非离子表面活性剂逆转肿瘤细胞多药耐药性的机制

目的探讨非离子表面活性剂聚氧乙烯醚﹑聚乙二醇300﹑曲拉通X100对肺癌耐药细胞A549/DDP(耐顺铂)多药耐药性的逆转及其机制。方法用四氮唑盐(MTT)法进行体外耐药逆转实验,Westernblot检测P-gp(P-糖蛋白)蛋白的表达。结果①合用非离子型表活剂前后,A549/DDP对化疗药物阿霉素、顺铂、丝裂霉素、5-氟尿嘧啶、依托泊甙和长春新碱的敏感性显著增加(各组都为P<0.01);②三种非离子型表面活性剂能抑制P-gp蛋白的表达。结论三种非离子表面活性剂具有逆转A549/DDP耐药性的作用,逆转机制与其抑制P-gp蛋白的表达有关。     

注射用黄芪多糖对耐顺铂人肺腺癌细胞A549/DDP耐药逆转作用研究

目的 探讨注射用黄芪多糖药物血清在体外对耐顺铂（DDP）人肺腺癌A549/DDP细胞株的耐药逆转作用。方法 通过建立小鼠肿瘤模型,运用血清药理学方法,以人肺腺癌敏感细胞A549和耐药细胞A549/DDP为研究对象,采用细胞毒实验（MTT）方法,探讨注射用黄芪多糖对耐顺铂人肺腺癌细胞A549/DDP的耐药逆转作用。结果 注射用黄芪多糖药物血清高、中、低剂量组分别与DDP合用时对A549/DDP细胞的耐药逆转倍数分别为1.24、1.41、1.34;且中、高剂量组与阳性对照DDP组比较差异有统计学意义（P＜0.05）。结论 注射用黄芪多糖能明显增加A549/DDP耐药细胞对DDP的敏感性,提高细胞死亡率,具有耐药逆转作用。     

大黄素对人胆管癌多药耐药细胞QBC_（939）/ADM的耐药逆转作用

目的探讨大黄素（Emodin,EM）对人胆管癌多药耐药细胞QBC939/ADM的耐药逆转作用。方法细胞生长周期、凋亡率采用流式细胞术（FCM）,多药耐药P糖蛋白（P-gP）以免疫组织化学（SP）法检测。结果阿霉素（ADM）、紫杉醇分别与EM联合作用于人胆管癌多药耐药细胞QBC939/ADM的凋亡率比单独作用有显著提高。细胞周期分布显示：ADM、紫杉醇分别与EM联合作用于人胆管癌多药耐药细胞QBC939/ADM,使QBC939/ADM阻滞于G2/M期的细胞数明显增加。EM和紫杉醇联合作用后,人胆管癌多药耐药细胞QBC939/ADM中多药耐药P糖蛋白（P-gP）的表达由72.00%降低到46.00%（P〈0.01）。结论EM对QBC939/ADM细胞的多药耐药性有逆转作用。其作用机理可能与人胆管癌细胞P-gP的表达有关,通过与化疗药物竞争性结合P-gP的结合位点发挥疗效。     

注射用黄芪多糖对耐顺铂人肺腺癌细胞A549/DDP耐药逆转作用研究

目的探讨注射用黄芪多糖药物血清在体外对耐顺铂（DDP）人肺腺癌A549/DDP细胞株的耐药逆转作用。方法通过建立小鼠肿瘤模型,运用血清药理学方法,以人肺腺癌敏感细胞A549和耐药细胞A549/DDP为研究对象,采用细胞毒实验（MTT）方法,探讨注射用黄芪多糖对耐顺铂人肺腺癌细胞A549/DDP的耐药逆转作用。结果注射用黄芪多糖药物血清高、中、低剂量组分别与DDP合用时对A549/DDP细胞的耐药逆转倍数分别为1.24、1.41、1.34;且中、高剂量组与阳性对照DDP组比较差异有统计学意义（P〈0.05）。结论注射用黄芪多糖能明显增加A549/DDP耐药细胞对DDP的敏感性,提高细胞死亡率,具有耐药逆转作用。     

