Modulation of EGFR Signaling by Antibody Conjugated DNA Nano-Forceps

Abstract

The spatial distribution of EGFR (Epithelial Growth Factor Receptor) is tightly regulated for the maintenance of various cellular metabolisms as proliferation, differentiation, polarity and migration in mammalian cell. However, in case of cancer cells, the spatial distribution of EGFR is dysregulated by the abnormal expression of EGFR and its phosphorylation still generates regardless of the binding of EGF (Epithelial Growth Factor).Therefore, in order to modulate EGFR signaling regardless of EGF in cancer cells, we developed EGFR antibody conjugated DNA Nano-Forceps with multiple arms and measured the phosphorylation level of EGFR by the treatment of this DNA Nano-Forceps. EGFR conjugated DNA Nano-Forceps inhibited the phosphorylation by EGFR dimerization in dose dependent manner even if we treated EGF in A549 as an EGFR hyper-activated lung cancer cell line. Also, EGFR downstream signaling pathways as the phosphorylation of ERK2 (Extracellular signal–Regulated Kinase 2) and STAT3 (Signal Transducer and Activator of Transcription 3) was inhibited in same cell line.And then, in order to examine whether this DNA Nano-Foeces can modulate the internalization by EGFR activation in this cell, we monitored the internalization level of this protein after treatment of EGF in the DNA Nano-Forceps treated cell through both epi-fluorescence and TIRF (total internal reflection fluorescence microscopy) microscopy. Interestingly, the treatment of EGFR antibody conjugated DNA Nano-Forceps inhibited the internalization of EGFR even if EGF was treated. Based on these results, we conclude that EGFR antibody conjugated DNA Nano-Forceps can modulate EGFR and related signaling pathways through inhibition of dimerization by dysregulated lateral diffusion and internalization of EGFR simultaneously. This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) (Project No. NRF-2014R1A1A2A16053486).