1.Increase of NKG2D ligands and sensitivity to NK cell-mediated cytotoxicity of tumor cells by heat shock and ionizing radiation.
Joo Young KIM ; Young Ok SON ; Soon Won PARK ; Jae Ho BAE ; Joo Seop CHUNG ; Hyung Hoi KIM ; Byung Seon CHUNG ; Sun Hee KIM ; Chi Dug KANG
Experimental & Molecular Medicine 2006;38(5):474-484
In this study, we have investigated if current cancer therapeutic modalities including hyperthermia and ionizing radiation can increase the expression of NKG2D ligands in human cancer cell lines. The expressions of NKG2D ligands were induced by both heat shock and ionizing radiation in various cell lines including KM12, NCI-H23, HeLa and A375 cells with peaks at 2 h and 9 h after treatment, respectively, although inducibility of each NKG2D ligand was various depending on cell lines. During the induction of NKG2D ligands, heat shock protein 70 was induced by heat shock but not by ionizing radiation. These results were followed by increased susceptibilities to NK cell-mediated cytolysis after treatment with heat shock and ionizing radiation. These results suggest that heat shock and ionizing radiation induce NKG2D ligands and consequently might lead to increased NK cell-mediated cytotoxicity in various cancer cells.
Tumor Cells, Cultured
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Receptors, Immunologic/*metabolism
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Radiation, Ionizing
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Neoplasms/immunology/*radiotherapy/therapy
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*Ligands
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Killer Cells, Natural/*immunology
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Hyperthermia, Induced/methods
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Humans
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Hela Cells
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*Heat-Shock Response/physiology
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Heat
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HSP70 Heat-Shock Proteins/metabolism/radiation effects
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Gene Expression Regulation, Neoplastic/radiation effects
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Cytotoxicity, Immunologic/*physiology/*radiation effects
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Antigens, Surface/metabolism/radiation effects