新型多肽聚酰胺-胺型靶向药物载体的载药性能及细胞吸收和毒性

背景：前期研究通过噬菌体展示体内筛选方法获得了一条NCI-H460非小细胞肺癌特异结合的多肽（Lung cancer targetingpe ptide,LCTP）,将该多肽与修饰的聚酰胺-胺型（Polyamidoamine,PAMAM）树枝状高分子材料连接制备了纳米靶向药物载体PAMAM-Ac-FITC-LCTP,该载体在体内外对非小细胞肺癌NCI-H460具有很好的靶向性。目的：在前期研究基础上,进一步研究PAMAM-Ac-FITC-LCTP靶向载体对阿霉素的包埋、释放及其细胞吸收和毒性性能。方法：以筛选到的多肽LCTP为靶向剂,构建了PAMAM-Ac-FITC-LCTP靶向载体。采用物理包埋法将PAMAM-Ac-FITC-LCTP与阿霉素连接,通过体外透析实验观察载体对药物的缓释功能,共聚焦显微镜观察细胞对药物的吸收。以游离阿霉素作为对照,MTT法观察载体载药后对NCI-H460细胞的作用。结果与结论：PAMAM-Ac-FITC-LCTP对阿霉素的最大包埋率为7.46%。载体对药物具有明显的缓释作用,离子浓度、pH和温度对药物的释放具有影响,说明PAMAM-Ac-FITC-LCTP主要是通过静电相互作用与阿霉素结合。PAMAM-Ac-FITC-LCTP/阿霉素短时间内较单独药物更高效进入NCI-H460细胞,而复合物24h的细胞毒性与阿霉素对细胞的毒性基本一致。以上结果说明PAMAM-Ac-FITC-LCTP可能是一个肿瘤治疗和诊断中很有用的药物靶向传输载体。     

生物素化聚乙二醇/聚乳酸纳米粒子的体外主动靶向行为

背景:目前研究的大部分高分子药物载体没有靶向性,在应用上有局限性,只有几个国外课题组报道生物素化聚乙二醇/聚乳酸(Biotin-PEO-PLA)纳米粒子的体外靶向行为,国内没有这方面的研究报道.目的:分析Biotin-PEO-PLA纳米粒子作为靶向药物载体的可行性.方法:透析法制备包埋紫杉醇的Biotin-PEO-PLA纳米粒子并表征;通过高效液相色谱研究包埋紫杉醇的Biotin-PEO-PLA纳米粒子的体外释放行为;利用细胞毒性法比较研究生物素-亲和素三步法实施的包埋紫杉醇的Biotin-PEO-PLA纳米粒子对OVCAR-3(表面表达CA-125抗体)和SKOV-3(表面不表达CA-125抗体)细胞的体外靶向行为.结果与结论:包埋在Biotin-PEO-PLA纳米粒子中的紫杉醇的释放呈现初期的快速释放以及随后的缓慢释放.利用三步法处理的OVCAR-3细胞存活率明显低于SKOV-3细胞,表明通过Biotin-PEO-PLA/avidin/biotinylated MAB X306与OVCAR-3细胞表面CA-125抗原的特异性相互作用,包埋紫杉醇的Biotin-PEO-PLA纳米粒子被更为有效地传递进了OVCAR-3细胞.     

盐酸表阿霉素纳米靶向制剂的缓释效应***◆

背景:盐酸表阿霉素是一种广谱抗生素,目前临床使用的不足多为药物释放快、目标组织药物浓度低,静脉给药后广泛分布于体内各种组织器官,不良反应明显.目的:针对盐酸表阿霉素临床应用的不足,制备盐酸表阿霉素纳米靶向注射制剂.方法:以叶酸偶联牛血清白蛋白为载体,采用乳化-高压匀质法,制备盐酸表阿霉素纳米靶向注射制剂,以激光粒度分析仪测定纳米颗粒的粒径大小、粒径分布及 Zeta 电位,扫描电镜观察纳米颗粒的表面形态,高效液相色谱法分析白蛋白负载盐酸表阿霉素纳米制剂的包封率、载药量和释药性能.结果与结论:制备的盐酸表阿霉素纳米粒外观呈均匀球型,粒径分布较窄,平均粒径为(157.73±0.40) nm,平均 Zeta 电位为(-30.85±0.43) mV,载药量22.78%,包封率可达96.24%.体外模拟释药结果表明药物释放曲线分为两个阶段,突释阶段微球释药量在24 h内达42.6%,缓释阶段纳米粒释药持续时间长,在112 h 时释药量达84.1%,载药纳米粒的药物释放速率持续稳定.结果表明乳化结合高压匀质法制备的盐酸表阿霉素纳米靶向制剂粒径均匀,粒径范围分布窄,载药量和包封率高,具有一定的缓释作用.     

