Theranostics 2017; 7(12):2982-2995. doi:10.7150/thno.19374

Research Paper

Discovery of Aptamer Ligands for Hepatic Stellate Cells Using SELEX

Zhijin Chen, Hao Liu, Akshay Jain, Li Zhang, Chang Liu, Kun Cheng

Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, United States

Abstract

Insulin like growth factor II receptor (IGFIIR) is a transmembrane protein overexpressed in activated hepatic stellate cells (HSCs), which are the major target for the treatment of liver fibrosis. In this study, we aim to discover an IGFIIR-specific aptamer that can be potentially used as a targeting ligand for the treatment and diagnosis of liver fibrosis. Systematic evolution of ligands by exponential enrichment (SELEX) was conducted on recombinant human IGFIIR to identify IGFIIR-specific aptamers. The binding affinity and specificity of the discovered aptamers to IGFIIR and hepatic stellate cells were studied using flow cytometry and Surface Plasmon Resonance (SPR). Aptamer-20 showed the highest affinity to recombinant human IGFIIR protein with a Kd of 35.5 nM, as determined by SPR. Aptamer-20 also has a high affinity (apparent Kd 45.12 nM) to LX-2 human hepatic stellate cells. Binding of aptamer-20 to hepatic stellate cells could be inhibited by knockdown of IGFIIR using siRNA, indicating a high specificity of the aptamer. The aptamer formed a chimera with an anti-fibrotic PCBP2 siRNA and delivered the siRNA to HSC-T6 cells to trigger silencing activity. In Vivo biodistribution study of the siRNA-aptamer chimera also demonstrated a high and specific uptake in the liver of the rats with CCl4-induced liver fibrosis. These data suggest that aptamer-20 is a high-affinity ligand for antifibrotic and diagnostic agents for liver fibrosis.

Keywords: aptamer, SELEX, siRNA chimera, liver fibrosis, hepatic stellate cells, IGFIIR, imaging, targeted delivery, PCBP2.

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How to cite this article:
Chen Z, Liu H, Jain A, Zhang L, Liu C, Cheng K. Discovery of Aptamer Ligands for Hepatic Stellate Cells Using SELEX. Theranostics 2017; 7(12):2982-2995. doi:10.7150/thno.19374. Available from http://www.thno.org/v07p2982.htm