Fig. 4

Overexpression of Activin A shows similar extracellular matrix protein regulation in ACVRIB-expressing ESCC. a-c Hematoxylin and eosin staining of parent, empty, and Fibro-ActA organotypic cultures, cultured with TE-2 ESCC cells. d-f Three-dimensional organotypic Fibro-ActA cultures exhibit no alterations in epithelial ECdnT E-cadherin (E-cad) expression, however vimentin (Vim) is downregulated in the fibroblasts, as examined by immunofluorescence. g-i αSMA and podoplanin (PDPN) expression was significantly downregulated in the fibroblasts and epithelial cells, respectively. The asterisks(*) in the parental and empty vector cultures denote co-localization. j-l Fibronectin (FN) deposition was decreased in Fibro-ActA cultures compared to parent and empty vector controls. m-o Ki67 staining was decreased in epithelial TE-2 cells cultured with Fibro-ActA, compared to parent and empty vector cultures (quantification in Additional file 3: Figure S3). p-r Laminin 5γ2, a marker of basal cell differentiation, was unchanged between conditions. s-u Collagen IV deposition, a primary component of basement membrane deposition, was decreased in Fibro-ActA compared to control. v-x Collagen IV staining, higher magnification of boxed region in s-u. Arrows indicate the collagen IV basement membrane, laid by the epithelial cells. (Short scale bar = 20 μm; long scale bar = 5 μm) (n = 2)