Effects for Sequential Treatment of siAkt and Paclitaxel on Gastric Cancer Cell Lines

Real-time screening of cellular response on the drugs could provide valuable insights for the early detection of therapeutic efficiency and the evaluation of disease progression. Cancer cells have the ability to vary widely in response to stress in a manner to adjust the signaling pathway to promote the survival or having a resistance to stimulation. Cell-based label-free technologies using electronic impedance sensor have strategies for constructing the signature profiles of each cells. To achieve exquisite sensitivity to substantially change of live-cell response have an important role that predict the potential of therapeutic effects. In this study, we use an impedance-based real-time cell analysis system to investigate dynamic phenotypes of cells described as a cellular index value. We show that gastric cancer cells generated characteristic kinetic patterns that corresponded to the treatment order of therapeutics. The kinetic feature of the cells offers insightful information that cannot be acquired from a conventional single end-point assay. Furthermore, we employ a ''sequential treatment strategy'' to increase cytotoxic effects with minimizing the use of chemotherapeutics. Specifically, treatment of paclitaxel (PTX) after down-regulating Akt gene expression using RNAi reduces the cell proliferation and increases apoptosis. We propose that the sequential treatment may exhibit more effective approach rather than traditional combination therapy. Moreover, the dynamic monitoring of cell-drug interaction enables us to obtain a better understanding of the temporal effects in vitro.     

载紫杉醇聚己内酯-聚乙二醇-聚己内酯胶束的制备及药代动力学研究简

目的制备新型可注射用载紫杉醇聚己内酯-聚乙二醇-聚己内酯（PCl-PEG-PCL）胶束,并评价和比较其与市售紫杉醇注射液在大鼠体内的药代动力学性质。方法以PCL-PEG-PCL为载体材料,通过薄膜-水化-超声法制备出载紫杉醇PCl-PEG-PCL胶束,并对其进行表征。以市售紫杉醇注射液为对照．采用SD大鼠尾静脉注射后观察载紫杉醇PCL-PEG-PCL胶束的体内药代动力学．并用DAS2．0药代动力学数据软件计算相关参数。结果载紫杉醇PCL-PEG-PCL胶束呈大小均匀的球形,具有明显的核壳结构;平均粒径为93nm,多分散系数为0．19;载药量为28．98％,药物包封率为94．36％。体外释放研究表明．载紫杉醇PCL-PEG-PCL胶束具有缓释效果。药代动力学研究表明．两种制剂均符合二房室模型．市售紫杉醇注射液和紫杉醇聚合物胶束消除半衰期（t1/2）分别为（1．96±0．27）h和（12．65±1．77）h,平均滞留时间（MRT）分别为（0．93±0．19）h和（11．18±1．41）h,体内总清除率（CL）分别为（0．44±0．05）L·kg／h和（0．10±0．01）L·kg／h,药-时曲线下面积（AUC0-∞）分别为（17．15±2．35）mg·h／L和（73．82±10．38）mg．h／L。结论成功制备了新型可注射用载紫杉醇PCL-PEG-PCL胶束．药代动力学研究表明．所研制的载紫杉醇PCL-PEG-PCL胶束明显延长紫杉醇在血液中的循环时间及消除半衰期．显著提高生物利用度,是一种有潜力的紫杉醇缓控释新剂型。     

两种普朗尼克材料联合聚氰基丙烯酸正丁酯载紫杉醇的控药释放能力

背景：包含普朗尼克P123的载紫杉醇聚合物胶束能够有效的延长药物体内循环时间,并且能够改变紫杉醇的作用靶位.但是,这种紫杉醇聚合物胶束在溶液中的稳定性以及载药能力仍有待提高. 目的：观察载紫杉醇聚氰基丙烯酸正丁酯-普朗尼克P123/F68胶束的药剂学特性和体外抗肿瘤能力.方法：采用薄膜水化法,以聚氰基丙烯酸正丁酯为交联剂,普朗尼克P123/F68为载体材料,制备载疏水性药物-紫杉醇纳米胶束.应用透射电镜观察胶束形态;电位粒度分析仪测定胶束电位和粒径;高效液相色谱分析方法测定胶束载药量和包封率;荧光探针法测定胶束临界胶束浓度;体外试验考察胶束的释药情况、稳定性以及抗肿瘤情况. 结果与结论：实验制备的载药胶束为圆形,粒径和电位分别在100 nm和-10 mV左右,包封率和载药量为（93.3±2.15）%和（1.82±0.04）%,临界胶束浓度为0.067 g/L.药物体外释放试验和稳定性试验显示,该载药胶束具有一定的缓释功能和抗稀释能力.MTT试验结果表明,与游离药物相比,载药胶束具有更强的杀伤乳腺癌细胞MCF-7的能力.可见,载紫杉醇聚氰基丙烯酸正丁酯-普朗尼克P123/F68胶束具有明显的控制药物释放的能力和良好的稳定性,抗肿瘤能力强.     

