EDIL3 is a novel regulator of epithelial-mesenchymal transition controlling early recurrence of hepatocellular carcinoma.

BACKGROUND & AIMS: Patients with advanced hepatocellular carcinoma (HCC) continue to have a dismal prognosis. Early recurrence, metastases and angiogenesis are the major obstacles to improve the outcome of HCC. Epithelial-mesenchymal transition (EMT) is a key contributor to cancer metastasis and recurrence, which are the major obstacles to improve prognosis of HCC. METHODS: Combining gene expression profiles of HCC samples with or without early recurrence and established cell lines with epithelial or mesenchymal phenotype, EDIL3 was identified as a novel regulator of EMT. The expression of EDIL3 was evaluated by quantitative PCR, Western blotting or immunohistochemistry. The effects of EDIL3 on the angiogenesis and metastasis of HCC cells were examined by wound healing, Matrigel invasion and tube formation assay in vitro and orthotopic xenograft mouse model of HCC in vivo. The signaling pathways of EDIL3 mediated were investigated through microarray and Western blotting analysis. RESULTS: EDIL3 was identified as a novel regulator of EMT, which contributes to angiogenesis, metastasis and recurrence of HCC. EDIL3 induces EMT and promotes HCC migration, invasion and angiogenesis in vitro. Mechanistically, overexpression of EDIL3, which was regulated by the downregulation of miR-137 in HCC, triggered the activation of ERK and TGF-ß signaling through interactions with αvß3 integrin. Blocking ERK and TGF-ß signaling overcomes EDIL3 induced angiogenesis and invasion. Using the orthotopic xenograft mouse model of HCC, we demonstrated that EDIL3 enhanced the tumorigenic, metastatic and angiogenesis potential of HCC in vivo. CONCLUSIONS: EDIL3-mediated activation of TGF-ß and ERK signaling could provide therapeutic implications for HCC.