Chemokine ligand 18 (CCL18) has been associated with hepatocellular carcinoma (HCC) metastasis. Here, we demonstrated a novel mechanism through which CCL18 enhances cell migration, invasion, and epithelial-mesenchymal transition (EMT) in HCC. (1) Using immunohistochemistry, we analyzed the expression of PITPNM3, a molecule that correlated with CCL18 signaling, in 149 HCC tissue specimens. The results showed that PITPNM3 expression is highly associated with tumor metastasis and differentiation; (2) in vitro experiments showed that CCL18 enhances cell migration, invasion, and EMT in PITPNM3((+)) HCC cells but not in PITPNM3((-)) cells. Silencing of PITPNM3 by short interfering RNA (siRNA) inhibited the induction of cell migration, invasion, and EMT by CCL18; (3) Cell migration, invasion, and EMT induced by CCL18 accompanied with the phosphorylation of IKK and IKBα as well as p65 nuclear translocation in PITPNM3((+)) HCC cells, but not in the cells that PITPNM3 is silenced with siRNA, implying that the activation of NF-κB signaling is involved in the action of CCL18/PITPNM3. These results suggest that CCL18 enhances HCC cell migration, invasion, and EMT through the expression of PITPNM3 and the activation of the NF-κB signaling pathway.
Keywords: CCL18; EMT; HCC; Metastasis; NF-κB; PITPNM3.