微乳丹参酮逆转肿瘤多药耐药的观察

背景：肿瘤多药耐药的出现，增加了肿瘤治疗的难度。肿瘤多药耐药的形成机制复杂，涉及多个环节，选择不同作用机制的药物联合应用，对肿瘤多药耐药的临床效果可能更有效。 目的：观察中药新剂型微乳丹参酮对人白血病细胞株及其阿霉素耐药株的多药耐药性逆转效果。 设计：观察对比实验。 单位：吉林大学附属第一医院中心实验室。 材料：人红白血病细胞株及其阿霉素耐药株，由中科院天津血研所提供。丹参酮、微乳丹参酮，由吉林大学药学院制剂室提供。阿霉素（辉瑞法玛西亚药业），P糖蛋白-PE荧光抗体、B细胞淋巴瘤／白血病-2基因-FITC荧光抗体（Immunotech公司），二甲基亚砜（北京化工厂），噻唑蓝（华美生物）。 方法：实验于2003—03／2004—01在吉林大学附属一院中心实验室完成。①将人红白血病敏感细胞株与含100g／L小牛血清、100U／mL青霉素和链霉素的RMPI1640培养液中，在37℃，饱和湿度及体积分数为0．05的CO2细胞培养箱内传代；阿霉素耐药株连续培养于阿霉素上述培养液中，培养条件相同。②将中药制剂微乳丹参酮作为逆转剂，丹参酮和微乳体系作为对照，作用于人红白血病细胞株和阿霉素耐药株。③采用四甲基偶氮唑盐法检测微乳丹参酮，丹参酮及微乳的细胞毒性及抗药性逆转倍数。④分别在对数生长期的细胞株中加入10，20，40，60mg／L的阿霉素，采用荧光分光光度法检测微乳丹参酮，丹参酮及微乳对人红白血病细胞株及阿霉素耐药株中细胞内阿霉素浓度的影响。⑤流式细胞术检测给予10mg／L阿霉素的人红白血病细胞株及加入微乳丹参酮，丹参酮及微乳的阿霉素耐药株中P糖蛋白和B细胞淋巴瘤／白血病-2基因蛋白表达及肿瘤细胞凋亡碎片百分比。 主要观察指标：①微乳丹参酮，丹参酮及微乳的细胞毒性及抗药性逆转倍数。②微乳丹参酮，丹参酮及微乳对人红白血病细胞株及阿霉素耐药株中细胞内阿霉素浓度的影响。③给予10mg／L阿霉素的人红白血病细胞株及加入微乳丹参酮，丹参酮及微乳的阿霉素耐药株中P糖蛋白和B细胞淋巴瘤／白血病-2基因蛋白表达及肿瘤细胞凋亡碎片百分比。 结果：④微乳丹参酮，微乳体系，中药丹参酮均可显著降低阿霉素耐药株的耐药性，以浓度为0．2mg／L、0．5mg／L的微乳丹参酮的逆转倍数显著高于其他两组（P〈0．05）。②微乳丹参酮，微乳体系，中药丹参酮均可使细胞内药物浓度升高，微乳丹参酮作用后的阿霉素耐药株细胞中阿霉素的浓度最高，差异有显著性（P〈0．05）。③微乳丹参酮，微乳体系，丹参酮均可降低阿霉素耐药株的P糖蛋白和B细胞淋巴瘤／白血病-2基因表达水平，使肿瘤细胞凋亡比率上升，微乳丹参酮的作用最强，可显著降低P糖蛋白和B细胞淋巴瘤／白血病-2基因表达水平，使肿瘤细胞在ADM作用下的凋亡比率增加（P〈0．05）。 结论：微乳丹参酮0．5mg／L可引起阿霉素耐药株内药物浓度增加，与P糖蛋白、B细胞淋巴瘤／白血病-2基因表达下调的结论相印证；微乳丹参酮对多药耐药逆转作用较丹参酮和微乳逆转效果更显著。     

膀胱肿瘤的耐多药机制及逆转

本文综述了膀胱肿瘤耐多药机制中的mdrl基因、P-gp和相关蛋白、TopoⅡ、GST、MT、MGMT等多种因素,并对使用多种药物及反义寡核苷酸等物质对膀胱肿瘤的MDR进行逆转的研究现状作了评述,将有助于临床选择更合理的化疗方案,提高患者生存率。     

膀胱肿瘤的耐多药机制及逆转

本文综述了膀胱肿瘤耐多药机制中的mdr1基因、P gp和相关蛋白、TopoⅡ、GST、MT、MGMT等多种因素 ,并对使用多种药物及反义寡核苷酸等物质对膀胱肿瘤的MDR进行逆转的研究现状作了评述 ,将有助于临床选择更合理的化疗方案 ,提高患者生存率。     

