Highly expressed UNC119 promotes hepatocellular carcinoma cell proliferation through Wnt/β-catenin signaling and predicts a poor prognosis.

UNC119, also known as Retinal Protein 4 (HRG4) is significantly up-regulated in hepatocellular carcinoma (HCC) tissues. However, the clinical significance of UNC119 and its biological roles and associated mechanisms in HCC tumorigenesis remain unknown. In current study, quantitative real-time PCR, western bolt and immunohistochemical analyses were applied to evaluate the expression of UNC119 in HCC tissues and cell lines. The roles of UNC119 in cell proliferation, cell growth and cell cycle were analyzed by both loss- and gain-function assays in vitro and in vivo. Luciferase reporter assays and western blot were employed to investigate the mechanisms. We found that compared with normal liver, UNC119 is highly expressed in HCC tissues both in published GSE datasets and in our fresh or TMA tissues. We further found that highly expressed UNC119 is not only closely correlated with liver cirrhosis, tumor size and TNM stage but also predicts a poor prognosis of patients. Cellular function assays reveal that UNC119 promotes cell proliferation. In addition, it might through enhancing the activity of Wnt/β-catenin signaling to promote the progression of cell cycle and ultimate promotes cell proliferation and growth. Taken together, we found that UNC119 is commonly highly expressed HCC tissues and the expression pattern makes a difference in the prognosis of patients. Furthermore, it promotes cell proliferation and growth through Wnt/β-catenin signaling.