Downregulation of desmoglein 2 promotes EMT progression in gallbladder cancer

Abstract

Objective. To explore the correlation between the expression level of Desmoglein 2 (DSG2) and the epithelial-mesenchymal transition (EMT) progression in gallbladder cancer (GBC). Method. 106 GBC tissue specimens and corresponding clinical information were collected to make a tissue microarray. Immunohistochemical method was used to test the expression level of DSG2 in GBC tissues. DSG2 was knocked down in the GBC cell line GBC-SD to detect the change of its invasion and metastasis ability. Then RT-qPCR and Western Blot were applied on the DSG2-knocked down GBC-SD cells to detect the expression level change of genes associated with EMT. Result. The high expression rate of DSG2 was significantly correlated with the N, M and TNM staging of patients (P<0.05). Survival analysis identified that GBC patients with high DSG2 expression level had significantly better survival (P<0.05). To further investigate the potential mechanism of DSG2 on regulating GBC tumor progression, we used knockdown DSG2 on GBC-SD cell lines. The results showed that GBC-SD cell lines with DSG2 knockdown showed a promotion of cell invasion and metastatic ability. The mRNA levels of EMT-related genes E-Cadherin, Snail, Twist, ZEB1, and β-catenin, which is a key protein in the Wnt signaling pathway, were also significantly altered. Besides, protein levels of E-cadherin and Snail showed consistent results. Conclusion. The downregulation of DSG2 in gallbladder cancer is hypothesized to be associated with the invasion and metastasis progression of gallbladder cancer cells by regulating EMT-related pathways. Its expression level can be a novel biomarker for gallbladder cancer, providing new perspectives for diagnosis and treatment strategies.