与逆转肿瘤多药耐药相关的研究进展

本文针对多药耐药（ＭＤＲ）的主要机制,对同介导的多药耐药的逆转方法、ＭＤＲ１基因的检测、逆转剂对化疗药物的药代学影响、逆转的相关毒笥等方面的研究进展进行综述。     

Mdrl基因所致肿瘤多药耐药逆转的基因治疗进展

多药耐药（multidrugresistance，MDR）是肿瘤治疗过程中的重要现象，直接影响到肿瘤化疗的效果，因而一直是肿瘤研究领域的热点。多药耐药是指肿瘤细胞同时对一种或几种结构和功能各不相同的药物产生耐受的现象。近年来，基因治疗逆转肿瘤多药耐药的研究进展很快，特别是RNA干扰技术，被认为是最有前景的手段。[第一段]     

肿瘤及白血病细胞多药耐药相关蛋白基因的研究与进展

肿瘤细胞多药耐药性的形成机理中除了Ｐ１７０糖蛋白过度表达，ＤＮＡ拓扑异构酶Ⅱ量和质的异常外，最近又发现了多药耐药相关蛋白（ＰＲＰ）过度表达所致的多药耐药。本文综述了关于ＭＲＰ研究的新进展。     

中药逆转肿瘤多药耐药的研究进展

虽然联合化疗对恶性肿瘤患者的生存期有积极的临床意义,但肿瘤细胞产生的耐药性又是化疗失败最常见而又最难解决的问题之一。进一步了解肿瘤细胞对化疗产生的耐药机制,不仅能增加细胞毒化疗药物对晚期恶性肿瘤的疗效,而且能改进辅助治疗,延长患者的带瘤存活期和生存率。[1]多药     

肿瘤及白血病细胞多药耐药相关蛋白基因的研究与进展

肿瘤细胞多药耐药性的形成机理中除了P_(170)糖蛋白过度表达,DNA拓扑异构酶Ⅱ量和质的异常外,最近又发现了多药耐药相关蛋白(MRP)过度表达所致的多药酎药。本文综述了关于MRP研究的新进展。     

载药微泡逆转恶性肿瘤多药耐药的研究进展

恶性肿瘤是严重威胁人类生命健康的重大疾病,化学药物在恶性肿瘤治疗中起着重要的作用。尽管新的抗癌药物和化疗方案不断推出,临床治疗仍达不到理想的预期效果。究其原因,肿瘤对化疗药物产生耐药性是严重影响治疗效果的重大难题,直接影响化疗的成败。     

LRP——一种新的肿瘤多药耐药相关蛋白

ＬＲＰ是新发现的一种多药耐药蛋白，又称ＭＶＰ，广泛表达于正常组织及肿瘤细胞中，实验研究表明，ＬＲＰ在体外预测优于Ｐ１７０及ＭＶＰ，而且其预测价值可以延伸到非ＭＤＲ类药物顺铂类，尤其对急性非淋巴细胞白血病（ＡＭＬ）及卵巢癌是一个预测化疗敏感性的独立预后因素。     

MRP-siRNA逆转子宫内膜癌细胞多药耐药的研究

目的:研究以MRP基因为靶标的siRNA逆转子宫内膜癌耐药细胞株B-MD-C1(ADR+/+)耐药的作用.方法:合成以MRP基因为靶标的siRNA,转染入子宫内膜癌细胞株,RT-PCR检测转染后细胞MRP基因mRNA表达水平,WesternBlotMRP蛋白表达率.转染MRP-siRNA6 h后分剐给予不同浓度的ADR、DDP及PTX,另设相同剂量的单纯化疗组,以未作任何处理的对数生长期细胞为空白对照,化疗药物处理24、48、72 h后,用MTT法检测细胞生长抑制率,对比MRP-siRNA+化疗组和单纯化疗药物组的IC<,50>,流式细胞仪检测细胞凋亡率和死亡率.结果:以MRP为靶标的siRNA可显著抑制瘤细胞MRP基因的mRNA及蛋白的表达,细胞对化疗敏感性明显增高,差异有统计学意义(P<0.01),细胞凋亡率、死亡率也显著升高(P<0.05).结论:以MRP为靶标的siRNA,通过静寂MRP基因表达,明显增加子宫内膜癌细胞对化疗的敏感性.     

