title: Romidepsin (FK228), a potent histone deacetylase inhibitor, induces apoptosis through the generation of hydrogen peroxide.
abstract: Romidepsin (FK228) is a potent histone deacetylase (HDAC) inhibitor, which has a potent anticancer activity, but its molecular mechanism is unknown. We investigated the mechanism of FK228-induced apoptosis in the human leukemia cell line HL-60 and its hydrogen peroxide (H(2)O(2))-resistant sub-clone, HP100, and the human colon cancer cell line Caco-2. Cytotoxicity and DNA ladder formation induced by FK228 could be detected in HL-60 cells after a 24-h incubation, whereas they could not be detected in HP100 cells. Trichostatin A (TSA), an HDAC inhibitor, induced DNA ladder formation in both HL-60 and HP100 cells. In contrast, FK228 inhibited HDAC activity in both HL-60 and HP100 cells to a similar extent. These findings suggest that FK228-induced apoptosis involves H(2)O(2)-mediated pathways and that TSA-induced apoptosis does not. Flow cytometry revealed H(2)O(2) formation and a change in mitochondrial membrane potential (Δψm) in FK228-treated cells. FK228 also induced apoptosis in Caco-2 cells, which was prevented by N-acetyl-cysteine, suggesting that reactive oxygen species participate in apoptosis in various types of tumor cells. Interestingly, in a cell-free system, FK228 generated superoxide (O(2)(-)) in the presence of glutathione, suggesting that H(2)O(2) is derived from dismutation of O(2)(-) produced through redox-cycle of FK228. Therefore, in addition to HDAC inhibition, H(2)O(2) generated from FK228 may participate in its apoptotic effect.
authors.affiliation: College of Pharmacy, Kinjo Gakuin University, Nagoya, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Mizutani
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Hiraku
authors.forename: Saeko
authors.initials: S
authors.lastname: Tada-Oikawa
authors.forename: Mariko
authors.initials: M
authors.lastname: Murata
authors.forename: Kenji
authors.initials: K
authors.lastname: Ikemura
authors.forename: Takuya
authors.initials: T
authors.lastname: Iwamoto
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kagawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Okuda
authors.forename: Shosuke
authors.initials: S
authors.lastname: Kawanishi
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D047630:Depsipeptides / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D006877:Hydroxamic Acids / Q000494:pharmacology
chemical_list: D047630:Depsipeptides; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; C012589:trichostatin A; D006861:Hydrogen Peroxide; C087123:romidepsin; D005978:Glutathione; D000111:Acetylcysteine