Published online Jan 14, 2015. doi: 10.3748/wjg.v21.i2.475
Peer-review started: April 21, 2014
First decision: May 13, 2014
Revised: June 8, 2014
Accepted: July 11, 2014
Article in press: July 11, 2014
Published online: January 14, 2015
AIM: To identify the mechanisms of chemokine ligand 20 (CCL20)-induced hepatocellular carcinoma (HCC) metastasis and evaluate it as a prognostic marker.
METHODS: Expression of CCL20 was evaluated by immunohistochemistry in HCC tissues from 62 patients who underwent curative resection. The relationship between CCL20 expression and clinicopathologic features was analyzed. Univariate and multivariate analyses were performed to evaluate its predictive value for recurrence and survival of HCC patients. The expression levels of epithelial-mesenchymal transition (EMT)-and signaling pathway-related proteins were evaluated by Western blotting and immunocytochemistry. The effects of CCL20 on HCC cell proliferation and migration were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenoltetrazolium bromide (MTT) and Transwell assays.
RESULTS: CCL20 immunoreactivity was detected in all 62 patient specimens. CCL20 expression was associated with preoperative alpha-fetoprotein level (P = 0.043), tumor size (P = 0.000), tumor number (P = 0.008), vascular invasion (P = 0.014), and tumor differentiation (P = 0.007). Patients with high CCL20 expression had poorer recurrence-free and overall survivals compared to those with low CCL20 expression (both P < 0.001). CCL20 induced EMT-like changes in HCC cells and increased their proliferation and migration ability (P < 0.05). Western blotting and immunofluorescence staining showed that CCL20 induced an EMT-like phenotype in HCC cells, and increased expression of phosphorylated AKT, β-catenin and vimentin, and decreased E-cadherin expression (P < 0.05). The correlation analysis revealed that high CCL20 expression in HCC tissue specimens was negatively correlated with E-cadherin expression (13.33%, 4/30), and positively correlated with vimentin (90.0%, 27/30), β-catenin (96.67%, 29/30) and p-AKT (76.67%, 23/30) expression.
CONCLUSION: CCL20 expression is associated with HCC recurrence and patient survival and promotes HCC cell proliferation and migration by inducing EMT-like changes via PI3K/AKT and Wnt/β-catenin pathways.
Core tip: This study examined the expression and prognostic value of chemokine ligand 20 in hepatocellular carcinoma. The results indicate that increased expression of this protein regulates the growth and migration of hepatocellular carcinoma cells and epithelial-mesenchymal transition via phosphoinositide kinase-3/AKT, and Wnt/β-catenin signaling pathways and is therefore a potential treatment target.