抗血管生成药物筛选和研究的体内外模型

抗血管生成治疗是当今国际上抗肿瘤研究的热点之一。研究抗血管生成药物,必须建立有效实用的实验模型和评价标准,近年来的在这方面有较多新的进展。本文介绍分子、细胞、器官组织和整体水平上目前常用以及新创建的抗血管生成药物筛选和研究的体内外模型,并分析了这些模型的特点。分子细胞水平等体外模型的 实验容易控制,操作较简单,实验费用较低,样品所需量较少。体内模型的优点是实验条件比较接近今后药物使用的环境。筛选的     

抗血管内皮细胞生长因子（VEGF）靶向治疗在肺癌中的研究进展

血管内皮生长因子(vascular endothelial growth factor,VEGF)是血小板源性生长因子(PDGF)家族成员,分子质量(34～45)×103 u,其基因位于染色体6p21.3上[1].     

FGF和VEGF在血管生成中的作用

血管生成因子,诸如成纤维细胞生长因子（FGF）和血管内皮生长因子（VEGF）是目前研究的一大热点。人们试图通过抑制它们来抑制疾病态的血管形成,例如癌症中的血管形成。FGF和VEGF是通过特异性地结合于那些表达在细胞表面上的受体而发挥作用,这些受体都具有酪氨酸激酶活性。这些受体激酶活性的活化使得它们与下游的信号转导途径偶联,而这些途径调节着内皮细胞的增殖、迁移和分化。对FGF和VEGF介导的信号转导途径的抑制剂目前正在进行临床试验。本文主要对现在已知的FGF和VEGF介导的信号转导途径作一综述,这些途径均导致特定中的生物学效应。此外,还将讨论目前已知的这些途径调节血管生成的方式。     

促血管生成素-2（Ang-2）在非小细胞肺癌（NSCLC）中的表达与肿瘤血管生成的关系

目的检测促血管生成素-2（Ang-2）在非小细胞肺癌（NSCLC）中的表达，研究它与血管内皮生长因子（VEGF）表达及微血管密度（MVD）的关系，探讨其在非小细胞肺癌血管生成中的作用。方法用免疫组化法检测37例非小细胞肺癌组织及15例癌旁正常组织中Ang-2、VEGF及CD34相关抗原的蛋白表达情况，分析各个指标在各组表达的差异，研究各个指标的相互关系。结果非小细胞肺癌组织中Ang-2表达阳性率、VEGF记分和微血管密度计数（MVD）均明显高于癌旁正常组织；Ang-2表达与VEGF和MVD表达有明显相关性（r分别0．509和0．615，P〈0．05）；非小细胞肺癌中Ang-2表达阳性者与Ang-2表达阴性者相比，VEGF记分和MVD显著不同（P〈0．05）；Ang-2表达与非小细胞肺癌的淋巴结转移及肿瘤的分级有关（P〈0．05）。结论Ang-2与非小细胞肺癌的浸润、进展密切相关；其对非小细胞肺癌肿瘤血管生成有促进作用，这种作用具有明显的VEGF依赖性。     

恩度抗血管生成和在肿瘤血管正常化中的研究进展

实体瘤的生长和转移依赖于肿瘤新生血管生成,由此提出了抗肿瘤血管生成治疗。由于其靶点主要是肿瘤新生血管,因此现已成为抗肿瘤治疗最受瞩目的领域之一。随着对其研究的深入,又指出并非是最大限度抗肿瘤血管生成,而是应该使肿瘤血管正常化,以增加氧供和降低组织间质压力,使化疗药物更好更均匀的进入肿瘤组织内,但是这种正常化是有一定时间限制的。如何将抗血管生成药物和放化疗进一步更好的结合以达到更好的疗效,用更有效更无创的分子影像技术等手段对其进行评价,以便更好的运用于临床将是我们研究的重点。     

VEGF165_b的抗血管生成作用在肾癌发生、发展中的研究进展

肾癌是一种高度血管化的恶性实性肿瘤,其生长和转移依赖于新生血管的形成,而血管形成主要是由促血管生成因子和抑制因子调控失衡、促血管生成因子增多所致。血管内皮生长因子(VEGF)亚型VEGF165是机体内含量最多,生物活性最强的促血管生成因子,且在肾癌组织中高表达,与肿瘤的生长、转移密切相关。最新研究发现一种新的VEGF异构体VEGF165b具有抑制VEGF165介导的血管生成作用,有可能成为肾癌治疗过程中新的作用靶点,具有重要的临床应用价值。本文对VEGF165b的结构、作用机制进行综述。     

