Antitumor activity of cationic liposome-mediated Bax gene transfer in osteosarcoma cells: induction of apoptosis and caspase-independent cell death.
The purpose of this study was to evaluate the anti-tumor effects of osteosarcoma (HOSM-1) cells via transfer of the Bax gene using a cationic liposome. We evaluated the levels of Bax, Bcl-xL, Bcl-2 and cytochrome c expression by Western blot analysis, and caspase-9 and -3 activities were determined in a colorimetric assay. Apoptosis was detected using a TUNEL assay, and cell growth inhibition was determined in an MTT assay. Following Bax gene transfer, release of cytochrome c to the cytosol was detected, the activities of caspase-9 and -3 increased, and TUNEL-positive cells (37.5%) were detected. Cell survival rate was 50.8% under these conditions. Induction of apoptosis was inhibited by a caspase inhibitor (zVAD-fmk), but only a slight increase in cell survival rate occurred. Hence, since not only apoptosis but also caspase-independent cell death is induced in HOSM-1 cells, we anticipate that Bax gene therapy with cationic liposomes will be useful for osteosarcoma.
Okumura
Kenya
K
Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Mie University, Tsu, Mie 514-8507, Japan. okuken@clin.medic.mie-u.ac.jp
Nakase
Minoru
M
Nakamura
Shinnosuke
S
Inui
Madoka
M
Hiramoto
Kenichi
K
Tagawa
Toshiro
T
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D015153:Blotting, Western; D053148:Caspase 3; D053453:Caspase 9; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002412:Cations / Q000737:chemistry; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D006801:Humans; D020287:In Situ Nick-End Labeling; D008081:Liposomes / Q000737:chemistry; D012516:Osteosarcoma / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D014162:Transfection / Q000379:methods*
D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D002412:Cations; D008081:Liposomes; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases