Morrison Joanne, Briggs Simon S, Green Nicola K, Thoma Clemens, Fisher Kerry D, Kehoe Sean, Seymour Leonard W
Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital, Headington, Oxford, United Kingdom.
Hum Gene Ther. 2009 Mar;20(3):239-51. doi: 10.1089/hum.2008.167.
Gene and virotherapy of ovarian cancer, using type 5 adenovirus (Ad5), has demonstrated good activity in preclinical animal studies, particularly after intraperitoneal administration of virus; however, success in clinical trials has been limited by poor infectivity of ovarian cancer cells and inflammatory responses to Ad5. We previously demonstrated that covalent modification of Ad5 with reactive copolymers on the basis of poly(hydroxypropylmethacrylamide) can shield the virus, offering protection from neutralizing antibodies and enabling retargeting to cancer-upregulated receptors with peptide ligands (basic fibroblast growth factor [bFGF] and murine epidermal growth factor [EGF]). These ligands may be less than ideal for clinical use, however, because they are potential mitogens. Accordingly, in this study we investigated the use of an anti-EGF receptor (EGFR) antibody, cetuximab, to retarget adenoviral transduction of EGFR-positives in vitro and in vivo. Cetuximab retargeting altered the physicochemical characteristics of Ad5, although it did not cause particle aggregation. Although cetuximab stimulated internalization of EGFR, similarly to EGF, it inhibited EGFR phosphorylation. Adenoviral transduction was inhibited after polymer coating, but was rescued in EGFR-positive cells (and not in EGFR-negative cells) by cetuximab retargeting. Cetuximab retargeting of wild-type adenovirus serotype 5 (Ad5WT) prolonged survival in an animal model of human ovarian cancer, similar to unmodified Ad5WT, but polymer coating ameliorated stimulation of adhesion formation. We conclude that polymer coating and covalent attachment of cetuximab successfully retargeted adenovirus to EGFR-positive cells, retained in vivo efficacy of an oncolytic adenovirus, and ameliorated side effects caused by unmodified adenovirus.
使用5型腺病毒（Ad5）对卵巢癌进行基因治疗和病毒治疗，在临床前动物研究中已显示出良好的活性，尤其是在腹腔内注射病毒后；然而，临床试验的成功受到卵巢癌细胞感染性差以及对Ad5炎症反应的限制。我们之前证明，基于聚（羟丙基甲基丙烯酰胺）的反应性共聚物对Ad5进行共价修饰可以保护病毒，使其免受中和抗体的影响，并能够通过肽配体（碱性成纤维细胞生长因子[bFGF]和小鼠表皮生长因子[EGF]）重新靶向癌细胞上调的受体。然而，这些配体可能不太适合临床使用，因为它们是潜在的促细胞分裂剂。因此，在本研究中，我们研究了使用抗表皮生长因子受体（EGFR）抗体西妥昔单抗在体外和体内重新靶向EGFR阳性细胞的腺病毒转导。西妥昔单抗重新靶向改变了Ad5的物理化学特性，尽管它没有导致颗粒聚集。虽然西妥昔单抗与EGF类似，刺激了EGFR的内化，但它抑制了EGFR的磷酸化。聚合物包被后腺病毒转导受到抑制，但通过西妥昔单抗重新靶向，在EGFR阳性细胞（而非EGFR阴性细胞）中得以恢复。西妥昔单抗对野生型5型腺病毒（Ad5WT）的重新靶向延长了人卵巢癌动物模型的生存期，与未修饰的Ad5WT相似，但聚合物包被改善了粘连形成的刺激。我们得出结论，聚合物包被和西妥昔单抗的共价连接成功地将腺病毒重新靶向EGFR阳性细胞，保留了溶瘤腺病毒的体内疗效，并改善了未修饰腺病毒引起的副作用。
