肿瘤耐药的逆转

综述和分析了P-糖蛋白与肿瘤多药耐药的关系，包括P一糖蛋白的结构，作用机制，在正常组织和肿瘤中的表达等。并叙述了环孢素及其结构类似物对肿瘤多药耐药的逆转。     

中药逆转肿瘤多药耐药的研究进展

目的综述逆转肿瘤多药耐药(MDR)的研究进展。方法检索中药提取物或中药单体联合化疗药物逆转肿瘤MDR的研究。结果一些中药提取物或中药单体能使耐药株对化疗药物变得敏感,使耐药蛋白的转运活性下降。结论中药具有逆转肿瘤MDR的活性,其作用机制大多是与耐药相关蛋白相关的。     

中药逆转肿瘤多药耐药非经典机制的研究进展

目前认为,由肿瘤多药耐药(MDR)基因编码的P-糖蛋白(P-gp)过度表达介导的药物外排是产生MDR的经典机制[1]。除此外,MDR还与多药耐药相关蛋白(MRP)、谷光甘肽-S-转移酶(GST)、拓扑异构酶Ⅱ(TopoⅡ)、细胞凋亡等多种非经典机制密切相关。由于中药不同于一般的化学制剂只有单一的逆转作用靶点,一种中药单体就是一个复杂的化学分子复合体,往往同时具有数种逆转机制,故从中药中筛选有效的MDR逆转剂已成为近年的研究热点。然而,中药逆转肿瘤MDR研究现存的主要问题是无论何种剂型,其研究机制偏于单一,大多数的研究主要集中在经典机制上。…     

白血病细胞多药耐药逆转方法的研究进展

白血病细胞耐药的产生是药物治疗中的一大阻碍,耐药细胞过表达的跨膜转运蛋白（主要为P-糖蛋白）导致胞内药物浓度降低是产生耐药的主要原因。此外,凋亡基因的异常表达、药物作用靶点的改变也产生多药耐药（MDR）。针对这些特点寻找合适的药品与化疗药合用以增加肿瘤细胞对化疗药的敏感性,或者利用高分子材料改变释药系统,以及开发新型药物是逆转白血病细胞耐药的主要手段。通过对逆转白血病MDR的方法进行探讨,旨在为白血病治疗提供新思路。     

冠心病患者血浆内皮素及血小板四项的相关性及临床意义

目的探讨内皮素(ET)、血小板四项在冠心病中的相关性及临床意义。方法选择2007年7月至2008年5月就诊于山西省人民医院并确诊的126例冠心病患者及同期45名经冠状动脉CT或冠状动脉造影除外冠状动脉病变并根据临床及实验室检查排除心脏疾患的健康对照组作为研究对象。冠心病组据世界卫生组织(WHO)的诊断标准和国内冠心病分类标准分为稳定型心绞痛组(SAP)、不稳定型心绞痛组(UAP)、急性心肌梗死组(AMI),分别检测血浆ET含量及血小板参数值。冠心病组中有16例进行经皮冠状动脉腔内成形术(PT-CA),检测术前与术后ET与血小板参数值。结果发现冠心病组测得ET、平均血小板体积(MPV)、血小板分布宽度(PDW)值显著高于健康对照组,差异有统计学意义(P<0.01),血小板计数(PLT)冠心病组低于对照组,差异无统计学意义(P<0.05)。试验结果显示随着病变程度的加重,ET、MPV、PDW值有不同程度的升高,均显著高于健康对照组。PTCA术前上述指标明显高于术后,差异有统计学意义(P<0.05)。结论ET、血小板参数存在相关性,且对冠心病的诊治及预后具有重要临床意义。     

shRNA对人白血病K562/ADM细胞多药耐药性的逆转观察

目的 探讨利用RNA干扰(RNAi)技术来逆转人白血病K562/ADM细胞多药耐药能力的可行性.方法 设计两条针对MDR1基因的发夹状RNA (shRNA),并将其分别构建在pGenSil-1质粒中;然后将这两条shRNA分别转染K562/ADM.利用罗丹明外排法、荧光定量PCR来检测这两条shRNA对K562/ADM的多药耐药性的逆转作用.结果 在稳定转染的细胞中可以观察到不同程度的多药耐药(MDR)逆转现象.在两个稳定转染的克隆中,MDR现象被完全逆转.结论 本研究显示可以利用shRNA逆转K562/ADM细胞的多药耐药问题.     

