ABSTRACT
@#Objective:To explore the mechanism by which SRY-related high mobility group-box 9 (SOX9) promotes the epithelial mesenchymal transition (EMT) of non-small cell lung cancer (NSCLC) A549 cells via the Wnt/β-catenin pathway. Methods: The human NSCLCA549 cell line was divided into three groups: OE-NC group, OE-SOX9 group and OE-SOX9+XAV-939 group. The cells in OESOX9 group were transfected with SOX9 pcDNA plasmid to up-regulate the expression level of SOX9; The cells in OE-SOX9+XAV939 group were transfected with SOX9 pcDNA plasmid while the β-catenin inhibitor XAV-939 (1.0 μmol/L) was added to the medium. qPCR was used to detect SOX9 mRNA levels; CCK-8 was used to examine the proliferation of A549 cells; Wound-healing assay and Transwell chamber assay were used to detect the migration and invasion ofA549 cells, respectively; and WB was used to detect protein expressions of SOX9, β-catenin, E-cadherin, γ-catenin, N-cadherin and vimentin. Results: The mRNA and protein levels of SOX9 in OE-SOX9 group and OE-SOX9+XAV-939 group were significantly higher than those in the OE-NC group after transfection (all P< 0.05), while there was no significant difference between the OE-SOX9 group and the OE-SOX9+XAV-939 group (P>0.05). The proliferation, migration and invasion of cells in OE-SOX9 group were significantly higher than those in OE-NC group; however, those abilities in OE-SOX9+XAV-939 group were significantly lower than those in OE-SOX9 group (all P<0.05). The level of β-catenin protein in OE-SOX9 group was significantly higher than that in the OE-NC group, while the level of β-catenin protein in OE-SOX9+XAV-939 group was lower than that in OE-SOX9 group (all P<0.05). Compared with the OE-NC group, the levels of phenotypic markers of epithelial cells, E-cadherin and γ-catenin, were down-regulated, and the phenotypic markers of mesenchymal cells, N-cadherin and vimentin, were up-regulated in cells of OE-SOX9 group; however, E-cadherin and γ-catenin were higher, and N-cadherin and vimentin were lower in OE-SOX9+XAV-939 group than those in OE-SOX9 group (all P<0.05). Conclusion: SOX9 could promote proliferation, migration and EMT of NSCLCA549 cells by activating the Wnt/β-catenin pathway. ··