他莫昔芬在乳腺癌治疗中的耐药性机制研究

他莫昔芬用于治疗乳腺癌病人依赖于雌激素受体（ER）的存在，但大约一半ER阳性的病人会发展为耐药性表型，可有原因有；他莫昔芬的药理学特性，ER结构及功能的改变。肿瘤环境和肿瘤细胞遗传性改变的相互作用等，但关于耐药性产生的机制仍不明确，研究表明BCAR基因在体外可把雌激素依赖性乳腺癌细胞转化为雌激素非依赖性，他莫昔芬耐药性细胞。且ER阳性初期乳腺癌患者高水平的BCAR1/P130蛋白与其对他莫昔芬治疗的内在耐药性有关。     

补中益气汤对EAC小鼠癌细胞膜LPO含量的影响

本文利用测定癌细胞膜表面过氧化脂质(LPO)含量的方法,研究了补中益气汤对艾氏腹水癌(EAC)小鼠细胞膜 LPO 含量的影响。实验结果表明,补中苴气汤对 EAC 小鼠癌细胞膜上 LPO 的生成有显著的对抗作用,这一作用可能是补中益气汤抑制小鼠 EAC 的作用机理之一。     

多西他赛他莫昔芬复方脂质体逆转乳腺癌细胞耐药性的研究

目的 在体外考察多西他赛(Docetaxel, DTX)他莫昔芬(Tamoxifen, TMX)复方脂质体对乳腺癌细胞耐药性的逆转作用。方法 在体外,利用乳腺肿瘤细胞MCF-7和耐药乳腺肿瘤细胞MCF-7/ADR,通过MTU实验和中效原理评价多西他赛和他莫昔芬不同浓度时的协同作用。通过薄膜分散法制备具有协同作用的多西他赛他莫昔芬复方脂质体。在体外通过MTT实验考察复方脂质体细胞毒性和逆转肿瘤耐药作用。结果 在MCF-7细胞和MCF-7/ADR细胞,TMX-DUX混合物(M∶M=7∶1)的中效原理联合指数值都小于1,具有协同作用。对MCF-7细胞,游离药物DTX在浓度0.001 nM到50 nM有细胞毒性,游离TMX没有细胞毒性,DTX-TMX复方脂质体具有细胞毒性。对耐药MCF-7/ADR细胞,游离药物DTX在浓度0.001 nM到50 nM没有细胞毒性,游离TMX没有细胞毒性,DTX-TMX复方脂质体具有细胞毒性,并且细胞毒性强度大于对MCF-7细胞。结论 DTX-TMX复方脂质体能够逆转肿瘤耐药性。     

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。     

多西他赛他莫昔芬脂质体体外释放研究

目的考察多西他赛他莫昔芬复方脂质体体外释放。方法薄膜分散法制备单方和复方脂质体样品,通过透析法进行脂质体体外释放,采用高效液相色谱法测定他莫昔芬和多西他赛药物浓度,并对体外释放曲线进行数学模型拟合。结果单方和复方脂质体中,他莫昔芬和多西他赛均无突释,多西他赛较他莫昔芬释放快,他莫昔芬和多西他赛释放模型符合一级释放方程,他莫昔芬和多西他赛的释放曲线相似。结论他莫昔芬和多西他赛在单方和复方脂质体体外释放并无显著差异。     