丹参酮ⅡA对肺腺癌NCI-H460细胞增殖和凋亡的影响

目的:探讨丹参酮ⅡA对肺癌细胞株NCI-H460的增殖抑制作用与促凋亡的影响。方法:分别以不同浓度的丹参酮ⅡA干预肺腺癌H460细胞,应用四甲基偶氮唑蓝(MTT)比色法检测细胞的增殖抑制,应用流式细胞仪观察丹参酮ⅡA对NCI-H460肺腺癌细胞的促凋亡作用。结果:丹参酮ⅡA可显著抑制肺腺癌NCI-H460细胞的生长,抑制程度与作用时间和药物浓度成正相关,流式细胞仪结果显示:用0.3125μg/mL的丹参酮ⅡA作用NCI-H460细胞24、48、72h后,细胞凋亡率分别为3.69%、6.67%、12.01%,成时间依赖性。结论:丹参酮ⅡA对NCI-H460细胞的增殖具有明显的抑制以及诱导凋亡的作用。     

肝癌靶向载体药物的靶向作用与应用分析

背景：肝癌是常见的恶性肿瘤之一,选择有效的治疗药物及治疗方法具有重要的意义。目的：评价载体缓释化疗药物对肝癌的靶向治疗作用及效果。方法：分析临床常用的肝癌化疗药物5-氟尿嘧啶、丝裂霉素以及表阿霉素载体缓释系统对肝脏肿瘤的靶向性特征以及对肿瘤的抑制和杀伤作用。并观察总结海南省农垦总医院肿瘤内科163例中晚期肝癌患者应用化疗药物5-氟尿嘧啶、丝裂霉素、表阿霉素,同时采用导管动脉化疗栓塞辅助治疗的临床效果。结果与结论：5-氟尿嘧啶、丝裂霉素以及表阿霉素载体缓释系统通过不同的作用机制显示出对肝脏肿瘤的靶向性特征,并且对肝脏肿瘤具有较高的抑制和杀伤作用,减少药物用量,降低毒副作用,提高治疗效果。此外,治疗时辅助应用导管动脉化疗栓塞可以延长患者的生存期,提高肝癌的治疗效果。     

透明质酸在临床医学中的应用

透明质酸是广泛分布在软结缔组织细胞外基质中的主要蛋白多糖，具有良好的生物相容性和生物降解性，在临床医学中具有广泛的应用。在医药领域，透明质酸及其衍生物作为优良的药物载体，能够达到药物增稠、药物缓释、促进药物透皮能力及靶向性的目的。透明质酸作为眼用制剂的媒介，能够明显提高药物生物利用度，且具有保湿润滑、抗炎和促修复作用；作为药物缓释载体，能够延缓药物释放速度，且对一些生物大分子药物还具有生物黏附作用；作为抗肿瘤药物的靶向载体，能够增加抗肿瘤药在肿瘤和淋巴结中的吸收和滞留时间，提高药物的疗效。     

