Fig. 2
HMGB1 regulates the expression of PD-L1 through the STAT3 signaling. (A, B) Immunoblots representing the expression of p-STAT3, STAT3, p-ERK1/2, ERK1/2, p-p65, p65, p-AKT, and AKT in MDA-MB-231 cells transfected with empty vector or Myc-HMGB1 plasmid (A) or siCtrl or siHMGB1 (B). (C) MDA-MB-231 cells were transfected with Myc-HMGB1 for 24 h and treated with 20 µM Stattic for 16 h. (D) MDA-MB-231 cells were transfected with Myc-HMGB1 for 48 h and treated with 0.31 µM SCH772984 for 42 h. (E) MDA-MB-231 cells were transfected with Myc-HMGB1 for 48 h and treated with 0.62 µM BMS-345541 for 42 h. (F) MDA-MB-231 cells were transfected with Myc-HMGB1 for 24 h and treated with 5 µM MK-2206 for 16 h. (G) Immunoblots representing the expression of p-STAT3, STAT3, PD-L1 in MEFHMGB1 KO cells transfected with empty vector or Myc-HMGB1. n = 3 samples per group for all immunoblot data. (H) GSEA enrichment plot for the STAT3 signaling target gene set (STAT3_02) comparing the top 10% and bottom 10% of HMGB1 expression in the TCGA Firehose Legacy dataset. Data are presented as the mean ± SEM. The two-tailed unpaired Student t-test was used for statistical analysis. ns, not significant. *p < 0.05 and *** p < 0.001. E/V, Empty Vector; H, Myc-HMGB1; GSEA, Gene Set Enrichment Analysis; NES, normalized enrichment score