Figure 4.

Overexpression of WT or mutant ERK3 does not affect lung cancer cell proliferation. A, an MTS cell proliferation assay was performed for A549 cells with stable overexpression of an empty vector or WT or mutant myc-ERK3 as described in Fig. 1C. Cell viability at different time points (days) was measured and expressed as A₄₉₀. B, an MTS cell proliferation assay was performed for H1299 cells with stable overexpression of an empty vector, WT, or mutant HA-ERK3 as indicated. Cell viability is expressed as A₄₉₀ normalized to values of day 1 for each condition. C,ERK3 overexpression and ERK3-Ser¹⁸⁹ phosphorylation in the generated H1299 stable cells were verified by Western blotting. Values represent mean ± S.D. (n ≥ 3). Statistical analysis was conducted to compare A₄₉₀ of the different cell lines at each time point by two-way ANOVA. No significant difference was detected between the cell lines at p < 0.05.