TY - JOUR
T1 - Modulation of benzo[a]pyrene-induced p53 DNA activity by acrolein
AU - Biswal, Shyam
AU - Maxwell, Terrie
AU - Rangasamy, Tirumalai
AU - Kehrer, James P.
N1 - Funding Information:
We thank Sara Sukumar, Johns Hopkins School of Medicine for the p53 reporter vector. This work was supported by the Maryland Cigarette Restitution fund (S.B.), a young clinical scientist award from FAMRI (S.B.), NIEHS Center grants ES03819 and ES07784, and RO1 ES09791. J.P.K. is the Gustavus and Louise Pfeiffer Professor of Toxicology. S.B. was supported at the University of Texas by NRSA ES05896 during a portion of this research.
PY - 2003/8/1
Y1 - 2003/8/1
N2 - Acrolein, a highly electrophilic α,β-unsaturated aldehyde, is by far the most reactive amongst the aldehydes present in smoke. The relative contribution of acrolein to complex mixture toxicity of smoke at the molecular level remains unknown. The current study examines the ability of acrolein to modulate the effect of benzo[a]pyrene (B[a]P), a major carcinogen found in smoke, on p53. Exposure of human lung adenocarcinoma A549 cells to 1 mM B[a]P for 48 h strongly activated the expression of p53 as seen by western blotting, and its DNA binding as shown by an electrophoretic mobility shift assay. Treatment of A549 cells with a non-lethal dose of acrolein alone (50 fmol/cell for 0.5 h) depleted 80% of total cellular glutathione but had no effect on basal p53 protein levels. When B[a]P-treated cells (48 h) were exposed to acrolein for 0.5 h there was also no effect on B[a]P-induced p53 protein levels. However, acrolein treatments profoundly inhibited the DNA binding of p53 under both basal and B[a]P-induced conditions. Depleting glutathione with buthionine sulfoximine in B[a]P-treated cells to levels similar to those obtained with acrolein decreased p53 DNA binding substantially less than with acrolein. Using a p53 dual luciferase reporter assay, acrolein caused an 83% decrease in the p53 activity induced by B[a]P (1 mM for 24 h post-transfection). The p53 protein that was immunoprecipitated after acrolein treatment was reactive with an anti-acrolein antibody indicating covalent modification. Results from this study suggest that acrolein can inhibit p53 DNA binding and activity by direct covalent modification as well as alteration of intracellular redox status. As both acrolein and B[a]P are found in cigarette smoke, this type of interaction may play an important role in the initiation of lung cancer by altering the tumor suppressor activity of p53.
AB - Acrolein, a highly electrophilic α,β-unsaturated aldehyde, is by far the most reactive amongst the aldehydes present in smoke. The relative contribution of acrolein to complex mixture toxicity of smoke at the molecular level remains unknown. The current study examines the ability of acrolein to modulate the effect of benzo[a]pyrene (B[a]P), a major carcinogen found in smoke, on p53. Exposure of human lung adenocarcinoma A549 cells to 1 mM B[a]P for 48 h strongly activated the expression of p53 as seen by western blotting, and its DNA binding as shown by an electrophoretic mobility shift assay. Treatment of A549 cells with a non-lethal dose of acrolein alone (50 fmol/cell for 0.5 h) depleted 80% of total cellular glutathione but had no effect on basal p53 protein levels. When B[a]P-treated cells (48 h) were exposed to acrolein for 0.5 h there was also no effect on B[a]P-induced p53 protein levels. However, acrolein treatments profoundly inhibited the DNA binding of p53 under both basal and B[a]P-induced conditions. Depleting glutathione with buthionine sulfoximine in B[a]P-treated cells to levels similar to those obtained with acrolein decreased p53 DNA binding substantially less than with acrolein. Using a p53 dual luciferase reporter assay, acrolein caused an 83% decrease in the p53 activity induced by B[a]P (1 mM for 24 h post-transfection). The p53 protein that was immunoprecipitated after acrolein treatment was reactive with an anti-acrolein antibody indicating covalent modification. Results from this study suggest that acrolein can inhibit p53 DNA binding and activity by direct covalent modification as well as alteration of intracellular redox status. As both acrolein and B[a]P are found in cigarette smoke, this type of interaction may play an important role in the initiation of lung cancer by altering the tumor suppressor activity of p53.
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U2 - 10.1093/carcin/bgg061
DO - 10.1093/carcin/bgg061
M3 - Article
C2 - 12807757
AN - SCOPUS:0041386256
SN - 0143-3334
VL - 24
SP - 1401
EP - 1406
JO - Carcinogenesis
JF - Carcinogenesis
IS - 8
ER -