N-(4-Hydroxyphenyl)retinamide (4-HPR) induces leukemia cell death via generation of reactive oxygen species.
The role of reactive oxygen species (ROS) in the cytotoxicity of N-(4-hydroxyphenyl)retinamide (4-HPR) was studied with use of the B-precursor lymphoblastic leukemia cell line YCUB-2. The increase in intracellular ROS measured with 2'-7'-dichlorodihydrofluorescein diacetate after 3 hours' incubation was 3.7-fold with 1 microM 4-HPR and 5.8-fold with 5 microM 4-HPR. The rate of apoptosis after 48 hours' incubation was 9.8% and 56.4% in comparison with untreated cells. Hydroethidine, which is a more specific indicator of superoxide anion radical level, did not effectively detect 4-HPR-induced ROS. The antioxidant 3-methyl-1-phenyl-2-pyrazolin-5-one suppressed 4-HPR-induced ROS production and apoptosis. The cytotoxicity of 4-HPR was analyzed in 4 other leukemia/lymphoma lines (CCRF-HSB2, Molt-4, KG-1, HL-60). We found that the cytotoxicity of 4-HPR correlated with the amount of ROS produced in cell lines, except in HL-60 cells. The intracellular glutathione level varied among the 5 cell lines, the highest levels occurring in Molt-4 and KG-1, which were less sensitive to 4-HPR. Suppression of glutathione by buthionine sulfoximine enhanced the level of 4-HPR-induced ROS production and apoptosis in Molt-4. Our findings suggest that ROS play a significant role in the antileukemia effect of 4-HPR and that the glutathione level in leukemias may be associated the sensitivity of the cells to 4-HPR.
Goto
Hiroaki
H
Department of Pediatrics, Yokohama City University School of Medicine, Yokohama, Japan.
Takahashi
Hiroyuki
H
Fujii
Hisaki
H
Ikuta
Koichiro
K
Yokota
Shumpei
S
D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D017313:Fenretinide / Q000494:pharmacology*; D005978:Glutathione / Q000032:analysis / Q000037:antagonists & inhibitors; D006801:Humans; D007938:Leukemia / Q000473:pathology*; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism*
D000970:Antineoplastic Agents; D017382:Reactive Oxygen Species; D017313:Fenretinide; D019328:Buthionine Sulfoximine; D005978:Glutathione