Significant increase of a series of antioxidants in HL60/LR cells compared with parental HL60. (A) Comparison of mRNA expression of antioxidant genes in HL60 and HL60/LR cells by real-time PCR analysis. Numbers indicate fold increase in HL60/LR cells. Bars represent mean ± SD from 3 experiments. GCLC indicates glutamate-cysteine ligase, catalytic subunit; and GCLM, glutamate-cysteine ligase, modifier subunit. (B) Cell lysates of HL60 and HL60/LR were analyzed for the indicated antioxidant protein expression using immunoblot assay. β-Actin was used as loading control. (C) Increase of cellular GSH level in HL60/LR cells. Bars represent mean ± SD from 3 experiments. *P < .01 (Student t test). (D) HL60 cells were treated with 1μM vorinostat (Vor) for 18 hours, and cells were labeled with Het for 1 hour followed by flow cytometric analysis to detect O2− levels. Ctrl indicates control cells without treatment. (E-F) Representative histograms of significant decrease of O2− and H2O2 levels in HL60/LR cells versus HL60 as detected by fluorescent probe Het and DCF-DA, respectively.