异钩藤碱逆转人肺腺癌细胞A549/DDP对顺铂耐药性

目的 研究异钩藤碱(IR)在体外对耐药人肺腺癌细胞系A549/DDP对顺铂(DDP)的耐药性.方法 采用MTT法检测药物细胞毒性作用及耐药细胞逆转倍数,电感耦合等离子体质谱(ICP-MS)法测定细胞内顺铂浓度.结果 IR无细胞毒浓度组(3.0μg·mL-1)使A549/DDP细胞对DDP的IC50由16.81 mg·L-1降至3.36 mg·L-1;低细胞毒浓度(8.0μg·mL-1)组的IC50降至2.34 mg·L-1;2组均明显提高DDP在A549/DDP细胞内的浓度.结论 研究表明IR能部分逆转A549/DDP细胞的MDR,并可增加肿瘤细胞内DDP药物浓度.     

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。     

消岩汤对耐顺铂人肺腺癌A549/DDP细胞多药耐药基因调控作用的研究

目的 探讨具有"扶正解毒祛瘀"作用的中药复方消岩汤对耐顺铂人肺腺癌A549/DDP细胞多药耐药基因(MDR)的表达产物P糖蛋白(P-gP)及其mRNA表达水平的影响。方法 选择耐顺铂人肺腺癌A549/DDP细胞系作为获得性耐药模型,给予消岩汤含药血清,采用Western Blotting 免疫印迹法及RT-PCR技术检测MDR的表达产物P-gP的含量及其mRNA表达水平。结果 与对照组比较,随着消岩汤含药血清药物浓度的增加,P-gP蛋白表达逐渐减弱(P<0.05);与对照组比较,经不同浓度消岩汤含药血清作用后,A549/DDP细胞中的MDR1基因的mRNA水平均有所下降(P<0.05),且随着药物浓度的增加,基因表达抑制作用越明显。结论 消岩汤逆转肺癌耐药的可能机制为通过抑制细胞膜上P-gP及其基因的表达而阻止细胞对顺铂的输出,从而聚集细胞内的药物浓度达到有效逆转肺癌耐药的效果。     

单端孢菌素逆转肺癌耐药A549/DDP细胞耐药性及其机制研究

目的 探讨单端孢菌素对肺癌耐顺铂细胞系A549/DDP顺铂耐药性的逆转作用及机制。方法 应用MTS法检测单端孢菌素对A549/DDP细胞顺铂敏感性的影响,流式细胞术检测肿瘤细胞表面P-糖蛋白（P-Glycoprotein,P-pg）表达以及胞内罗丹明-123（Rhodamine-123,Rh-123）含量的变化,生化法检测细胞内SOD和GSH的水平,Western blot法和Real time PCR检测肿瘤细胞多药耐药蛋白MDR1、MRP1和Survivin表达的变化,Western blot法检测Akt磷酸化的变化,液相芯片法检测TGF-β,IL-6和IL-8的变化,应用双萤光报告基因技术检测细胞NF-κB和AP-1转录活性。结果 单端孢菌素可增加细胞对顺铂的敏感性,经5 μg·mL^-1和10 μg·mL^-1单端孢菌素作用72 h后,耐药逆转倍数（RF）为1.84和3.95倍。经5 μg·mL^-1和10 μg·mL^-1单端孢菌素作用24 h后,肿瘤细胞P-gp表达分别下降了62.6%和19.8%,细胞中Rh-123含量分别提高了183.3%和308.3%,细胞内SOD水平下降65.2%和50.1%,GSH水平下降 71.6%和46.3%,MDR1的mRNA水平下降了72.7%和52.3%,MRP1的mRNA水平下降了64.0%和22.5%,Survivin的mRNA水平下降了45.8%和14.7%,Akt磷酸化水平下降,TGF-β分泌水平下降了80.2%和51.5%,IL-6分泌水平下降了73.4%和37.2%,IL-8分泌水平下降了71.2%和43.2%,NF-κB转录活性下降42.3%和22.7%,AP-1的转录活性下降了57.4%和32.5%。结论 单端孢菌素逆转A549/DDP对顺铂的耐药性,这一作用与抑制药物外排,负调控肿瘤耐药相关蛋白的表达有关。     

