Fig. 5.

Effect of the phosphatase inhibitor vanadate on the extracellular signal-regulated kinase-1/2 (ERK-1/2) phosphorylation and proliferation of immortalized HT22 cells. A : Cells were treated with 10 µM of vanadate for indicated times. Phosphorylation and expression of ERK-1/2 were examined by Western blot analysis, as described in materials and methods. Representative Western blots of three independent experiments are shown. B : Cells were treated with 0.5 µM of triptolide or 10 µM of vanadate for 24 h. Cell proliferation was determined by 3H-thymidine incorporation, as described in materials and methods. Values represent mean ± SE of four replicates in three different experiments. ^*p < 0.05 versus untreated control cells.