Induction of proteins involved in multidrug resistance (P-glycoprotein, MRP1, MRP2, LRP) and of CYP 3A4 by rifampicin in LLC-PK1 cells

P-glycoprotein, multidrug resistance-related proteins (MRPs) and lung resistance-related protein (LRP) are involved in multidrug resistance in tumor cells but are also expressed in normal tissues. In the LLC-PK(1) tubular renal cell line, a 15-day treatment with 25 microM rifampicin significantly increased the mRNA levels of P-glycoprotein, MRP1, MRP2, LRP and cytochrome P450 3A4 (CYP 3A4). Western blot analysis confirmed a moderate increase in the expression of P-glycoprotein and MRP2, but not MRP1 also at the protein level. The intracellular uptake of doxorubicin was significantly lower in rifampicin pretreated cells. A pretreatment with 6-[82S,4R,6E)-4-methyl-2-(methylamino)-3-oxo-6-octenoic acid]cyclosporin D, valspodar (PSC 833), a specific inhibitor of P-glycoprotein, with (3-(3-(2-(7-chloro-2-quinidinyl)ethenyl-phenyl)((3-diimethyl amino-3oxo propyl)thio)methyl)thio)propanoic acid, sodium salt (MK-571), a specific inhibitor of MRP1, and with verapamil, that inhibits both proteins, significantly increased doxorubicin cell accumulation in rifampicin pretread cells. In rifampicin treated cells cultured on porous membranes, doxorubicin showed a polarized transport, that was reduced by a pretreatment with PSC 833. A chronic treatment with rifampicin induces the expression of transport proteins and of CYP 3A4 and could therefore alter the renal elimination kinetics of drugs that are their substrates.     

YAN,a novel microtubule inhibitor,inhibits P-gp and MRP1 function and induces mitotic slippage followed by apoptosis in multidrug-resistant A549/Taxol cells

Lung cancer is the most common cause of cancer-related death worldwide. The occurrence of multidrug resistance (MDR) affects the therapeutic efficacy of chemotherapeutics. Therefore, to develop new anticarcinogen which can overcome MDR is urgent. Here, the novel microtubule inhibitor 5-(4-ethoxyphenyl)-1-(3,4,5-trimethoxyphenyl)-1H-1,2,4-triazol-3-amine (YAN) exhibited strong cytotoxicity towards A549 and MDR-phenotype A549/Taxol cells. We demonstrated that YAN was a poor substrate of P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) which were over-expressed in A549/Taxol cells, and YAN inhibited their expression and function. Moreover, YAN arrested cells at mitosis phase by inhibiting microtubule polymerization. Further, YAN induced caspase-dependent apoptosis in A549 cells via mitochondria-mediated intrinsic pathway. In contrast, the multinucleation of A549/Taxol cells after YAN-treatment indicated the occurrence of mitotic catastrophe, and the subsequent apoptosis was mediated by apoptosis-inducing factor (AIF) nuclear translocation instead of p53- and caspase-dependent manner. Moreover, the inhibitory effect of YAN on PI3K/Akt activity was involved in the regulation of P-gp, MRP1 and AIF in A549/Taxol cells. Taken together, our finding indicates that YAN is a novel microtubule inhibitor and overcomes MDR by suppressing P-gp and MRP1 function and inducing cell death independent of p53 and caspase in A549/Taxol cells. Therefore, YAN possesses great potential for future development into an effective anticarcinogen especially for drug-resistant cancer.     

MAPK/ERK通过诱导纤维蛋白A磷酸化抑制垂体瘤细胞增殖、凋亡、迁移及相关信号转导

目的 探讨MAPK/ERK对垂体瘤细胞增殖、凋亡、迁移及相关信号转导的影响.方法 通过CCK-8法确定SB203580(MAPK/ERK抑制剂)的最佳安全浓度,然后将体外培养的垂体瘤细胞分为SB203580组和对照组,通过CCK-8法检测垂体瘤细胞的增殖情况,流式细胞术检测垂体瘤细胞的细胞凋亡百分数,RT-PCR和We...     

