The goal of this study was to determine the effects of tobacco compounds on gene expression in a human fetal lung cell line (WI38). In the present study, we investigated the effects of tobacco compounds (nicotine, benzo(a)pyrene (B(a)P), and 2-Naphthylamine) on gene expression profiles in human fetal fibroblasts using cDNA microarray and real-time PCR. WI38 cells were cultured in Eagle's minimum essential medium (MEM) supplemented with 10% fetal bovine serum, 2% 200 mM L-glutamine, and a 2% penicillin and streptomycin solution. Tissue culture flasks (T-25 cm(2)) containing confluent lung fibroblasts were incubated at 37 degrees C for 24 h with 5 mL of medium supplemented with 10 microM of a tobacco compound (nicotine, B(a)P, or 2-Naphthylamine). The gene expression profiles for the W138 cells varied depending on the tobacco compound. The cDNA microarray analysis revealed that apoptosis-related genes such as DNASE2, MADD, MST1, NME3, RARG, TNFRSF1A, BAD, and DFFB genes were down-regulated in tobacco compound-treated WI38 cells. We also observed significant increases in Arnt gene expression by real-time PCR in tobacco compound-treated WI38 cells. Tobacco compounds can affect apoptosis, immunity, and growth in WI38 cells. A microarray-based genomic survey is a high-throughput approach for the evaluation of gene expression in cell lines treated with tobacco compounds.