Zebularine inhibits the growth of HeLa cervical cancer cells via cell cycle arrest and caspase-dependent apoptosis.
Zebularine (Zeb) as a DNA methyltrasferase (DNMT) inhibitor has various cellular effects such as cell growth inhibition and apoptosis. In the present study, we evaluated the effects of Zeb on the growth and death of HeLa cervical cancer cells. Zeb inhibited the growth of HeLa cells with an IC(50) of approximately 130 μM at 72 h in a dose-dependent manner. DNA flow cytometric analysis indicated that Zeb induced an S phase arrest of the cell cycle, which was accompanied by the increased levels of cdk2 and cyclin A proteins. This agent also induced apoptosis, which was accompanied by the loss of mitochondrial membrane potential (Ψ(m)), PARP-1 cleavage and the activation of caspase-3, -8 and -9. All of the tested caspase inhibitors significantly rescued some cells from Zeb-induced HeLa cell death. In relation to reactive oxygen species (ROS) and glutathione (GSH) levels, O (2) (•-) level was significantly increased in 100 μM Zeb-treated HeLa cells and caspase inhibitors reduced O (2) (•-) level in these cells. Zeb induced GSH depletion in HeLa cells, which was attenuated by caspase inhibitors. In conclusion, this is the first report that Zeb inhibited the growth of HeLa cells via cell cycle arrest and apoptosis.
Department of Physiology, Medical School, Research Institute for Endocrine Sciences, Chonbuk National University, Jeonju 561-180, Republic of Korea.
Bo Ra
BR
You
Woo Hyun
WH
Park
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D061945:Caspase Inhibitors / Q000494:pharmacology; D020169:Caspases / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects*; D003562:Cytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors; D004354:Drug Screening Assays, Antitumor; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009842:Oligopeptides / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D059807:S Phase Cell Cycle Checkpoints / Q000187:drug effects*; D002583:Uterine Cervical Neoplasms
D000970:Antineoplastic Agents; D061945:Caspase Inhibitors; D009842:Oligopeptides; D017382:Reactive Oxygen Species; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C403753:benzyloxycarbonyl-isoleucyl-glutamyl-threonyl-aspartic acid fluoromethyl ketone; C403754:benzyloxycarbonyl-leucyl-glutamyl-histidyl-aspartic acid fluoromethyl ketone; C517629:benzyloxycarbonyl-valyl-alanyl-aspartic acid; D003562:Cytidine; C009131:pyrimidin-2-one beta-ribofuranoside; D015254:DNA Modification Methylases; D020169:Caspases; D005978:Glutathione