Fig. 5: EGFR signaling pathway-related electron transfer-triggered imaging in vivo during EGFR inhibition.

a Schematic of electron transfer-triggered imaging of EGFR-inhibited mice with a single established A549 tumor. Mice with 50 mm³ subcutaneous tumors were administered with PBS or cetuximab intraperitoneally twice per week. b, c Afterglow images of A549 xenograft mice treated with PBS or cetuximab at day 0 (b) and day 14 (c). The afterglow imaging was performed after 1.0 s of white light excitation. The afterglow signal intensities are displayed as color maps, color scale: (b) 3.5 × 10⁵–3.0 × 10⁶, (c) 6.0 × 10⁴–1.0 × 10⁶. d, e Corresponding quantitative data analysis of relative total radiance in tumor area of mice shown in b (d) and c (e). Data presented as mean values ± s.d., n = 5 mice. f Western blot analysis on expression of EGFR, P-EGFR, and β-catenin protein in tumors after the final treatment. A representative image of five biologically independent samples from each group is shown. g IHC analysis of tumor sections. EGFR and P-EGFR in the tumor sections of each group were observed by IHC analysis. Scale bar: 50 μm. A representative image of five biologically independent samples from each group is shown. h Afterglow images of harvested tumors from the tumor-bearing mice treated with PBS or cetuximab after 14 days treatment. Color scale: 6.0 × 10⁴–3.0 × 10⁶. i, j Quantitative analysis of P-EGFR in tumor sections observed by western blot analysis (i) and IHC analysis (j). k Quantitative analysis of afterglow intensity in the tumor site. Data are presented as the mean values ± s.d.; unpaired two-tailed Student’s t-test; n = 5 mice.