title: Diethyldithiocarbamate-induced cytotoxicity and apoptosis in leukemia cell lines.
abstract: Diethyldithiocarbamate (DDTC) has been shown to induce cytotoxicity in several different systems. We examined whether the DDTC-induced cytotoxicity was via apoptosis, or in relation to intracellular glutathione (GSH) in various murine and human leukemia cell lines. The cells most sensitive to DDTC-induced cytotoxicity were P388 lymphoid neoplasma cells and NALM-6, a B cell line of acute lymphocytic leukemia (ALL). The next level of susceptible cells included J774.1, having a macrophage function, HL-60 premyelocytic leukemia cells, MOLT-4, an acute lymphoblastic leukemia cell, and Jurkat, a T-cell leukemia. U937 (expressing many monocyte-like characteristics), K562 erythroleukemia and K562/DXR (a multidrug-resistant clone derived from K562) were almost unaffected by DDTC. P388 was also highly susceptible to H(2)O(2), a most useful exogenous reactive oxygen species generator, and was lower in intracellular total GSH content than other leukemia cells. DDTC-induced cytotoxicity was closely related to intracellular GSH, but the level of cellular GSH did not always correlate with H(2)O(2)-induced cytotoxicity in this experiment. K562 had a higher intracellular total GSH content and showed lower susceptibility to DDTC and H(2)O(2), but with the combination of DDTC and DL-buthionine-(S,R)-sulfoximine (BSO), cytotoxicity increased significantly. The ratio of GSH/GSSG in P388 was reduced by DDTC or H(2)O(2). H(2)O(2)-induced cytotoxicity was completely blocked by catalase (CAT), while it was enhanced by superoxide dismutase (SOD). CAT or SOD did not affect DDTC-induced cytotoxicity. N-Acetylcysteine (NAC: 1 mM), a vanguard substance of GSH, and aurintricarboxylic acid (ATA: 100 microM), an endonuclease inhibitor, ameliorated DDTC-induced cytotoxicity and apoptosis. In conclusion, we suggest that DDTC-induced cytotoxicity was via an oxidative shift in the intracellular redox state, and accompanied the activation of endonuclease through apoptosis in leukemia cell lines.
authors.affiliation: Department of Pharmacology and Toxicology, Cancer Research Institute, Tohoku Pharmaceutical University, Sendai, Japan. syu-kan@tohoku-pharm.ac.jp
authors.forename: Syu-ichi
authors.initials: S
authors.lastname: Kanno
authors.forename: Emi
authors.initials: E
authors.lastname: Matsukawa
authors.forename: Ai
authors.initials: A
authors.lastname: Miura
authors.forename: Ai
authors.initials: A
authors.lastname: Shouji
authors.forename: Keiko
authors.initials: K
authors.lastname: Asou
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ishikawa
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004050:Ditiocarb / Q000633:toxicity*; D018922:HL-60 Cells; D006801:Humans; D019169:Jurkat Cells; D007938:Leukemia / Q000378:metabolism*; D020298:U937 Cells
chemical_list: D004050:Ditiocarb