Abstract: Objective To investigate the role of HMGB1 in epithelial-mesenchymal transition. Methods Specific siRNA of HMGB1 were designed and synthesized. Cultured typeⅡ alveolar epithelial cell line-A549 cells were divided into 4 groups: (1) control group, (2) model group induced by TGF-β1, (3) HMGB1 RNAi group, (4) RNAi negative control group. Cellular morphology changes were observed by phase-contrast microscope. HMGB1 and α-SMA expression in A549 cells was detected by RT-PCR and Western blotting respectively. Results mRNA and protein expression of HMGB1 and α-SMA in TGF-β1 group increased significantly than that in normal control group(P＜0.01). Both of HMGB1 and α-SMA mRNA and protein expression in siRNA-treated cells were decreased significantly compared with that in TGF-β1 group (P<0.01). Conclusions HMGB1 may participate in the TGF- β 1 induced EMT．

Key words: Key words: RNAi, High mobility group B1, α-smooth muscle actin, epithelial-mesenchymal transition