p38MAPK activity enhances COX-2 mRNA stability. A) Autoradiogram of Northern blot showing the effects of p38MAPK and PI3K/Akt inhibition on COX-2 mRNA degradation. Cells were stimulated with BBS for 4 h, and attenuated 4 μM actinomycin D was added (t = 0) alone or with SB203580 or LY294002 and total RNA isolated at 15, 30, 60, and 90 min. Blots were reprobed for 18S ribosomal RNA to ensure equivalent loading and transfer of total RNA in each lane. B) Graph of densitometric analysis of blot in panel A.