EGF RECEPTOR AND P185(ERB-2)-SPECIFIC SINGLE-CHAIN ANTIBODY TOXINS DIFFER IN THEIR CELL-KILLING ACTIVITY ON TUMOR-CELLS EXPRESSING BOTH RECEPTOR PROTEINS
EGF RECEPTOR AND P185(ERB-2)-SPECIFIC SINGLE-CHAIN ANTIBODY TOXINS DIFFER IN THEIR CELL-KILLING ACTIVITY ON TUMOR-CELLS EXPRESSING BOTH RECEPTOR PROTEINS
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DOI：
10.1002/ijc.2910600120
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发表时间：
1995-01-03
影响因子：
6.4
通讯作者：
HYNES, NE
中科院分区：
文献类型：
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作者：
WELS, W;BEERLI, R;HYNES, NE
许多人类肿瘤过表达erbB-2和EGF受体。这些受体酪氨酸激酶的膜定位使它们成为定向肿瘤治疗的合适靶点。我们利用重组DNA技术制备了特异性结合erbB-2和EGF受体的单链抗体外毒素A （scFv-ETA）融合蛋白。scFv部分由单克隆抗体的重链和轻链可变结构域组成，单克隆抗体识别每个受体的细胞外部分。我们之前已经描述了细菌产生的scFv(FRP5)-ETA针对erbB-2受体的抗肿瘤活性。本文描述了一种结合EGF受体的蛋白scFv(225)-ETA的特性。细菌产生的重组蛋白与受体高亲和力结合，抑制过表达EGF受体的肿瘤细胞系A431和MDA-MB468的体外生长。scFv(FRP5)-ETA和scFv(225)-ETA联合处理对A431细胞体外生长具有加性抑制作用。表达低水平EGF受体但高水平p185 （erbB-2）的SKBR3细胞不受scFv(225)-ETA处理的影响，但对scFv(FRP5)-ETA敏感。用EGF刺激表达人erbB-2的SKBR3细胞和HCI I RI#II小鼠乳腺上皮细胞导致scFv(FRP5)-ETA活性增加，表明EGF诱导的erbB-2活化可以增强erbB-2导向毒素的作用。用scFv(FRP5)-ETA和两种scFv-ETA蛋白联合治疗胸腺裸小鼠可导致已建立的A431肿瘤的生长短暂停止。scFv(225)-ETA单独治疗是最有效的，在治疗过程中导致肿瘤缩小，而用亲本单克隆抗体225治疗导致肿瘤生长迟缓。(C) 1995 Wiley-Liss, Inc。
Many human tumors over-express erbB-2 and EGF receptors. The membrane localization of these receptor tyrosine kinases make them appropriate targets for directed tumor therapy. We have used recombinant DNA technology to produce single-chain antibody exotoxin A (scFv-ETA) fusion proteins which specifically bind the erbB-2 and EGF receptors. The scFv portion is composed of the heavy- and light-chain variable domains of monoclonal antibodies which recognize the extracellular portion of each receptor. We have previously described the anti-tumor activity of the bacterially produced scFv(FRP5)-ETA directed to the erbB-2 receptor. In this paper we describe the characteristics of scFv(225)-ETA, a protein which binds the EGF receptor. The bacterially produced recombinant protein binds to the receptor with high affinity and inhibits the in vitro growth of the EGF receptor over-expressing tumor cell lines A431 and MDA-MB468. Combination treatment with scFv(FRP5)-ETA and scFv(225)-ETA led to an additive inhibitory effect on the in vitro growth of A431 cells. SKBR3 cells expressing low levels of EGF receptor but high levels of p 185(erbB-2) were not affected by scFv(225)-ETA treatment but were sensitive to scFv(FRP5)-ETA. Stimulation of SKBR3 cells and HCI I RI#II mouse mammary epithelial cells expressing the human erbB-2 with EGF led to an increase in scFv(FRP5)-ETA activity, showing that the EGF-induced activation of erbB-2 can potentiate the action of the erbB-2-directed toxin. Treatment of athymic nude mice with scFv(FRP5)-ETA and the combination of both scFv-ETA proteins led to the transient arrest of growth of established A431 tumors. scFv(225)-ETA treatment alone was the most effective, leading to tumor shrinkage during the course of treatment, whereas treatment with the parental monoclonal antibody 225 led to retarded tumor growth. (C) 1995 Wiley-Liss, Inc.