Remodeling of Metastatic Vasculature Reduces Lung Colonization and Sensitizes Overt Metastases to Immunotherapy

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抗血管生成蛋白与多肽研究进展

多项动物实验和临床实啦已经充分证实,抗血管生成疗法可以抑制肿瘤生长。在可抑制肿瘤生长的分子中,许多是蛋白与多肽,包括细胞因子、趋化因子、血管内皮生长因子及其受体的抗体、可溶性受体、胞外基质蛋白片段及小分子合成多肽等。简要综述其中部分分子的作用机理及临床应用情况。     

The Use of Phage-Displayed Peptide Libraries to Develop Tumor-Targeting Drugs

Monoclonal antibodies have been successfully utilized as cancer-targeting therapeutics and diagnostics, but the efficacies of these treatments are limited in part by the size of the molecules and non-specific uptake by the reticuloendothelial system. Peptides are much smaller molecules that can specifically target cancer cells and as such may alleviate complications with antibody therapy. Although many endogenous and exogenous peptides have been developed into clinical therapeutics, only a subset of these consists of cancer-targeting peptides. Combinatorial biological libraries such as bacteriophage-displayed peptide libraries are a resource of potential ligands for various cancer-related molecular targets. Target-binding peptides can be affinity selected from complex mixtures of billions of displayed peptides on phage and further enriched through the biopanning process. Various cancer-specific ligands have been isolated by in vitro, in vivo, and ex vivo screening methods. As several peptides derived from phage-displayed peptide library screenings have been developed into therapeutics in current clinical trials, which validates peptide-targeting potential, the use of phage display to identify cancer-targeting therapeutics should be further exploited.

胃癌血管靶向肽GX2 对胃癌血管内皮细胞靶向性的鉴定

目的:证明胃癌血管靶向肽GX2能够与胃癌血管内皮细胞特异性结合,在体内对胃癌血管具有靶向性。方法:体外实验,合成GX2与FITC的复合物FITC-GX2,分离原代人脐静脉内皮细胞HUVEC,将HUVEC与人胃癌细胞系SGC7901共培养,建立共培养血管内皮细胞模型来模拟胃癌血管,利用免疫荧光的方法观察GX2与共培养内皮细胞Co-HUVEC的结合情况;体内实验,构建99mTc标记的GX2分子示踪探针,SPECT显像观察GX2的胃癌血管靶向性。结果:免疫荧光结果显示GX2能与Co-HUVEC特异性结合,而与人胃癌细胞SGC7901不结合;SPECT显像结果证明了GX2在荷瘤裸鼠体内能够浓集到肿瘤部位,具有良好的靶向性。结论:GX2能与胃癌血管内皮细胞特异性结合,且具有在体靶向到胃癌血管的能力;GX2具有胃癌诊断的潜在价值,并能应用于胃癌血管抑制治疗。     

CAR-T 对肿瘤的特异性治疗研究进展

嵌合抗原受体T细胞免疫疗法(CAR-T疗法)是一种治疗肿瘤的新免疫疗法,通过向患者自身T细胞中导入已被修饰的CAR基因,使T细胞表达结合肿瘤表面抗原的特异性受体来实现对肿瘤的精准治疗.目前已发展到第四代.该免疫疗法在血液瘤和实体瘤治疗中都有一定疗效,同时也存在一些待解决难题.本文就近年来CAR-T在血液瘤和实体瘤中的研究治疗进展及存在的问题进行综述.     

肿瘤靶向治疗的新型细胞载体

肿瘤靶向性病毒作为一种特殊的肿瘤治疗药物和基因治疗载体近年来已得到长足发展,许多高效、靶向性病毒载体已被相继研究开发,但仍不能满足临床上肿瘤靶向治疗的需要,如何将这些靶向病毒准确而高效地运输到肿瘤病变部位仍然未得到充分解决.细胞因子诱导杀伤细胞(cytokine-inducedkillercells,CIK)作为肿瘤的细胞治疗方法之一已成功地在临床上得到了广泛应用.最近科学家使用CIK细胞作为病毒运载工具,成功地将病毒运载到肿瘤组织部位并显示出高效的抗肿瘤作用,该方法为病毒运输定位于肿瘤病变部位找到了突破口,实验资料显示其具有潜在的应用价值.     

