The involvement of cell surface nucleolin in the initiation of CCR6 signaling in human hepatocellular carcinoma.

In recent years, the chemokine CC receptor 6 (CCR6) and its ligand CCL20 were reported to play an essential role in hepatocellular carcinoma (HCC). However, the role of cell surface nucleolin in the CCR6 pathway of HCC is not well featured. Using immunohistochemistry, Western blotting, siRNA, wound healing and transwell assay, we investigated the relationships of cell surface nucleolin and CCR6 signaling in HCC. In the present study, our findings identified that cell surface nucleolin and CCR6 protein were stained in most of HCC tissues (64, 68 %, respectively) and differently expressed in HCC cell lines; meanwhile, both expression has an association with advanced stage, lymph node metastasis and poor 5-year prognosis. According to in vitro assays, we found that the silencing of either cell surface nucleolin or CCR6 inhibited the protein expression of p-ERK, p-AKT, MMP2, MMP9 and ICAM-1 in the CCL20-stimulated HCCLM6 cells. Functional analysis revealed that cell surface nucleolin or CCR6 silencing significantly hampered HCCLM6 cell motility and invasiveness ability, when compared with control. In conclusion, this work suggests that cell surface nucleolin participates in the initiation of CCR6 pathway and biological behaviors of HCC, leading to HCC cell adhesion, migration and invasive behavior. In the clinical practice, cell surface nucleolin and CCR6 are recommended to predict poor prognosis and be used as a useful target for HCC patients.