表面修饰二氧化硅的脂质体对阿霉素的包埋与释放性质木水

背景:脂质体药物载体近年来被用以增加药物的稳定性,提高药效,降低药物的毒副作用.然而研究发现由于稳定性较差,脂质体药物载体难以实现药物缓释与长效给药.大量研究表明,二氧化硅无毒,具有化学惰性和生物相容性,是很好的修饰材料.目的:为了提高脂质体药物载体的稳定性,延长给药时间,采用二氧化硅对脂质体进行表面修饰并用于抗癌药物盐酸阿霉素的包埋.设计、时间及地点:体外观察实验,于2007 05/2008-06在哈尔滨工业大学生物医学工程中心的纳米医药与生物传感器实验室完成.材料:L-α-二棕榈酰磷酯酰胆碱购自南京康森特化工有限公司,正硅酸乙酯购自美国Aldrich公司,盐酸阿霉素购自北京华奉联博科技有限公川,葡聚糖凝胶G-50购自瑞典Amersham公司,其他化学试剂均为分析纯.方法:通过溶胶-凝胶沉积二氧化硅的方法修饰模板L-α-二棕榈酰磷酯酰胆碱脂质体.主要观察指标:通过激光粒度仪与Zeta电位仪测定二氧化硅修饰后的脂质体粒径分布与表面电荷;通过透射电镜观察二氧化硅修饰后脂质体的形态;通过傅里叶变换红外光谱表征材料的化学结构;通过荧光光谱仪测定溶液中阿霉素浓度;通过阿霉素浓度回归方程计算脂质体药物包封率与脂质体体外释放速率.结果:①成功制备了二氧化硅包裹修饰的脂质体.②傅里叶变换红外光谱结果显示在1 166cm-1,1 080cm-1,859cm-1和526cm-1存在Si-O-Si振动峰.③二氧化硅修饰的脂质体对阿霉素的包封率为72.4%.④药物体外释放结果显示二氧化硅包裹修饰的脂质体使阿霉索达到缓释效果.结论:由于在脂质体的表面形成纳米级厚度的无机Si-O-Si网络作为保护层,使得脂质体的稳定性显著提高,并且对阿霉素有缓释效果.     

表面修饰二氧化硅的脂质体对阿霉素的包埋与释放性质

背景：脂质体药物载体近年来被用以增加药物的稳定性,提高药效,降低药物的毒副作用。然而研究发现由于稳定性较差,脂质体药物载体难以实现药物缓释与长效给药。大量研究表明,二氧化硅无毒,具有化学惰性和生物相容性,是很好的修饰材料。 目的：为了提高脂质体药物载体的稳定性,延长给药时间,采用二氧化硅对脂质体进行表面修饰并用于抗癌药物盐酸阿霉素的包埋。 设计、时间及地点：体外观察实验,1：200705／2008—06存哈尔滨工业大学生物医学工程中心的纳米医药与生物传感器实验室完成。材料：L-α二棕榈酰磷酯酰胆碱购自南京康森特化工有限公司,正硅酸乙酯购自美国Aldrich公司,盐酸阿霉素购白北京华奉联博科技有限公司,葡聚糖凝胶G-50购自瑞典Amersham公司,其他化学试剂均为分析纯。 方法：通过溶胶凝胶沉积二氧化硅的方法修饰模板L-α二棕榈酰磷酯酰胆碱脂质体。主要观察指标：通过激光粒度仪与Zeta电位仪测定二氧化硅修饰后的脂质体粒径分布与表面电荷;通过透射电镜观察二氧化硅修饰后脂质体的形态;通过傅里叶变换红外光谱表征材料的化学结构;通过荧光光谱仪测定溶液中阿霉素浓度;通过阿霉素浓度回归方程计算脂质体药物包封率与脂质体体外释放速率。 结果：①成功制各了二氧化硅包裹修饰的脂质体。②傅里叶变换红外光谱结果显示在1166cm^-1,1080cm^-1,859cm^-1和526cm^-1存在Si-O-Si振动峰。③：氧化硅修饰的脂质体对阿霉素的包封率为724％。④药物体外释放结果移示二氧化硅包裹修饰的脂质体使阿霉素达到缓释效果。结论：由于在脂质体的表面形成纳米级厚度的无机Si-O-Si网络作为保护层,使得脂质体的稳定性显著提高,并且对阿霉素有缓释效果。     

