Structure Based Innovative Approach to Analyze Aptaprobe-GPC3 Complexes in Hepatocellular Carcinoma
Abstract Background Glypican-3 (GPC3), a membrane-bound heparan sulfate proteoglycan, is a biomarker of hepatocellular carcinoma (HCC) progression. Aptamers specifically binding to target biomolecules have recently emerged as clinical disease diagnosis targets. Here, we describe 3D structure-based aptaprobe platforms for detecting GPC3, such as aptablotting, aptaprobe-based sandwich assay (ALISA), and aptaoptical imaging analysis. Results For preparing the aptaprobe–GPC3 platforms, we obtained 12 high affinity aptamer candidates (GPC3_1 to GPC3_12) that specifically bind to target GPC3 molecules. Structure-based molecular interactions identified distinct aptatopic residues responsible for binding to the paratopic nucleotide sequences (nt-paratope) of GPC3 aptaprobes. Sandwichable and overlapped aptaprobes were selected through structural analysis. The aptaprobe specificity for using in HCC diagnostics were verified through Aptablotting and ALISA. Moreover, Aptaoptical imaging showed that the binding property of GPC3_3 and their GPC3 specificity were maintained in HCC xenograft models, which may indicate a new HCC imaging diagnosis.Conclusion Aptaprobe has the potential to be used as an affinity reagent to detect the target in vivo and in vitro diagnosing system.