PEG10 is imperative for TGF-β1-induced epithelial‑mesenchymal transition in hepatocellular carcinoma

Substantial evidence indicates that transforming growth factor-beta 1 (TGF-β1) plays a vital role in epithelial-mesenchymal transition (EMT). PEG10 has been shown involved in invasion and metastasis of tumors. The present study investigated the role of PEG10 in TGF-β1-triggered EMT in hepatocellular carcinoma (HCC) progression. Immunohistochemistry and real-time PCR were used to measure the expression level of PEG10 in clinical HCC tissues with or without lymph node metastasis, and normal tissues. The results showed that PEG10 expression is higher in HCC tissues and associated with overall survival (OS) and lymph node metastasis. Moreover, PEG10 expression level was remarkably higher in hepatic cancer cells than the normal hepatic cell line L02. In the present study, we constructed an adenovirus vector containing the coding area of PEG10 (Ad-PEG10) and infected HepG2 cells and found that overexpression of PEG10 promoted the cell migration, invasion ability and EMT of HepG2 cells. TGF-β1 acted on HepG2 cells by enhancing cell migration, invasion, EMT and upregulating PEG10 expression level. However, cells pretreated with adenovirus vector of PEG10 shRNAs (Ad-shRNA1 and Ad-shRNA2) did not occur EMT prior to TGF-β1 stimulation. Moreover, TGF-β1 did not increase the migration and invasion of cells with PEG10 knockdown and overexpression of PEG10 confers chemoresistance to HepG2 cells. Accordingly, sufficient PEG10 expression level is essential for TGF-β1 induced EMT and associated with the chemoresistance in HepG2 cells.