Effect of KCP10043F on the IL-6-induced STAT3 signaling pathway in A549 and NCI-H358 cells. (A) A549 and NCI-H358 cells were treated with 20 μM KCP10043F for the indicated times (5, 15, 30, 60, or 120 min). IL-6 production in the cell culture media was quantified using an EIA kit. Data represent the mean ± S.D. of the results from three independent experiments. ** p < 0.01 vs. untreated control group. After pretreatment with KCP10043F (5, 10, or 20 μM) for 1 h, the cells were stimulated with recombinant human IL-6 (10 ng/mL) for 30 min, and STAT3 activation was determined by (B) Western blot and (C) immunofluorescence analyses. Cells were transfected with pMXs-gw and pMXs-STAT3C for the overexpression of STAT3. (D) Transfected A549 cells were treated with 20 μM KCP10043F for 12 h and analyzed by flow cytometry with annexin V-FITC and PI staining. Data represent the mean ± SD. of the results from three independent experiments. *** p < 0.001 vs. pMXs-gw-transfected control group. ##
p < 0.001 vs. KCP10043F-treated control group. (E) Western blot analyses were performed to detect apoptotic cell death.