Figure 3

Compound C inhibits transcription. (a) A549, SMMC-7721 and HeLa cells were treated with indicated amounts of compound C or physiological saline for 24 h in medium containing 0.5% FBS. The cells were pulsed with [³H]thymidine (1 μCi per well) for 6 h, and then fixed with 5% trichloroacetic acid and solubilized before scintillation counting. DRB was used as the positive control. (b) A549, SMMC-7721 and HeLa cells were treated with 2.5 μg/ml tunicamycin (Tun) or 1 μmol/l thapsigargin (Tg) for 12 h with or without 10 μmol/l compound C pretreatment for 1 h, and GRP78 mRNA levels were analyzed using real-time RT-PCR. (c) A549 cells were treated with 2.5 μg/ml Tun or 1 μmol/l Tg for 12 h with or without 10 μmol/l compound C pretreatment for 1 h, and EGFR mRNA levels were analyzed using real-time RT-PCR. (d) A549, SMMC-7721 and HeLa cells were treated with indicated amounts of compound C for 24 h and cell lysates were analyzed for the levels of indicated proteins. DRB was used as the positive control. (e) A549 and HeLa cells were treated with 10 μmol/l of compound C for 24 h and cell lysates were analyzed for the levels of indicated proteins. DRB was used as the negative control and ActD was used as the positive control. Data are presented as mean values±S.D. of three measurements. Columns, mean of three individual experiments; bars, S.D. * Significantly different from control value; ** Significantly different from *value