Background: Circular RNAs (circRNAs) play a critical regulatory role in cancer progression. However, the underlying mechanisms of circRNAs in hepatocellular carcinoma (HCC) metastasis remain mostly unknown. Methods: Has_circ_0003998 (circ0003998) was identified by RNAs sequencing in HCC patients with /without portal vein tumor thrombus (PVTT) metastasis. The expression level of circ0003998 was further detected by in situ hybridization on tissues microarray (ISH-TMA) and qRT-PCR in 25 HCC patients with PVTT metastasis. Moreover, the 25 HCC patients with PVTT metastasis and 50 HCC patients without PVTT metastasis were recruited together to analyze the correlation between circ0003998 expression and HCC clinical characteristics. Transwell, migration and CCK8 assays, as well as nude mice model of lung or liver metastasis were used to evaluate the role of circ0003998 in epithelial to mesenchymal transition (EMT) in HCC. The regulatory mechanisms of circ0003998 in miR-143-3p and PCBP1 were determined by dual-luciferase reporter assay, nuclear-cytoplasmic fractionation, fluorescent in situ hybridization, RNA pull- down, microRNA sequence, western blot and RNA immunoprecipitation. Results: Compared with adjacent normal liver tissues (ANL), circ0003998 expression was significantly upregulated in PVTT tissues and HCC tissues, and its expression correlates with the aggressive characteristics of HCC patients. Further assays suggested that circ0003998 promoted EMT of HCC both in vitro and in vivo. Mechanistically, our data indicated that circ0003998 may act as a ceRNA (competing endogenous RNA) of microRNA-143-3p to relieve the repressive effect on EMT-related stimulator, FOSL2; meanwhile, circ0003998 could bind with PCBP1-poly(rC) binding protein 1 (PCBP1) to increase the expression level of EMT-related genes, CD44v6. Conclusion: Circ0003998 promotes EMT of HCC by circ0003998/miR-143-3p/FOSL2 axis and circ0003998 /PCBP1/CD44v6 axis.

Given the adverse effects of drugs used for NAFLD treatment, identifying novel and effective natural compound to prevent NAFLD is urgently needed. In the present study, the effects of phytosterol esters (PSEs) on NAFLD were explored. Adult SD rats were randomized into five groups: normal chow diet (NC), high-fat diet (HF), low-, medium- and high-dose PSE treatment plus high-fat diet groups (PSEL, PSEM, and PSEH). Our results showed that the levels of LDL-C in the PSEL group and hepatic TG, TC, and FFA in the three PSEs groups were significantly decreased. Notably, the uric acid (UA) level was significantly decreased by PSEs intervention. The hepatic inflammatory stress was ameliorated via the inhibition of the cytokines, including TGF-β, IL-6, IL-10 and CRP in the PSEs intervention groups. Further, the oxidative status was improved by PSE treatment through adjusting the enzyme activity (SOD and XOD) and decreasing the MDA level. These beneficial effects of PSE may have been partly due to its regulation on the expression of TGF-β1, TGF-β2, TNF-α, UCP-2, PPAR-α and PPAR-γ in hepatic tissue at both mRNA and protein level. The results of this study suggest that PSEs may be used as therapeutic agents for the prevention and progression of NAFLD and that hyperuricemia is induced by high-fat diet consumption.

The aim of this study was to investigate the combined effect of n-3 fatty acids (EPA and DHA, at an EPA:DHA ratio of 150:500) and phytosterol esters (PS) on non-alcoholic fatty liver disease (NAFLD) patients. We conducted a randomised, double-blind, placebo-controlled trial. Ninety-six NAFLD subjects were randomly assigned to the following groups: the PS group (receiving 3·3 g/d PS); the FO group (receiving 450 mg EPA + 1500 mg DHA/d); the PS + FO combination group (receiving 3·3 g/d PS and 450 mg EPA + 1500 mg DHA/d) and the PO group (a placebo group). The baseline clinical characteristics of the four groups were similar. The primary outcome was liver:spleen attenuation ratio (L:S ratio). The percentage increase in liver–spleen attenuation (≤1) in the PS + FO group was 36 % (P = 0·083), higher than those in the other three groups (PS group, 11 %, P = 0·519; FO group, 18 %, P = 0·071; PO group, 15 %, P = 0·436). Compared with baseline, transforming growth factor-β (TGF-β) was significantly decreased in the three study groups at the end of the trial (PS, P = 0·000; FO, P = 0·002; PS + FO, P = 0·001) and TNF-α was significantly decreased in the FO group (P = 0·036), PS + FO group (P = 0·005) and PO group (P = 0·032) at the end of the intervention. Notably, TGF-β was reduced significantly more in the PS + FO group than in the PO group (P = 0·032). The TAG and total cholesterol levels of the PS + FO group were reduced by 11·57 and 9·55 %, respectively. In conclusion, co-supplementation of PS and EPA + DHA could increase the effectiveness of treatment for hepatic steatosis.