分子靶向抗肿瘤药物研究进展

分子靶向抗肿瘤药物有独特的靶向抗肿瘤作用,在当前临床治疗中已发挥重要作用,并显示出良好的应用前景。根据其分子的大小可将分子靶向抗肿瘤药物分为大分子单克隆抗体类和小分子化合物类,我们简要综述了这2类分子靶向抗肿瘤药物的研究进展。     

基于活性和基因从海洋微生物中筛选烯二炔类抗生素

【目的】高质量的海洋微生物菌种库及其天然产物库是新药开发的重要来源。在本研究中我们通过筛选新的烯二炔类抗生素来对已经构建的海洋微生物天然产物库进行质量评价。【方法】首先我们根据烯二炔类抗生素能引起DNA断裂的活性构建了活性筛选模型,并对我们的天然产物库进行筛选;其次根据合成烯二炔核心结构的独特且保守的重复I型聚酮合成酶设计了引物,通过PCR扩增的方法对海洋微生物库进行序列筛选。【结果】通过活性筛选从我们的海洋微生物天然产物库中获得一个阳性的发酵产物。对该阳性菌(LS481)的系统发育学分析表明该菌属于能产生烯二炔类化合物—Dynemicin的Micromonospora chersina,对其发酵产物TLC分析证明该菌确实产生Dynemicin类化合物。通过基因筛选得到了2个具备合成烯二炔核心结构聚酮合成酶的菌株,16S rRNA基因分析显示其中一个很可能为灰色链霉菌(MS098),另外一株菌则同Streptomyces vinaceus NBRC 13425T和Streptomyces cirratus NRRLB-3250T最相近。【结论】我们的活性筛选模型能够有效获得烯二炔类物质,结合基因筛选能够进一步获得可能产生烯二炔物质的菌株。初筛结果也再一次验证了我们海洋微生物天然产物库的质量较好。     

阿霉素靶向给药系统研究进展

近年来,癌症的发病率和死亡率不断上升,对人类健康造成极大的威胁。阿霉素作为一种广谱抗肿瘤药物,对正常细胞亦有严重毒副作用,从而使其临床应用受到限制。提高阿霉素肿瘤靶向性、降低其毒性由此成为该药物的热点研究方向。对阿霉素靶向给药系统的研究进展进行了综述。     

靶向抗肿瘤药物研究进展

肿瘤的分子靶向治疗是癌症的现代治疗手段。相对于传统的化学治疗而言,靶向治疗准确高效,且毒副作用小,应用前景广泛。靶向治疗作用的位点是细胞癌变过程中的基因、受体和信号转导途径中的关键酶,有赖于细胞癌变机制的研究。目前,部分细胞癌变的机制已经研究得较为清晰,相应的靶向抗肿瘤药物也被开发应用。就抗原抗体标靶、酪氨酸激酶抑制剂和表观遗传调节剂三个方面,对当前的肿瘤靶向治疗研究和相关药物的开发现状作一综述。     

EGF类生长因子来源的新型靶向肽在抗肿瘤药物蛋白中的应用

许多肿瘤细胞表面表皮生长因子受体EGFR都存在过表达现象。考察了牛痘病毒生长因子(VGF)中的EGFR结合域(S3)与人的肝素样表皮生长因子(HB-EGF)来源的肝素结合域(命名为HE)重组后对肿瘤细胞的选择性。通过重组表达带有靶向和穿膜结构域的EGFP-S3-HE和EGFP-S3-HE-TATm两种融合蛋白与正常细胞和肿瘤细胞的共孵育实验来研究其对肿瘤细胞的特异性靶向吸附和穿膜效应。进一步将S3-HE-TATm靶向穿膜序列与苦瓜来源的核糖体失活蛋白MAP30融合,可显著提高MAP30对肿瘤细胞的抑杀作用,但这种抑杀作用却对正常细胞仍保持在较低水平。由此表明S3-HE-TATm是一种新型优异的肿瘤细胞靶向药物运输载体,可用于肿瘤治疗的进一步开发研究。     