红霉素逆转人肝癌细胞BEL-7402多药耐药性的研究

目的　研究红霉素 (ERY)对BEL 740 2细胞 (人肝癌细胞 )多药耐药性的逆转作用。方法　将BEL 740 2细胞连续培养在含阿霉素 (ADM )的培养液中诱导耐药细胞株BEL 740 2 /ADM ,用cell ELASA法检测细胞膜表面P gp的表达 ,细胞毒试验采用MTT法 ,用荧光分光光度法测定细胞内ADM浓度。结果　BEL 740 2 /ADM细胞表面P gp高度表达 ,除对ADM耐药外 ,对长春新碱 (VCR)和丝裂霉素(MMC)也有不同程度的交叉耐药 ;ERY可增强ADM、VCR、MMC对BEL 740 2 /ADM细胞的增殖抑制作用 ,可增加BEL 740 2 /ADM细胞内ADM的浓度而对细胞膜表面P gp的表达没有影响。结论　ERY通过竞争性地饱和BEL 740 2 /ADM细胞表面P gp通道 ,使细胞内药物外排减少、浓度增加 ,从而发挥对BEL 740 2 /ADM细胞多药耐药性的逆转作用     

红霉素逆转人肝癌细胞BEL-7402多药耐药性的研究

目的研究红霉素(ERY)对BEL-7402细胞(人肝癌细胞)多药耐药性的逆转作用.方法将BEL-7402细胞连续培养在含阿霉素(ADM)的培养液中诱导耐药细胞株BEL-7402/ADM,用cell-ELASA法检测细胞膜表面P-gp的表达,细胞毒试验采用MTT法,用荧光分光光度法测定细胞内ADM浓度.结果 BEL- 7402/ADM细胞表面P-gp高度表达,除对ADM耐药外,对长春新碱(VCR)和丝裂霉素(MMC)也有不同程度的交叉耐药;ERY可增强ADM、VCR、MMC对BEL-7402/ADM细胞的增殖抑制作用, 可增加BEL-7402/ADM细胞内ADM的浓度而对细胞膜表面P-gp的表达没有影响.结论 ERY通过竞争性地饱和BEL-7402/ADM细胞表面P-gp通道,使细胞内药物外排减少、浓度增加,从而发挥对BEL-7402/ADM细胞多药耐药性的逆转作用.     

Bcl-XL siRNA对肺腺癌细胞A549/DDP药物敏感性及凋亡的影响

目的：探讨小干扰RNA沉默Bcl-XL对肺腺癌耐药细胞株A549／DDP药物敏感性的影响及其凋亡机制。方法：将Bcl-XL siRNA质粒载体转染至A549／DDP细胞，MTT、流式细胞仪检测细胞药物敏感性的改变；丫啶橙／溴化乙锭（AO／EB）染色法检测细胞凋亡；RT-PCR检测Bcl-XL mRNA水平；Western-Blot检测Bcl—XL、caspase-3蛋白表达的变化。结果：分别用0．2、2、20、200μg／mL顺铂处理细胞48h，MTT显示转染Bcl-XL siRNA细胞组A570吸光度值较阴性siRNA细胞组和未转染对照组明显降低，细胞生长抑制率明显增高；用20μg/mL顺铂处理细胞48h，流式细胞仪检测，转染Bcl-XL siRNA组凋亡率较转染阴性siRNA组和未转染组增加；AO／EB染色显示转染Bcl-XL siRNA的细胞较转染阴性siRNA及未转染者凋亡率增加；转染Bcl-XL siRNA降低了Bcl-XL mRNA和蛋白水平，升高了caspase-3活性形式蛋白表达。结论：Bcl-XL siRNA特异性下调A549／DDP细胞Bcl-XL的表达，活化caspase-3蛋白，促进A549／DDP细胞凋亡，增强该肺腺瘤细胞对顺铂的敏感性。     

