Fig. 2

CAF-derived IL-6 and its effect on PD-L1 expression. A The level of IL-6 in CMs of different NFs and CAFs. Bar graphs represent the mean ± SD of three independent experiments. *P < 0.05, **P < 0.01 compared to BNF using one-way ANOVA. NS, no significance. B The representative morphology of parental MDA-MB-231 and HCC70 cells, scramble, and siIL-6R KD cells and the representative histogram of IL-6R detection by flow cytometry. C, D Effect of CAF-derived IL-6 on PD-L1 in MDA-MD-231 and HCC70 scramble and siIL-6R KD cells determined by Western blot analysis. β-actin was used as a housekeeping reference protein for semiquantitative analysis. Bar graphs represent the mean ± SD of three independent experiments. ^#P < 0.05 compared to UT condition using one-way ANOVA. *P < 0.05 compared within group using Student's t test. CMs, conditioned-media; NFs, normal fibroblasts; HDF, human dermal fibroblasts; BNF, breast normal fibroblast; CAFs, cancer-associated fibroblasts; NS, no significance; IL-6R KD, IL-6R knocked down; UT, untreated cells; rhIL-6, recombinant human IL-6