Overexpression of Agrin promotes tumor proliferation and correlates with poor prognosis in cholangiocarcinoma

Abstract Background Agrin exists as a shorter Type II Transmembrane form with an internal signal peptide, and is closely correlated with the activation of multiple intercellular signaling pathways. The aim of the present study was to investigate the role of Agrin in the development of cholangiocarcinoma (CCA). Methods RT-qPCR and western blotting were performed to detect the expressional level of target genes, including Agrin, in CCA tissues or cell lines. The correlation between Agrin, and tumor characteristics and prognosis, was analyzed using independent sample t-test, the Kaplan-Meier method and Cox proportional hazard model, respectively. Proliferation, migration, invasion and tumorigenesis in CCA cells was determined by CCK8 assay, cell cycle detection, Transwell assay and nude mouse tumorigenicity assay, respectively. Results Agrin was significantly upregulated in CCA tissues, as compared to the adjacent non-tumor tissues, and was correlated with poorer tumor characteristics such as portal vein tumor thrombus, intrahepatic metastasis and poor survival. The Agrin overexpression in CCA cell lines clearly promoted proliferation, colony formation, migration, invasion and cell cycle progression, but Agrin knockdown had the opposite effect. Furthermore, CCA cells with inhibitory Agrin expression presented with less and smaller tumors, as compared with the control group in vivo. Mechanistic analysis indicated that Agrin was able to activate the Hippo signaling pathway and induce yap to enter the cell nucleus. Conclusions We found that Agrin promotes the CCA progression via activating the Hippo signaling pathway, which could be a potentially promising target for CCA treatment.