S100A8 facilitates cholangiocarcinoma metastasis via upregulation of VEGF through TLR4/NF-κB pathway activation

A growing body of evidence indicates that S100 calcium-binding protein A8 (S100A8) is frequently overexpressed in malignant tumor tissues and regulates tumor progression; however, the role of S100A8 in cholangiocarcinoma (CCA) remains unclear. The present study demonstrated that the protein expression of S100A8 was significantly higher in pathological tissues compared with adjacent normal tissues from patients with CCA. In addition, S100A8 expression was significantly associated with differentiation, lymph node metastasis and poor prognosis in patients following surgical resection of CCA. Furthermore, both in vitro and in vivo experiments revealed that overexpression of S100A6 promoted, while S100A8 knockdown attenuated, the migration and metastasis of CCA cells. Of note, the present results indicated that S100A8 promoted the CCA tumor cell-induced migration of vascular endothelial cells. Finally, S100A8 was demonstrated to positively regulate the expression of vascular endothelial growth factor (VEGF) in CCA cells, which was mediated by activation of the Toll-like receptor 4 (TLR4)/NF-κB pathway. In conclusion, the present study demonstrated that S100A8 had an important role in facilitating CCA cell migration and metastasis via upregulation of VEGF expression by activating the TLR4/NF-κB pathway. These findings may provide a novel target for CCA treatment.