Coordinate regulation of UDP-glucuronosyltransferase UGT1A6 induction by 3-methylcholanthrene and multidrug resistance protein MRP2 expression by dexamethasone in primary rat hepatocytes

Concentration-dependent regulation of 3-methylcholanthrene (MC) inducibility of UDP-glucuronosyltransferase UGT1A6 by the synthetic glucocorticoid, dexamethasone (DEX) was studied. Treatment of cultured rat hepatocytes with MC, 0.1, 1, and 10 microM DEX, and MC combined with DEX, resulted in different induction patterns measured in the intact cells compared to that observed in the microsomes prepared from the same cells. DEX treatment in various concentrations caused a concentration-dependent increase in p-nitrophenol (p-NP) conjugation in intact cells (3-, 4-, and 5-fold over control, respectively), and it positively regulated MC induction (4-, 5-, and 6-fold over control, respectively). In contrast, DEX had smaller effect on microsomal p-NP conjugation (115, 200, 220% of control, respectively) and although MC induction was increased significantly by 0.1 microM DEX (520% of control), but higher concentrations of DEX (10 microM) decreased the degree of induction to 410%. Similar results obtained from in vivo experiments showed that at high DEX concentration (100mg/kg), the rate of MC induction (540%) decreased (420%). Permeabilization of the plasma membrane resulted in a 15-fold increase of p-NP conjugation indicating the importance of transport in the rate of overall p-NP elimination, and the induction pattern was similar to that observed in microsomes isolated from cells. Hyper-osmolarity (405 mOsmol/L) led to a 3-fold decrease of p-NP conjugation, the loss of DEX inducibility and reduction of the MRP2 protein level. Our results suggest coordinated regulation of UGT1A6 inducibility and substrate or product transport by DEX.     

Kinetic analysis of fluorescein and dihydrofluorescein effluxes in tumour cells expressing the multidrug resistance protein,MRP1

Multidrug resistance (MDR) in tumour cells is often caused by the overexpression of two transporters the P-glycoprotein (P-gp) and the multidrug resistance-associated protein (MRP1) which actively pump out multiple chemically unrelated substrates across the plasma membrane. A clear distinction in the mechanism of translocation of substrates by MRP1 or P-gp is indicated by the finding that, in most of cases, the MRP1-mediated transport of substrates is inhibited by depletion of intracellular glutathione (GSH), which has no effect on their P-gp-mediated transport. The aim of the present study was to quantitatively characterise the transport of anionic compounds dihydrofluorescein and fluorescein (FLU). We took advantage of the intrinsic fluorescence of FLU and performed a flow cytometric analysis of dye accumulation in the wild-type drug sensitive GLC4 that do not express MRP1 and its MDR subline which display high level of MRP1. The measurements were made in real time using intact cells. The kinetics parameters, k(a)=V(M)/K(m), which is a measure of the efficiency of the transporter-mediated efflux of a substrate, was very similar for the two FLU analogues. They were highly comparable with values for k(a) of other negatively charged substrates, such as GSH and calcein. The active efflux of both FLU derivatives was inhibited by GSH depletion.     

Chamaecypanone C, a novel skeleton microtubule inhibitor, with anticancer activity by trigger caspase 8-Fas/FasL dependent apoptotic pathway in human cancer cells

Microtubule is a popular target for anticancer drugs. Chamaecypanone C, is a natural occurring novel skeleton compound isolated from the heartwood of Chamaecyparis obtusa var. formosana. The present study demonstrates that chamaecypanone C induced mitotic arrest through binding to the colchicine-binding site of tubulin, thus preventing tubulin polymerization. In addition, cytotoxic activity of chamaecypanone C in a variety of human tumor cell lines has been ascertained, with IC₅₀ values in nanomolar ranges. Flow cytometric analysis revealed that chamaecypanone C treated human KB cancer cells were arrested in G₂-M phases in a time-dependent manner before cell death occurred. Additional studies indicated that the effect of Chamaecypanone C on cell cycle arrest was associated with an increase in cyclin B1 levels and a mobility shift of Cdc2/Cdc25C. The changes in Cdc2 and Cdc25C coincided with the appearance of phosphoepitopes recognized by a marker of mitosis, MPM-2. Interestingly, this compound induced apoptotic cell death through caspase 8-Fas/FasL dependent pathway, instead of mitochondria/caspase 9-dependent pathway. Notably, several KB-derived multidrug resistant cancer cell lines overexpressing P-gp170/MDR and MRP were sensitive to Chamaecypanone C. Taken together, these findings indicated that Chamaecypanone C is a promising anticancer compound that has potential for management of various malignancies, particularly for patients with drug resistance.