Fig 6. Effect of cycloheximide on ERK-1/2 phosphorylation and MKP-1 expression.
The inhibition of ERK1/2 phosphorylation by NECA was blocked by 10 μg/ml of cycloheximide (CHX) suggesting that protein synthesis is mandatory for the NECA effect (A). Stimulation of A2B receptors in MDA-MB-231 with NECA cells causes and increase in MKP-1 expression (B), treatment with 1 μM forskolin shows the same effect (C). The increase caused by NECA is blocked by cycloheximide (D). Western blots show a representative experiment, the columns represent mean values from n = 7 (A), 4 (B), 7 (C), and 6 (D) independent experiments (* p < 0.001, significantly different from control).