针刺对肺癌大鼠体内紫杉醇脂质体趋向性的影响

目的观察针刺“肺俞”、“太渊”对紫杉醇脂质体在肺癌大鼠体内趋向性的影响,为抗肿瘤药物的靶向性研究开辟新的途径。方法,紫杉醇脂质体用”“锝标记,选用单纯尾静脉注射药物以及注射药物分别与针刺“肺俞”、“太渊”（相关穴位）、“神门”（无关穴位）相结合等4种方法对造模成功的肺癌大鼠进行干预（每组18只）。分别于静脉注射后60、90、120min（每个时间点取6只）后处死大鼠,用γ-放射免疫记数器分别测定肺、肝、肾等脏器紫杉醇脂质体的药物含量。结果针剌“肺俞”和“太渊”在全部或部分时间点使肺癌大鼠肺组织紫杉醇脂质体含量增加。针刺“神门”未能使肺组织药物含量升高。结论针刺“肺俞”和“太渊”对紫杉醇脂质体在肺癌大鼠体内的分布具有趋向性影响,“肺俞”对药物在肺脏的靶向性影响大于“太渊”。     

Reassembling of albumin-bound paclitaxel mitigates myelosuppression and improves its antitumoral efficacy via neutrophil-mediated targeting drug delivery

Albumin-bound paclitaxel (abPTX) has been widely used in cancer treatment. However, dose-related side effects, such as myelosuppression, restrict its clinical application. Cell-based targeting drug delivery is a promising way to mitigate systematic side-effects and improve antitumoral efficacy. In this study, we demonstrated that reassembled abPTX could be engulfed by neutrophils in vivo and delivered to tumor site, thus improving therapeutic efficacy and mitigating myelosuppression. First, in vitro analysis confirmed that reassembling of abPTX formed uniform and stable serum albumin nanoparticles (NP-abPTX) with size of 107.5 ± 2.29 nm and reserved the ability to kill tumor cells. Second, we found that NP-abPTX could be engulfed by activated neutrophil in vitro and in vivo but do not affect neutrophils’ function, such as chemotaxis and activation. In a murine tumor model, we further proved that local radiotherapy (RT) induced inflammation activated peripheral neutrophils to capture venous infused NP-abPTX and carry them into tumor tissue. As compared to abPTX, infusion of NP-abPTX dramatically enhanced inhibition of tumor growth treated by local RT and mitigated hematotoxicity. Therefore, our study demonstrated a novel strategy to mitigate side-effects and to improve tumor killing efficacy of abPTX through neutrophil-mediated targeting drug delivery.     

A triplet chemotherapy regimen of cisplatin,fluorouracil and paclitaxel for locoregionally recurrent nasopharyngeal carcinoma cases contraindicated for re-irradiation/surgery

Objective: Salvage treatment for locoregionally recurrent nasopharyngeal carcinoma remains a significant challenge. The present study was conducted to evaluate the efficacy, toxicity and prognostic factors of a triplet chemotherapy regimen involving cisplatin, fluorouracil and paclitaxel (TPF) for locoregionally recurrent nasopharyngeal carcinoma (NPC) cases contraindicated for re-irradiation/surgery.

Methods: Patients with locoregionally recurrent NPC unsuitable for re-irradiation/surgery were treated with TPF therapy. The chemotherapy drugs were administered as follows: 135 mg/m² paclitaxel on day 1, 25 mg/m²/day cisplatin on days 1–3, followed by continuously infused intravenous fluorouracil for 120 h at a variable dosage from 600 to 800 mg/m²/day, depending on prior radiation.

