Increases in expression of α7 nicotinic acetylcholine receptor protein in NCI-H69 after treatment with 100 pM of the tobacco carcinogen NNK as assessed by western blot analysis. Protein was isolated with the ReadyPrep protein extraction kit (signal) (Biorad). Nitrocellulose membranes were incubated with the rabbit polyclonal antibody to the alpha 7 nicotinic acetylcholine receptor (Abcam). 1) control; 2) 5 min; 3) 30 min; 4) 60 min; 5) 150 min; 6) 24 hour. The arrow indicates the 56 kDa band (expected size). Increases were seen in expression of protein for alpha 7 nicotinic acetylcholine receptor after 60 min and 150 min of NNK treatment.