Induction of apoptosis in cultured colon cancer cells by transfection with human interferon beta gene.
The growth of SW480 colon cancer cells following the transfection with the human interferon beta (hIFNbeta) gene entrapped in cationic multilamellar liposomes was effectively inhibited, but not that of the cells transfected with the gene from which the secretion signal sequence of hIFNbeta had been deleted. The amount of hIFNbeta secreted in the medium from SW480 cells transfected with hIFNbeta gradually increased and became maximum 3 days after the transfection, but no hIFNbeta was detected in the medium of the cells transfected with the secretion signal-deleted hIFNbeta. These findings indicate that the growth inhibition of SW480 cells after the transfection with hIFNbeta was caused by hIFNbeta secreted from the transfected cells. At that time, SW480 cells were induced to undergo apoptosis, which was identified by morphological aspects, viz., chromatin condensation, nuclear segmentation, and nucleosomal DNA fragmentation. The hIFNbeta-induced apoptosis was found to be linked to the activation of caspases 3 and 8 as evidenced by immunoblot, enzymological, and cell death inhibition analyses.
Kito
M
M
Institute of Applied Biochemistry, Gifu International Institute of Biotechnology, Yagi Memorial Park, Mitake, 505-0116, Japan.
Akao
Y
Y
Ohishi
N
N
Yagi
K
K
D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002467:Cell Nucleus / Q000378:metabolism; D048429:Cell Size / Q000187:drug effects; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D053938:DNA Fragmentation; D004789:Enzyme Activation; D006801:Humans; D016899:Interferon-beta / Q000235:genetics / Q000378:metabolism*; D008970:Molecular Weight; D021382:Protein Sorting Signals / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D017384:Sequence Deletion; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured
D061945:Caspase Inhibitors; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D016899:Interferon-beta; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases