Abstract: Objective To investigate the abnormal expression of interferon-induced transmembrane protein 3 (IFITM3) in
hepatocellular carcinoma (HCC) and the effect of IFITM3 knock-down on the biological behaviors of hepatocellular carcinoma
HepG2 cells. Methods Western blot analysis and immunohistochemical staining were used to determine the expression of
IFITM3 protein in 60 HCC samples and paired adjacent tissues. A small interfering RNA fragments of IFITM3 (IFITM3 siRNA)
was transiently transfected into HepG2 cells and expressions of IFITM3 at mRNA and protein levels were examined by
qRT-PCR and Western blotting. The changes in the proliferation of the transfected cells were determined using cell counting
kit 8 (CCK8) assay, and the cell invasion and migration were tested using Transwell assay and wound-healing assay. Results
Compared with the adjacent tissues, HCC tissues expressed significantly higher levels of IFITM3. In HepG2 cells, transfection
with IFITM3 siRNA resulted in significant down-regulation of IFITM3 expression at both the protein and mRNA levels and
obviously suppressed cell proliferation, invasion, and migration ability as compared with the cells transfected with scrambled
siRNA and control cells (P<0.05). Conclusion IFITM3, which is overexpressed in HCC, plays a vital role in the proliferation
and invasion of HCC cells and may serve as a potential target for gene therapy of HCC.