MicroRNAs (miRNAs) have been reported to be involved in tumor metastasis. In this study, we investigated the function of miR-506 in the metastasis of human hepatocellular carcinoma (HCC). We found that miR-506 is significantly downregulated in the primary tissue of metastatic HCC and in highly metastatic HCC cell lines. Overexpression of miR-506 suppressed HCC cell migration, invasion, and metastasis both in vitro and in vivo. Furthermore, miR-506 was found to specifically target the 3' untranslated region (3'-UTR) of interleukin 8 (IL8) mRNA. Spearman's correlation analysis revealed that miR-506 expression inversely correlated with IL8 mRNA and protein expression in HCC tissue samples. IL8 treatment reversed miR-506-induced suppression of HCC cell migration and invasiveness. Thus, miR-506 acts as a tumor suppressor that may inhibit the migration, invasiveness, and metastasis of HCC cells by targeting IL8.
Keywords: IL8; hepatocellular carcinoma; invasion; metastasis; miR-506.