Selective growth inhibition of ductal pancreatic adenocarcinoma cells by the lysosomotropic agent chloroquine.

Pancreatic adenocarcinoma cells show characteristics of macrophages as phagocytosis and exocytosis. These phagocytic activities can be inhibited in macrophages by antirheumatic drugs, e.g. gold compounds and antimalarials. We have now tested the activity of auranofin and chloroquine to inhibit growth of a pancreatic tumor cell line (PaTu II) and of human foreskin fibroblasts (HFF) as a control. We found that auranofin (greater than or equal to 2 microM) inhibits both PaTu II cell and HFF growth. In contrast, chloroquine (4-18 microM) selectively interferes with the growth of PaTu II cells. This specific vulnerability of PaTu II cells was confirmed in cocultures of tumor cells and fibroblasts.