Fig. 1. MMP expression in pancreatic cancer cell lines and mesenchymal cells. (A) Gelatin zymography (Zymo) of tumor cell and PSC supernatant reveals that MMP-2 is predominantly expressed in PSC. Supernatant was loaded adapted to the DNA level of the wells corresponding to the samples. (B) Gelatin zymography: the indicated volume of supernatant conditioned by MiaPaCa2, Panc1 and SW850 (TC SN) was incubated with PSC for 24 hours. Serum-free culture media was added to yield a total volume of 2000 µl. Supernatant of cancer cells stimulated the expression of MMP-2 in PSC. Supernatant was loaded adjusted to the DNA level of the wells corresponding to the samples. Results are representative of at least three independent experiments. (C) Densitometry of the zymography: each condition was determined in quandruplicate and values are expressed as means. Boxes represent the s.e.m. and error bars the s.d. The asterisk denotes a statistically significant difference (P<0.01) for MMP-2 in the supernatant of the group of PSC stimulated with 1000 µl cancer cell supernatant compared with control.