Kurarinol restrains non-alcoholic fatty liver disease-associated hepatocellular carcinoma (HCC) progression by suppressing EGFR signaling

Abstract

Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome and a key factor for hepatocellular carcinoma (HCC) development. As a metabolic hepatic damage, there is still a lack of efficient therapy for NAFLD-HCC. Kurarinol (KUR) is a flavanone extracted from the root of Sophora flavescens, and exerts excellent hepatoprotective and lipid-lowering activities. But its potential on NAFLD-HCC still remains unclear, and thus was explored in our present study. Firstly, in vitro experiments revealed that KUR treatments markedly reduced lipid deposition and inflammatory response in hepatocytes under palmitate and oleic acid stimulation (PO) with decreased expression levels of fatty acid synthesis markers including fatty acid synthase (FASN), stearoyl-CoA desaturase-1 (SCD1) and sterol receptor element binding protein-1 (SREBP-1). Importantly, the proliferation of HCC cell lines was strongly limited by KUR in a dose-dependent manner. Of note, PO stimulation accelerated the proliferative capacity of HCC cells, whereas being significantly suppressed by KUR. Mechanistically, we found that epidermal growth factor receptor (EGFR) and its phosphorylation protein expression levels were highly down-regulated in hepatocytes and HCC cell lines under PO stimuli. More importantly, the functions of KUR to restrain lipid accumulation and HCC cell proliferation were diminished upon EGFR overexpression, confirming that EGFR suppression was necessary for KUR to treat NAFLD-HCC. Murine mouse models were finally established by the use of diethylnitrosamine (DEN) with high-fat/high-cholesterol diet (HFHC) feeding to determine the role of KUR in NAFLD-HCC. Oral gavage of KUR efficiently suppressed NAFLD-HCC formation in mice, as evidenced by the decreased tumor number and loading. KUR also ameliorated lipid accumulation, liver dysfunction, fibrosis and HCC cell proliferation in DEN/HFHC-challenged mice, along with decreased EGFR expression. Collectively, KUR may be an effective strategy for NAFLD-HCC prevention via EGFR signaling suppression.