Clonorchis sinensis granulin promotes malignant transformation of human biliary epithelial cells by interacting with M2 macrophages via regulating STAT3 phosphorylation and MEK/ERK pathway

Abstract Objective Clonorchis sinensisgranulin (CsGRN) is a multifunctional growth factor that can promote the progression of cholangiocarcinoma (CCA). Here, we investigated the effect of CsGRN on human biliary epithelial cells (HIBECs) malignant transformation and its possible underlying mechanism. Methods HIBECs were treated with 10μg/ml of CsGRN recombinant proteins and 20 μg CsGRN recombinant plasmid was intravenously injected into each BALB/c wild-type mice. EdU-488 staining, colony formation assay, wound-healing assay, transwell assay, Western-blot, q-PCR, Immunohistochemistry staining, Immunofluorescence, H&E staining. flow cytometry and ELISA assay were carried out. Results CsGRN promoted excessive hyperplasia and abnormal metastasis of HIBECs by enhanced secretion of hepatic pro-inflammatory cytokines and chemokines as well as biliary injuries. In addition, CsGRN induced the M2-type polarization in macrophages both in vitro and in vivo. In addition, high expression of IL-6 was observed in the CsGRN treated co-cultured mediums, which activated the phosphorylation of STAT3, JAK2, MEK and ERK. Conclusion CsGRN induced the M2-type polarization of macrophages which further mediate the inflammation and malignant transformation of HIBECs by mediating the interactions between HIBECs and macrophages via IL-6/JAK2/STAT3 and MEK/ERK pathways.