CREB在血管新生、抗凋亡以及肺癌中的研究进展

cAMP反应元件结合蛋白（CREB）作为一种转录因子在长期记忆形成和多种恶性肿瘤的发生及治疗领域 已被广泛研究,本文就 CREB基因在血管新生、细胞增殖及抗凋亡、与尼古丁致癌过程的关联以及在肿瘤（尤其是肺 癌）中的研究进展进行综述,以期为今后 CREB家族蛋白的研究提供参考。     

微环境在肿瘤生长及耐受抗血管生成疗法中的作用

血管生成对多种类型肿瘤的生长具有重要作用,抗血管生成药物的开发为肿瘤治疗开辟了新纪元。然而,与其他的抗肿瘤疗法相同,肿瘤患者对抗肿瘤药物固有／获得性耐受通常导致疾病复发。近年来多种实验模型研究提示,肿瘤及非肿瘤（基质）细胞均参与并导致了治疗反应性的降低。该综述主要总结基质细胞在肿瘤生长及耐受抗血管内皮生长因子疗法中的作用。     

Rho GTP酶在姜黄素抑制人肺癌细胞增殖和转移中的作用

目的 探讨姜黄素对人肺癌细胞株(A549)增殖和转移的影响,并通过检测姜黄素对细胞内Rho GTP酶蛋白表达及细胞骨架重组的影响,揭示Rho GTP酶在姜黄素抑制肺癌转移中的作用。方法 应用MTT法观察姜黄素对A549增殖能力的影响,体外侵袭实验和迁移实验观察姜黄素对肺癌细胞转移的影响。Western blot和半定量RT-PCR法分别检测姜黄素对与细胞骨架重组相关的RhoA,Rac1,Cdc42蛋白和mRNA表达的影响。免疫荧光细胞化学法标记微丝,激光共聚焦扫描显微镜观察姜黄素对细胞骨架重组的影响。结果 姜黄素能抑制A549细胞增殖,增殖抑制率均随处理浓度增大和作用时间延长而增加。与对照组比较,2.5,5 μmol·L^-1的姜黄素处理24 h后的A549细胞增殖抑制率较低,但体外侵袭和迁移能力均显著下降(P<0.01)。姜黄素能显著下调RhoA,Rac1,Cdc42蛋白和mRNA表达(P<0.01),并能明显影响细胞内微丝骨架的结构和分布。结论 姜黄素可通过下调 Rho GTP 酶基因表达,调控肺癌细胞微丝骨架结构,进而抑制体外增殖和转移能力。     

In vitro, in vivo and in silico models of drug distribution into the brain

Achieving sufficient brain penetration to elicit efficacy in humans is one of the most challenging tasks for scientists in CNS Drug Discovery. Substantial progress has been made in the past decade in understanding the factors influencing the rate and extent of brain distribution via a variety of in vivo, in vitro and in silico methodologies, and hence, predict their likelihood of success in man. This purpose of this review is to summarize the current approaches with a special focus on parameters related to free drug concentrations in brain which are the most pharmacologically relevant for the majority of CNS disease targets. Due to the dynamic and complex nature of this targeted organ, it is inevitable that these approaches have not been able to provide a fully comprehensive assessment of brain distribution and are expected to evolve further in the years to come.     

Novel calcitriol analogue with an oxolane group: In vitro,in vivo,and in silico studies

The active form of vitamin D₃, calcitriol, is a potent antiproliferative compound. However, when effective antitumor doses of calcitriol are used, hypercalcemic effects are observed, thus blocking its therapeutic application. To overcome this problem, structural analogues have been designed with the aim of retaining or even increasing the antitumor effects while decreasing its calcemic activity. This report aims at gaining insights into the structure–activity relationships of the novel oxolane‐containing analogue, AM‐27, recently synthesized. We herein demonstrate that this compound has antiproliferative and antimigratory effects in squamous cell carcinoma, glioblastoma, and breast cancer cell lines. Analyses of the mechanisms underlying the AM‐27 effects on cell viability revealed induction of apoptosis by the analogue. Importantly, nonmalignant cell lines were little or not affected by the compound. In addition, the analogue did not produce hypercalcemia in mice. Also, in silico studies involving docking and molecular dynamics techniques showed that AM‐27 is able to bind to the human vitamin D receptor with a higher affinity than the natural ligand calcitriol, a feature that is mostly derived from an electrostatic interaction pattern. Altogether, the proapoptotic effect observed in cancer cells, the lack of calcemic activity in mice, and the differential effects in normal cells suggest the potential of AM‐27 as a therapeutic compound for cancer treatment.     

