Sodium-glucose cotransporter 2 inhibitors (SGLT2-Is) comprise a new class of antidiabetic agents that inhibit glucose reabsorption in the renal proximal tubules. Although a recent report demonstrated the potential ability of SGLT2-Is to attenuate cancer growth of SGLT2-expressing cancer cells, little is known about the effects of SGLT2-Is on hepatocellular carcinoma (HCC). Here, we investigate the anti-cancer properties of a SGLT2-I, canagliflozin, against human liver cancer cells. SGTL2 mRNA and protein expression were detected in Huh7 and HepG2 cells, although not in HLE as well as primary human hepatocytes and hepatic stellate cells. Canagliflozin exerted antiproliferative effects on SGLT2-expressing Huh7 and HepG2 cells in a dose-dependent manner by inhibiting glycolytic metabolism including glucose uptake, lactate and intracellular ATP production. This agent also induced G2/M arrest and apoptosis with inhibited phosphorylation of ERK, p38 and AKT and cleavage of caspase3. Xenograft tumor growth assay showed that oral administration of canagliflozin (10 mg/kg/day) significantly reduced subcutaneous tumor burdens in a glycemic status-independent manner, and attenuated intratumor vascularization in Huh7- and HepG2-derived xenograft tumors in BALB/c nude mice. In vitro, canagliflozin suppressed the increased human umbilical vein endothelial cell (HUVEC) proliferation and tubular formation which were observed in Huh7 or HepG2 co-cultures. By contrast, canagliflozin had no effect on tumor growth and intratumor angiogenesis in SGLT2-null HLE-derived xenograft models. These results indicate that SGLT2-I therapy is a potential new strategy for the treatment of HCC.

Nonalcoholic steatohepatitis (NASH) may cause fibrosis, cirrhosis, and hepatocellular carcinoma (HCC); however, the exact mechanism of disease progression is not fully understood. Angiogenesis has been shown to play an important role in the progression of chronic liver disease. The aim of this study was to elucidate the role of angiogenesis in the development of liver fibrosis and hepatocarcinogenesis in NASH. Zucker rats, which naturally develop leptin receptor mutations, and their lean littermate rats were fed a choline-deficient, amino acid-defined diet. Both Zucker and littermate rats showed marked steatohepatitis and elevation of oxidative stress markers (e.g., thiobarbital acid reactive substances and 8-hydroxydeoxyguanosine). In sharp contrast, liver fibrosis, glutathione-S-transferase placental form (GST-P)-positive preneoplastic lesions, and HCC developed in littermate rats but not in Zucker rats. Hepatic neovascularization and the expression of vascular endothelial growth factor (VEGF), a potent angiogenic factor, only increased in littermate rats, almost in parallel with fibrogenesis and carcinogenesis. The CD31-immunopositive neovessels were mainly localized either along the fibrotic septa or in the GST-P-positive lesions. Our in vitro study revealed that leptin exerted a proangiogenic activity in the presence of VEGF. In conclusion, these results suggest that leptin-mediated neovascularization coordinated with VEGF plays an important role in the development of liver fibrosis and hepatocarcinogenesis in NASH. Supplementary material for this article can be found on the HEPATOLOGY website

The relative contribution of hepatocyte growth factor (HGF)/MET and epidermal growth factor (EGF)/EGF receptor (EGFR), two key signal transduction systems in the normal and diseased liver, to fate decisions of adult hepatic progenitor cells (HPCs) has not been resolved. Here, we developed a robust culture system that permitted expansion and genetic manipulation of cells capable of multilineage differentiation in vitro and in vivo to examine the individual roles of HGF/MET and EGF/EGFR in HPC self-renewal and binary cell fate decision. By employing loss-of-function and rescue experiments in vitro, we showed that both receptors collaborate to increase the selfrenewal of HPCs through activation of the extracellular signal-regulated kinase (ERK) pathway. MET was a strong inducer of hepatocyte differentiation by activating AKT and signal transducer and activator of transcription (STAT3). Conversely, EGFR selectively induced NOTCH1 to promote cholangiocyte specification and branching morphogenesis while concomitantly suppressing hepatocyte commitment. Furthermore, unlike the deleterious effects of MET deletion, the liver-specific conditional loss of Egfr facilitated rather than suppressed progenitormediated liver regeneration by switching progenitor cell differentiation toward hepatocyte lineage. These data provide new insight into the mechanisms regulating the stemness properties of adult HPCs and reveal a previously unrecognized link between EGFR and NOTCH1 in directing cholangiocyte differentiation.

DPP4-I markedly inhibits liver fibrosis development in rats via suppression of HSCs proliferation and collagen synthesis. These suppressive effects are associated with dephosphorylation of ERK1/2, p38 and Smad2/3 in the HSCs. Since DPP4-I is widely used in clinical practice, this drug may represent a potential new therapeutic strategy against liver fibrosis in the near future.

