Statin increases KLF2 expression and enhances tBHQ-induced γ-globin gene expression. (A) Effect of statin on KLF2, NQO1, and γ-globin steady-state mRNA levels. K562 cells were treated with increasing doses of statin for 24 hours before RNA isolation. (B) Effect of statin on KLF2 nuclear protein levels. K562 cells were treated with 25μM tBHQ or 1 or 5μM of statin for 24 hours before nuclear protein harvest. (C) Effect of tBHQ and statin on K562 cell growth. 3.0 × 105 cells were treated with 25μM tBHQ or 1, 2.5, or 5μM statin and counted at 24 and 48 hours. (D) Effect of tBHQ and combination of tBHQ and statin treatment on γ-globin and NQO1 steady-state mRNA levels at 24 and 48 hours. Results expressed as the fold increase over untreated controls. (E) Statin dose response enhances tBHQ-induced γ-globin and NQO1 steady-state mRNA levels. K562 cells were treated with 25μM tBHQ or 25μM tBHQ and statin (1μM-5μM) for 48 hours before RNA isolation. Real-time PCR results are expressed as the fold increase over untreated controls. Error bars represent ± SEM. *P < .05 compared with tBHQ alone.
