Figure 1: Effect of ERK5 knockdown using a siRNA-expressing vector on ERK5 and proliferation in U2OS cells. A: Real-time PCR showed decreased ERK5 mRNA expression in U2OS cells stably expressing a control or ERK5-specific siRNA 1 and 2. B: Western blot showed decreased ERK5 protein expression in U2OS cells stably expressing a control or ERK5-specific siRNA 1 and 2. C: Proliferation in U2OS cells stably expressing a control or ERK5- specific siRNA 1 and 2 by MTT assay (*P<0.05).