Anticancer effect of tert-butyl-2(4,5-dihydrogen-4,4,5,5-tetramethyl-3-O-1H-imidazole-3-cationic-1-oxyl-2)-pyrrolidine-1-carboxylic ester on human hepatoma HepG2 cell line.
Tert-butyl-2(4,5-dihydrogen-4,4,5,5-tetramethyl-3-O-1H-imidazole-3-cationic-1-oxyl-2)-pyrrolidine-1-carboxylic ester (L-NNP) is a stable nitroxyl nitroxide radical, which have displayed cytotoxicity on human breast cancer MCF-7 and MDA-MB-231 cell lines. In the present study, we investigated the selective cytotoxicity of L-NNP on isogenetic human hepatoma HepG2 and normal L-02 cell lines. Cell growth inhibition, intracellular reactive oxygen species production, the mitochondrial membrane potential loss, malondialdehyde generation and glutathione levels were analyzed. The expression of Bax, Bcl-2 and NF-κBp65 proteins was also examined. The anticancer activity was evaluated in a HepG2 cell xenograft nude mice model. The results showed that 10, 20, 40 μg/ml L-NNP exposure for 48 h caused 52%, 82% and 91% cell growth inhibition of HepG2 cells, compared with 5%, 10% and 15% that of L-02 cells (p < 0.01). Concentrations of 10, 20, 40 μg/ml L-NNP induced cell death by increasing the generation of intracellular reactive oxygen species and MDA, by depolarizing the mitochondrial membrane potential, and by decreasing intracellular GSH levels in HepG2 cells. Western blot assay showed that Bax, Bcl-2 and NF-κBp65 might be implicated in L-NNP-induced selective HepG2 cell death. L-NNP was also found to inhibit HepG2 hepatoma growth and extend the life span of nude mice model (p < 0.01). The pretreatment and co-treatment of 10 mM N-acetyl-cysteine alleviated L-NNP exposure induced intracellular reactive oxygen species increase and cell growth inhibition demonstrated that L-NNP exhibited neoplasm-selective cytotoxicity and pro-apoptotic activities via reactive oxygen species mediated oxidative damage in HepG2 cells. It might be promising for developing a new class of anticancer agent for liver cancer.
Department of Radiological Medicine, Fourth Military Medical University, No. 17, Changle West Road, Xi'an, Shaanxi 710032, PR China.
Juan
J
Guo
Yanjun
Y
Zhang
Jie
J
Zhang
Jun
J
Liang
Lihua
L
Zeng
Guozhen
G
Guo
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000473:pathology; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D005978:Glutathione / Q000378:metabolism; D056945:Hep G2 Cells / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D011759:Pyrrolidines / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D000970:Antineoplastic Agents; C494826:BAX protein, human; D007093:Imidazoles; D011759:Pyrrolidines; D017382:Reactive Oxygen Species; D051028:bcl-2-Associated X Protein; C559687:tert-butyl-2-(4,5-dihydrogen-4,4,5,5-tetramethyl-3-O-1H-imidazole-3-cationic-1-oxyl-2-pyrrolidine-1-carboxylic ester); D008315:Malondialdehyde; D005978:Glutathione