CCL16 inhibits tumor proliferation and metastasis in HCC by impacting CK19 phenotype.

BACKGROUND AND AIMS

Cytokeratin 19-positive (CK19+) hepatocellular carcinoma (HCC) is an aggressive subtype with poor outcomes. The initiation and development of CK19+ HCC in the background of liver cirrhosis remains unclear. This study investigated the role of the cirrhosis-related gene C-C motif chemokine ligand 16 (CCL16) in the development of CK19+ HCC.

METHODS

Datasets from Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) were analyzed to screen and validate the genes associated with CK19+ HCC. A total of 102 HCC patients were included for tissue microarray analysis. Gain-of-function experiments were conducted to investigate the biological functions of CCL16. CIBERSORT was used to investigate the correlation of CCL16 and immune infiltration.

RESULTS

GEO dataset analysis showed that CK19+ HCC had lower expression of CCL16. In both TCGA dataset and our HCC cohort, CCL16 expression was negatively correlated with CK19 expression ( ​< ​0.05) and its expression was higher in para-tumor than tumor tissues ( ​< ​0.001). Moreover, low CCL16 expression was related to advanced stage and poor overall survival ( ​< ​0.05). CCL16 overexpression downregulated CK19 expression and impacted the sphere formation ability of HCC cells. Overexpression of CCL16 inhibited the cell proliferation, migration, and invasion of HCC cell lines. Immune analysis showed HCC with high CCL16 expression had more infiltration of mast cells. HCC patients with both low CCL16 expression and low mast cells had the worst prognosis ( ​< ​0.001).

CONCLUSION

Our data indicated that CCL16 downregulated the expression of CK19 and inhibited the malignant phenotype of HCC.