HER2-affitoxin: a potent therapeutic agent for the treatment of HER2-overexpressing tumors.
HER2-affitoxin: a potent therapeutic agent for the treatment of HER2-overexpressing tumors.
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DOI：
10.1158/1078-0432.ccr-10-2887
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发表时间：
2011-08-01
期刊：
影响因子：
--
通讯作者：
Capala J
中科院分区：
文献类型：
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作者：
Zielinski R;Lyakhov I;Hassan M;Kuban M;Shafer-Weaver K;Gandjbakhche A;Capala J
过度表达HER 2/neu基因的癌症通常更具侵袭性，并且与预后不良相关。尽管曲妥珠单抗显著改善了预后，但许多肿瘤对目前的治疗没有反应或产生耐药性。为了提供替代的HER 2靶向治疗，我们开发并表征了一种新的重组蛋白，其组合了HER 2特异性亲和体和修饰的铜绿假单胞菌外毒素A（PE 38），其在与HER 2结合后被内化并递送至肿瘤细胞的胞质溶胶，在那里其通过eEF-2的ADP核糖基化阻断蛋白质合成。使用CellTiter-Glo（Promega，麦迪逊，WI）评估阿菲毒素对细胞活力的影响。为了评估HER 2特异性功效，用Affitoxin（HER 2特异性或Tag特异性）处理携带BT-474乳腺癌、SK-0 V-3卵巢癌和NCI-N87胃癌异种移植物的无胸腺裸鼠，每三天注射一次。使用标准抗体产生和脾细胞增殖测定法研究了雌性BALB/c小鼠中的Affitoxin免疫原性。体外实验表明，HER 2-阿菲毒素是一种强效药物，在低皮摩尔浓度下可消除HER 2过表达细胞。疗效研究显示，相对较大的BT-474肿瘤完全根除，对SK-0 V-3和NCI-N87肿瘤有显著影响。HER 2-阿菲毒素从循环中快速清除（T1/2 < 10分钟），并且在0.5 mg/kg及以下的剂量下被小鼠良好耐受。免疫原性研究表明，第三次注射剂量后，HER 2-阿菲毒素诱导抗体产生。我们的研究结果表明，HER 2-Affitoxin是一种有效的抗癌药物，是临床研究的潜在候选药物。
Cancers overexpressing the HER2/neu gene are usually more aggressive and are associated with poor prognosis. Although trastuzumab has significantly improved the outcome, many tumors do not respond or acquire resistance to current therapies. To provide an alternative HER2-targeted therapy, we have developed and characterized a novel recombinant protein combining an HER2-specific Affibody and modified Pseudomonas aeruginosa exotoxin A (PE 38), which, after binding to HER2, is internalized and delivered to the cytosol of the tumor cell, where it blocks protein synthesis by ADP ribosylation of eEF-2. The effect of the Affitoxin on cell viability was assessed using CellTiter-Glo (Promega, Madison, WI). To assess HER2-specific efficacy, athymic nude mice bearing BT-474 breast cancer, SK-OV-3 ovarian cancers, and NCI-N87 gastric carcinoma xenografts were treated with the Affitoxin (HER2- or Tag-specific), which was injected every third day. Affitoxin immunogenicity in female BALB/c mice was investigated using standard antibody production and splenocyte proliferation assays. In vitro experiments showed that HER2-Affitoxin is a potent agent that eliminates HER2-overexpressing cells at low picomolar concentrations. Therapeutic efficacy studies showed complete eradication of relatively large BT-474 tumors and significant effects on SK-OV-3 and NCI-N87 tumors. HER2-Affitoxin cleared quickly from circulation (T1/2) < 10 minutes) and was well tolerated by mice at doses of 0.5 mg/kg and below. Immunogenicity studies indicated that HER2-Affitoxin induced antibody development after the third injected dose. Our findings demonstrated that HER2-Affitoxin is an effective anticancer agent and a potential candidate for clinical studies.