背景:癌症-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。已经证实亲和体分子,一个新的小的(6.5kDa)靶向蛋白家族,是分子成像和靶向肿瘤治疗的有用药物。作为MAGE-A3阳性肿瘤体内分子成像检测的新型药物,本研究评估了亲合分子的疗效.
方法:在本研究中,三个周期的噬菌体展示文库筛选导致分离了附着于MAGE-A3的两个新的亲和体分子(ZMAGE-A3:172和ZMAGE-A3:770)。然后将这些分子在细菌中表达并纯化。使用蛋白质印迹法评估具有高亲和力和特异性的亲和体分子,免疫组织化学,间接免疫荧光,表面等离子体共振,和荷瘤裸鼠的近红外光学成像。
结果:选择的ZMAGE-A3亲和体可以精确地结合活细胞中的MAGE-A3蛋白,并在分子水平上显示与MAGE-A3蛋白的高亲和力结合。此外,DyLight755标记的ZMAGE-A3:172或ZMAGE-A3:770在MAGE-A3阳性肿瘤中的积累早在注射后30分钟就达到,并在注射后48小时消失.
结论:我们的发现支持两种MAGE-A3蛋白结合亲和体分子作为分子显像剂的潜力。
BACKGROUND: 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.
METHODS: In this study, three cycles of phage display library screening resulted in the isolation of two new
affibody molecules (ZMAGE-A3:172 and ZMAGE-A3:770) 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.
RESULTS: The selected ZMAGE-A3 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 ZMAGE-A3:172 or ZMAGE-A3:770 in MAGE-A3-positive tumors was achieved as early as 30 min and disappeared at 48 h post-injection.
CONCLUSIONS: Our findings support the potential of the two MAGE-A3 protein-binding
affibody molecules for their use as molecular imaging agents.