Purified EPI and/or CAF inoculated in vivo. (A) Immunofluorescence of purified EPI-HI, CAF-HI or EPI-HI+CAF-HI. (Upper panel) Cytokeratin staining (CK; Rabbit polyclonal antibody Dako). (Lower panel) SMA (Mouse monoclonal antibody, Sigma Aldrich). Anti-rabbit and anti-mouse secondary antibodies coupled to FITC (Vector Laboratories) were used for CK and SMA staining, respectively (green). Cells were seeded on chamber slides and fixed in 100% ethanol for 30 minutes at -20°C. Immunofluorescence was performed as described in Materials and Methods. Nuclei were counterstained with PI (red). Original magnification: 400×. Bar: 60 μm. (B) Tumor growth of purified EPI-HD or EPI-HI cells and CAF-HI (2 × 105 cells) alone or EPI (2 × 105 cells) plus CAF-HI (2 × 105) that was implanted sc in female BALB/c mice (n = 6). EPI-HI or EPI-HI+CAF-HI were prepared as described in Materials and Methods. **: p < 0.01; *: p < 0.05. No tumor growth was observed in EPI-HD, CAF-HI or EPI-HD+CAF-HI. Tumor size: Mean ± s.e.m.