title: Irradiated pancreatic cancer cells undergo both apoptosis and necrosis, and could be phagocytized by dendritic cells.
abstract: The interaction of immature dendritic cells (DC) with irradiated pancreatic cancer cells was examined. Flow cytometric analysis using annexin V and propidium iodide revealed that ionizing radiation (25-35 Gy X-ray) induced both apoptosis and necrosis in pancreatic cancer cell lines. After irradiation, PK-1 and Panc-1 cells were likely to undergo necrosis, whereas MIAPaCa-2 cells underwent apoptosis. When DiO-stained immature DCs were co-incubated with DiI-stained irradiated MIAPaCa-2, it was observed under fluorescent microscopy that DCs phagocytized dead tumor cells as early as 4 h after co-incubation. The DCs' phagocytosis of irradiated tumor cells was also confirmed by flow cytometry. These results suggest that irradiated pancreatic cancer cells, which undergo both apoptosis and necrosis, could be a good source of tumor-associated antigens for cross-presentation by DCs.
authors.affiliation: Department of Gastroenterological Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Shimamura
authors.forename: M
authors.initials: M
authors.lastname: Sunamura
authors.forename: K
authors.initials: K
authors.lastname: Tsuchihara
authors.forename: S
authors.initials: S
authors.lastname: Egawa
authors.forename: K
authors.initials: K
authors.lastname: Takeda
authors.forename: S
authors.initials: S
authors.lastname: Matsuno
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D044584:Carcinoma, Ductal; D045744:Cell Line, Tumor / Q000502:physiology / Q000528:radiation effects; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D009336:Necrosis; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000532:radiotherapy; D010587:Phagocytosis / Q000502:physiology*; D010641:Phenotype