三氧化二砷对人肺腺癌耐药细胞A549/R的逆转作用

目的探讨三氧化二砷(As2O3)对肺腺癌耐药细胞株(A549/R)耐药性的逆转作用.方法采用四甲基偶氮唑蓝(MTT)法及荧光分光光度计分别检测As203的细胞毒性、A549/R细胞的药敏性及As203作用前后细胞内药浓的变化;采用生化方法检测A549/R细胞谷胱甘肽-S-转移酶(GSTs)活性,观察非细胞毒性剂量(0.15μmol·L-1)和低毒剂量(0.375 μmol·L-1)的As203对肺腺癌A549/R耐药细胞内GSTs活性的影响.结果As203在非细胞毒剂量下可显著降低耐药细胞对ADM的IC50值;As203作用后A549/R细胞内ADM积聚增加,其逆转倍数为2.3倍;A549/R细胞中GSTs活性增高,不同浓度的As203可降低GSTs活性;结论As203可通过降低GSTs活性而部分逆转A549/R细胞对ADM耐药.     

Cell-type dependent response of melanoma cells to aloe emodin

Intrinsic characteristics of melanoma cells such as expression of inducible nitric oxide synthase (iNOS), redox status, and activity of signaling pathways involved in proliferation, differentiation and cell death define the response of the cells to the diverse treatments. In this context we compared the effectiveness of herbal antaquinone aloe emodin (AE) against mouse B16 melanoma and human A375, different in initial activity of ERK1/2, constitutive iNOS expression and basal level of reactive oxygen species (ROS). Both cell lines are sensitive to AE treatment. However, while the agent induces differentiation of B16 cells toward melanocytes, in A375 cells promoted massive apoptosis. Differentiation of B16 cells, characterized by enhanced melanin production and tyrosinase activity, was mediated by H₂O₂ production synchronized with rapid p53 accumulation and enhanced expression of cyclins D1 and D3. Caspase mediated apoptosis triggered in A375 cells was accompanied with Bcl-2 but not iNOS down-regulation. In addition, opposite regulation of Akt-ERK1/2 axis in AE treated B16 and A375 cells correlated with different outcome of the treatment. However, AE in a dose-dependent manner rescued both B16 and A375 cells from doxorubicin- or paclitaxel-induced killing. These data indicate that caution is warranted when AE is administrated to the patients with conventional chemotherapy.     

蛇床子素对耐阿霉素人乳腺癌细胞耐药的逆转作用

目的:研究蛇床子素(Ost)对人乳腺癌细胞阿霉素耐药株多药耐药(MDR)的逆转作用及其机制。方法:采用MTT比色法测定药物的细胞毒性,高效液相-紫外检测法检测细胞内ADR浓度。结果:Ost对MCF-7及MCF-7/ADR细胞均有增殖抑制作用,IC50值分别为(58.1±2.3)μmol.L-1和(59±5)μmol.L-1;在5~15μmol.L-1范围内,Ost可以不同程度地增强ADR对MCF-7细胞杀伤作用,与ADR联合用药降低ADR对MCF-7/ADR的IC50值,显著增加MCF-7/ADR细胞内ADR的积累。结论:Ost对人乳腺癌细胞株MCF-7及其阿霉素耐药株MCF-7/ADR细胞均有增殖抑制作用,而且Ost通过明显增加MCF-7/ADR细胞内ADR的浓度,逆转其阿霉素耐药性。     

Determinants of cisplatin and irinotecan activities in human lung adenocarcinoma cells: evidence of cisplatin accumulation and topoisomerase I activity

To elucidate the sensitivity of adenocarcinoma of the lung to cisplatin and irinotecan, intracellular glutathione (GSH) and glutathione S-transferase (GST)-pi concentrations and topoisomerase (topo) I activity were investigated using six adenocarcinoma cell lines. The antiproliferative activity was determined by MTT assay in terms of inhibition concentration (IC50) values. The IC50 values to cisplatin were not correlated with the amounts of intracellular GSH or GST-pi, but with intracellular accumulation of platinum (r = -0.91, p = 0.013). IC50 values to SN-38 were correlated with topo I activity determined by relaxation assay of pBR322 (r = -0.83, p = 0.040). These results suggest that platinum accumulation and topo I activity have definite impacts on the sensitivity of lung adenocarcinoma to cisplatin and irinotecan, respectively.     