Screening and Identification of a Specific Binding Peptide to Ovarian Cancer Cells from a Phage-Displayed Peptide Library

To select specific binding peptides for imaging and detection of human ovarian cancer. The phage 12-mer peptide library was used to select specific phage clones to ovarian cancer cells. After four rounds of biopanning, the binding specificity of randomly selected phage clones to ovarian cancer cells was determined by enzyme-linked immunosorbent assay (ELISA). DNA sequencing and homology analysis were performed on specifically bound phages. The binding ability of the selected peptides to SKOV3 cells was confirmed by fluorescence microscopy and flow cytometry. After four rounds of optimized biological panning, phage recovery was 34-fold higher than that of the first round, and the specific phage clones bound to SKOV3 cells were significantly enriched. A total of 32 positive phage clones were preliminarily identified by ELISA from 54 randomly selected clones, and the positive rate was 59.3%. S36 was identified as the clone with best affinity to SKOV3 cells via fluorescence microscopy and flow cytometry. A representative clone of OSP2, S36 is expected to be an effective probe for diagnosis and treatment of ovarian cancer.

     

肿瘤血管生成的实验模型

血管生成在肿瘤的生长、侵袭和转移中起着重要的作用。通过抑制新生血管的形成和发展来达到杀伤肿瘤细胞的目的,是一种确实有效的"饥饿"疗法。近年来对抗血管生成治疗肿瘤的研究取得了很大的进展,目前已建立了多种实验模型和评价标准,包括体内和体外两大类。每种模型都有其优缺点,可根据研究内容选择合适、有效的实验模型。     

pH-Dependent Binding of Synthetic β-Amyloid Peptides to Glycosaminoglycans

The seinile plaques found within the cerebral cortex and hippocampus of the Alzheimer disease brain contain β-amyloid peptide (Aβ) fibrils that are associated with a variety of macromolecular species, including dermatan sulfate proteoglycan and heparan sulfate proteoglycan. The latter has been shown recently to bind tightly to both amyloid precursor protein and A/β, and this binding has been attributed largely to the interaction of the core protein of heparan sulfate proteoglycan with Aβ and its precursor. Here we have examined the ability of synthetic Aβ s to bind to and interact with the glycosaminoglycan moieties of proteoglycans. Aβ(1–28) associates with heparin, heparan sulfate, dermatan sulfate, and chondroitin sulfate. The interaction of these sulfated polysaccharides with the amyloid peptide results in the formation of large aggregates that are readily sedimented by centrifugation. The ability of both Aβ(1–28) and Aβ(1–40) to bind glycosaminoglycans is pH-dependent, with increasing interaction as the pH values fall below neutrality and very little binding at pH 8.0. The pH profile of heparin-induced aggregation of Aβ(1–28) has a midpoint pH of approximately 6.5, suggesting that one or more histidine residues must be protonated for binding to occur. Analysis of the Aβ sequence reveals a consensus heparin-binding domain at residues 12–17, and this motif contains histidines at positions 13 and 14 that may be involved in the interaction with glycosaminoglycans. This hypothesis is supported by the following observations: (a) Aβ(13–17) binds tightly to a heparin affinity column at pH 4.0, but not at pH 8.0; and (b) an Aβ(13–17) in which histidine residues 13 and 14 have been replaced with serines does not bind to a heparin column at either pH 8.0 or 4.0. Together, the data indicate that Aβ is capable of binding to the glycosaminoglycan chains of proteoglycans, and such an interaction may be relevant to the etiology and pathology of Alzheimer's disease.     

