Effects of Low-dose and High-dose Rifaximin in the Treatment of Covert Hepatic Encephalopathy

BACKGROUND AND AIMS

Rifaximin is effective in preventing and treating hepatic encephalopathy (HE). This study aimed to investigate the efficacy and safety of different dosages of rifaximin in the treatment of cirrhotic patients with covert HE (CHE).

METHODS

In this single-center, randomized, controlled, open-label study, CHE was diagnosed using a combination of the psychometric HE score and the EncephalApp Stroop test. Cirrhotic patients with CHE were recruited and randomly assigned to low-dose rifaximin 800 mg/day, high-dose rifaximin (1,200 mg/day), and control groups, and were treated for 8 weeks. The sickness impact profile (SIP) scale was used to evaluate the health-related quality of life (HRQOL) of patients. Forty patients were included in the study, 12 were assigned to the low-dose group, 14 to the high-dose group, and 14 patients to the control group.

RESULTS

The percentage of patients with CHE reversal was significantly higher in both the low-dose (41.67%, 5/12) and high-dose (57.14%, 8/14) groups than in the control group (7.14%, 1/14) at 8 weeks (p=0.037 and p=0.005, respectively). In addition, both doses of rifaximin resulted in significant improvement of the total SIP score compared with the control group. There were no significant differences in the CHE reversal rate, total SIP score improvement, and incidence of adverse event between the low-dose and high-dose groups (p>0.05).

CONCLUSIONS

Low-dose rifaximin reverses CHE and improves HRQOL in cirrhotic patients with comparable effects and safety to high-dose rifaximin.

Sustained ameliorating effects and autonomic mechanisms of transcutaneous electrical acustimulation at ST36 in patients with chronic constipation

BACKGROUND AND AIMS

The treatment of chronic constipation is still a great challenge in clinical practice. This study aimed to determine the efficacy and sustained effects of transcutaneous electrical acustimulation (TEA) at acupoint ST36 on the treatment of chronic constipation and explore possible underlying mechanisms.

METHODS

Forty-four patients with chronic constipation were recruited and randomly assigned to a TEA group or sham-TEA group. A bowel diary was recorded by the patients. The Patient Assessment of Constipation Symptom (PAC-SYM) and the Patient Assessment of Constipation Quality of Life (PAC-QoL) questionnaires were administered during each visit. Anal and rectal functions were evaluated with anorectal manometry. Autonomic functions were assessed by the special analysis of heart rate variability derived from the ECG recording.

RESULTS

Compared with sham-TEA, 2-week TEA treatment significantly increased the number of spontaneous bowel movements (SBMs) (5.64 ± 0.54 vs. 2.82 ± 0.36, P < 0.001) and lowered the total scores of PAC-SYM (0.90 ± 0.14 vs. 1.35 ± 0.13, P < 0.001) and PAC-QoL (0.89 ± 0.13 vs. 1.32 ± 0.14, P < 0.05). TEA improved symptoms, as reflected by a reduction in the straining (P < 0.001), the incomplete defecation (P < 0.05), the frequency of emergency drug use (P < 0.05), the days of abdominal distension (P < 0.01) and an increase in intestinal satisfaction (P < 0.01). Interestingly, the effects of TEA on the improvement of weekly SBMs sustained four weeks after the cessation of treatment (P < 0.001). Anorectal manometry indicated that 2-week treatment of TEA lowered the threshold of first sensation (P < 0.05), desire of defecation (P < 0.01) and maximum tolerable volume (P < 0.001) compared with sham-TEA group. TEA also significantly enhanced vagal activity, reflected by high-frequency band of heart rate variability, compared with sham-TEA (57.86 ± 1.83 vs. 48.51 ± 2.04, P < 0.01).

CONCLUSION

TEA ameliorates constipation with sustained effects, which may be mediated via improvement of rectal sensitivity and enhancement of vagal activity.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/], identifier [ChiCTR210004267].

The HLF/IL-6/STAT3 feedforward circuit drives hepatic stellate cell activation to promote liver fibrosis

BACKGROUND AND AIMS

Liver fibrosis is a wound-healing response that disrupts the liver architecture and function by replacing functional parenchyma with scar tissue. Recent progress has advanced our knowledge of this scarring process, but the detailed mechanism of liver fibrosis is far from clear.

METHODS

The fibrotic specimens of patients and HLF (hepatic leukemia factor)^PB/PB mice were used to assess the expression and role of HLF in liver fibrosis. Primary murine hepatic stellate cells (HSCs) and human HSC line Lx2 were used to investigate the impact of HLF on HSC activation and the underlying mechanism.

RESULTS

Expression of HLF was detected in fibrotic livers of patients, but it was absent in the livers of healthy individuals. Intriguingly, HLF expression was confined to activated HSCs rather than other cell types in the liver. The loss of HLF impaired primary HSC activation and attenuated liver fibrosis in HLF^PB/PB mice. Consistently, ectopic HLF expression significantly facilitated the activation of human HSCs. Mechanistic studies revealed that upregulated HLF transcriptionally enhanced interleukin 6 (IL-6) expression and intensified signal transducer and activator of transcription 3 (STAT3) phosphorylation, thus promoting HSC activation. Coincidentally, IL-6/STAT3 signalling in turn activated HLF expression in HSCs, thus completing a feedforward regulatory circuit in HSC activation. Moreover, correlation between HLF expression and alpha-smooth muscle actin, IL-6 and p-STAT3 levels was observed in patient fibrotic livers, supporting the role of HLF/IL-6/STAT3 cascade in liver fibrosis.