苯妥英钠逆转胶质母细胞瘤多药耐药实验研究

目的研究不同浓度苯妥英钠(PHT)对化疗耐药胶质母细胞瘤细胞系(8-MG-BA)化疗耐药逆转的影响。方法用不同浓度苯妥英钠对8-MG-BA及H4细胞系处理后,以MTT法检测其对上述两种细胞系化疗耐药逆转的影响,并与维拉帕米(VRP)处理组进行对照。结果用PHT 5、10μg/mL和VRP 5μg/mL处理后,8-MG-BA细胞对卡莫司汀(BCNU)的逆转倍数分别为:25.34、34.97和14.27,对替尼泊苷(VM-26)的逆转倍数分别为:13.44、21.71和11.10。结论 PHT逆转作用大于VRP,且呈现剂量依赖关系。     

补骨脂素逆转肿瘤细胞多药耐药的进展

多药耐药是乳腺癌化疗失败的关键。发掘、探索低毒、高效、多阶段性作用的中药是目前研究的热点。研究发现,补骨脂素对多药耐药具有一定的逆转作用,现就其逆转机制及其原理进行阐述。     

Melanoma differentiation associated gene-7/interleukin-24 reverses multidrug resistance in human colorectal cancer cells

Overexpression of the multidrug resistance 1 (MDR1) gene, encoding P-glycoprotein (P-gp), facilitates resistance to diverse chemotherapeutic drugs and current P-gp inhibitors display high toxicity. We studied the effects of melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24), which exhibits cancer-specific apoptosis-inducing properties, in drug-sensitive (SW620) and drug-resistant (SW620/Dox) colorectal carcinoma cells. Adenovirus administered mda-7/IL-24, Ad.mda-7, effectively reversed resistance to doxorubicin-induced apoptosis in SW620/Dox cells by increased intracellular accumulation and decreased efflux of doxorubicin. Unexpectedly, P-gp-overexpressing cells (SW620/Dox) displayed increased apoptosis following Ad.mda-7 infection compared with parental SW620 cells, which correlated with more MDA-7/IL-24 protein in SW620/Dox than SW620 cell and potentially explains the increased sensitivity of P-gp-overexpressing cells to mda-7/IL-24. Transient overexpression of MDR1 in SW620 cells significantly increased apoptosis, decreased anchorage-independent growth, and increased MDA-7/IL-24 protein following Ad.mda-7 infection, whereas down-modulation of MDR1 in SW620/Dox cells by small interfering RNA decreased apoptosis following Ad.mda-7 infection. The increased mda-7/IL-24 sensitivity observed in SW620/Dox cells was partly due to increased reactive oxygen species generation and lower mitochondrial membrane potential. These findings confirm that mda-7/IL-24 is a potent MDR reversal agent, preferentially causing apoptosis in P-gp-overexpressing MDR cells, suggesting significant expanded clinical implications for the use of mda-7/IL-24 in treating neoplasms that have failed chemotherapy mediated by the P-gp MDR mechanism.     

小柴胡汤逆转人肝癌细胞BEL-7402／5-FU 的多药耐药作用

目的:研究小柴胡汤对BEL-7402/5-FU细胞多药耐药的逆转作用,并初步探讨其作用机制。方法:采用四甲基偶氮唑蓝(MTT)法检测不同化疗药物以及小柴胡汤对BEL-7402/5-FU细胞的半数抑制浓度(IC50),计算耐药指数和小柴胡汤的逆转倍数;流式细胞仪检测细胞内阿霉素的荧光强度;RT-PCR检测mdr1基因表达;western blot检测p-gp蛋白表达。结果:BEL-7402/5-FU耐药株对5-FU和阿霉素顺铂均具有耐药性,耐药指数分别是6 501.99和31.73;0.5 mg/ml小柴胡汤和5-FU、阿霉素联合应用,其逆转倍数分别是1.66、1.50;1.0 mg/ml小柴胡汤和5-FU、阿霉素联合应用,其逆转倍数分别是3.44、5.58;小柴胡汤增强阿霉素的荧光强度;小柴胡汤降低mdr1基因表达和p-gp蛋白表达,各个浓度均具有统计学意义。结论:小柴胡汤可以抑制mdr1基因编码蛋白产物p-gp的表达,增加细胞内化疗药物的浓度,从而逆转了肝癌细胞的多药耐药性。     

Bisbenzylisoquinolines as modulators of chloroquine resistance in Plasmodium falciparum and multidrug resistance in tumor cells.

Ten naturally occurring bisbenzylisoquinolines (BBIQ) and two dihydro derivatives belonging to five BBIQ subgroups were evaluated in vitro for their ability to inhibit Plasmodium falciparum growth and, in drug combination, to reverse the resistance to chloroquine of strain FcB1. The same alkaloids were also assessed in vitro for their potentiating activity against vinblastine with the multidrug-resistant clone CCRF-CEM/VLB, established from lymphoblastic acute leukemia. Three of the BBIQ tested had 50% inhibitory concentrations of less than 1 microM. The most potent antimalarial agent was cocsoline (50% inhibitory concentration, 0.22 microM). Regarding the chloroquine-potentiating effect, fangchinoline exhibited the highest biological activity whereas the remaining compounds displayed either antagonistic or slight synergistic effects. Against the multidrug-resistant cancer cell line, fangchinoline was also by far the most active compound. Although there were clear differences between the activities of tested alkaloids, no relevant structure-activity relationship could be established. Nevertheless, fangchinoline appears to be a new biochemical tool able to help in the comprehension of the mechanism of both chloroquine resistance in P. falciparum and multidrug resistance in tumor cells.     

