Fig. 7: The Myristoylated GKVL-TAT peptide inhibits the growth of EGFR-overexpression tumors.

a, b On day 0, A549 cells were set up as in Fig. 1a. On day 2, cells were treated with 10 μM Myr-GKVL-TAT or GKVL-TAT for 20 h. Cells were then incubated with serum-free medium, including the peptides, for 4 h. a Immunostaining assays were performed using the anti-EGFR antibodies. The upper panel shows the sequence of the two peptides. Scale bar, 20 μm. b Cells were treated with 100 ng/ml EGF for the indicated time, harvested, and subjected to western blot. c On day 0, A549 cells were set up at 7 × 10³ cells per well in a 96-well plate. From day 1, cells were treated with various concentrations of Myr-GKVL-TAT or GKVL-TAT for two days. On day 3, cell viability was determined by cell counting kit-8 (Topscience, C0005). Each value represents the mean ± SEM of a triplicate. The statistical analysis was performed by a student’s two-tailed paired t-test. IC₅₀ was analyzed using Graphpad Prism 5. d–f On day 0, A549 cells were injected into nude mice subcutaneously at 1 × 10⁷ cells per mouse (n = 7). Starting from day 24, when tumors grew to around 100 mm³, mice were treated with a daily subcutaneous injection of vehicle, Myr-GKVL-TAT (2 mg/kg), or GKVL-TAT (2 mg/kg). Tumor sizes were measured every 2 days (d). On day 34, mice were euthanized and tumors were dissected. Tumor weights were weighed (e), and representative images of mice and tumors were shown (f). Each value represents the mean ± SEM of seven samples. The statistical analysis was performed by a student’s two-tailed paired t-test. g A working model shows ARF6 mediates palmitoylated EGFR sorting to PM, facilitating cancer cell proliferation. Source data are provided as a Source Data file.