Effect of DMSO-induced differentiation of HL-60 cells onp40^phox mRNA expression and promoter function.

(A) Northern blot analysis of differentiating HL-60 cells. Cells were harvested after treatment with 1.25% DMSO for the indicated times, and total RNA was isolated. RNA (10 μg) was separated on a 1% agarose denaturing gel, transferred to nitrocellulose, and probed with a³²P-labeled p40^phox cDNA probe. For a loading control, the blot was stripped and reprobed with labeled cDNA of human acidic ribosomal phosphoprotein 36B4. (B) Effect of differentiation on p40^phox promoter function. HL-60 cells were transfected with pGL3-Basic, pGL3-p40-106, or pGL3-p40-106-PU.1Mt and were treated with DMSO for 38 hours before assay for luciferase activity. Data are the means (± SE) of 3 independent experiments.