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。     

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”。     

注射用紫杉醇脂质纳米粒的制备、体外释放及体内药动学研究

 目的 制备注射用紫杉醇脂质纳米粒,并考察其理化性质、体外释放及体内药动学性质。 方法 采用高压乳匀结合冷冻干燥工艺制备注射用紫杉醇脂质纳米粒;考察脂质纳米粒形态、粒径分布、载药量及超滤离心法测定包封率;考察了制剂的稳定性和安全性;以市售紫杉醇注射液为对照,考察其体外释放特性及大鼠体内药动学行为。 结果 注射用紫杉醇脂质纳米粒的平均粒径为 25.6 nm ;包封率为（ 99.55 ± 0.25 ） % ,载药量为（ 1.37 ± 0.78 ） % ;与 5% 葡萄糖溶液或 0.9%NaCl 注射液配伍 8 h 内稳定;安全性良好,无溶血现象;在 0.8 mol·L^-1 水杨酸钠溶液中 24 h 的累积释放百分率分别为 99.8% 和 99.9% ,释放行为符合一级动力学方程;紫杉醇注射液与脂质纳米粒溶液在大鼠体内的平均滞留时间 (mean residence time , MRT) 分别为 1.10 和 1.85 h ,两者 24 h 内药 - 时曲线下面积 (AUC) 分别为 6.78 和 33.6 mg·h·L^-1 。 结论 采用高压乳匀 - 冷冻干燥工艺制备注射用紫杉醇脂质纳米粒,对纳米粒起到了很好的保护作用,避免了药物的渗漏;载药量和包封率较高,粒径分布均匀;与注射液相比,脂质纳米粒的体外释放显著慢于注射液,具有缓释效果。     

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.     

Reuse of carboplatin and paclitaxel in patients with relapsed endometrial cancer--the British Columbia Cancer Agency experience

ObjectiveTo evaluate the efficacy of reusing carboplatin and taxol in women with relapsed endometrial cancer.MethodsRetrospective analysis of our database of newly diagnosed high-risk patients with endometrial cancer treated with carboplatin–paclitaxel at diagnosis, with subsequent relapse for the period of 1995–2007.Results111 patients of 200 relapsed. They had either endometroid or papillary serous histologies. Strategies utilized upon first relapse were: no treatment (n = 33), surgery (n = 4), hormones (n = 8), irradiation (n = 14) and chemotherapy (n = 52). Carboplatin and paclitaxel was reused in 31 (60% of 52 retreated with chemotherapy or 29% of the total cohort of 111). There was no statistically significant difference in stage at diagnosis or grade at diagnosis between those retreated with chemotherapy or not or with carboplatin–paclitaxel versus another regimen. The patients retreated were a selected subgroup as only those with initial response or treated adjuvantly were offered carboplatin–paclitaxel. CR or PR were achieved in 8 (42%) patients with endometroid type cancer. In the papillary serous group 6 (50%) had CR or PR. Median PFS from first relapse was 8 months for endometroid and 9 months for papillary serous histology. OS was 15 months and 26 months respectively from first relapse.ConclusionCarboplatin–taxol regimen is an efficacious treatment. Due to the patient selection these outcomes reported are likely to be an overstatement of what could be achieved in practice.     

Cancer stem-like cells contribute to paclitaxel resistance in esophageal squamous cell carcinoma

Objective: To examine the role of esophageal squamous cell carcinoma (ESCC) stem cells in paclitaxel resistance through the molecular characterization of ESCC stem cells. Methods: A resistant cell line (RR-ECl09) of cells were established using intermittent induction and time increments of high-dose paclitaxel in a human esophageal squamous cell carcinoma line (EC109). The multidrug resistance of RR-ECl09 cells to anticancer agents was evaluated by MTT assay. The RR-EC109 and EC109 cells were used for sphere formation assays, clonogenicity assays, stem cell gene expression, and the expression of epithelial-mesenchymal transition markers. Results: The RR-EC109 cells were established over 7 months. RR-ECl09 cells had 67.258 fold resistance to paclitaxel. The percentage of sphere formation and clone proliferation ability of RR-EC109 cells was higher than that of EC109 cells (P < 0.05). The amount of side population cells in RR-EC109 cells was higher than that of EC109 cells (P < 0.05). RR-EC109 cells produced more mRNA for Bmi1, Nanog, Oct4, Sox2, ABCG2, Nestin, and Ki-67 than EC109 cells (P < 0.05). E-cadherin expression was lower in RR-EC109 cells than in EC109 cells, while N-cadherin, Snail, and Twist expressions were higher in RR-EC109 cells than in EC109 cells (P < 0.05). Conclusions: Cancer stem cell (CSC)-like cells exist among paclitaxel-resistant cells in ESCC and may play a role in ESCC drug resistance.     

Linking Medicinal/Nutraceutical Products Research with Commercialization

Abstract

Thousands of bioactive phytochemicals have potential or established pharmaceutical, medicinal, or nutraceutical applications. Developing crops for bioactive compound extraction presents both research and development challenges and market-related considerations. Demonstrating that cultivation is economically viable is not sufficient. Using examples from both cultivated medicinals and our experience with Taxus canadensis. Marsh., we discuss two types of market factors that must be considered before commercialization can proceed. Bioproduct market factors include availability of a cheaper product elsewhere from the same species; other species with the same bioactive compound; existence of a synthetic alternative to the naturally sourced phytochemical; the patent suite covering bioproduct extraction and use; commodification; and government bioresource regulation. The role and suitability of an industrial collaborator proposing to fund R&D activities also must be gauged by the R&D partner. The assessment should include the company's knowledge of the marketplace; its capacity to sustain the proposed R&D funding; whether the intent is to market raw biomass or a value-added product; and how it is proposed to handle exclusivity and proprietary information. The economics of cultivating elite T. canadensis. cultivars are also briefly summarized. It is concluded that consideration of bioproduct marketing realities can help to focus R&D goals and timelines based on both biomass cost reduction (or improvement in quality) and meeting the industrial collaborator's specific needs.     

Seasonal Changes in the Concentration of Major Taxanes in the Biomass of Wild Canada Yew (Taxus canadensis. Marsh.)

Abstract

Seasonal variations in taxane concentrations in Taxus canadensis. Marsh. (Canada yew) were measured at 15 sampling dates from September 2004 to September 2005 by clipping 3-year-old shoots from the same 15 plants. Four age classes of needles and stems were separated and individually weighed and analyzed for the three major taxanes in T. canadensis.: 10-deacetylbaccatin III (10-DAB III), 9-dihydro-13-acetylbaccatin III (9-DHAB III), and paclitaxel (PAC). The dry weight fraction of each foliage age class decreased with increasing age; that is, proportionately more young than old foliage (current > current + 1 year > current + 2 year) was present in a 3-year-old stem. The ratio of needle:stem dry weight also decreased with increasing foliage age. Taxane concentrations varied widely, depending on the tissue, its age, and time of year. Peak concentrations were observed for a short period at the end of the growing season (August–September). The lowest taxane levels were found during the period of active growth: April through July. PAC and 9-DHAB III concentrations were higher in needles, but young stems contained the highest amounts of 10-DAB III. Levels of all three taxanes were higher in young than in old stems, likely due to increasing amounts of taxane-poor stem wood. Composite taxane concentrations were calculated for 3-year-old foliage from the component needle and stem weights and taxane analyses. It is suggested that summer harvesting between April and July (the low point in annual taxane levels) yields the poorest quality biomass, and harvesting from August onward is preferable.