蛇床子素联合顺铂对人肺癌细胞的杀伤效应及机制

目的探讨蛇床子素联合顺铂对人肺癌细胞NCI-H460的杀伤效应及机制。方法采用噻唑蓝(MTT)法检测蛇床子素(50、100、200μmol/L)、顺铂(1.5、3.0、6.0μmol/L)及两者联合(50μmol/L蛇床子素+1.5μmol/L顺铂)对NCI-H460细胞增殖的影响。采用膜联蛋白(AnnexinⅤ)/碘化丙啶(PI)染色法、二氢乙啶(DHE)染色法检测蛇床子素(50μmol/L)、顺铂(1.5μmol/L)及两者联合(50μmol/L蛇床子素+1.5μmol/L顺铂)对NCI-H460细胞凋亡及活性氧簇(ROS)的影响。用ROS抑制剂N-乙酰半胱氨酸(NAC)进行预处理,然后检测蛇床子素(50μmol/L)、顺铂(1.5μmol/L)及两者联合(50μmol/L蛇床子素+1.5μmol/L顺铂)对NCIH460细胞的凋亡诱导能力。以未加药物的NCI-H460细胞作为对照组。结果蛇床子素和顺铂均呈剂量依赖性地抑制NCI-H460细胞的增殖。50μmol/L蛇床子素联合1.5μmol/L顺铂可明显抑制NCI-H460细胞的增殖并诱导其发生凋亡。与蛇床子素及顺铂单独作用比较,二者联合作用后ROS阳性细胞明显增加(P0.05)。与对照组(未用NAC预处理)比较,用NAC预处理过的NCI-H460细胞在用蛇床子素联合顺铂作用后产生的ROS明显降低(P0.05),且凋亡率和对细胞增殖的抑制作用也同样明显降低(P0.05)。结论蛇床子素联合顺铂可通过诱导ROS的产生,引起人肺癌细胞NCI-H460发生凋亡。     

阿霉素异体脱钙骨基质骨粒骨水泥缓释体的制备及体外试验

目的研制阿霉素异体脱钙骨基质骨粒骨水泥缓释体,并研究分析其体外药物缓释性能及对OS-9001骨肉瘤细胞的抑制能力。方法按Urist等的方法制备异体脱钙骨基质骨粒,通过冻干、真空吸附等处理,将阿霉素载入其中并与骨水泥按1:1比例复合,制得阿霉素异体脱钙骨基质骨粒骨水泥缓释体,对该缓释体进行体外药物释放及其浸出液的体外抑瘤试验。结果该缓释体第1天释放量为总含量的19.23%,其第1、20、40及70天的浸出液对OS-9901骨肉瘤细胞的抑制率分别为64.27%、41.68%、28.71%及24.32%。结论该缓释体具有良好的缓释功能,在70d内对OS-9901骨肉瘤细胞维持良好有效的抑制率。     

A Novel Peptide Enhances Therapeutic Efficacy of Liposomal Anti-Cancer Drugs in Mice Models of Human Lung Cancer

Lung cancer is the leading cause of cancer-related mortality worldwide. The lack of tumor specificity remains a major drawback for effective chemotherapies and results in dose-limiting toxicities. However, a ligand-mediated drug delivery system should be able to render chemotherapy more specific to tumor cells and less toxic to normal tissues. In this study, we isolated a novel peptide ligand from a phage-displayed peptide library that bound to non-small cell lung cancer (NSCLC) cell lines. The targeting phage bound to several NSCLC cell lines but not to normal cells. Both the targeting phage and the synthetic peptide recognized the surgical specimens of NSCLC with a positive rate of 75% (27 of 36 specimens). In severe combined immunodeficiency (SCID) mice bearing NSCLC xenografts, the targeting phage specifically bound to tumor masses. The tumor homing ability of the targeting phage was inhibited by the cognate synthetic peptide, but not by a control or a WTY-mutated peptide. When the targeting peptide was coupled to liposomes carrying doxorubicin or vinorelbine, the therapeutic index of the chemotherapeutic agents and the survival rates of mice with human lung cancer xenografts markedly increased. Furthermore, the targeting liposomes increased drug accumulation in tumor tissues by 5.7-fold compared with free drugs and enhanced cancer cell apoptosis resulting from a higher concentration of bioavailable doxorubicin. The current study suggests that this tumor-specific peptide may be used to create chemotherapies specifically targeting tumor cells in the treatment of NSCLC and to design targeted gene transfer vectors or it may be used one in the diagnosis of this malignancy.     

