FIGURE 3.

PGE₂-induces activation of CREB, AP-1 and NF-κB transcription factors in PMKs. PMKs were incubated with vehicle (control, lane 2) or with PGE₂ (10 µM) (lanes 3–7) for 15 min. To demonstrate the effect of phamacological inhibitors on PGE₂-induced transcription factor-binding, PMKs were treated with PD98059, AG1478, H-89 or wortmannin for 30 min prior to PGE₂ treatment. Nuclear extracts were subjected to electrophoretic mobility shift assay analysis, as described in experimental procedures. A. PGE₂-induced CREB activation in PMKs. The arrow indicates the specific binding of CREB to its consensus oligonucleotide. B. PGE₂-induced AP-1 activation in PMKs. The arrow indicates the specific binding of AP-1 to its consensus oligonucleotide. C. PGE₂-induced NF-κB activation in PMKs. The arrows indicate the specific binding of NF-κB to its consensus oligonucleotide (upper arrow) and non-specific (ns) binding (lower arrow). D. EGFR, ERK1/2, PKA/CREB and PI3-K/Akt signaling cascades are involved in PGE₂-stimulated cell proliferation. PMKs were treated with various kinase inhibitors 30 min prior to PGE₂ (10 µM) treatment for 20 h and pulsed with (³H)-thymidine 2 h before harvest. The (³H)-thymidine incorporated by PMKs was measured in triplicate samples and normalized to protein concentration as described in experimental procedures. Representative data from at least 2 independent experiments are presented as the means ± SD. *p<0.05, significant when compared to vehicle-treated groups and #p<0.05, significant when compared to PGE₂-treated groups.