FIGURE 2.

Regulatory effects of p38 MAPK and JNK pathways on ectopic expression of hMSH2 in oxidative stress. A and B, analysis of the phosphorylation (P-) of the p38 MAPK and JNK pathways in G401 cells at several time points after GO-mediated oxidative stress. β-Actin was used as the protein loading control (30 μg of total proteins/lane). C, expression of phospho-c-Jun in G401 cells treated with GO. Histone H3 was used as the protein loading control (30 μg of total proteins/lane). D, transcription of hMSH2 in G401 cells during oxidative stress in the presence or absence of the p38 MAPK pathway inhibitor (SB203580), the JNK pathway inhibitor (420119), or the MEK/ERK pathway inhibitor (U0126) was assessed by real-time RT-PCR. Data were normalized as -fold changes (mean ± S.D.) compared with the transcriptional level of hMSH2 in G401 cells without GO treatment. n = 5 independent experiments. *, p < 0.05. E and F, surface expression of hMSH2 on GO (100 ng/ml)-treated G401 cells in the presence or absence of p38 MAPK or JNK pathway inhibitor (n = 5 independent experiments). Error bars, S.D. *, p < 0.05. G–J, total expression of hMSH2 in GO (100 ng/ml)-stimulated G401 cells treated with or without specific inhibitors for the p38 MAPK (labeled as GO p38-) or JNK (displayed as GO JNK-) pathway (n = 4 independent experiments). Error bars, S.D. *, p < 0.05. K and L, total protein expression of hMSH2 in PX-12-stimulated G401 cells. Lane 1, positive control; lanes 2 and 3, expression of hMSH2 in G401 cells treated by PX-12 (50 μm) for 24 or 36 h, respectively (labeled as PX-12 24h and 36h). Lane 4, G401 cells treated with a combination of PX-12 (50 μm) and NAC (5 mm). Lane 5, normal control. M, ectopic expression of hMSH2 on G401 cells stimulated by PX-12 in the presence or absence of NAC (5.0 mm) or calyculin A (5.0 nm) for 36 h.