Increased apoptosis in U937T cells expressing MT-HNE proteins. (A) Induction of apoptosis with camptothecin (CPT) in U937T cells expressing wild-type HNE (WT) or MT-HNE proteins (P110L, ΔV145-C152, R191Q). Evaluation of apoptosis by quantification of annexin V-positive cells by flow cytometry. Data are given as mean ± SD. (B) Real-time PCR analysis of relative BiP (GRP78) RNA expression in cells expressing wild-type HNE (WT) or MT-HNE proteins (P110L, ΔV145-C152, R191Q) with or without CPT treatment. Immunoblot using anti-HNE (29-34 kDa) confirms induction of transgene expression in corresponding cell lysates. Data are given as mean ± SD.