Effect of NNK and beta-adrenoceptors on cell apoptosis.

<p>Variously treated KYSE410 (A) and HET-1A (B) cells were stained with annexin V-FITC and PI, and then analyzed by flow cytometer. Annexin V-FITC is a sensitive probe that identifies apoptotic cells. PI is a standard viability probe for flow cytometry, which is used to distinguish viable from nonviable cells. Cells that stain positive for both annexin V-FITC and PI are either late apoptotic or necrotic cells (Q2). Early apoptotic cells stain positive for annexin V-FITC and negative for PI (Q4). Data are representative of three independent experiments. ^ε p<0.05 compared with the blank group; ^ζ p<0.05 compared with the negative group; ^ξ p<0.05 compared with the negative+NNK group. Negative is representative of nonspecific control siRNA for beta-adrenoceptors.