Expanded Genetic Systems Combined with Cell Engineering and Laboratory Evolution Give Aptamers against Glypican-3-Overexpressing Tumor Cells

• Published in: Angewandte Chemie International Edition Vol. 55; no. 40; pp. 12372 - 12375
• Main Authors: Zhang, Liqin, Yang, Zunyi, Le Trinh, Thu, Teng, I-Ting, Wang, Sai, Bradley, Kevin M, Hoshika, Shuichi, Wu, Qunfeng, Cansiz, Sena, Rowold, Diane J, McLendon, Christopher, Kim, Myong-Sang, Wu, Yuan, Cui, Cheng, Liu, Yuan, Hou, Weijia, Stewart, Kimberly, Wan, Shuo, Liu, Chen, Benner, Steven A., Tan, Weihong
• Format: Journal Article
• Language: English
• Published: 07.09.2016
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201605058

Laboratory in vitro evolution (LIVE) might deliver DNA aptamers that bind proteins expressed on the surface of cells. Here, we use cell engineering to place on the surface of a liver cell line glypican 3 (GPC3), a possible marker for liver cancer diagnostics and theranostics. Libraries were then built from a six-letter genetic alphabet containing standard nucleobase and two added nucleobases (2-amino-8H-imidazo[1,2-a] [ 1 , 3 , 5 ] triazin-4-one and 6-amino-5-nitropyridin-2-one, trivially Z and P), Watson-Crick complements from an artificially expanded genetic information system (AEGIS). With counterselection against un-engineered cells, eight AEGIS-containing aptamers were recovered. Five bound selectively to GPC3 overexpressing cells. This selection-counterselection scheme had acceptable statistics, notwithstanding the possibility that cells engineered to overexpress GPC3 might also express different off-target proteins. This is the first example of such a combination.