人端粒酶催化亚单位启动子调控自杀基因HSV-TK肿瘤细胞特异性表达载体的构建

将自杀基因形插入质粒pGL3-hTp和pGL3-Control中,取代其上的荧光素酶基因,分别构建hTERT启动子和SV40启动子调控的TK基因表达质粒pGL3-hWp-TK和pGL3-SV40-TK,酶切和PCR鉴定结果显示重组质粒pGL3-hTp-TK和pGL3-SV40-TK构建成功;用脂质体法将pGL3-hTp-TK和pGL3-SV40-TK瞬时转染端粒酶阳性的人肺腺癌细胞株A549及端粒酶阴性的人胚肺成纤维细胞株MRC-5,RT-PCR显示转染pGL3-SV40-TK的细胞A549和MRC-5均有TK mRNA表达,转染pGL3-hTp-TK的A549细胞中也有形mRNA表达,但转染pGL3-hTp-TK的MRC-5细胞无TK mRNA表达,提示hTERT启动子可以调控自杀基因HSV-TK在肺癌细胞中靶向表达,可能是肿瘤靶向性基因治疗中比较理想的转录调控元件．     

Although Abundant in Tumor Tissue,Mast Cells Have No Effect on Immunological Micro-milieu or Growth of HPV-Induced or Transplanted Tumors

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利用噬菌体表面展示技术筛选转铁蛋白黏附肽的研究

为了筛选转铁蛋白黏附肽,应用噬菌体表面展示技术经过三轮生物淘选,成功地从随机七肽库中得到黏附转铁蛋白的重组噬菌体克隆,经过相对亲和力常数测定和DNA测序得到4个转铁蛋白黏附肽的序列。实验中以回收率和选择比为操作参数,对淘选进行了优化,并发展了一种基于噬菌体滴度的相对亲和力常数测定方法。转铁蛋白受体是一种有效的肿瘤标记物,利用转铁蛋白为载体可以实现药物靶向运输,因此转铁蛋白黏附肽将是重组蛋白质药物连接转铁蛋白的有用标签。     

Periostin Limits Tumor Response to VEGFA Inhibition

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Utility of Targeted Glucocorticoids in Cancer Therapy

Glucocorticoids can inhibit solid tumor growth via downregulation of tumor-associated inflammation/angiogenesis. In this minireview we describe the possible mechanisms of glucocorticoid action in tumor growth inhibition. We also present an overview of the current status of tumor-targeted glucocorticoid delivery. It appears that long-circulating liposomes are the only targeting system currently being explored for this purpose.     

茶儿茶素抑制肿瘤血管生成的作用

对近几年茶儿茶素抑制肿瘤血管生成的研究进展进行了综述。从抑制血管内皮细胞生长、抑制细胞黏附分子表达和抑制基底膜降解三个部分讨论了其抗肿瘤血管生成的机制,并对儿茶素研究存在的问题和儿茶素开发前景进行了探讨。     

细胞穿膜肽在肿瘤靶向治疗及疾病诊断中的应用

近年来细胞穿膜肽(cell-penetrating peptides,CPP)在生物医药领域被广泛应用,它为生物分子的胞内递送提供了有效的策略。关注CPP在肿瘤治疗及疾病诊断中的作用,并重点介绍其在肿瘤靶向治疗和医学影像诊断中的应用及优势。同时,根据CPP在药物传递系统中的特点,改进CPP存在的不足,扩大其联合用药的可能性,这也成为CPP研究的热点。对CPP及其在肿瘤等疾病的诊断及治疗中的应用作一综述,并简述其优化及改进策略,以期促进CPP在临床中的应用。     

Rho GTPases对肿瘤血管生成相关分子的作用

探讨RhoGTPases的 3个主要分子RhoA、Rac1和Cdc4 2对肿瘤血管生成相关分子的作用 .构建负显性RhoA、Rac1和Cdc4 2的真核表达质粒 ,在Lipofectamine2 0 0 0 介导下转染胃癌细胞AGS ,应用ELISA检测细胞培养上清中VEGF的含量 ,应用Western印迹检测肿瘤血管生成相关分子HIF 1α、P5 3和PTEN的表达水平 .成功地构建了负显性RhoA、Rac1和Cdc4 2的真核表达质粒 ,转染胃癌细胞AGS并经G4 18筛选出单克隆 .ELISA表明转染细胞培养上清中VEGF的含量可被明显抑制 ;Western印迹表明 ,负显性RhoGTPases在蛋白水平上可下调HIF 1α表达水平 ,上调P5 3的表达水平 .结果表明 ,Rho家族的 3个主要分子可能通过调节血管生成相关分子的表达来促进肿瘤血管生成 .     