Results: Twenty-seven patients were enrolled. The overall response was 66.7%. The median progression-free survival (PFS) and overall survival (OS) were 8.5 and 27.2 months, respectively. Toxicity was mild to moderate. Neutropenia and leukopenia were the primary grade 3–4 chemotherapy toxicities. 6 patients who regained the potential for re-radiotherapy or surgery showed significantly better outcomes than those treated with chemotherapy alone (median PFS: 20.8 vs. 7.1 months, P = 0.005; median OS: 54.2 vs. 20.6 months, P = 0.021).

Conclusion: TPF triplet chemotherapy showed a high response rate for locoregionally recurrent NPC with an acceptable toxicity profile.     

联合使用脱甲基化药物和紫杉醇对肾癌细胞的侵袭能力影响机制研究

目的：观察联合使用脱氧杂胞苷（ DAC）与紫杉醇（ PTX）对肾患细胞是否存在协同作用,并探究其机制。方法离体培养肾透明细胞癌ACHN细胞株,将120培养皿随机分为空白对照组、DAC组、PTX组、联合组,每组30个。 DAC组：用DAC：0．5、1、2、4、8μmol／L处理3 d;PTX组：用PTX：1、2、4、8、16 nmol／L处理3 d;联合组：用DAC＋PTX处理3 d。使用高速分选流式细胞仪观察T肽协同树突状细胞对肾癌细胞的凋亡率;通过ELISA检测淋巴细胞增强因子（LEF1）和E－cadherin在肾癌细胞中的表达;通过ELISA技术检测凋亡蛋白caspass－3在肾癌细胞中的表达。结果 DAC组、PTX组以及联合组对肿瘤细胞的抑制作用明显,其中联合组对肿瘤细胞的抑制作用最强（ P＜0．05）,而且DAC和PTX对肿瘤细胞的抑制作用与药物浓度成正比（P＜0．05）。与DAC组、PTX组比较,联合组中LEF1的表达水平最低（P＜0．05）,E－cadherin、caspass－3的表达水平最高（P＜0．05）,而且DAC和PTX对LEF1表达的抑制作用、对E－cadherin、caspass－3的表达的促进作用与药物浓度成正比（P＜0．05）。结论 DAC与 PTX联合干预肾癌细胞,具有协同作用,而且LEF1是新的肾癌治疗靶点,DAC与 PTX合用可以提高肾癌细胞的凋亡率,并且降低肾癌细胞的侵袭转移能力。     

Population pharmacokinetics of orally administered paclitaxel formulated in Cremophor EL

AIM: The vehicle Cremophor EL (CrEL) has been shown to impair the absorption of paclitaxel by micellar entrapment of the drug in the gastrointestinal tract. The goal of this study was to develop a semimechanistic population pharmacokinetic model to study the influence of CrEL on the oral absorption of paclitaxel. METHOD: Paclitaxel plasma-concentration time profiles were available from 55 patients (M:F, 17 : 38; total 67 courses; 797 samples), receiving paclitaxel orally once or twice daily (dose range 60-360 mg m(-2)) together with 12-15 mg kg(-1) cyclosporin A. A population pharmacokinetic model was developed using the nonlinear mixed effect modelling program NONMEM. RESULTS: After absorption, paclitaxel pharmacokinetics were best described using a two-compartment model with linear distribution from the central compartment into a peripheral compartment and first-order elimination. Paclitaxel in the gastrointestinal tract was modelled as free fraction or bound to CrEL, with only the free fraction available for absorption into the central compartment. The equilibrium between free and bound paclitaxel was influenced by the concentration of CrEL present in the gastrointestinal tract. The concentration of CrEL in the gastrointestinal tract decreased with time with a first order rate constant of 1.73 h(-1). The bioavailability of paclitaxel was independent of the dose and of CrEL. Estimated apparent paclitaxel clearance and volume of distribution were 127 l h(-1) and 409 l, respectively. Large interpatient variability was observed. Covariate analysis did not reveal significant relationships with any of the pharmacokinetic parameters. CONCLUSION: A pharmacokinetic model was developed that described the pharmacokinetics of orally administered paclitaxel. CrEL strongly influenced paclitaxel absorption from the gastrointestinal tract resulting in time-dependent but no significant dose-dependent absorption over the examined dose range studied.     

应用动物活体生物发光技术观察紫杉醇混合胶束的抑瘤效果

活体动物成像技术是近年来发展成熟并得到认可的一种新型影像检测技术,其突出优越性是可以对活体病灶的形态大小进行在体无损伤直观准确检测[1]。活体动物成像技术的基本原理是透过体表,接