miR-30a-5p在人乳腺癌MCF-7细胞对他莫昔芬耐药性中的作用研究

目的 探究miR-30a-5p在人乳腺癌MCF-7细胞对他莫昔芬(tamoxifen,TAM)耐药性中的作用,并阐明相关作用机制。方法 通过短时间高浓度TAM刺激MCF-7细胞诱导耐药株,MTT法检测细胞耐药性的改变;qRT-PCR法检测MCF-7细胞及其耐药细胞株MCF-7/TAM中miR-30a-5p的表达情况;吖啶橙染色及Western blotting检测MCF-7/TAM细胞相对于MCF-7细胞自噬的变化;转染miR-30a-5p模拟物后,采用MTT法检测MCF-7/TAM细胞对TAM敏感性的变化,并通过吖啶橙染色和Western blotting观察miR-30a-5p对MCF-7/TAM细胞自噬的影响;采用生物信息学方法对miR-30a-5p进行靶基因预测,荧光素酶报告基因试验验证miR-30a-5p对ATG5的靶向调控作用;Western blotting检测miR-30a-5p对ATG5表达的影响。结果 TAM对MCF-7/TAM细胞的抑制作用明显弱于对MCF-7细胞;miR-30a-5p在MCF-7/TAM细胞中的表达水平明显低于在MCF-7细胞中;相对于MCF-7细胞,MCF-7/TAM细胞的自噬水平明显升高;过表达miR-30a-5p后,MCF-7/TAM细胞对TAM敏感性显著增加,自噬水平显著降低;Targetscan软件分析表明ATG5是miR-30a-5p的下游靶基因,通过荧光素酶报告基因试验进一步证明miR-30a-5p靶向调控ATG5;MCF-7/TAM细胞中上调miR-30a-5p能够抑制ATG5的表达。结论 miR-30a-5p靶向调控ATG5,并能够抑制细胞的自噬,进而增强乳腺癌细胞对TAM的敏感性。     

他莫昔芬介导脂质体细胞内化的机制研究

文献报道他莫昔芬能够增强载药脂质体的细胞摄取,其具体机制仍有待研究,有研究者推测此现象是由他莫昔芬抑制P-糖蛋白对药物的外排作用而造成的。本研究为进一步阐明该作用的机理,制备了PEG修饰、共包载他莫昔芬的P-糖蛋白底物阿霉素脂质体及非底物香豆素-6脂质体,研究了不同P-糖蛋白表达水平的细胞对载药脂质体的摄取情况,及包载他莫昔芬后脂质体与脂膜的相互作用。结果表明,共包载他莫昔芬能显著提高所选三种细胞对阿霉素脂质体的摄取,且摄取增加水平与P-糖蛋白表达水平相关。同时,共包载他莫昔芬能显著增加非P-糖蛋白底物香豆素-6脂质体的摄取,对阿霉素脂质体在P-糖蛋白表达阴性的Hela细胞中的摄取也有显著促进作用。表面等离子共振技术证明他莫昔芬脂质体与模型生物膜的亲和力强于不载药的空白脂质体,等温滴定量热技术证明游离他莫昔芬与模型生物膜有明显亲和作用。综上,他莫昔芬能够增强脂质体和生物膜的亲和力,通过抑制P-糖蛋白对药物的外排、提高脂质体和细胞膜的结合两方面的共同作用提高细胞对脂质体的摄取。     

3-溴丙酮酸-胆固醇酯增强乳腺癌细胞对他莫昔芬敏感性研究

目的：探讨3-溴丙酮酸-胆固醇酯（3-bromopyruvate cholesterol ester,3-BP-Cl）增强乳腺癌对他莫昔芬（tamoxifen,TAM）敏感性作用及机制。方法：MTT法检测药物对乳腺癌细胞活力的影响,并使用金氏公式检验3-溴丙酮酸-胆固醇酯与他莫昔芬是否具有协同抗乳腺癌作用。Calcein AM/PI染色法检测药物对细胞的毒性作用,集落克隆形成法检测药物对乳腺癌细胞的增殖抑制作用。流式细胞术检测药物诱导乳腺癌细胞的凋亡作用。Western blot检测药物对细胞己糖激酶2、Bcl-2、Bax蛋白表达的影响。结果：MTT结果显示3-溴丙酮酸-胆固醇酯具有抑制乳腺癌作用,与他莫昔芬联用能显著抑制MCF-7细胞生长活性（P<0.05）。金氏公式测算结果显示3-溴丙酮酸-胆固醇酯与他莫昔芬具有协同抑制乳腺癌细胞增殖作用（q>1.15）。Calcein AM/PI染色结果显示两药联用组细胞死亡数量最多。集落克隆形成实验结果显示两药联用组MCF-7细胞的集落数量最少。Annexin V凋亡结果显示与单药组相比,联用组细胞凋亡数量显著升高（P<0.0...     

