Figure 3: PK2 expression and oxidative stress in GC-2 cells. GC-2 cells were cocultured with various concentrations of H2O2(0, 200, 400, and 600 μmol l−1) for 6 h. (a) The basal expression levels of PK2 and PKR1 in GC-2 cells were determined by immunofluorescence. The scale bars represent 100 μm. (b) The viability of GC-2 cells in the different groups was determined by CCK8 assay. (c) Alterations in the mRNA expression of PK2 in GC-2 cells in the different groups were determined by qPCR. (d) Alteration of the protein expression of PK2 in GC-2 cells in the different groups was analyzed by Western blot. All experiments were replicated in three independent experiments from different cell samples. Each treatment group was compared with the control group, *P < 0.05, **P < 0.01, ***P < 0.001 (one-way ANOVA). PK2: prokineticin 2; PKR1: prokineticin receptor 1; qPCR: quantitative real-time PCR assays; ANOVA: analysis of variance.