Fig. 1

LXY30 specifically binds to integrin α3β1-expressing NSCLC cells and their derived exosomes. Chemical structures of LXY30-FITC (a) and scrambled-LXY30 (S-LXY30)-FITC (b) are illustrated. A549 cells growing in DMEM medium were collected and incubated with LXY30-FITC or S-LXY30-FITC for 2 h, and the binding specificity of LXY30 was evaluated by flow cytometry (c) and fluorescence microscopy (d). Exosomes were isolated from the supernatant of two integrin α3β1-expressing NSCLC cells (A549 and H1975) and a patient’s malignant pericardial effusion (e). Exosomes were incubated with TentaGel bead coated with LXY30 (left panel) or S-LXY30 (right panel) for 2 h, followed by incubation with Alexa 647 mouse anti-CD63 antibody (red) for 1 h before being visualized by fluorescence microscopy (e). The expression of integrin α3, integrin β1, and exosomal marker CD63 in 4 NSCLC cell lines and one patient pericardial effusion were determined by Western blots (f). Beta-actin was used as loading control for cellular protein expression. The protein loading for cell lysate is around 5 times lower than that of exosomes. h, hour(s); FITC, fluorescein isothiocyanate; NSCLC, non-small cell lung carcinoma