Yang W, Barth R F, Wu G, Tjarks W, Binns P, Riley K
Department of Pathology, The Ohio State University, 165 Hamilton Hall, 1645 Neil Avenue, Columbus, OH 43210, USA.
Appl Radiat Isot. 2009 Jul;67(7-8 Suppl):S328-31. doi: 10.1016/j.apradiso.2009.03.030. Epub 2009 Mar 27.
In the present report we have summarized studies carried out over the past five years on molecular targeting of the epidermal growth factor receptor (EGFR) and its mutant isoform, EFGRvIII, for BNCT of genetically engineered F98 rat gliomas, expressing either wildtype (F98(EGFR)) or mutant receptors (F98(npEGFRvIII)). EGF or the monoclonal antibodies (mAbs), cetuximab (IMC-C225) and L8A4, which recognize wildtype EGFR and EGFRvIII, respectively, were heavily boronated using polyamidoamine (PAMAM) dendrimers (BD) linked to the targeting vehicles by means of heterobifunctional reagents. Boronated EGF or mAbs, alone or in combination with i.v. boronophenylalanine (BPA), were administered intracerebrally (i.c.) by either intratumoral (i.t.) injection or convection enhanced delivery (CED) to rats bearing F98 gliomas following which BNCT was initiated. The best survival data were obtained in rats bearing F98(npEGFRvIII) gliomas that had received CED of BD-L8A4 either alone or in combination with i.v. boronophenylalanine (BPA). Studies carried out in rats bearing composite tumors (F98(EGFR)/F98(npEGFRvIII)) demonstrated that it was essential to target both tumor cell populations in order to obtain an optimal therapeutic effect. Based on these observations, we have concluded that EGFR targeting vehicles are useful, but not stand-alone boron delivery agents due to the heterogeneity of receptor expression in brain tumors. They could, however, be quite useful in combination with the two drugs that currently are being used clinically, BPA and sodium borocaptate (BSH) for BNCT of either brain tumors or head and neck cancers.
在本报告中,我们总结了过去五年针对表皮生长因子受体(EGFR)及其突变异构体EFGRvIII进行分子靶向研究的情况,该研究用于对基因工程改造的F98大鼠胶质瘤进行硼中子俘获治疗(BNCT),这些胶质瘤分别表达野生型(F98(EGFR))或突变型受体(F98(npEGFRvIII))。使用通过异双功能试剂与靶向载体相连的聚酰胺胺(PAMAM)树枝状大分子(BD)对识别野生型EGFR和EGFRvIII的表皮生长因子(EGF)或单克隆抗体(mAb)西妥昔单抗(IMC-C225)和L8A4进行了重度硼化。硼化的EGF或mAb单独或与静脉注射的硼苯丙氨酸(BPA)联合,通过瘤内(i.t.)注射或对流增强递送(CED)的方式脑内(i.c.)给药至患有F98胶质瘤的大鼠,随后开始进行BNCT。在单独接受BD-L8A4的CED或与静脉注射硼苯丙氨酸(BPA)联合接受BD-L8A4的CED的患有F98(npEGFRvIII)胶质瘤的大鼠中获得了最佳生存数据。在患有复合肿瘤(F98(EGFR)/F98(npEGFRvIII))的大鼠中进行的研究表明,为了获得最佳治疗效果,对两种肿瘤细胞群体进行靶向至关重要。基于这些观察结果,我们得出结论,EGFR靶向载体是有用的,但由于脑肿瘤中受体表达的异质性,它们不是独立的硼递送剂。然而,它们与目前临床上正在使用的两种药物BPA和硼卡钠(BSH)联合使用时,对于脑肿瘤或头颈癌的BNCT可能非常有用。