The effects of N-acetyl cysteine, buthionine sulfoximine, diethyldithiocarbamate or 3-amino-1,2,4-triazole on antimycin A-treated Calu-6 lung cells in relation to cell growth, reactive oxygen species and glutathione.
Antimycin A (AMA) inhibits mitochondrial electron transport between cytochrome b and c. We recently demonstrated that AMA inhibits the growth of lung cancer Calu-6 cells and the changes of reactive oxygen species (ROS) and glutathione (GSH) levels affect apoptosis in Calu-6 cells. Here, we examined the effects of N-acetyl-cysteine (NAC, a well known antioxidant), L-buthionine sulfoximine (BSO, an inhibitor of GSH synthesis), diethyl-dithiocarbamate (DDC, an inhibitor of Cu, Zn-SOD) or 3-amino-1,2,4-triazole (AT, an inhibitor of catalase) on AMA-treated Calu-6 cells in relation to cell death, ROS and GSH levels. Treatment with AMA induced cell growth inhibition, apoptosis and the loss of mitochondrial membrane potential (MMP) (DeltaPsim) in Calu-6 cells. While the intracellular ROS level was decreased in 50 microM AMA-treated Calu-6 cells, O2.- levels among ROS were significantly increased. AMA also induced GSH depletion in Calu-6 cells. Treatment with NAC showed decreasing effect on O2.- levels in AMA-treated cells preventing apoptosis, MMP (DeltaPsim) loss and GSH depletion in these cells. BSO significantly increased GSH depletion and apoptosis in AMA-treated cells. While both DDC and AT increased ROS levels in AMA-treated Calu-6 cells, only DDC intensified GSH depletion and apoptosis. BSO and AT increased the ROS level in Calu-6 control cells, but these agents did not induce apoptosis and GSH depletion. In conclusion, our results suggest that GSH depletion rather than ROS level in AMA-treated Calu-6 cells is more tightly related to apoptosis.
Han
Yong Hwan
YH
Department of Physiology, Medical School, Institute for Medical Sciences Chonbuk National University, JeonJu 561-180, Korea.
Park
Woo Hyun
WH
D000111:Acetylcysteine / Q000494:pharmacology*; D000230:Adenocarcinoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000640:Amitrole / Q000494:pharmacology*; D000968:Antimycin A / Q000494:pharmacology*; D019328:Buthionine Sulfoximine / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004050:Ditiocarb / Q000494:pharmacology*; D005978:Glutathione / Q000032:analysis*; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*
D017382:Reactive Oxygen Species; D019328:Buthionine Sulfoximine; D000968:Antimycin A; D004050:Ditiocarb; D005978:Glutathione; D000111:Acetylcysteine; D000640:Amitrole