FIG. 1.

JNK signaling is involved in Cr(VI)-induced cell death in JB6 cells. (A) JB6 cells were incubated with Na₂Cr₂O₇ at various concentrations (0–10μM) for 24 h. (B) Cells were exposed to 10μM Na₂Cr₂O₇ for various times (0–48 h). Protein lysates were analyzed by a NuPAGE Bis-Tris electrophoresis system, and the levels of phosphorylated JNK and total JNK were detected by Western blot analysis. JB6 cells were transfected with si-RNAs specific to JNK1 or JNK2. After 24 h incubation, they were exposed to 10μM Na₂Cr₂O₇. Finally, the protein levels were analyzed by Western blot at 24 h (C), and MTT assay was performed at 48 h (D). β-Actin and GAPDH were used as control protein and control transfection, respectively. The results are shown as the mean ± SE of three separate experiments. *p < 0.05 and **p < 0.01 versus the Na₂Cr₂O₇ treatment alone (ANOVA, Scheffe's test).