Fig. 1

Effects and mechanism of PM on PD-L1 expression in different tumor cells. A, B Detection of PD-L1, pAMPK, and AMPK protein by western blot in CT26 and 4T1 cells after treatment by different concentrations of PM for 24 h (n = 3). C Detection of PD-L1 protein expression in CT26 and 4T1 cells by western blot after 30 μM PM treatment for different time (n = 3). D–G Quantification of PD-L1 protein in CT26 or 4T1 tumor cells in western blot assay by ImageJ (n = 3). H, I Quantification of pAMPK and AMPK protein in western blot assay by ImageJ in CT26 and 4T1 cells after treatment with different concentrations of PM for 24 h (n = 3). J–L Detection and quantification of PD-L1, pAMPK, and AMPK protein in CT26 cells by western blot after 60 μM PM treatment in the presence or absence of 10 μM AMPK phosphorylation inhibitor Compound C for 24 h (n = 3). Data were demonstrated as mean ± SD. Statistical analysis was performed via the two-tail Student’s t-test. ND, no significant difference; * p < 0.05; ** p < 0.01