Figure 5

Casein and gelatin zymograms from cell culture supernatants of direct and indirect co-cultures. Casein zymograms show that pro-MMP-1 was produced only by fibroblasts (A, B) and MMP-7 was produced exclusively by CSCC7 cells (A, B) in both systems. According to gelatin zymograms MMP-2 was present both in its active and inactive forms (A, C, D) and MMP-9 enzyme activity was not detected in any created setup (A, C, D). In direct co-cultures, the presence of CSCC7 cells activated MMP-2 (A). However, in indirect co-cultures the presence of CSCC7 cells reduced the amount of both active and inactive MMP-2, both in case of NFs and TFs (C, D). Indirect co-culture clearly demonstrates that MMP2 is produced by the fibroblasts and the activity detected in the medium of CSCC7 cells is not higher than that of 0.3% serum, used for the cultivation of tumor cells.