A Bispecific Chimeric Aptamer Design Platform Based on c‐MET Aptamer with a Replaceable Redundant Region

Abstract

AbstractMolecular engineering enables the creation of aptamers with novel functions, but the prerequisite is a deep understanding of their structure and recognition mechanism. The cellular‐mesenchymal epithelial transition factor (c‐MET) is garnering significant attention due to the critical role of the c‐MET/HGF signaling pathway in tumor development and invasion. This study reports a strategy for constructing novel chimeric aptamers that bind to both c‐MET and other specific proteins. c‐MET was identified to be the molecular target of a DNA aptamer, HF3‐58, selected through cell‐SELEX. The binding structure and mechanism of HF3‐58 with c‐MET were systematically studied, revealing the scaffold, recognition, and redundancy regions. Through molecular engineering design, the redundancy region was replaced with other aptamers possessing stem‐loop structures, yielding novel chimeric aptamers with bispecificity for binding to c‐MET and specific proteins. A chimeric bispecific aptamer HF‐3b showed the ability to mediate the adhesion of T‐cells to tumor cells, suggesting the prospective utility in tumor immunotherapy. These findings suggest that aptamer HF3‐58 can serve as a molecular engineering platform for the development of diverse multifunctional ligands targeting c‐MET. Moreover, comprehensive understanding of the binding mechanisms of aptamers will provide guidance for the design of functional aptamers, significantly expanding their potential applications.