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Abstract. Insulin resistance (IR) is reportedly involved in the progression of hepatocellular carcinoma (HCC). Since neovascularization plays an important role in hepatocarcinogenesis and IR, an angiostatic therapy may be considered as one of the promising approaches for chemoprevention against HCC. The aim of the current study was to examine the combination effect of a clinically used branched-chain amino acid (BCAA) and an angiotensin-converting enzyme inhibitor (ACE-I), both reportedly possess anti-angiogenic and IR-improving activities, on the cumulative recurrence after curative therapy. BCAA granules (Livact; 12 g/day) and/or ACE-I (perindopril; 4 mg/day) were administered after the curative therapy for HCC, and several indices were analyzed. A 48-month followup revealed that the combination treatment with BCAA and ACE-I markedly inhibited the cumulative recurrence of HCC under IR conditions, whereas neither single treatment exerted a significant inhibition. The soluble form of the vascular endothelial growth factor (VEGF; a central angiogenic factor) receptor-2 (sVEGFR2) was significantly decreased only three months after the treatment without recurrence. We also observed that IR, determined by the homeostasis model assessment (HOMA-IR), was significantly improved by this regimen, indicating that an inhibitory effect was achieved, at least partly, by coordinated effects of anti-angiogenesis and IR improvement. In conclusion, since both BCAA and ACE-I are widely used in clinical practice with safety, this combination therapy may represent a potential new strategy for chemoprevention against IR-based HCC recurrence in the future. Moreover, sVEGFR2 may become a useful clinical predictive marker of this combination treatment.

To investigate the role of enhancer of zeste homolog (EZH) 1 and EZH2 in liver homeostasis, mice were generated that carried Ezh1 2/2 and EZH2 fl/fl alleles and an Alb-Cre transgene. Only the combined loss of EZH1 and EZH2 in mouse hepatocytes caused a depletion of global trimethylation on Lys 27 of histone H3 (H3K27me3) marks and the specific loss of over ∼1900 genes at 3 mo of age. Ezh1Alb-Cre mice exhibited progressive liver abnormalities manifested by the development of regenerative nodules and concomitant periportal fibrosis, inflammatory infiltration, and activation of A6-positive hepatic progenitor cells at 8 mo of age. In response to chronic treatment with carbon tetrachloride, all experimental mice, but none of the controls (n = 27 each), showed increased hepatic degeneration associated with liver dysfunction and reduced ability to proliferate. After two-thirds partial hepatectomy, mutant mice (n = 5) displayed increased liver injury and a blunted regenerative response. Genomewide analyses at 3 mo of age identified 51 genes that had lost H3K27me3 marks, and their expression was significantly increased. These genes were involved in regulation of cell survival, fibrosis, and proliferation. H3K27me3 levels and liver physiology were unaffected in mice lacking either EZH1 globally or EZH2 specifically in hepatocytes. This work demonstrates a critical redundancy of EZH1 and EZH2 in maintaining hepatic homeostasis and

Previous clinical studies have demonstrated that endotoxin/toll-like receptor 4 (TLR4) signaling is critical in the inflammatory pathways associated with non-alcoholic steatohepatitis (NASH). In human and animal studies, NASH was associated with portal lipopolysaccharide (LPS) and the plasma LPS level was hypothesized to be associated with small intestinal bacterial overgrowth, change in composition of the microbiota and increased intestinal permeability. The aim of the present study was to investigate the roles of endogenous endotoxin and TLR4 in the pathogenesis of NASH. The effects of antibiotics were assessed in vivo using a choline deficiency amino acid (CDAA)-induced experimental liver fibrosis model. Antibiotics, including polymyxins and neomycins, were orally administered in drinking water. Antibiotics attenuated hepatic stellate cell (HSC) activation and liver fibrosis via TGF-β and collagen in an experimental hepatic fibrosis model. The mechanism by which antibiotics attenuated LPS-TLR4 signaling and liver fibrosis was assessed. Notably, TLR4 mRNA level in the liver was elevated in the CDAA group and the CDAA-induced increase was significantly reduced by antibiotics. However, no significant differences were observed in the intestine among all groups. Elevated mRNA levels of LPS binding protein, which was correlated with serum endotoxin levels, were recognized in the CDAA group and the CDAA-induced increase was significantly reduced by antibiotics. The intestinal permeability of the CDAA group was increased compared with the choline-supplemented amino acid group. The tight junction protein (TJP) in the intestine, determined by immunohistochemical analysis was inversely associated with intestinal permeability. Antibiotics improved the intestinal permeability and enhanced TJP expression. Inhibition of LPS-TLR4 signaling with antibiotics attenuated liver fibrosis development associated with NASH via the inhibition of HSC activation. These results indicated that reduction of LPS and restoration of intestinal TJP may be a novel therapeutic strategy for treatment of liver fibrosis development in NASH.