Characterization and targeting ability evaluation of cell-penetrating peptide LyP-1 modified alginate-based nanoparticles

Doxorubicin hydrochloride (DOX) shows a powerful treatment effect on breast cancer. However, for its indiscriminate distribution after systemic administration, the therapeutic response of DOX will reduce and even result in serious adverse reactions during the long-term administration. To achieve better treatment, in this study we established a non-condensing sodium alginate-based nanoparticle-encapsulated DOX (DOX/NP), the surface of which was modified with cell-penetrating peptide LyP-1 (namely LyP-1-DOX/NP) to attain active targeting towards breast cancer cells. The size of LyP-1-DOX/NP was 138.50 ± 4.65 nm, with a polydispersity index (PDI) of 0.22 ± 0.02, and the zeta potential was 18.60 ± 0.49 mV. The drug loading efficiency (DLE) for the preparation was 91.21 ± 2.01%, with an encapsulation efficiency (EE) of 12.37 ± 0.35%. The nanoparticles exhibited good stability in vitro and slower release trend compared with free DOX in PBS at pH7.4. In vitro cytopharmacodynamics showed that LyP-1-DOX/NP had an excellent anti-breast cancer effect against MDA-MB-231 cells by the MTT test. The uptake amount of LyP-1-DOX/NP by MDA-MB-231 cells was much higher than that of free DOX or unmodified DOX/NP at all time points. Further in vivo pharmacokinetics studies showed that the concentration of LyP-1-DOX/NP was higher than that of free DOX or DOX/NP both in plasma and in tumor, suggesting its favorable long circulation and enhancing targeting property. The present study provides a promising strategy for using the LyP-1 cell-penetrating peptide to modify nanoparticles for enhancing their targeting ability towards breast cancer.

Doxorubicin hydrochloride (DOX) shows a powerful treatment effect on breast cancer.     

不同甲基化检测技术对模拟肺癌患者血浆中APC基因甲基化的检测

目的 研究模拟肺癌患者血浆DNA中APC基因甲基化最低检测限,确定不同甲基化检测技术在早期肺癌诊断中的价值.方法 用普通甲基化特异性基因扩增（methylation specific PCR,MSP）方法检测肺癌细胞株NCI-H460细胞APC基因,以酚-氯仿经典方法提取NCI-H460细胞DNA,紫外分光光度计定量并以10倍稀释的浓度梯度依次投入相同的健康人血浆200μl中去,得到模拟肺癌患者血浆,利用磁珠核酸提取方法从模拟血浆样本中提取血浆DNA.对血浆DNA模板进行亚硫酸氢盐化学修饰,并以Sybr-Green Ⅰ为染料进行实时荧光定量MSP检测,同时进行普通MSP检测.结果 NCI-H460细胞中的APC基因启动子1A区719位点存在甲基化,实时荧光定量MSP检测模拟肺癌患者血浆APC基因甲基化的最低检测限为在200 μl血浆中能检测出10^2个肿瘤细胞的DNA,而以普通MSP检测,200 μl血浆中需投入10^3个以上肿瘤细胞的DNA才有弱阳性条带.实时荧光定量MSP检测技术比普通MSP检测的敏感性至少高出10倍.结论 实时荧光定量MSP比普通MSP检测灵敏度高,该技术用于肺癌患者血浆DNA甲基化检测,可能有助于肺癌早期诊断.     

