RNA Aptamer Binds Heparin-Binding Epidermal Growth Factor-Like Growth Factor with High Affinity and Specificity and Neutralizes Its Activity

• Main Authors: Masaki Yamato, Takashi Matsuzaki, Ryo Araki, Shota Tsuchida, Keiji Okuda, Hai Ying Fu, Shoji Sanada, Hiroshi Asanuma, Yoshihiro Asano, Masanori Asakura, Hiroomi Torii, Kentaro Noi, Hirotsugu Ogi, Ryo Iwamoto, Eisuke Mekada, Seiji Takashima, Masafumi Kitakaze, Yasushi Sakata, Tetsuo Minamino
• Format: Article
• Language: English
• Published: Taiwan Society of Geriatric Emergency and Critical Medicine (TSGECM) 2017-09-01
• Series: International Journal of Gerontology
• Subjects: aptamer; heparin-binding epidermal growth factor-like growth factor
• Online Access: http://www.sciencedirect.com/science/article/pii/S1873959817300145

Background: Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a member of the EGF family and is involved in various diseases including cancers. Aptamers are synthetic oligonucleotides (RNA or DNA) that fold into unique three-dimensional structures and specifically bind to their targets with high affinity. We aimed to generate an aptamer with high affinity and specificity for HB-EGF. Methods: Recombinant human HB-EGF (rhHB-EGF), comprised of the extracellular EGF-like and heparin-binding domains of HB-EGF, was used as the target. The aptamer against HB-EGF (the anti-HB-EGF aptamer) was obtained by systematic evolution of ligands by exponential enrichment (SELEX). Results: After the 10th round of SELEX, aptamers were reverse-transcribed and PCR-amplified. Within obtained forty-six clones, twenty-three were identical (the anti-HB-EGF aptamer). The analysis using wireless-electrodeless quartz crystal microbalance revealed that the anti-HB-EGF aptamer had high affinity for rhHB-EGF (KD value: 12.2 ± 1.1 nmol/L). The dot-blot analysis revealed that the anti-HB-EGF aptamer specifically bound to rhHB-EGF. The analysis using confocal microscopy indicated that the anti-HB-EGF aptamer also bound to membrane-bound HB-EGF. Western-blot assay indicated that the anti-HB-EGF aptamer inhibited the phosphorylation of rhHB-EGF-mediated EGF receptor (EGFR). Conclusion: We identified a novel RNA aptamer that bound with high affinity and specificity to rhHB-EGF and potently inhibited the rhHB-EGF-mediated phosphorylation of EGFR. The anti-HB-EGF aptamer may be a promising therapeutic agent for specifically neutralizing HB-EGF signaling.