Trans10, cis12-conjugated linoleic acid induces mitochondria-related apoptosis and lysosomal destabilization in rat hepatoma cells.
Conjugated linoleic acid (CLA) is a powerful anti-carcinogenic fatty acid. Previously, we showed that 10trans 12cis (10t, 12c) CLA induced apoptotic cell death in rat hepatoma. Here, we demonstrated significant cytotoxic effects of 1 muM 10t, 12c-CLA, but not 9c, 11t-CLA, on dRLh-84 rat hepatoma cells. 9t, 11t and 9c, 11c-CLA also showed low levels of cytotoxic activity. 10t, 12c-CLA activated caspase-3, 9 followed by cytochrome c release from mitochondria into the cytosol. Inhibitors of caspase-3, 9 blocked the cytotoxicity of 10t, 12c-CLA. 10t, 12c-CLA also induced translocation of Bax protein into the mitochondrial membrane and cleavage of Bid protein. Lysosomal destabilization induced by 10t, 12c-CLA was observed by monitoring the re-localization of Acridine Orange and the leakage of beta-hexosaminidase from lysosomes. 10t, 12c-CLA directly degraded the isolated lysosomes from the rat liver. Our observations indicate that 10t, 12c-CLA induces mitochondria-related apoptosis accompanied by lysosomal destabilization in rat hepatoma cells.
Yamasaki
Masao
M
Division of Food Science and Nutrition, Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, Miyazaki University, Miyazaki 889-2192, Japan. myamasaki@cc.miyazaki-u.ac.jp
Miyamoto
Yumi
Y
Chujo
Hitomi
H
Nishiyama
Kazuo
K
Tachibana
Hirofumi
H
Yamada
Koji
K
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D051023:BH3 Interacting Domain Death Agonist Protein; D006528:Carcinoma, Hepatocellular; D002352:Carrier Proteins / Q000378:metabolism; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D007700:Kinetics; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D008113:Liver Neoplasms; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D051028:bcl-2-Associated X Protein
D051023:BH3 Interacting Domain Death Agonist Protein; C494828:Bax protein, rat; C494816:Bid protein, rat; D002352:Carrier Proteins; D044243:Linoleic Acids, Conjugated; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C496197:trans-10,cis-12-conjugated linoleic acid; C505410:Casp3 protein, rat; C506435:Casp9 protein, rat; D053148:Caspase 3; D053453:Caspase 9; D020169:Caspases