Promotion of ERK and JNK in the MG-63 cells treated with HMGB1 under normoxia or hypoxia. (A and B) mRNA levels of extracellular signal-regulated kinases (ERK) (A) and c-Jun N-terminal kinases (JNK) (B) in MG-63 cells which were cultured under normoxia or hypoxia, and were treated with 0.2 μg/mL HMGB1 for 6, 12, 24 or 48 hours, under normoxia or under hypoxia, and then were examined with MTT assay. (C) Western blot analysis of ERK or phosphorylated ERK, of JNK or phosphorylated JNK in MG-63 cells under normoxia or hypoxia, treated with or without with 0.2 μg/mL HMGB1, for 24 or 48 hours, with tubulin as internal control; (D) Relative phosphorylated ERK or phosphorylated JNK to total ERK or total JNK in the HMGB1-treated MG-63 cells under normoxia or hypoxia. The data represent three independent experiments, and shown as Mean ± SE. *P < 0.05, **P < 0.01, ns: no significance.