Synergistic anti-tumor effects of the combination of a benzofuroxan derivate and sorafenib on NCI-H460 human large cell lung carcinoma cells

Lung cancer is the most frequent and lethal human cancer in the world. Because is still an unsolved health issue, new compounds or therapeutic strategies are urgently needed. Furoxans are presented as potentials candidates for lung cancer treatment. Accordingly, we evaluated the efficacy of a benzofuroxan derivative, BFD-22, alone and combined with sorafenib against NCI-H460 cell line. We showed that BFD-22 has cytotoxic effects on the NCI-H460 cells. Importantly, the Combination Index (CI) evaluation revels that BFD-22 combined with sorafenib has a stronger cytotoxic effect. In addition, the combination induces apoptosis through extrinsic pathway, leading to TRAIL-R1/DR4-triggered apoptosis. Furthermore, BFD-22 combined with sorafenib increases ROS production and simultaneously reduces perlecan expression in the NCI-H460 cells. In accordance, tumor cells were arrested in the S-phase, and these anti-proliferative effects also inhibit cell migration. This is the first study reporting an advantage of BFD-22 combined with sorafenib as a new therapeutic strategy in the fight against lung cancer.     

Deoxypodophyllotoxin triggers necroptosis in human non-small cell lung cancer NCI-H460 cells

Deoxypodophyllotoxin (DPT), a naturally occurring microtubule destabilizer, inhibits tubulin polymerization and causes cell cycle arrest at G₂/M phase in tumor cells. However, the anti-tumor effect and specific mechanism of DPT in non-small cell lung cancer (NSCLC) are still poorly understood. In this study, we determined the anti-tumor effect and potential mechanism of DPT in the NSCLC cell line, NCI-H460 (H460). First, we demonstrated that DPT significantly inhibits the proliferation of H460 cells in vitro and the growth of H460 xenografts in vivo. In further studies, DPT triggered necroptosis in H460 cells with the following characteristics: (I) necrotic cell death morphology; (II) autophagy; (III) loss of plasma membrane integrity; (IV) loss of mitochondria membrane potential; (V) elevation of reactive oxygen species levels; and (VI) specific inhibition of necroptosis via a small molecule, necrostatin-1. This study also revealed that DPT has a similar effect towards the drug-sensitive cancer cell line, H460, and the drug-resistant cell line, H460/Bcl-xL. To our knowledge, this is the first report to document the induction of necroptosis by a microtubule-targeting agent to circumvent cancer drug resistance, thereby providing a new potential choice for clinical cancer therapy, especially drug-resistant cancer therapy.     

Combined therapy with chemotherapeutic agents and herpes simplex virus type 1 ICP34.5 mutant (HSV-1716) in human non-small cell lung cancer

A replication-selective herpes simplex virus type 1 ICP34.5 mutant (HSV-1716) has shown efficacy both in vitro and in vivo against human non-small cell lung cancer (NSCLC) cell lines but complete eradication of tumor has not been accomplished with a single viral treatment in our murine xenograft models. Therefore, strategies to enhance the efficacy of this treatment were investigated. We determined the oncolytic activity of HSV-1716 in NCI-H460 cells in combination with each of four chemotherapeutic agents: mitomycin C (MMC), cis-platinum II (cis-DDP), methotrexate (MTX), or doxorubicin (ADR). Isobologram analysis was performed to evaluate the interaction between the viral and chemotherapeutic agents. The oncolytic effect of HSV-1716 in combination with MMC was synergistic in two of five NSCLC cell lines. In the other three cell lines, the combined effect appeared additive. No antagonism was observed. The in vivo effect of this combination was then examined in a murine xenograft model. NCI-H460 flank tumors were directly injected with HSV-1716 (4 x 106 PFU) followed by intravenous MMC administration (0.17 mg/kg) 24 hr later. After 3 weeks, the mean tumor weight in the combined treatment group was significantly less than either individual treatment in an additive manner. The synergistic dose of MMC neither augmented nor inhibited viral replication in vitro and HSV-1716 infection did not upregulate DT-diaphorase, which is the primary enzyme responsible for MMC activation. In summary, the combination of HSV-1716 with common chemotherapeutic agents may augment the effect of HSV-based therapy in the treatment of NSCLC.     

