Figure 2.
Metformin suppresses the IL6 signaling pathway and downregulates the expression of PD-L1 in vitro. KYSE-450 and TE-7 cells were treated with increasing concentrations of metformin (5 to 10 mM), IL-6 (0.1 to 0.3 ng/ml) or PBS for 36 (h) (A) The expression of IL-6 in each group was detected by ELISA. (B) mRNA expression levels of PD-L1 in cells treated with metformin or IL-6 were analyzed by RT-PCR. (C) The expression of PD-L1 by flow- cytometric analysis after metformin or IL-6 treatment. (D) Western blot analysis and quantification of PD-L1, phosphorylated- Jak2 (p-Jak2), Jak2, phosphorylated- Stat3 (p-Stat3), Stat3, and GAPDH were performed. Error bars represent the standard deviation. *p < 0.05, **p < 0.01.