Effects of BPS and 8-Br-cAMPon p27kip1mRNA expression during hypoxia. Cultured HPASMC were exposed to 21% or 2% oxygen concentrations with or without 10 μM of BPS or 1 mM 8-Br-cAMP for indicated periods. Expression of p27kip1 mRNA was measured using Real-time RT-PCR using LightCycler™. (a) BPS suppressed p27kip1 mRNA reduction under both normoxic and hypoxic conditions. Expression of p27kip1 mRNA between normoxic and hypoxic conditions did not significantly change. Graph shows ratio of p27kip1 to β-actin mRNA expression. Open and solid bars, 21% and 2% oxygen, respectively. Data are expressed as means ± SE (n = 6). *P < 0.05 versus control. (b) Agarose gel electrophoresis with EB staining revealed single amplification of predicted PCR products (lane 1, DNA molecular weight markers; lane 2, p27kip1; 109 bp; lane 3, β-actin 144 bp).