Detection of phenotype-dependent apoptosis induced by treatments with DMSO, TNF-α, 17-DMAG, or TNF- α plus 17- DMAG. The normal human bronchial epithelium cell line (NuLi-1) and three lung cancer cell lines (MS-1, A549, and LK-2) were treated with either vehicle control (DMSO), TNF-α (10 ng/ml), 17-DMAG (0.05 μM), or both of TNF-α (10 ng/ml) and 17-DMAG. Cells were harvested 48 h later. Hoechst 33258-stained cells were examined for apoptotic characteristics (nuclear margination and chromatin condensation) using a fluorescence microscope. Apoptotic incidence was calculated. Data were expressed as means ± SD for three independent experiments.