β-Arrestin 2 Accelerates Hepatocellular Carcinoma By Inhibiting AMPK Pathways

Objective: To detect the expression of β-arrestin2 in hepatocellular carcinoma(HCC),and to explore the effect of β-arrestin2 on the biological behavior of HCC cells,and study the preliminary mechanismMethods: Immunohistochemistry was used to detect the expression of β-arrestin2 in 20 cases of hepatocellular carcinoma and adjacent tissues.Western blot and q-PCR were carried out to detect the expression of β-arrestin2 in different HCC cells,Establish transient and stable expression of β-arrestin2 knockdown cells by small interfering RNA technique,and establish cell lines that stable overexpress β-arrestin2 by plasmid monoclonal selection technique.MTT assay was used to determine the cell proliferation of interfering,overexpressed and untreated HCC cell lines.Transwell assay was used to determine the migration and invasion ability of the treated and untreated HCC cell lines.The apoptosis of interfering cell lines was detected by the flow cytometry.The changes of AMPK and mTOR phosphorylation in hepatocellular carcinoma cell lines were assayed by the western blot,Student t-test was used to analyze the data.Results: Immunohistochemical results showed that β-arrestin2 was highly expressed in 17 cases of HCC and 6 cases of adjacent tissues,the difference was statistically significant(P <0.05),Western blot and qPCR showed that the protein expression of β-arrestin2 was significantly higher in hepatocellular carcinoma than in adjacent tissues.Suppression of ARRB2 inhibited cell proliferation,migration and invasion while overexpression of ARRB2 promoted it,Suppression of ARRB2 also induced the apoptosis of the HCC cells.The cells transfected with ARRB2-SiRNA accompanied by enhanced phosphorylation levels of AMP-activated protein kinase(AMPK),and the p-mTOR was decreased.What’s more,suppression of ARRB2 accompanied by high expression of AMPK enhanced the acetylation and stability of p53 in HCC cell lines with wild-type p53.Conclusions: β-arrestin2 can promote the proliferation,migration and invasion of hepatocellular carcinoma cells.The knockdown of β-arresting2 can increase the apoptosis of hepatocellular carcinoma cells,Its mechanism may be related to inhibition of AMPK signal pathway.This study suggests ARRB2 plays a critical role in HCC progression and downregulation of it has promising anti-tumor effects in HCC.