Figure 3.

Effect of PGE₂ on DNMT activity and expression. A, B) IMR-90 cells (n=4–6; A) and adult lung fibroblasts (n=3; B) were treated for 48 h with the indicated concentrations of PGE₂ and assayed for nuclear DNMT activity, as described in Materials and Methods. C, D) DNMT1, DNMT3a, and DNMT3b mRNA levels in IMR-90 fibroblasts (n=6; C) and adult lung fibroblasts (n=4; D) treated for 24 h with the indicated concentrations of PGE₂ were assayed by quantitative real-time RT-PCR. DNMT mRNA levels were normalized to β-actin and are expressed as fold change relative to no PGE₂-treatment controls. E, F) DNMT1, DNMT3a, and DNMT3b protein expression in IMR-90 cells (n=4; E) and adult lung fibroblasts (n=3; F) treated for 48 h with varying concentrations of PGE₂ were assayed by immunoblot analysis. Top panels: representative immunoblots. Bottom panels: fold change in expression based on mean densitometric analysis, normalized to α-tubulin. All results are expressed as means ± se. *P < 0.05.