Menadione Induces Both Necrosis and Apoptosis in Rat Pancreatic Acinar AR4-2J Cells

This study evaluated the action of menadione on cell proliferation and integrity of the rat pancreatic acinar cell line, AR4-2J. Menadione at 1–20 μM dose- and time-dependently inhibited cell proliferation of AR4-2J cells. In contrast, a high concentration of menadione (100 μM) caused rapid cell death (>90% of cells took up trypan blue within 4-h). While the high concentration of menadione (100 μM) induced DNA smear in electrophoresis indicative of necrosis, lower concentrations (10–20 μM) induced a DNA ladder indicative of apoptosis. Similar results were obtained using a DNA fragmentation ELISA. Glutathione (1 mM), the calcium chelator EGTA (500 μM), and the cystein protease inhibitor NCO-700 (5 mM) partly inhibited the effect of 1–10 μM menadione on cell proliferation and DNA fragmentation. Menadione at 1–20 μM induced wild-type P53, whereas the 100 μM menadione had a minor effect on wild-type P53. It is concluded that menadione induced necrosis at high concentrations and apoptosis at low concentrations in AR4-2J cells. Apoptosis induced by lower concentrations of menadione may be mediated by wild-type P53, intracellular calcium, and mechanisms which decrease the intracellular concentration of reduced glutathione.