Figure 3

Interferon response gene induction in co-cultivated cells. (a) MDA-MB231 breast cancer cells and CCL-171 fibroblasts were labeled before co-culture with the fluorescent carbocyanine dye DiO and isolated after co-culture using FACS, which allowed a purification of 95%. Comparing gene expression patterns of the cells cultivated in monoculture to the same cell type after co-cultivation showed that the CCL-171 fibroblasts up-regulate the interferon response genes 2.8-fold on average, whereas the MDA-MB-231 breast cancer cell line up-regulates them about 11-fold. (b) Immunohistochemistry for STAT1. STAT1 expression in a normal breast (left panel) and in a breast cancer specimen (right panel). STAT1 is predominantly expressed in the malignant epithelial cells at the stromal interface in a centrifugal gradient.