Gemcitabine Induces the VMP1-Mediated Autophagy Pathway to Promote Apoptotic Death in Human Pancreatic Cancer Cells

PARDO R; LO RÉ A; ARCHANGE C; ROPOLO A; PAPADEMETRIO DL; GONZALEZ C; ALVAREZ, E; IOVANNA J; VACCARO M

PANCREATOLOGY

KARGER

Año: 2010 p. 19 - 26

1424-3903

Background/Aim: Autophagy is a degradation process of cytoplasmic cellular constituents. We have described the vacuole membrane protein-1 (VMP1) whose expression triggers autophagy in mammalian cells. The aim of this study was to analyze the role of autophagy in human pancreatic cancer cell death. Methods/Results: Here we show that gemcitabine, the standard chemotherapy for pancreatic cancer, induced autophagy in PANC-1 and MIAPaCa-2 cells, as evidenced by the accumulation of acidic vesicular organelles, the recruitment of microtubule-associated protein-1 light chain-3, and electron microscopy. In addition, gemcitabine treatment induced early expression of VMP1 in cancer cells. Gemcitabine also induced apoptosis detected by morphology, annexin V-positive cells, and cleavage of caspase-3. Surprisingly, 3-methyladenine, an autophagy inhibitor, decreased apoptosis in gemcitabine-treated cells, showing that autophagy leads to cancer cell apoptotic death. Finally, VMP1 knockdown decreased autophagy and  apoptosis in gemcitabine-treated cancer cells. Conclusions: The VMP1-autophagy pathway promotes apoptosis in pancreatic cancercells and mediates gemcitabine-induced cytotoxicity.Autophagy is a degradation process of cytoplasmic cellular constituents. We have described the vacuole membrane protein-1 (VMP1) whose expression triggers autophagy in mammalian cells. The aim of this study was to analyze the role of autophagy in human pancreatic cancer cell death. Methods/Results: Here we show that gemcitabine, the standard chemotherapy for pancreatic cancer, induced autophagy in PANC-1 and MIAPaCa-2 cells, as evidenced by the accumulation of acidic vesicular organelles, the recruitment of microtubule-associated protein-1 light chain-3, and electron microscopy. In addition, gemcitabine treatment induced early expression of VMP1 in cancer cells. Gemcitabine also induced apoptosis detected by morphology, annexin V-positive cells, and cleavage of caspase-3. Surprisingly, 3-methyladenine, an autophagy inhibitor, decreased apoptosis in gemcitabine-treated cells, showing that autophagy leads to cancer cell apoptotic death. Finally, VMP1 knockdown decreased autophagy and  apoptosis in gemcitabine-treated cancer cells. Conclusions: The VMP1-autophagy pathway promotes apoptosis in pancreatic cancercells and mediates gemcitabine-induced cytotoxicity.