Department of Chemistry and Applied Biosciences, ETH Zürich, Institute of Pharmaceutical Sciences, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland.
Eur J Nucl Med Mol Imaging. 2010 Aug;37(8):1559-65. doi: 10.1007/s00259-010-1446-9. Epub 2010 Apr 20.
Matrix metalloproteinases (MMPs), a group of more than 20 zinc-containing endopeptidases, are upregulated in many diseases, but several attempts to use radiolabelled MMP inhibitors for imaging tumours have proved unsuccessful in mouse models, possibly due to the limited specificity of these agents or their unfavourable pharmacokinetic profiles. In principle, radiolabelled monoclonal antibodies could be considered for the selective targeting and imaging of individual MMPs.
We cloned, produced and characterized high-affinity monoclonal antibodies specific to murine MMP-1A, MMP-2 and MMP-3 in SIP (small immunoprotein) miniantibody format using biochemical and immunochemical methods. We also performed comparative biodistribution analysis of their tumour-targeting properties at three time points (3 h, 24 h, 48 h) in mice bearing subcutaneous F9 tumours using radioiodinated protein preparations. The clinical stage L19 antibody, specific to the alternatively spliced EDB domain of fibronectin, was used as reference tumour-targeting agent for in vivo studies.
All anti-MMP antibodies and SIP(L19) strongly stained sections of F9 tumours when assessed by immunofluorescence methods. In biodistribution experiments, SIP(SP3), specific to MMP-3, selectively accumulated at the tumour site 24 and 48 h after intravenous injection, but was rapidly cleared from other organs. By contrast, SIP(SP1) and SIP(SP2), specific to MMP-1A and MMP-2, showed no preferential accumulation at the tumour site.
Antibodies specific to MMP-3 may serve as vehicles for the efficient and selective delivery of imaging agents or therapeutic molecules to sites of disease.
基质金属蛋白酶（MMPs）是一组含有 20 多种锌的内肽酶，在许多疾病中上调，但将放射性标记的 MMP 抑制剂用于成像肿瘤的几次尝试在小鼠模型中均未成功，这可能是由于这些药物的特异性有限或其不利的药代动力学特征。原则上，可以考虑使用放射性标记的单克隆抗体来选择性地靶向和成像个体 MMP。
我们使用生化和免疫化学方法，以 SIP（小型免疫蛋白）小抗体形式克隆、生产和表征了针对小鼠 MMP-1A、MMP-2 和 MMP-3 的高亲和力单克隆抗体。我们还使用放射性碘标记的蛋白质制剂在携带皮下 F9 肿瘤的小鼠中进行了三个时间点（3 h、24 h、48 h）的肿瘤靶向特性比较生物分布分析。临床阶段 L19 抗体，特异性针对纤连蛋白的 EDB 结构域的剪接变体，被用作体内研究的参考肿瘤靶向剂。
通过免疫荧光方法评估，所有抗 MMP 抗体和 SIP（L19）均强烈染色 F9 肿瘤切片。在生物分布实验中，特异性针对 MMP-3 的 SIP（SP3）在静脉注射后 24 和 48 小时选择性地在肿瘤部位积聚，但迅速从其他器官清除。相比之下，特异性针对 MMP-1A 和 MMP-2 的 SIP（SP1）和 SIP（SP2）在肿瘤部位没有优先积聚。
针对 MMP-3 的抗体可以作为将成像剂或治疗分子高效和选择性递送至疾病部位的载体。