他莫昔芬的临床应用

乳腺癌、子宫内膜癌是女性最常见的恶性肿瘤 ,发病率逐年增高且发病年龄有变小的趋势。他莫昔芬 (ＴＡＭ)作为人工合成的非甾体类雌激素拮抗药 ,已广泛用于乳腺癌、子宫内膜癌的内分泌治疗。1　他莫昔芬与乳腺癌10ａ间随访服ＴＡＭ 1,2 ,5ａ的 3 0 0 0名女性乳腺癌患者 ,肿瘤复发率减少依次为 2 1% ,2 9% ,47% ,死亡率下降依次为12 % ,17% ,2 6% ,在服药最初 5ａ肿瘤延迟复发确有大的改善 ,最初 10ａ生存率平稳增加。淋巴结阳性、阴性者死亡率下降相似 ,但绝对死亡率减少前者居多 ,服ＴＡＭ约 5ａ的 10ａ期生存率改善是肯定的 ,淋巴结阳性为…     

雌激素受体拮抗剂他莫昔芬和4-羟基他莫昔芬治疗非小细胞肺癌的实验研究

[目的]探讨雌激素受体拮抗剂在非小细胞肺癌治疗中的作用。[方法]用逆转录多聚酶链式反应（RT-PCR）测定肺腺癌细胞株SPC-A-1的雌激素受体mRNA(ER-mRNA)表达，分别在去激素培养条件下观察不同浓度的他莫昔芬（Tam)，4-羟基他莫昔芬（OHTam)和雌二醇（E2）对其生长速度，细胞周期时相，ER-mRNA水平和细胞形态学的影响。[结果]SPC-A-1肺腺癌细胞株有ER-mRNA表达，低浓度E2（10^-8mol/L)可促进其生长，Tam(10^-6mol/L)和O-HTam(10^-6mol/L）可抑制E2（10^-8mol/L)的生长刺激作用，去激素环境下细胞生长明显减慢，在无激素环境中亦能抑制细胞生长，抑制发生在G0/G1期，并有细胞内质网扩张等结构改变，ER-mRNA表达水平下降，[结论]肺腺癌SPC-A-1细胞株的生长具有雌激素依赖性，应用ER拮抗剂Tam和OHTam能抑制其生长。肺癌细胞中ER水平存在自身调节现象。     

抗阿霉素的中国仓鼠卵巢上皮细胞系的抗药性

用细胞生物学和SDS-PAGE电泳方法,研究抗阿霉素(Dox)CHO细胞系(RCl)的特性。用间接免疫荧光法,未测到RCl超表达P-糖蛋白。RCl降低Dox的摄入,增加膜的流动性,Dox在CHO中主要分布在细胞核,在RCl中则分布在细胞质和细胞核。RCl中有一种分子质量为30—40 kDa的核蛋白的表达被抑制,而在敏感CHO中其表达正常。     

Enhanced antitumour activity of doxorubicin and simvastatin combination loaded nanoemulsion treatment against a Swiss albino mouse model of Ehrlich ascites carcinoma

Doxorubicin (DOX) is the most commonly used anticancer drug; however, it has limited use because prolonged administration may result in severe cardiotoxicity. Simvastatin (SIM), generally prescribed for hypercholesterolaemia, has also shown salubrious results in the monotherapy or combinational drug therapy of different cancers in various models. Nanoparticle drug delivery systems are a novel way of improving therapeutics and also improving the absorption and specificity of drugs towards tumour cells. In this study, we exploited this technology to increase drug specificity and minimize imminent adverse effects. In this study, the antitumour activity of the combination formulas of DOX and SIM, either loaded in water (DOX‐SIM‐Solution) or nanoemulsions (NEs) (DOX‐SIM‐NE), was evaluated in a Swiss albino mouse model of Ehrlich ascites carcinoma. The anticancer effect was assessed by quantifying the change in body weight, mean survival time, and percent increase in lifespan (%ILS), determining haematological and serum biochemical parameters (liver function test, kidney function test and lipid profile parameters) as well as studying the histopathological alterations in liver tissues. We observed a clear increase in %ILS of the DOX‐SIM‐Solution group (265.30) that was double the %ILS of the DOX‐SIM‐NE group (134.70). However, DOX‐SIM‐NE had a non‐toxic effect on the haematological parameters, whereas DOX‐SIM‐Solution increased the levels of haemoglobin and lymphocytes. Furthermore, the encapsulation of SIM and DOX into NEs improved the levels of all serum biochemical parameters compared to the DOX‐SIM‐Solution. A reduction in the side effects of DOX‐SIM‐NE on the liver was also established using light microscopy, which revealed that the morphologies of the hepatocytes of the mice were less affected by administration of the DOX‐SIM‐NE treatment than with the DOX‐SIM‐Solution treatment. The study showed that incorporating SIM into the DOX‐loaded‐NE formulation remarkably improved its efficiency and simultaneously reduced its adverse effects.     

