Cai Yiqi, Ren Jiahuan, Jin Jinji, Shao Huanyi, Wang Pengfei, Cheng Kai, Jiang Peipei, Jiang Pengfei, Zhu Shanli, Zhu Guanbao, Zhang Lifang
Department of Gastrointestinal Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, PR China.
Department of Pediatric Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, PR China.
Environ Res. 2023 Nov 15;237(Pt 1):116895. doi: 10.1016/j.envres.2023.116895. Epub 2023 Aug 14.
The cancer-testis protein melanoma antigen A3 (MAGE-A3) is highly expressed in a broad range of malignant tumor forms. It has been confirmed that affibody molecules, a novel family of small (∼6.5 kDa) targeting proteins, are useful agents for molecular imaging and targeted tumor treatment. As a novel agent for in vivo molecular imaging detection of MAGE-A3-positive tumors, the efficacy of affibody molecules was assessed in this research.
In this study, three cycles of phage display library screening resulted in the isolation of two new affibody molecules (Z:172 and Z:770) that attach to MAGE-A3. These molecules were then expressed in bacteria and purified. The affibody molecules with high affinity and specificity were evaluated using western blotting, immunohistochemistry, indirect immunofluorescence, surface plasmon resonance, and near-infrared optical imaging of tumor-bearing nude mice.
The selected Z affibodies can precisely bind to the MAGE-A3 protein in living cells and display high-affinity binding to the MAGE-A3 protein at the molecular level. Furthermore, the accumulation of DyLight755-labeled Z:172 or Z:770 in MAGE-A3-positive tumors was achieved as early as 30 min and disappeared at 48 h post-injection.
Our findings support the potential of the two MAGE-A3 protein-binding affibody molecules for their use as molecular imaging agents.
癌-睾丸蛋白黑色素瘤抗原A3（MAGE-A3）在多种恶性肿瘤形式中高度表达。已证实，亲和体分子是一类新型的小（约6.5 kDa）靶向蛋白，是分子成像和靶向肿瘤治疗的有用试剂。作为一种用于体内分子成像检测MAGE-A3阳性肿瘤的新型试剂，本研究评估了亲和体分子的功效。
在本研究中，通过三轮噬菌体展示文库筛选，分离出两种与MAGE-A3结合的新型亲和体分子（Z:172和Z:770）。然后在细菌中表达并纯化这些分子。使用蛋白质印迹、免疫组织化学、间接免疫荧光、表面等离子体共振以及对荷瘤裸鼠进行近红外光学成像，评估具有高亲和力和特异性的亲和体分子。
所选的Z亲和体可以在活细胞中精确结合MAGE-A3蛋白，并在分子水平上显示出与MAGE-A3蛋白的高亲和力结合。此外，DyLight755标记的Z:172或Z:770在MAGE-A3阳性肿瘤中的蓄积在注射后30分钟即可实现，并在48小时后消失。
我们的研究结果支持这两种与MAGE-A3蛋白结合的亲和体分子作为分子成像剂的潜力。
