Figure 1

Effect of CSC on viability and apoptosis in A549 cells and NHBEs. Cells were grown to about 70% confluence in 12-well plates (Panel A, viability) or 8-well chamber slides (Panel B, apoptosis). Cells were exposed to the indicated concentration of CSC for 30 min then rinsed with PBS and processed for each assay. Viability was determined by trypan blue vital staining and expressed as percent of total cells. Apoptosis was measured by fluorescent TUNEL assay and is expressed as the percent of cells exhibiting apoptosis relative to the total number of cells. The values are the mean ± SEM for n = 3. (--●-- A549; --▲-- NHBE) CSC = cigarette smoke condensate; NBHE = normal human bronchial epithelial cell; PBS = phosphate-buffered saline; SEM = standard error of the mean; TUNEL = deoxynucleotidyl transferase-mediated dUTP nick end labeling