cIAP2 promotes gallbladder cancer invasion and lymphangiogenesis by activating the NF‐κB pathway

Abstract Several studies have produced contradictory findings about the prognostic implications for inhibitor of apoptosis proteins (IAPs) in different types of cancer. Cellular inhibitor of apoptosis 2 (cIAP2/BIRC) is one of the most extensively characterized human IAPs. To date no studies have focused on the expression level of cIAP2 in human gallbladder cancer (GBC), and the mechanism of cIAP2 in GBC invasion and lymphangiogenesis remains unclear. Therefore, in the present study, cIAP2 expression in GBC was detected using qRT-PCR and immunohistochemistry, and the relationship between cIAP2 levels in cancer tissues and the clinicopathological characteristics of patients was analysed. The biological effect of cIAP2 in GBC cells was tested using the Cell Counting Kit-8 assay, transwell assays and the ability of human dermal lymphatic endothelial cells (HDLECs) to undergo tube formation. The role of cIAP2 in activating the NF-κB pathway was determined using a dual-luciferase reporter assay, immunofluorescence staining, Western blotting and ELISA. Finally, an animal model was used to further confirm the role of cIAP2 in lymphangiogenesis. We showed that cIAP2 expression was elevated in human GBC tissues and correlateed with a negative prognosis for patients. Moreover, cIAP2 was identified as a lymphangiogenic factor of GBC cells and thus promoted lymph node metastasis in GBC cells. Our study is the first to suggest that cIAP2 can promote GBC invasion and lymphangiogenesis by activating the NF-κB pathway. This article is protected by copyright. All rights reserved.