ACSBAIA方法及其在烯丙胺类抗真菌药物设计中的应用

根据活性类似物活性基团在能量补偿许可范围内能够到达受体活性部位与各作用位点结合 ,而无 (低 )活性类似物的活性基团由于构象限制因素等不能与之结合的原理 ,建立一种新的搜寻药物分子的活性构象程序ACSBAIA .该程序包括 4个子系统 :构象抽样、活性构象限定、无活性构象排除、活性预测 .用此方法搜寻了烯丙胺类抗真菌药物的活性构象 ,并对 2个高活性和无活性的类似物进行了预测和检验 ,证明该方法较科学实用 .该方法的应用不受受体三维结构知识多少的限制 ,对目前绝大多数受体三维结构未知的情况尤其适用     

驱动蛋白Eg5及其靶向治疗药物的抗肿瘤机制

Eg5又名Kif11（kinesin family member 11）是驱动蛋白家族成员之一,在增殖组织细胞中高表达,定位于有丝分裂期的微管,主要与细胞分裂中染色体的定位、中心体的分离以及双极纺锤体的形成和分离有关。Eg5是近年来研究较多的一种驱动蛋白分子,已开发出抑制其活性的肿瘤靶向治疗药物。该文介绍Eg5生物学特性、其抑制物在肿瘤靶向治疗中作用及与疾病关系等方面的最新研究进展。     

驱动蛋白Eg5及其靶向治疗药物的抗肿瘤机制

Eg5又名Kifll(kinesin family member 11)是驱动蛋白家族成员之一,在增殖组织细胞中高表达,定位于有丝分裂期的微管,主要与细胞分裂中染色体的定位、中心体的分离以及双极纺锤体的形成和分离有关.Eg5是近年来研究较多的一种驱动蛋白分子,已开发出抑制其活性的肿瘤靶向治疗药物.该文介绍Eg5生物学特性、其抑制物在肿瘤靶向治疗中作用及与疾病关系等方面的最新研究进展.     

细胞衰老及其在抗肿瘤研究中的应用

细胞衰老是细胞脱离细胞周期并不可逆地丧失增殖能力后进入的一种相对稳定的状态,虽然基本代谢过程仍然能够维持,但丧失合成DNA及增殖能力。细胞衰老具有复制衰老、癌基因诱导的衰老及加速衰老等类型。衰老细胞具有细胞体积大而扁平、细胞停止分裂及SA-β-gal反应阳性等明显特性,复制衰老还具有端粒缩短到无法维持染色体结构完整性的特征。目前已知,p53-p21和p16-pRB在细胞衰老过程中起着重要的调控作用,细胞衰老对肿瘤的形成起着天然的屏障作用。通过抑制端粒酶活性来诱导肿瘤细胞衰老和通过胞外刺激或化学治疗药物诱导肿瘤细胞发生衰老样生长停滞,已成为抗肿瘤研究的新思路。     

核甙类抗生素产生菌的筛选及其活性组分研究

从成都郊区土壤中筛选出一株能产生抗生素的放线菌 ,经过形态及培养特征观察、生理生化特性试验、细胞壁化学组成分析 ,确定其分类学归属为链霉菌属 ( Strep-tomyces)。从产生菌的固体培养物中分离得到活性物质、理化性质研究表明 ,该物质为胞嘧啶核苷衍生物。抗菌和抗肿瘤活性试验结果显示 ,此物质不仅具有抑菌活性 ,而且具有较强的抗肿瘤活性。     

Targeted Exosomes for Drug Delivery: Biomanufacturing,Surface Tagging,and Validation

