Anti-HER2 scFv-Directed Extracellular Vesicle-Mediated mRNA-Based Gene Delivery Inhibits Growth of HER2-Positive Human Breast Tumor Xenografts by Prodrug Activation.
Anti-HER2 scFv-Directed Extracellular Vesicle-Mediated mRNA-Based Gene Delivery Inhibits Growth of HER2-Positive Human Breast Tumor Xenografts by Prodrug Activation.
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DOI：
10.1158/1535-7163.mct-17-0827
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发表时间：
2018-05
影响因子：
5.7
通讯作者：
Matin AC
中科院分区：
文献类型：
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作者：
Wang JH;Forterre AV;Zhao J;Frimannsson DO;Delcayre A;Antes TJ;Efron B;Jeffrey SS;Pegram MD;Matin AC
本文涉及前药/酶方案的特异性靶向，hocB/HChrR 6，以治疗严重疾病，即HER 2 +ve人乳腺癌，具有最小的脱靶毒性。HChrR 6是一种改良的细菌酶，可将hocB转化为细胞毒性药物MCHB。细胞外囊泡（EV）用于基于mRNA的HchrR 6基因递送：EV可能引起最小的免疫排斥反应，mRNA可能上级DNA用于基因递送。为了将HChrR 6的产生和hocB的活化限制在癌症中，构建了EVHB嵌合蛋白。它含有高亲和力抗HER 2 scFv抗体（ML 39），并能够锁定在EV表面。用EVHB编码质粒转染的细胞产生展示该蛋白质的EV（“定向EV”）。用新质粒XPort/HChrR 6转染单独一批细胞，产生含有HChrR 6 mRNA的EV;用纯EVHB孵育使这些细胞能够靶向HER 2受体，产生“EXO-DEPT”EV。EXO-DEPT处理特异性地使HER 2过表达的BT474细胞能够以放线菌素D非依赖性方式将hocB转化为MCHB，显示HCHrR 6 mRNA的成功和特异性递送。EXO-DEPT-而不是无定向EV-加hocB在体内引起原位BT474异种移植物的几乎完全生长停滞，首次证明EV介导的功能性外源mRNA向肿瘤的递送。EXO-DEPT可以从患者自身的树突状细胞产生以逃避免疫排斥，并且没有质粒及其潜在有害的遗传物质，提高了该方案的临床使用的前景。这种方法可用于治疗任何过表达特定标志物的疾病。
This paper deals with specific targeting of the prodrug/enzyme regimen, CNOB/HChrR6, to treat a serious disease namely HER2+ve human breast cancer with minimal off-target toxicity. HChrR6 is an improved bacterial enzyme that converts CNOB into the cytotoxic drug MCHB. Extracellular vesicles (EVs) were used for mRNA-based HchrR6 gene delivery: EVs may cause minimal immune rejection, and mRNA may be superior to DNA for gene delivery. To confine HChrR6 generation and CNOB activation to the cancer, the EVHB chimeric protein was constructed. It contains high affinity anti-HER2 scFv antibody (ML39) and is capable of latching on to EV surface. Cells transfected with EVHB-encoding plasmid generated EVs displaying this protein (“directed EVs”). Transfection of a separate batch of cells with the new plasmid, XPort/HChrR6, generated EVs containing HChrR6 mRNA; incubation with pure EVHB enabled these to target the HER2 receptor, generating “EXO-DEPT” EVs. EXO-DEPT treatment specifically enabled HER2-overexpressing BT474 cells to convert CNOB into MCHB in actinomycin D independent manner, showing successful and specific delivery of HCHrR6 mRNA. EXO-DEPTs –but not undirected EVs– plus CNOB caused near-complete growth-arrest of orthotopic BT474 xenografts in vivo, demonstrating for the first time EV-mediated delivery of functional exogenous mRNA to tumors. EXO-DEPTs may be generated from patient’s own dendritic cells to evade immune rejection, and without plasmids and their potentially harmful genetic material, raising the prospect of clinical use of this regimen. This approach can be employed to treat any disease overexpressing a specific marker.