Poster Presentation HUPO 2019 - 18th Human Proteome Organization World Congress

Screening of DNA aptamers toward oral cancer biomarkers using plate-based SELEX and next-generation sequencing (#661)

CHIEN-CHUN LIU 1 , Yung-Chin Hsiao 1 , Jau-Song Yu 1
  1. Molecular Medicine Research Center, CHANG GUNG UNIVERSITY, TAOYUAN, Taiwan

Identification of proteins as biomarkers for early detection of cancer and therapeutic targets for cancer treatment are important issues in precision medicine. Oral cavity squamous cell carcinoma (OSCC) is a common cancer worldwide and represents a serious and growing problem in many parts of the globe, including Taiwan. To help early detection of OSCC, our group have put efforts in the past decades to discover/verify potential protein biomarkers using saliva, a kind of protein-rich body fluid that directly contacts the oral lesions, and we developed a four-protein marker panel, which may be a clinically effective tool for detecting OSCC and monitoring high-risk oral potentially malignant disorders (Yu et al., PNAS USA, 2016 Oct 11;113(41):11549-11554). Here, we attempted to screen DNA aptamers toward these four biomarkers for further diagnosis assay development. A plated-based platform of systematic evolution of ligands by exponential enrichment (SELEX) was developed for screening DNA aptamers against one of OSCC biomarkers, kininogen-1 (KNG1). After ten rounds of SELEX, the reserved DNA pools were submitted to next-generation sequencing (NGS), and six anti-KNG1 aptamers were discovered. The KD value of these aptamers toward KNG1 can achieve 10-9 M level. Aptamers have many advantage comparing with antibodies, such as small size, stability, easy modification, low cost, and batch-to-batch consistency. Using aptamer to develop detection kits is an alternative strategy for biomarker measurement. These newly generated anti-KNG1 aptamers represent valuable tools for future development of the sandwich-ELISA assay and lateral flow strip assay.