Exosomes hold great potential to deliver therapeutic reagents for cancer treatment due to its inherent low antigenicity. However, several technical barriers, such as low productivity and ineffective cancer targeting, need to be overcome before wide clinical applications. The present study aims at creating a new biomanufacturing platform of cancer‐targeted exosomes for drug delivery. Specifically, a scalable, robust, high‐yield, cell line based exosome production process is created in a stirred‐tank bioreactor, and an efficient surface tagging technique is developed to generate monoclonal antibody (mAb)‐exosomes. The in vitro characterization using transmission electron microscopy, NanoSight, and western blotting confirm the high quality of exosomes. Flow cytometry and confocal laser scanning microscopy demonstrate that mAb‐exosomes have strong surface binding to cancer cells. Furthermore, to validate the targeted drug delivery efficiency, romidepsin, a histone deacetylase inhibitor, is loaded into mAb‐exosomes. The in vitro anti‐cancer toxicity study shows high cytotoxicity of mAb‐exosome‐romidepsin to cancer cells. Finally, the in vivo study using tumor xenograft animal model validates the cancer targeting specificity, anti‐cancer efficacy, and drug delivery capability of the targeted exosomes. In summary, new techniques enabling targeted exosomes for drug delivery are developed to support large‐scale animal studies and to facilitate the translation from research to clinics.     

抗生素缓控释给药系统——载药微球的研究与开发

利用具良好生物相容性和生物可降解性的聚合物制得的微球作为一种新型药物载体, 具有良好的缓控释作用,并具有一定的靶向性,可用于口服和注射,在药学领域和临床上有着广阔的应用前景。综述近年来各种抗生素缓控释微球制剂的研究与开发。     

B3(ds-scFv)靶向超抗原的制备及活性鉴定

To construct the expression vector of a recombinant toxin composed of a disulfide stable single-chain antibody from mAbB3 and SEA(D227A),the binding ability and cytotoxicity of the purified renatured products against the B3 positive carcinoma cells was examined. The VH and VL fragments of the mAbB3 were ligated by overlap PCR, the PCR product was cloned to the pET22b expression vector, then the SEA fragment was inserted into the B3dsscFv-pET22b expression vector which was digested by the same restriction enzymes. The expression plasmid was identified by restriction endonucleases digestion and transformed into E.coli BL21(DE3) followed by IPTG induction. The inclusion body was purified through SP-Sepharose cation exchange column after denaturing and refolding and the binding and cytotoxic ability of the purified products was examined by cell-ELISA and non-radioactive cell proliferation assay seperately. The expression vector B3dsscFv-SEA-pET was constructed successfully and the expression product exists mainly in the inclusion body, amounting to 33% of the total protein. The refolding product remains the binding ability of the single-chain antibody and has cytotoxic effect on HT-29 colon carcinoma cells. The stability assay showed that the resulting protein was stable at 37℃. This genetically engineered B3dsscFv-SEA fusion protein has bifunction of tumor targeting and tumor cell killing and promises to be an effective reagent for tumor targeted immunotherapy.     

The novel EpCAM-targeting monoclonal antibody 3–17I linked to saporin is highly cytotoxic after photochemical internalization in breast,pancreas and colon cancer cell lines

The epithelial cell adhesion molecule (EpCAM) is expressed by a wide range of human carcinomas, making it an attractive diagnostic and therapeutic target in oncology. Its recent identification on cancer stem cells has raised further interest in its use for tumor targeting and therapy. Here, we present the characterization and therapeutic potential of 3–17I, a novel human EpCAM-targeting monoclonal antibody. Strong reaction of 3–17I was observed in all lung, colon, and breast human tumor biopsies evaluated. By flow cytometry and confocal fluorescence microscopy, we demonstrate that 3–17I specifically targets EpCAM-positive cell lines. We also show evidence for mAb-sequestration in endo-/lysosomes, suggesting internalization of 3–17I by receptor-mediated endocytosis. The ribosomal-inactivating toxin saporin was linked to 3–17I, creating the per se non-toxic immunotoxin 3–17I-saporin, a promising candidate for the drug delivery technology photochemical internalization (PCI). PCI is based on a light-controlled destruction of endolysosomal membranes and subsequent cytosolic release of the sequestered payload upon light exposure. EpCAM-positive human cancer cell lines MCF7 (breast), BxPC-3 (pancreas), WiDr (colon), and the EpCAM-negative COLO320DM (colon), were treated with 3–17I-saporin in combination with the clinically relevant photosensitizer TPCS2a (Amphinex), followed by exposure to light. No cytotoxicity was observed after treatment with 3–17I-saporin without light exposure. However, cell viability, proliferation and colony-forming capacity was strongly reduced in a light-dependent manner after PCI of 3–17I. Our results show that 3–17I is an excellent candidate for diagnosis of EpCAM-positive tumors and for development of clinically relevant antibody-drug conjugates, using PCI for the treatment of localized tumors.     

