Fig. 3

GC cell-derived activin B induces a CAF phenotype in fibroblasts. (A) Cell supernatant activin B level was determined by ELISA in different INHBB-expressing GC cells (n = 3). (B) Effects of activin B on the normal fibroblast’s protein expression levels of a-SMA and FAP were assessed by immunofluorescence assay. (C) Cell proliferation was verified by CCK-8 assay. The value of the absorbance (at 450 nm) was recorded from 0 to 72 h in normal fibroblasts co-cultured with different INHBB-expressing GC cells treated with activin B-neutralizing antibody or exogenous activin B (n = 3). (D) Cell migration and invasion were detected by transwell assay in normal fibroblasts co-cultured with different INHBB-expressing GC cells treated with activin B-neutralizing antibody or exogenous activin B (n = 3). (E) Western blot detected protein levels of a-SMA and Snail in normal fibroblasts co-cultured with different INHBB-expressing GC cells treated with activin B-neutralizing antibody or exogenous activin B. **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. rActivin B: Recombinant Human Activin B; Sup.: supernatant; Activin B Ab: activin B-neutralizing antibody; Isotype: isotype antibody