Abstract: Objective To investigate the expression level of basic leucine zipper and W2 domain-containing protein 1 (BZW1) in gastric cancer, its impact on patient prognosis and the underlying mechanisms. Methods TIMER, UALCAN and Kaplan-Meier Plotter databases were used for analyzing BZW1 expression level gastric cancer tissues and its correlation with tumor grade and stage and the patients' prognosis. We further analyzed BZW1 expressions, disease progression, and postoperative 5-year survival in 102 patients undergoing radical surgery for gastric cancer at our hospital between January, 2014 and December, 2016. Gastric cancer MGC803 cells were examined for changes in migration, invasion, and epithelial-mesenchymal transition (EMT) following lentivirus-mediated BZW1 overexpression or knockdown. Results The protein and mRNA expressions of BZW1 in gastric cancer tissues were 3.30 and 6.54 times of those in adjacent tissues, respectively (P<0.01). BZW1 expression in gastric cancer tissues were positively correlated with peripheral blood CEA and CA199 levels (P<0.01). A high BZW1 expression was an independent risk factor for 5-year survival of gastric cancer patients after radical surgery (P<0.05, HR=2.070, 95%CI: 1.021-4.196). At the cut-off value of 3.61, BZW1 expression had a sensitivity of 75.56% and a specificity of 71.93% for predicting postoperative 5-year mortality (P<0.01). In MGC803 cells, BZW1 overexpression obviously promoted cell migration and invasion (P<0.05), enhanced cellular expressions of N-cadherin and vimentin (P<0.05) and inhibited the expression of E-cadherin (P<0.05). Enrichment analysis suggested the involvement of BZW1 in the Wnt/β-catenin signaling pathway. Western blotting confirmed that BZW1 overexpression promoted while BZW1 knockdown inhibited the expressions of Wnt3a, β-catenin and C-myc in MGC803 cells (P<0.05). Conclusion BZW1 is highly expressed in gastric cancer tissues to affect the patient prognosis possibly by activation the Wnt/β-catenin signaling pathway to promote EMT of gastric cancer cells.

Key words: gastric cancer; basic leucine zipper and W2 domain-containing protein 1; prognosis; epithelial-mesenchymal transition; Wnt/β-catenin