Down-regulation of survivin expression reversed multidrug resistance in adriamycin-resistant HL-60/ADR cell line

AIM: To investigate the ability of an antisense RNA eukaryotic expression plasmid pcDNA3.1/survivin in downregulating the expression level of survivin mRNA and survivin protein and reversed multidrug resistance (MDR) in adriamycin-resistant HL-60/ADR cell line. METHODS: The expression of survivin mRNA was measured by RTPCR and the expression of survivin protein was measured by Western blot. Caspase-3 activity was determined by Phar Mingen colorimetric assay kit. Apoptosis was assessed by flow cytometry. The chemosensitivity of HL-60/ADR cells to adriamycin (ADR) was measured by MTT assay. RESULTS: pcDNA3.1/survivin down-regulated the expression level of survivin mRNA and survivin protein obviously, and induced apoptosis of HL-60/ADR cells in a time-dependent manner during 12-48 h. After transient transfection with pcDNA3.1/survivin for 48 h, survivin mRNA decreased by 67％, survivin protein decreased by 57％, caspase-3 activity increased 4.37 times, and the apoptosis rate increased by 4.41％ compared wi     

阿霉素诱导的人白血病细胞系K562/A02多药抗药性(英文)

目的:研究白血病细胞多药耐药发生的机制. 方法:用逐步增加培养基中阿霉素(Dox)浓度的方法,诱导出一株耐Dox的人白血病细胞系K562/A02.用[~3H]TdR参入法测定IC_(50),HPLC法测定细胞内药物浓度,免疫组织化学法检测P-糖蛋白的表达,RT-PCR法测定mdr1基因表达,点杂交测定基因组中mdr1DNA和拓扑异构酶Ⅱ(TopⅡ)基因表达,CDNB法测定谷胱甘肽-S-转移酶(GST)活性. 结果:K562/A02对Dox、HHT、Dau、VCR、m-AMSA、VP-16具有较强的交叉耐药性,而对Ara-C耐药较弱,对5-FU、Cis和MTX不交叉耐药,表现出典型的多药耐药表型.K562/A02细胞内药物浓度明显低于K562细胞,P-170阳性表达.K562/A02细胞中MDR1基因拷贝数与K562的无差异,但mdr1mRNA高表达.TopⅡ的mRNA水平低于K562,GST的活性增高. 结论:白血病细胞多药耐药的机制与mdr1基因表达密切相关,也与TopⅡ和GST有关.     

阿霉素脂质体对克服肿瘤多药耐药的细胞学体外评价

目的:评价市售阿霉素脂质体体外逆转肿瘤多药耐药(MDR)的作用。方法:MTT法比较阿霉素和阿霉素脂质体体外对敏感和耐药细胞的细胞毒作用;荧光显微镜观察2组药物对敏感和耐药细胞的影响;流式细胞仪检测2组分别在细胞内的积累和外排情况。结果:细胞毒性试验结果显示,尽管在敏感细胞中,阿霉素脂质体IC50远高于阿霉素溶液组,对于耐药细胞株,阿霉素脂质体的IC50与游离阿霉素无显著性差异(P>0.05);细胞荧光染色显示,阿霉素脂质体较溶液在耐药细胞核中有更强的红染;细胞摄取试验显示,相同浓度下,阿霉素脂质体较溶液组在耐药细胞中积累量差异无显著性(P>0.05),但外排试验显示,在耐药细胞KBv200中,相同浓度下的脂质体较溶液具有更强的细胞滞留能力(P<0.05)。结论:阿霉素脂质体较阿霉素溶液在体外能更多进入耐药细胞核,并表现出更强的药物滞留能力,可部分克服多药耐药。     

