FIG. 9.

In coculture with fibroblasts, the SISmuc scaffold is remodeled, and fibroblasts grow at the tip of tumor cells. The tumor cells alone (marked by PCK, green) do not remodel the collagen structure of the SISmuc (A–C). The basement membrane of the former crypts is clearly visible by immunohistochemical staining of collagen-IV (red in A–I) and is not interrupted (arrows in B). In coculture with fibroblasts (D–F), the distinct border of the former crypts is only partially visible (arrow in E) and the SISmuc is compacted with collagen-IV (E, F). In monoculture, the fibroblasts remodel the SISmuc (G, H). In some areas of the coculture, fibroblasts (stained by vimentin, red in J, K) intermingle with the tumor cells (stained by PCK, green in J, K) and grow in front of them into the collagen structure of the SISmuc (K). Scale bars in (G–I) represent 25 μm for (A–I). Scale bars in (J) and (K) represent 25 μm. Color images available online at www.liebertpub.com/tec