Abstract:   Background and purpose: High mobility group 1 (HMGB1), frequently found to be overexpressed in many human tumors, plays an important role in tumor progress and metastasis. This study aimed to investigate the mechanism of HMGB1 promoting A549 cell metastasis. Methods: A549 cells were untreated or treated with HMGB1 (200 ng/mL) in absence or presence of NF-κB inhibitors 6-amino-4-quinazoline (QNZ, 40 nmol/L) or Bortezomib (Bort, 20 nmol/L). Scratch assay and Transwell assay were performed to evaluate A549 cells migration and invasion ability. The activity of NF-κB was examined by luciferase reporter assay. NF-κBp65 and αvβ3 expressions were detected by Real-time RT-PCR or Western blot. Results: HMGB1 increased A549 cells migration and invasion ability. HMGB1 enhanced NF-κB protein level and NF-κB activity in A549 cells. Real-time RT-PCR and Western blot showed that HMGB1 up-regulated αvβ3 expression in A549 cells. NF-κB inhibitors QNZ or Bort reserved the promoting effects of HMGB1 on A549 cells migration and invasion, NF-κB expression and activity as well as αvβ3 expression. Conclusion: HMGB1 promotes A549 cell migration and invasion through activating NF-κB and up-regulating αvβ3.

Key words:  High mobility group box 1, A549, Invation, NF-κB, αvβ3