Figure 8.

Quantification of secreted endostatin by ELISA after treatment with small-molecule broad-spectrum inhibitors of MMP and cathepsin: MiaPaCa-2 and Panc-1 (400,000 cells per well) were cultured alone (A) or cocultured with PSCs (C) for 24 hours in the presence of a small-molecule broad-spectrum MMP inhibitor (50 µM), cathepsin inhibitor (10 µM), or DMSO as control. To assess their effect on the cleavage of endostatin from the secreted collagen XVIII by cancer cells, inhibitors were added to the cancer cell SNs that were used to incubate PSC (200,000 cells per well) for 24 hours (B). Changes are expressed as percentages compared with the appropriate control (sum of the DMSO controls of PCC and PSC: PCC + PSC, 100%). PCC & PSC denotes the coculture of PCC and PSC in the presence of DMSO (control), small-molecule broad-spectrum MMP inhibitor (50 µM), or cathepsin inhibitor (10 µM). Error bars show the SEM. The experiments were repeated using five different PSC clones and two different cancer cell lines. The amount of endostatin secreted was quantified by ELISA.