Phenotype alterations in fetal pancreatic cells. (a) shows RT-PCR for epithelial marker, CK-19, and mesenchymal marker, vimentin, along with TGF-β1, TGFβ2 and their receptors under various conditions indicated. (b) shows morphological changes in LV-Pdx1-transduced hTERT-FPC during culture with serum and in the absence of serum plus addition of Activin A (bottom panel). These data indicated that cells became more rounded and less flattened in the absence of serum and presence of Activin A. (c) shows changes in vimentin expression by immunostaining in LV-Pdx1-transduced hTERT-FPC cultured with serum (top left), and with Activin A and no serum (bottom left). No immunostaining was detected when vimentin antibody was omitted (top right). The panel at bottom right in c shows quantitation of vimentin immunofluorescence signals by image analysis to indicate that culture without serum and with activin A perturbed cell phenotype, which was in agreement with morphological changes in LV-Pdx1-transduced hTERT-FPC.