The effect of cafestol and kahweol on Sp1 mRNA and protein expression in MSTO-211H cells. The effect of cafestol (A, 0–90 μM) and kahweol (B, 0–60 μM) for 48 hours on Sp1 mRNA expression was determined by RT-PCR. The graphs indicate the ratio of Sp1 to β-actin expression. The effect of cafestol (C) and kahweol (D) for 48 hours on Sp1 protein expression was determined by western blotting. β-actin was probed to determine the equal loading of protein extract from each treatment. The graphs indicate the ratio of Sp1 to β-actin or Actin expression. Results are shown as the mean ± SD of three independent experiments. The asterisks (*, P < 0.05) indicated a significant change relative to cafestol or kahweol-treated cells compared with untreated cells. The effect of cafestol (E) and kahweol (F) on Sp1 protein turnover in MSTO-211H cells. The protein lysates were obtained from cells pretreated with protein synthesis inhibitor such as cyclohexmide (CHX) for 1 hour and then exposed to cafestol (E) and kahweol (F) for 48 hours. The protein expression of Sp1 were analyzed by western blot analysis.