OBJECTIVETo gain insights into the role of forkhead box protein 3 (Foxp3) in the pathogenesis of hepatocellular carcinoma (HCC) by performing a comparative analysis of Foxp3 mRNA expression and promoter methylation status in HCC and normal liver tissues.

METHODSThirty-nine HCC and 13 normal liver tissue specimens were evaluated by real-time quantitative PCR and pyrosequencing to measure the expression of Foxp3 mRNA and determine the methylation status of its promoter, respectively. Statistical analyses of the data were conducted by rank-sum test and Spearman's rank correlation coefficient test.

RESULTSThe HCC specimens showed significantly higher mRNA expression of Foxp3 (vs. normal liver tissues, Z =-2.770, P =0.0056). Moreover, the HCC specimens showed significant hypomethylation of the Foxp3 promoter site A (vs. normal liver tissues, Z =2.118, P =0.0339), and the Foxp3 mRNA level was negatively correlated with the methylation of site A (rs =-0.344, P =0.046). None of the other four sites in the Foxp3 promoter showed a significant difference in methylation, and the overall methylation was not significantly different between the HCC and normal liver tissues.

CONCLUSIONOverexpression and low methylation of Foxp3 may be involved in the oncogenic and progression processes of HCC.