靶向共价键药物的研究进展

药物与靶标的结合是启动药理作用的本源,共价键药物是以共享电子的方式来实现与靶标的结合,其中大多为抗感染、抗肿瘤以及心脑血管、神经系统和代谢类药物。简介共价键药物与非共价键药物的区别以及既往的重磅级共价键药物与靶标的结合特点,分类综述靶向共价键药物的理性设计及与靶标的结合反应。     

The novel EpCAM-targeting monoclonal antibody 3–17I linked to saporin is highly cytotoxic after photochemical internalization in breast,pancreas and colon cancer cell lines

The epithelial cell adhesion molecule (EpCAM) is expressed by a wide range of human carcinomas, making it an attractive diagnostic and therapeutic target in oncology. Its recent identification on cancer stem cells has raised further interest in its use for tumor targeting and therapy. Here, we present the characterization and therapeutic potential of 3–17I, a novel human EpCAM-targeting monoclonal antibody. Strong reaction of 3–17I was observed in all lung, colon, and breast human tumor biopsies evaluated. By flow cytometry and confocal fluorescence microscopy, we demonstrate that 3–17I specifically targets EpCAM-positive cell lines. We also show evidence for mAb-sequestration in endo-/lysosomes, suggesting internalization of 3–17I by receptor-mediated endocytosis. The ribosomal-inactivating toxin saporin was linked to 3–17I, creating the per se non-toxic immunotoxin 3–17I-saporin, a promising candidate for the drug delivery technology photochemical internalization (PCI). PCI is based on a light-controlled destruction of endolysosomal membranes and subsequent cytosolic release of the sequestered payload upon light exposure. EpCAM-positive human cancer cell lines MCF7 (breast), BxPC-3 (pancreas), WiDr (colon), and the EpCAM-negative COLO320DM (colon), were treated with 3–17I-saporin in combination with the clinically relevant photosensitizer TPCS2a (Amphinex), followed by exposure to light. No cytotoxicity was observed after treatment with 3–17I-saporin without light exposure. However, cell viability, proliferation and colony-forming capacity was strongly reduced in a light-dependent manner after PCI of 3–17I. Our results show that 3–17I is an excellent candidate for diagnosis of EpCAM-positive tumors and for development of clinically relevant antibody-drug conjugates, using PCI for the treatment of localized tumors.     

全球抗肿瘤药物研发报告（2015）

全球癌症发病形势严峻,发病率与死亡率呈持续上升趋势。近年来抗肿瘤创新药物的激增以及研发进程的强劲表现持续推动抗肿瘤 药物市场的快速发展。报告采用文献调研、数据库检索、数据统计与分析等定性定量情报研究方法,从药物数量、研发阶段、研发公司、 适应证、作用机制、技术类型、销售情况等角度对全球抗肿瘤药物的研发情况进行多角度、多层次的分析,旨在为我国抗肿瘤药物的研发 提供参考。     

新型纳米靶向给药系统载体材料的设计

新型纳米靶向给药系统的研究与开发对于难治愈性疾病（尤其是肿瘤）的治疗具有重大意义,而其发展很大程度上取决于载体材料 的设计。构思巧妙、设计合理的载体材料能使载体实现靶向功能,将药物定位浓集于病灶部位,并最大限度地发挥高效低毒的作用。基于 不同的靶向策略,包括被动靶向、主动靶向和响应肿瘤微环境的靶向,综述了近年来一些新型纳米载体材料的设计,为新型纳米靶向给药 系统的研究提供参考。