Liang Hui, Li Xiaoran, Wang Bin, Chen Bing, Zhao Yannan, Sun Jie, Zhuang Yan, Shi Jiajia, Shen He, Zhang Zhijun, Dai Jianwu
Key Laboratory for Nano-Bio Interface Research, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Sci Rep. 2016 Feb 17;6:18205. doi: 10.1038/srep18205.
Many tumors over-express collagen, which constitutes the physical scaffold of tumor microenvironment. Collagen has been considered to be a target for cancer therapy. The collagen-binding domain (CBD) is a short peptide, which could bind to collagen and achieve the sustained release of CBD-fused proteins in collagen scaffold. Here, a collagen-binding EGFR antibody fragment was designed and expressed for targeting the collagen-rich extracellular matrix in tumors. The antibody fragment (Fab) of cetuximab was fused with CBD (CBD-Fab) and expressed in Pichia pastoris. CBD-Fab maintained antigen binding and anti-tumor activity of cetuximab and obtained a collagen-binding ability in vitro. The results also showed CBD-Fab was mainly enriched in tumors and had longer retention time in tumors in A431 s.c. xenografts. Furthermore, CBD-Fab showed a similar therapeutic efficacy as cetuximab in A431 xenografts. Although CBD-Fab hasn't showed better therapeutic effects than cetuximab, its smaller molecular and special target may be applicable as antibody-drug conjugates (ADC) or immunotoxins.
许多肿瘤过度表达胶原蛋白,胶原蛋白构成肿瘤微环境的物理支架。胶原蛋白一直被认为是癌症治疗的一个靶点。胶原蛋白结合结构域(CBD)是一种短肽,它可以与胶原蛋白结合,并在胶原蛋白支架中实现与CBD融合蛋白的持续释放。在此,设计并表达了一种胶原蛋白结合表皮生长因子受体(EGFR)抗体片段,用于靶向肿瘤中富含胶原蛋白的细胞外基质。西妥昔单抗的抗体片段(Fab)与CBD融合(CBD-Fab),并在毕赤酵母中表达。CBD-Fab保留了西妥昔单抗的抗原结合能力和抗肿瘤活性,并在体外获得了胶原蛋白结合能力。结果还表明,在A431皮下异种移植瘤中,CBD-Fab主要富集于肿瘤中,且在肿瘤中的保留时间更长。此外,在A431异种移植瘤中,CBD-Fab显示出与西妥昔单抗相似的治疗效果。虽然CBD-Fab没有显示出比西妥昔单抗更好的治疗效果,但其较小的分子和特殊的靶点可能适用于抗体药物偶联物(ADC)或免疫毒素。