Sericin nanomicelles with enhanced cellular uptake and pH-triggered release of doxorubicin reverse cancer drug resistance

Drug resistance is the major challenge facing cancer chemotherapy and nanoscale delivery systems based on natural materials, such as sericin, are a promising means of overcoming drug resistance. Yet, no attempt of introducing synthetic poly(γ-benzyl-L-glutamate) (PBLG) onto sericin polypeptide to fabricate a facile biocompatible and biodegradable micelle has been tried. Here, we prepared a polypeptide-based amphiphilic polymer containing hydrophilic sericin polypeptide backbone and PBLG side chains via ring-opening polymerization (ROP) strategy. The introduction of PBLG side chains remarkably enhances the stability of sericin micelles in water. Meanwhile, the micelles exhibited a high loading capacity and pH-responsive release ability for antitumor drug doxorubicin (DOX), called sericin-PBLG-DOX. Owing to the excellent cell membrane penetration of sericin-PBLG, the cellular uptake of DOX when loaded into micelles was improved. Subsequently, sericin-PBLG-DOX was transferred into perinuclear lysosomes, where the release rate of DOX was accelerated. Compared to the same dose of DOX, sericin-PBLG-DOX could induce a more efficient anti-tumor effect both in vitro and in vivo, and these micelles have promise for future clinical applications in overcoming cancer drug resistance with good biosafety, enhanced cellular uptake, pH-triggered drug release, efficient anti-tumor effects, and minimized systemic toxicity.     

苦瓜素I抑制乳腺癌MCF-7/DOX细胞多柔比星耐药的研究

目的：研究苦瓜素I （momordicin I,MMI）对人乳腺癌耐多柔比星（doxorubicin,DOX） MCF-7/DOX细胞耐药的影响及其作用机制。方法：MTT比色法检测MMI对MCF-7/DOX细胞的毒性,考察MMI对MCF-7/DOX细胞多柔比星敏感性的影响;实时定量PCR和western blot方法检测DOX单独以及MMI与DOX联用后,MCF-7/DOX细胞中MDR1在mRNA和蛋白质水平的表达变化;进一步采用实时定量PCR方法检测DOX单独以及MMI与DOX联用后,MCF-7/DOX细胞中与甘油磷脂代谢相关的AGPAT2、CEPT1、CHKA、DGKA、PCYT1A、PLA2G15等基因表达的变化。结果：MMI （12.5,25,50 μg·mL^-1,）可明显抑制MCF-7/DOX细胞的增殖,MMI对MCF-7/DOX细胞的最大无毒浓度为6.25 μg·mL^-1。MMI 6.25 μg·mL^-1与DOX联用后,DOX对MCF-7/DOX细胞的半数抑制浓度（IC₅₀）下降,MMI使得MCF-7/DOX细胞对DOX的敏感性提高了13.88倍。与DOX 50 μg·mL^-1单独组相比,MMI 6.25 μg·mL^-1与DOX 50 μg·mL^-1联用后,MCF-7/DOX细胞中的MDR1 mRNA显著下调（P<0.05）,MDR1蛋白表达有下降趋势。进一步研究发现MMI 6.25 μg·mL^-1与DOX 50 μg·mL^-1联用可协同下调MCF-7/DOX细胞甘油磷脂代谢相关基因AGPAT2、CEPT1、CHKA、DGKA、PCYT1A、PLA2G15等表达。结论：MMI可增强乳腺癌MCF-7/DOX细胞多柔比星敏感性,抑制MDR1表达,逆转耐药,此作用可能与其抑制甘油磷脂代谢有关。     

