Figure 4

Activation of tumor-derived mesenchymal stromal cells by head and neck squamous cell carcinoma-conditioned medium. Individual tumor-derived mesenchymal stromal cell (TuMSC) lines were incubated in the presence of culture supernatants obtained from head and neck squamous cell carcinoma cell lines. After 36 to 48 hours, the FaDu/UM22B conditioned supernatant was aspirated and replaced by fresh standard culture medium. After another 24 hours, the TuMSC culture supernatant (a) or TuMSC (b) was collected. Concentration of interleukin (IL)-8 was measured by enzyme-linked immunosorbent assay (a) and expression of CD54 on activated TuMSC was analyzed by flow cytometry (b, c). The experiment was performed with TuMSC from seven independent donors designated #1 to #7. APC, Allophycocyanin; MFI, median fluorescence intensity; SN, supernatant.