Targeting self-assembled F127-peptide polymer with pH sensitivity for release of anticancer drugs

The treatment of breast cancer mainly relies on chemotherapy drugs, which present significant side effects. The most typical example is the cardiotoxicity and bone marrow suppression associated with doxorubicin (DOX). Therefore, this drug is not the first choice in clinical treatment. We designed ATN-FFPFF-ATN, a new targeted antitumor drug carrier, polymerized from phenylalanine dipeptide (FF), ATN-161 peptide, and Pluronic® F-127. The peptide and Pluronic® F-127 are linked with acetal and are, therefore, acid-sensitive. As cancer can reduce pH through complex mechanisms and subsequently maintain acid ambience, our vehicle can smartly unravel at a peculiar position, through which the drug can specifically accumulate inside the tumor. ATN-161 is a protein ligand of integrin α₅β₁, which is highly expressed on the surface of some breast cancer cells. This targeting peptide sequence can play a role in the selective delivery of DOX to tumor cells. The DOX-carrying vector was able to significantly inhibit cell proliferation and promote cell apoptosis in MDA-MB-231 cells. Based on these results, ATN-FFPFF-ATN with pH response is a promising vehicle for DOX delivery.

The treatment of breast cancer mainly relies on chemotherapy drugs, which present significant side effects.     

Bortezomib, but not cisplatin, induces mitochondria-dependent apoptosis accompanied by up-regulation of noxa in the non-small cell lung cancer cell line NCI-H460

Defects in the apoptotic machinery may contribute to chemoresistance of non-small cell lung cancer (NSCLC) cells. We have previously showed a deficiency in mitochondria-dependent caspase-9 activation in NSCLC H460 cells after exposure to cisplatin, a drug widely used to treat NSCLC. Here we show that, unlike cisplatin, the novel anticancer agent bortezomib efficiently induces caspase-9 activation and apoptosis in H460 cells. A comparative analysis of molecular events underlying cell death in bortezomib-treated versus cisplatin-treated H460 cells revealed that bortezomib, but not cisplatin, caused a rapid and abundant release of cytochrome c and Smac/DIABLO from mitochondria. This was associated with a marked increase in levels of the BH3-only proapoptotic protein Noxa and the antiapoptotic protein Mcl-1. Taken together, our data show that bortezomib, by promoting a proapoptotic shift in the levels of proteins involved in mitochondrial outer-membrane permeabilization, is a potent activator of the mitochondrial pathway of apoptosis in NSCLC cells. Our preclinical results support further investigation of bortezomib-based therapies as a possible new treatment modality for NSCLC.     

Controlled and targeted tumor chemotherapy by micellar-encapsulated drug and ultrasound.

The results of a comprehensive in vivo study of a novel tumor-targeting modality are reported. The technique utilized in this study is based on the encapsulation of the chemotherapeutic agent within polymeric micelles in combination with a local ultrasonic irradiation of the tumor. A doxorubicin (DOX) biodistribution, a yield of the internal tumors and a growth rate of the subcutaneous (s.c.) tumors was compared for molecularly dissolved and micellar-encapsulated DOX. This was done with and without tumor sonication, using an ovarian carcinoma tumor model in nu/nu mice. Pure and mixed Pluronic P-105, PEG2000-diacylphospholipid, and poly(ethylene glycol)-co-poly(beta-benzyl-L-aspartate) micelles were used as drug carriers. DOX intracellular uptake was characterized by flow cytometry. A local ultrasonic irradiation of the tumor resulted in a substantially increased drug accumulation in the tumor cells. The effect of the ultrasound was dependent on the time between ultrasound application and drug injection. Ultrasound did not enhance micelle extravasation; the ultrasonic enhancement of drug internalization by the tumor cells required a preliminary passive drug accumulation in the tumor interstitium. Due to the ultrasound-enhanced drug intracellular uptake and cell killing, the yield of intraperitoneal (i.p.) ovarian carcinoma tumors decreased from 70% for DOX dissolved in PBS (positive control) to 36% for the same concentration of DOX encapsulated in Pluronic micelles combined with a 30-s sonication of the abdominal region of a mouse (3 mg/kg DOX, i.p. injection 1 day after inoculation, n>or=10). For s.c. tumors, micellar delivery combined with localized ultrasonic tumor irradiation resulted in a substantial decrease of the tumor growth rates compared to a positive control (3 mg/kg DOX, i.v. injections, n=7, p<0.05). Possible mechanisms of the ultrasound bioeffects on in vivo drug targeting are discussed.