In vivo growth induces EpCAM and E-cadherin gene expression. MDA-MB-231TetR EpCAM cells were grown in vitro in 3D culture in collagen or in vivo in the chicken CAM. EpCAM (A) and E-cadherin (B) gene expression was quantified relative to the low expression levels in the parental cell line MDA-MB-231 (WT). RNA was isolated 24 h after stimulation with tetracycline (TET+, n=4) or without tetracycline (TET-, n=4) and analyzed by means of RT-qPCR. Xenografts (n=4/group) were grown for five days in the chicken embryo before isolation and analysis of RNA. Note, in vivo growth induced EpCAM and E-cadherin expression in MDA-MB-231 cells. EpCAM overexpression inhibited induction of E-cadherin gene expression in MDA-MB-231 cells. * indicates p value ≤0.05.