Dendrosomal curcumin significantly suppresses cancer cell proliferation in vitro and in vivo

Curcumin, the main compound of spice turmeric, is one of the natural products that has been shown to possess effective anti-cancer properties. However, the absorption efficacy of curcumin is too low to make dramatic results in therapy. Therefore, we based the main aim of this study on improving the bioavailability of curcumin taking advantage of dendrosome nanoparticles; and subsequently evaluating in vitro and in vivo anti-tumor properties of dendrosomal curcumin. In vitro studies were carried out utilizing A431 and WEHI-164 cell lines and mouse embryonic normal fibroblasts. Our data revealed that dendrosomal curcumin not only exhibits a much higher bioavailability than void curcumin (P<0.05) but also inhibits the proliferation of cancer cells (P<0.01) in a time- and dose-dependent manner that could be ascribed to the induction of apoptosis. However, dendrosome did not indicate any toxic effect on different types of cell lines. For in vivo studies, BALB/c tumor-bearing mice were treated with dendrosomal curcumin, void curcumin, dendrosome and PBS. The results indicated that dendrosomal curcumin reduces significantly the tumor size in comparison with void curcumin and control samples (P<0.05). Furthermore, in animals treated with dendrosomal curcumin a longer survival was observed (P<0.01). We also found that the mice treated with dendrosomal curcumin, showed a significant increase in splenocyte proliferation and IFN-γ production as well as a significant decrease in IL-4 production. This can be a proof of anti-tumor immunity caused by dendrosomal curcumin. The findings demonstrate that dendrosomal curcumin offers a great potential to be a promising anti-cancer therapeutic agent.     

Assessment of blood-brain barrier penetration: in silico,in vitro and in vivo

The amount of drug achieved and maintained in the brain after systemic administration is determined by the agent's permeability at blood-brain barrier (BBB), potential involvement of transport systems, and the distribution, metabolism and elimination properties. Passive diffusion permeability may be predicted by an in silico method based on a molecule's structure property. In vitro cell culture is another useful tool for the assessment of passive permeability and BBB transports (e.g. PGP, MRP). In situ or in vivo techniques like carotid artery single injection or perfusion, brain microdialysis, autoradiography, and others are used at various stages of drug discovery and development to estimate CNS penetration and PK/PD correlation. Each technique has its own application with specific advantages and limitations.     

Stability of angiogenic agents, ginsenoside Rg1 and Re, isolated from Panax ginseng: in vitro and in vivo studies

The study was designed to investigate the stability of ginsenoside Rg(1) (Rg(1)) and Re (Re), two natural herbal compounds isolated from Panax ginseng, based on their activity to promote angiogenesis in vitro and in vivo. After being treated at different temperatures, pHs, and solvent species for distinct durations, the remaining activities of Rg(1) and Re on human umbilical vein endothelial cell (HUVEC) proliferation, migration, and tube formation were examined in vitro. Additionally, the remaining activity of each treated test agent, mixed in a growth factor-reduced Matrigel, in stimulating angiogenesis was evaluated subcutaneously in a mouse model. Basic fibroblast growth factor (bFGF) was used as a control. It was found in vitro that HUVEC proliferation, migration in a Transwell plate, and tube formation on Matrigel were all significantly enhanced in the presence of bFGF, Rg(1), or Re. However, after being treated at different temperatures, pHs, or solvent species, the remaining activity of bFGF on HUVEC behaviors reduced significantly. This observation was more significant with increasing the duration of treatment. In contrast, the activities of Rg(1) and Re remained unchanged throughout the entire course of the study. The in vivo results observed on day 7 after implantation showed that the blank control (Matrigel alone) was slightly vascularized. In contrast, the density of neo-vessels in the Matrigel plug mixed with bFGF, Rg(1), or Re was significantly enhanced. However, after being treated, the density of neo-vessels was significantly reduced in the Matrigel plug mixed with bFGF, while those of Rg(1) and Re remained unchanged. The aforementioned results suggested that Rg(1) and Re could be a novel group of nonpeptide angiogenic agents with a superior stability and may be used for the management of tissue regeneration.     

Anticancer activity of Kalanchoe tubiflora extract against human lung cancer cells in vitro and in vivo

Uncontrolled cell proliferation is a common feature of human cancer. Some of herbal extract or plant‐derived medicine had been shown as an important source of effective anticancer agents. We previously reported that an n‐BuOH‐soluble fraction of Kalanchoe tubiflora has antiproliferative activity by inducing mitotic catastrophe. In this study, we showed that the H₂O‐soluble fraction of Kalanchoe tubiflora (KT‐W) caused cell cycle arrest, and senescence‐inducing activities in A549 cells. We used 2 dimensional PAGE to analyze the protein expression levels after KT‐W treatment, and identified that the energy metabolism‐related proteins and senescence‐related proteins were disturbed. In vivo experiments showed that the tumor growths in A549‐xenografted nude mice were effectively inhibited by KT‐W. Our findings implied that KT‐W is a putative antitumor agent by inducing cell cycle arrest and senescence. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1663–1673, 2016.