R-dl-型维拉帕米调低KBv200肿瘤细胞对长春新碱和多柔比星的多药抗药性

目的:研究R-型维拉帕米对多药耐药的降低作用及其急性动物毒性,并与消旋维拉帕米的相应结果作比较。方法:细胞毒性的测定用MTT法;细胞内多柔比星积累的测定用萤光分光光度计法。急性毒性试验用BALB/c小鼠腹腔注射法。结果:R-型维拉帕米部分调低KBv200细胞对长春新碱和多柔比星的耐药性,其调低效应与作用浓度和作用时间有关。1.25μmol·L~(-1)的R-型维拉帕米与长春新碱对细胞作用24h,能够显著增加KBv200细胞对长春新碱的敏感性。在增敏和增加细胞内多柔比星累积方面,R-型维拉帕米与消旋维拉帕米效果一样,但R-型维拉帕米的急性动物毒性明显低于消旋维拉帕米。结论:R-型维拉帕米1.25μmol·L~(-1)提高耐药肿瘤细胞对长春新碱和多柔比星的敏感性,增加对长春新碱敏感性所需的药物作用时间可缩短至24h。     

In vitro and in vivo antitumor activity of a methanol extract of Dregea volubilis leaves with its antioxidant effect

Context: In India, Dregea volubilis (L.f.) Benth. ex Hook.f. (Asclepediaceae), a large twining shrub with a woody vine, is used to treat tumors traditionally.

Objective: This study evaluated the in vitro and in vivo antitumor activity of the methanol extract of Dregea volubilis leaves (MEDV) and elucidated its possible mechanism of action.

Materials and methods: In vitro antitumor activity of MEDV was evaluated against Ehrlich ascites carcinoma (EAC) cell-line. In vivo antitumor and antioxidant activity of MEDV at three dose levels (50, 100, and 200?mg/kg) were determined against EAC tumor-bearing mice. After 24?h of EAC inoculation, the extract was administered for 9 consecutive days. After the administration of the last dose on the 9th day followed by 18?h fasting, mice from all groups were sacrificed to determine antitumor activity and hematological profiles along with liver related biochemical parameters like lipid peroxidation, antioxidant enzymatic activity, etc.

Results: For in vitro antitumor activity, IC₅₀ value of MEDV for EAC tumor cells was 85.51?±?4.07 µg/ml. The MEDV showed a decrease in tumor volume, packed cell volume and viable cell count and an increase in the non-viable cell count of the EAC tumor-bearing mice (p?<?0.001). Hematological profile reverted near to normal level in extract treated mice. MEDV decreased the hepatic lipid peroxidation level and enhanced superoxide dismutase and catalase level in tumor-bearing mice (p?<?0.001).

Discussion and conclusion: MEDV exhibited in vitro and in vivo antitumor activity in EAC tumor-bearing mice mediated through augmenting antioxidant defense system.     

小白菊内酯诱导耐药白血病细胞K562/ADR凋亡的研究

目的初步探讨小白菊内酯(PTL)对耐药白血病细胞K562/ADR细胞增殖和凋亡的影响及其作用机制。方法MTT法及LDH释放法检测小白菊内酯对K562和K562/ADR细胞增殖抑制作用,流式细胞术检测细胞凋亡和细胞内活性氧(ROS)的变化,Western blot法检测凋亡相关蛋白Bax、Bcl-2、caspase-3、caspase-9的表达变化。结果 PTL抑制K562/ADR细胞的增殖,呈剂量依赖,半数抑制浓度(IC50)值分别为(4.36±0.37)μmol.L-1、(10.6±2.81)μmol.L-1。10μmol.L-1PTL作用24 h诱导K562/ADR细胞的凋亡率为(31.21±0.40)%,其IC50值与凋亡率与K562细胞相比差异无显著性(P>0.05)。经10μmol.L-1PTL处理1 h,K562/ADR细胞内ROS增加;处理24 h,Bcl-2与Bax的比值降低、caspase-3、caspase-9酶源蛋白表达降低。用N-乙酰半胱氨酸(NAC)预处理细胞,能抑制细胞ROS水平升高和细胞凋亡。结论 PTL能诱导耐药白血病细胞凋亡,作用机制与其刺激细胞内ROS升高相关。