Hsa-miR-503-5p regulates CTDSPL to accelerate cisplatin resistance and angiogenesis of lung adenocarcinoma cells

The study aimed to assess the role of hsa-miR-503-5p in cisplatin resistance and angiogenesis in LUAD and its underlying mechanisms. Hsa-miR-503-5p expression in LUAD and the target gene downstream of hsa-miR-503-5p was predicted by bioinformatics analysis. Binding relationship between the two genes was verified by dual-luciferase reporter assay. qRT-PCR was conducted for detecting gene expression in cells, CCK-8 for IC₅₀ value, angiogenesis assay for human umbilical vein endothelial cell (HUVEC) angiogenic ability, flow cytometry for apoptosis ability, transwell assay for migration ability, and western blot for detecting the protein expression of vascular endothelial growth factor receptor 1 (VEGFR1), VEGFR2, and CTD small phosphatase like (CTDSPL). The results showed that hsa-miR-503-5p showed high expression, while its target gene CTDSPL presented decreased expression in LUAD. Hsa-miR-503-5p also had high expression in cisplatin-resistant LUAD cells. Knockdown of hsa-miR-503-5p resensitized LUAD cells to cisplatin, inhibited angiogenesis of drug-resistant cells, and reduced the protein expression of VEGFR1, VEGFR2, and EMT-related targets in cisplatin-resistant LUAD cells, but promoted the apoptosis ability. Hsa-miR-503-5p bound to CTDSPL gene and promoted cisplatin resistance and malignant progression of LUAD cells by negatively regulating CTDSPL. Our results revealed that hsa-miR-503-5p and CTDSPL may be novel targets for overcoming cisplatin resistance in LUAD.     

17-AAG协同顺铂抑制肺腺癌A549细胞的增殖

目的：观察热休克蛋白90（HsPg0）抑制剂17-AAG与顺铂（cispiatin,DDP）联用对肺腺癌细胞株A549增殖抑制的协同效应。方法：采用四甲基偶氮唑蓝（MTT）法检测不同浓度17-AAG、顺铂及两药联用对肺癌细胞株A549的生长抑制作用,并应用中效原理评价两药联用效应。结果：顺铂和17-AAG均对A549细胞的生长有较好的抑制作用,并呈现一定的剂量依赖性,顺铂作用48h时,其IC50值为69．627μmol／L;17-AAG的1C5。值为0．455ttmol／L。顺铂联合17-AAG显示更强的抑制作用,特别是在低剂量下协同作用更明显。结论：17-AAG联合顺铂对肺癌细胞的增殖具有协同抑制效应。     

Reversal effect of Dioscin on multidrug resistance in human hepatoma HepG2/adriamycin cells

Multidrug resistance is a serious obstacle encountered in cancer treatment. Since drug resistance in human cancer is mainly associated with overexpression of the multidrug resistance gene 1 (MDR1), the promoter of the human MDR1 gene may be a target for multidrug resistance reversion drug screening. In the present study, HEK293T cells were transfected with pGL3 reporter plasmids containing the 2 kb of MDR1 promoter, and the transfected cells were used as models to screen for candidate multidrug resistance inhibitors from over 300 purified naturally occurring compounds extracted from plants and animals. Dioscin was found to have an inhibiting effect on MDR1 promoter activity. The resistant HepG2 cell line (HepG2/adriamycin) was used to validate the activity of multidrug resistance reversal by Dioscin. Results showed that Dioscin could decrease the resistance degree of HepG2/adriamycin cells, and significantly inhibit P-glycoprotein expression, as well as increase the accumulation of adriamycin in HepG2/adriamycin cells as measured by Flow Cytometric analysis. These results suggest that Dioscin is a potent multidrug resistance reversal agent and may be a potential adjunctive agent for tumor chemotherapy.