Figure 5. Association between STAT3 and HMGB1.

A. Protein binding between HMGB1 and STAT3-P^Y705. Su-6 and Su-8 cell lines were treated with either IL-10 or HMGB1 for 4 hours. Proteins from cell extracts were precipitated with either a rabbit anti-STAT3-P^Y705 or a rabbit anti-HMGB1 antibodies. Rabbit IgG was used as a negative control. After Co-IP, blots were probed with a mouse anti-HMGB1 or a mouse anti-STAT3-P^Y705 antibodies, respectively. B. AG490-induced time- and dose-dependent HMGB1 release. Cells were either treated with 25 μM AG490 up to 24 hours or with different doses of AG490 for 24 hours. HMGB1 in the conditioned medium was determined by Western blotting. Numbers under each blot are ratios of M-HMGB1/BSA. C. Roles of IL-10 and AG490 on STAT3 activity and HMGB1 release. DLBCL cells were treated with IL-10 and or AG490 for 4 hours. Expression of STAT3-P^Y705 in the cell lysates and HMGB1 levels in the conditioned medium were determined by Western blotting.