Fig. 5. IL-8 derived from GCMSCs induced PD-L1 expression in GC cells via c-Myc regulated by STAT3 and mTOR signaling pathways.

a The expression of PD-L1 and c-Myc in GC cells treated with GCMSC-CM was detected by western blot. b The phosphorylation and activation of STAT3 in GC cells was detected by western blot. c GC cells were treated with 5 μM of a STAT3 inhibitor (Stattic) or 0.1 μM of an mTOR inhibitor (Rapamycin). d The expression of PD-L1 and the phosphorylation of AKT and S6 ribosomal protein in GC cells was detected by western blot. The concentration of IL-6/IL-8 neutralizing antibody was 5 μg/ml