title: The effects of N-acetyl cysteine on the MG132 proteasome inhibitor-treated lung cancer cells in relation to cell growth, reactive oxygen species and glutathione.
abstract: MG132 as a proteasome inhibitor has been shown to induce apoptotic cell death through formation of reactive oxygen species (ROS). Here, we investigated the effects of N-acetyl cysteine (NAC; a well-known antioxidant), L-buthionine sulfoximine (BSO; an inhibitor of GSH synthesis) or diethyldithiocarbamate (DDC; an inhibitor of Cu/Zn-SOD) on MG132-treated Calu-6 or A549 lung cancer cells in relation to cell growth, ROS and GSH levels. MG132 inhibited the growth of Calu-6 and A549 cells at 24 h. MG132 induced apoptosis in both cell lines, which was accompanied by the loss of mitochondrial membrane potential (MMP; DeltaPsim). ROS levels including O(2)(.-) were increased in both MG132-treated lung cells. MG132 also induced GSH depletion in both lung cell types. Treatment with 10 microM BSO or 1 microM DDC affected ROS and GSH levels in MG132-treated Calu-6 cells. However, these changes did not influence cell growth and death in the cells. NAC prevented cell growth inhibition and death in MG132-treated lung cells, which was accompanied by decreased ROS, but not by decreased GSH depletion. In conclusion, the changes of ROS and GSH by MG132, NAC, BSO or DDC were partially related to cell growth and death in the lung cancer cell lines Calu-6 and A549.
authors.affiliation: Department of Physiology, Medical School, Centers for Healthcare Technology Development Institutefor Medical Sciences, Chonbuk National University, JeonJu 561-180, Republic of Korea.
authors.forename: Yong Hwan
authors.initials: YH
authors.lastname: Han
authors.forename: Hwa Jin
authors.initials: HJ
authors.lastname: Moon
authors.forename: Bo Ra
authors.initials: BR
authors.lastname: You
authors.forename: Sung Zoo
authors.initials: SZ
authors.lastname: Kim
authors.forename: Suhn Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Woo Hyun
authors.initials: WH
authors.lastname: Park
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004050:Ditiocarb / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D007976:Leupeptins / Q000494:pharmacology*; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D007976:Leupeptins; D061988:Proteasome Inhibitors; D017382:Reactive Oxygen Species; D019328:Buthionine Sulfoximine; D004050:Ditiocarb; D046988:Proteasome Endopeptidase Complex; D005978:Glutathione; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde; D000111:Acetylcysteine