抑制血管生成治疗肿瘤的策略和展望

新生血管生成是绝大多数肿瘤得以生长和转移的必要前提。所以 ,通过抑制肿瘤血管生成来抑制肿瘤是非常有前途的一种方法 ,有望发展成为一种新型的癌症疗法。主要可以分为两大类 :一是通过抑制促血管生成信号或扩大抑制血管生成因子的作用来干扰肿瘤新生血管的形成过程 ,这领域的广泛研究已经发现了一系列促血管生成因子及其抑制剂和血管生成抑制因子 ;二是利用肿瘤血管与正常血管的差别来携带杀伤性药物直接特异性破坏已形成的肿瘤血管 ;另外 ,内皮细胞及其前体细胞制成疫苗也可起到直接杀伤作用。到目前为止 ,虽然很多抑制肿瘤血管的药物已经被用于临床试验 ,但结果往往不尽如人意 ,从长远来看 ,需要更有效的治疗方法。包括抗血管基因治疗策略 ,靶向药物导入系统的研究 ,以及抗血管生成药物和免疫疗法、化疗和放射治疗的联合应用都在探讨中。随着肿瘤模型评估系统的发展 ,抗血管治疗肿瘤的方法在不久的将来一定会广泛进入临床应用。     

Angiopoietin 1 Promotes Tumor Angiogenesis and Tumor Vessel Plasticity of Human Cervical Cancer in Mice

Angiopoietins have been increasingly implicated to play important roles in blood vessel formation, remodeling, maturation, and maintenance. However, their roles in tumor angiogenesis and hence tumor growth and metastasis still remain uncertain. In this work, angiopoietin 1 expression was amplified in human cervical cancer HeLa cells by stable transfection or recombinant human adenovirus-mediated gene transfer. We show that increased angiopoietin 1 expression promoted in vivo growth of human cervical cancers in mice by promoting tumor angiogenesis and inhibiting tumor cell apoptosis. Furthermore, we also show for the first time that overexpression of angiopoietin 1 also leads to increased tumor vessel plasticity with a large number of vessels lacking periendothelial supporting cells. These results indicate that angiopoietin 1 promotes tumor angiogenesis and tumor vessel plasticity of human cervical cancer in mice.     

Probing the structural and molecular diversity of tumor vasculature

The molecular diversity of the vasculature provides a rational basis for developing targeted diagnostics and therapeutics for cancer. Targeted imaging agents would offer better localization of primary tumors and metastases, and targeted therapies would improve efficacy and reduce side effects. The development of targeted pharmaceuticals requires the identification of specific ligand-receptor pairs, and knowledge of their cellular distribution and accessibility. Using in vivo phage display, a technique by which we can identify organ-specific and disease-specific proteins expressed on the endothelial surface, it is now possible to decipher the molecular signature of blood vessels in normal and diseased tissues. These studies have already led to the identification of peptides that target the normal vasculature of the brain, kidney, pancreas, lung and skin, as well as the abnormal vasculature of tumors, arthritis and atherosclerosis. Membrane dipeptidase in the lungs, interleukin-11 receptor in the prostate, and aminopeptidase N in tumors are examples of molecular targets on blood vessels. Corresponding confocal-microscopic imaging and ultrastructural studies are providing a more complete understanding of the cellular abnormalities of tumor blood vessels, and the distribution and accessibility of potential targets. The combined approach offers a strategy for creating a ligand-receptor map of the human vasculature, and forms a foundation for the development and application of targeted therapies in cancer and other diseases.