Figure 1

(A) Suppression of TSA-mediated upregulation of NF-κB transcriptional activity by Calphostin C, Staurosporine and its analogue UCN-01 in NSCLC cell H322 and EsC cell TE12. Cells were transiently transfected with NF-κB-Luc plasmid as described in Materials and Methods and then subsequently treated with TSA (0.1 and 1.0 μ M) with or without concurrent Calphostin C (CC – 2 μ M), Staurosporine (STP – 200 nM) or UCN-01 (500 nM). Staurosporine and UCN-01 exerted a potent PKC-inhibitory activity as evidenced by the complete depletion of p-adducin following 12 h of exposure to the respective drugs. Luciferase activity assayed 24 h after drug treatments were normalised for proteins of cell lysates and expressed as fold of activity of untreated control cells. Data are expressed as mean±s.e.m. of three independent experiments (#P<0.05–0.01 and +P<0.001 vs controls by ANOVA and pair-wise comparison by Bonferroni test). (B) Profound induction of apoptosis in H322 and TE12 cells treated with TSA+CC, TSA+STP and TSA+UCN-01 combinations. Cells were exposed to TSA (1 or 2 μ M) for 12 h, to CC (1 μ M) or STP (200 nM) or UCN-01 (500 nM) continuously for 36 h or TSA followed by other drugs. Cells were then harvested 48 h after the onset of treatment to assay for apoptosis. Representative data of three independent experiments that yielded similar results are shown here.