Figure 4

Dex-stimulated p38 MAPK phosphorylation/activation is increased in revertant CEM clones. CEM-C1-15 (C1-15 resistant), CEM-C1-6 (C1-6 spontaneous sensitive revertant), and CEM-IV B9 (IV B9 hypomethylated sensitive revertant) were treated with ethanol vehicle (C) or 1 μM Dex (D) for 16 hours after which time whole cell lysates were analyzed using immunoblots with an antibody specific to phospho-p38 protein. Membranes were subsequently re-probed with an antibody recognizing total p38 protein. Illustrated is a representative blot of 4 independent experiments for IV B9 cells, all with similar results. C1-15 and C1-6 are included for comparison n = 4. We have previously published detailed analysis of the MAPK pathway in these CEM clones [17].