OBJECTIVETo detect the expression of interleukin-17A(IL-17A) in hepatocellular carcinoma (HCCs) tissues, and to analyze its relationship with clinicopathological characteristics and epithelial-mesenchymal transition (EMT).

METHODSThe expression of IL-17A, E-cadherin, vimentin proteins and Snail mRNA were detected by immunohistochemistry and in situ hybridization histochemistry in the hepatocellular carcinoma (HCC) tissues of 74 patients.

RESULTSIL-17A staining was detected in 54.1% (40/74) specimens of human HCCs, but only 25.0% (5/20) in corresponding peritumoral tissues (P<0.05). The positive rate of IL-17A expression in HCC patients with grade III+IV and UICC stage III+IV tumors was significantly higher than those with grade I+II and UICC stage I+II tumors. The expression of IL-17A was positively correlated with portal vein tumor thrombus and microvascular invasion (all P<0.05). The 1- and 2-year recurrence-free survival rates were 27.6% and 17.2% in the patients with positive IL-17A expression, but 79.3% and 58.5% in IL-17A-negative HCCs. The 1- and 2-year overall survival rates were 69.0% and 27.8% in the cases with positive IL-17A expression, while 91.3% and 87.0% in IL-17A-negative cases. Patients with IL-17A-positive HCCs showed significantly shorter recurrence-free and overall survival compared with the patients with IL-17A-negative HCCs (P<0.05). Multivariate analysis indicated that IL-17A expression was an independent factor for recurrence-free and overall survival of HCCs. IL-17A-positive HCCs were characterized by increased expression of vimentin (r=0.492, P<0.01) or Snail (r=0.410, P<0.05) and loss of E-cadherin expression (r=-0.404, P<0.05).

CONCLUSIONSOur results suggest that IL-17A is closely related to epithelial-mesenchymal transition in hepatocellular carcinoma. IL-17A-positive hepatocellular carcinoma demonstrates more aggressive biological behavior, and IL-17A may serve as a potential prognostic marker for this cancer.