TY - JOUR
T1 - A549 subclones demonstrate heterogeneity in toxicological sensitivity and antioxidant profile
AU - Watanabe, Nobuo
AU - Dickinson, Dale A.
AU - Krzywanski, David M.
AU - Iles, Karen E.
AU - Zhang, Hongqiao
AU - Venglarik, Charles J.
AU - Forman, Henry Jay
PY - 2002/10
Y1 - 2002/10
N2 - In A549 cell culture, significant variability was found in sensitivity to actinomycin D. Using limiting dilution, actinomycin D-susceptible (G4S) and -resistant (D3R) subclones were isolated. G4S cells were also susceptible to protein synthesis inhibitors, a redox cycling quinone, and an electrophile with concomitant activation of caspases 3 and 9. D3R cells were resistant to these agents without caspase activation. Antioxidant profiles revealed that D3R cells had significantly higher glutathione and glutathione reductase activity but markedly lower catalase, glutathione peroxidase, and aldehyde reductase activities than G4S cells. Thus A549 cells contain at least two distinct subpopulations with respect to predisposition to cell death and antioxidant profile. Because sensitivities to agents and the antioxidant profile were inconsistent, mechanisms independent of antioxidants, including the apparent inability to activate caspases in D3R cells, may play an important role. Regardless, the results suggest that antioxidant profiles of asymmetrical cell populations cannot predict sensitivity to oxidants and warn that the use of single subclones is advisable for mechanistic studies using A549 or other unstable cell lines.
AB - In A549 cell culture, significant variability was found in sensitivity to actinomycin D. Using limiting dilution, actinomycin D-susceptible (G4S) and -resistant (D3R) subclones were isolated. G4S cells were also susceptible to protein synthesis inhibitors, a redox cycling quinone, and an electrophile with concomitant activation of caspases 3 and 9. D3R cells were resistant to these agents without caspase activation. Antioxidant profiles revealed that D3R cells had significantly higher glutathione and glutathione reductase activity but markedly lower catalase, glutathione peroxidase, and aldehyde reductase activities than G4S cells. Thus A549 cells contain at least two distinct subpopulations with respect to predisposition to cell death and antioxidant profile. Because sensitivities to agents and the antioxidant profile were inconsistent, mechanisms independent of antioxidants, including the apparent inability to activate caspases in D3R cells, may play an important role. Regardless, the results suggest that antioxidant profiles of asymmetrical cell populations cannot predict sensitivity to oxidants and warn that the use of single subclones is advisable for mechanistic studies using A549 or other unstable cell lines.
KW - Apoptosis
KW - Caspase
KW - Enzyme
KW - Genetic instability
KW - Oxidative stress
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U2 - 10.1152/ajplung.00025.2002
DO - 10.1152/ajplung.00025.2002
M3 - Article
C2 - 12225949
AN - SCOPUS:0036784105
SN - 0363-6135
VL - 283
SP - L726-L736
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 4 27-4
ER -