Ultrasound reverses multidrug resistance in human cancer cells by altering gene expression of ABC transporter proteins and Bax protein

Multidrug resistance (MDR) is the major obstacle to successful chemotherapy of human malignancies and strategies for overcoming MDR phenomena are still unavailable to clinical use. Previous results showed that ultrasound (US) exposure could make MDR cancer cells become more sensitive to anticancer drugs, and the physical parameters of US exposure could adjust the uptake and retention of rhodamine 123 in MDR cells. In this study, we investigated the mechanisms of therapeutic ultrasound as a physical approach to overcoming MDR in a multidrug resistant human hepatocarcinoma cell line (HepG2/ADM). Our results demonstrated that the percentage of P-glycoprotein⁺ (P-gp), multidrug resistance-associated protein⁺ (MRP) and lung resistance-related protein⁺ (LRP) cells was 96.97% ± 2.41%, 20.84% ± 3.12% and 1.16% ± 0.59% in HepG2/ADM cells, and 62.84% ± 3.42%, 10.26% ± 1.18% and 3.05% ± 0.37% in US-exposed HepG2/ADM cells, respectively. A significant decrease in the number of P-gp⁺ and MRP⁺ cells was observed between US-exposed HepG2/ADM and HepG2/ADM cells (p < 0.05). Using RT-PCR technique, we found that US could significantly downregulate the expression of P-glycoprotein (P-gp) and (MRP) at the mRNA level in HepG2/ADM cells. Compared with the control, the percentage of apoptotic cell death was significantly increased in HepG2/ADM after ultrasound exposure. Using immunocytochemistry, the percentage of Bcl-2⁺ and Bax⁺ cells was 21.7% and 4.1% in the control, and 18.46% and 8.1% in the US-exposed cells, respectively. The percentage of Bax⁺ cells was significantly higher in US-exposed HepG2/ADM cells (p < 0.05), suggesting that US exposure could lead to cellular apoptosis in HepG2/ADM cells. It is concluded that US exposure could reverse MDR in HepG2/ADM cells via decreasing P-gp and MRP levels and their mRNA expressions and increasing expression of Bax protein. It may lead to the development of a novel strategy of using a targeted, noninvasive physical approach for the induction of MDR reversal in cancer cells. (E-mail: mfengwu@yahoo.com)     

Gefitinib reverses breast cancer resistance protein-mediated drug resistance

Breast cancer resistance protein (BCRP) is an ATP binding cassette transporter that confers resistance to a series of anticancer agents such as 7-ethyl-10-hydroxycamptothecin (SN-38), topotecan, and mitoxantrone. In this study, we evaluated the possible interaction of gefitinib, a selective epidermal growth factor receptor tyrosine kinase inhibitor, with BCRP. BCRP-transduced human epidermoid carcinoma A431 (A431/BCRP) cells acquired cellular resistance to gefitinib, suggesting that BCRP could be one of the determinants of gefitinib sensitivity in a certain sort of cells. Next, the effect of gefitinib on BCRP-mediated drug resistance was examined. Gefitinib reversed SN-38 resistance in BCRP-transduced human myelogenous leukemia K562 (K562/BCRP) or BCRP-transduced murine lymphocytic leukemia P388 (P388/BCRP) cells but not in these parental cells. In addition, gefitinib sensitized human colon cancer HT-29 cells, which endogenously express BCRP, to SN-38. Gefitinib increased intracellular accumulation of topotecan in K562/BCRP cells and suppressed ATP-dependent transport of estrone 3-sulfate, a substrate of BCRP, in membrane vesicles from K562/BCRP cells. These results suggest that gefitinib may overcome BCRP-mediated drug resistance by inhibiting the pump function of BCRP. Furthermore, P388/BCRP-transplanted mice treated with combination of irinotecan and gefitinib survived significantly longer than those treated with irinotecan alone or gefitinib alone. In conclusion, gefitinib is shown to interact with BCRP. BCRP expression in a certain sort of cells is supposed to be one of the determinants of gefitinib sensitivity. Gefitinib inhibits the transporter function of BCRP and reverses BCRP-mediated drug resistance both in vitro and in vivo.