2.4. Tumor–Stromal Cell Cocultures

Tumor cells were cultured alone or together with TASCs or MASCs at a 1:1 ratio in tumor cell medium for five days. In specific experiments, cultures were supplemented with anti-IL-6 (R&D Systems, 10 μg/mL) neutralizing antibodies. Following coculture, cells were stained with EpCAM- or CD90-specific antibodies and analyzed by flow cytometry or sorted for subsequent chemo-invasion assays using Matrigel-coated transwell plates, as previously described [27,28], or gene expression analysis.