CONCLUSIONS

In aggregate, we delineate a paradigm of HLF/IL-6/STAT3 regulatory circuit in liver fibrosis and propose that HLF is a novel biomarker for activated HSCs and a potential target for antifibrotic therapy.

Chronic inflammation-elicited liver progenitor cell conversion to liver cancer stem cell with clinical significance

The substantial heterogeneity and hierarchical organization in liver cancer support the theory of liver cancer stem cells (LCSCs). However, the relationship between chronic hepatic inflammation and LCSC generation remains obscure. Here, we observed a close correlation between aggravated inflammation and liver progenitor cell (LPC) propagation in the cirrhotic liver of rats exposed to diethylnitrosamine. LPCs isolated from the rat cirrhotic liver initiated subcutaneous liver cancers in nonobese diabetic/severe combined immunodeficient mice, suggesting the malignant transformation of LPCs toward LCSCs. Interestingly, depletion of Kupffer cells in vivo attenuated the LCSC properties of transformed LPCs and suppressed cytokeratin 19/Oval cell 6-positive tumor occurrence. Conversely, LPCs cocultured with macrophages exhibited enhanced LCSC properties. We further demonstrated that macrophage-secreted tumor necrosis factor-α triggered chromosomal instability in LPCs through the deregulation of ubiquitin D and checkpoint kinase 2 and enhanced the self-renewal of LPCs through the tumor necrosis factor receptor 1/Src/signal transducer and activator of transcription 3 pathway, which synergistically contributed to the conversion of LPCs to LCSCs. Clinical investigation revealed that cytokeratin 19/Oval cell 6-positive liver cancer patients displayed a worse prognosis and exhibited superior response to sorafenib treatment.

CONCLUSION

Our results not only clarify the cellular and molecular mechanisms underlying the inflammation-mediated LCSC generation but also provide a molecular classification for the individualized treatment of liver cancer. (Hepatology 2017;66:1934-1951).

MicroRNA-370 Attenuates Hepatic Fibrogenesis by Targeting Smoothened

BACKGROUND AND AIMS

Recent research shows that abnormal expression of microRNA plays an important role in the process of hepatic fibrosis . miR-370 has been reported to be involved in liver function and is suppressed during hepatic carcinogenesis. The aim of this study was to investigate the role of miR-370 in hepatic fibrosis.

METHODS

The expression levels of miR-370 in rat fibrotic livers and activated hepatic stellate cells (HSCs) were evaluated by quantitative real-time PCR. The effect of miR-370 on the activation of HSCs was analyzed by flow cytometric analyses, real-time PCR and Western blot. Adenovirus carrying miR-370 was injected through the tail vein to access the effect of miR-370 on hepatic fibrosis induced by CCl4 in rats. The downstream targets of miR-370 were predicted by the Target Scan database and verified by luciferase assays, real-time PCR and Western blot in HSCs and were further confirmed by immunohistochemistry in vivo.

RESULTS

Real-time PCR showed that miR-370 expression was significantly reduced in rat fibrotic livers and TGFβ1-stimulated HSCs. Overexpression of miR-370 inhibited the proliferation of HSC-T6 cells via inducing cell apoptosis and suppressed the activation of HSCs. Upregulation of miR-370 obviously attenuated the CCl4-induced liver fibrosis in rats. miR-370 was directly bound to the 3'UTR of Smoothened (SMO) and suppressed the expression of SMO in HSCs and fibrotic livers.

CONCLUSIONS

Our study demonstrated that miR-370 plays an inhibitory role in hepatic fibrogenesis by targeting SMO. Restoration of miR-370 may have beneficial effects on the treatment of liver fibrosis.

Hepatocyte nuclear factor 4α-nuclear factor-κB feedback circuit modulates liver cancer progression

Hepatocyte nuclear factor 4α (HNF4α) is a liver enriched transcription factor and is indispensable for liver development. However, the role of HNF4α in hepatocellular carcinoma (HCC) progression remains to be elucidated. We report that reduced HNF4α expression correlated well with the aggressive clinicopathological characteristics of HCC and predicted poor prognosis of patients. HNF4α levels were even lower in metastatic HCCs, and ectopic HNF4α expression suppressed the metastasis of hepatoma cells both in vitro and in vivo. Forced HNF4α expression attenuated the expression and nuclear translocation of RelA (p65) and impaired NF-κB activation through an IKK-independent mechanism. Blockage of RelA robustly attenuated the suppressive effect of HNF4α on hepatoma cell metastasis. MicroRNA (miR)-7 and miR-124 were transcriptionally up-regulated by HNF4α, which repressed RelA expression by way of interaction with RelA-3' untranslated region (UTR). In addition, nuclear factor kappa B (NF-κB) up-regulated the expression of miR-21 in hepatoma cells, resulting in decreased HNF4α levels through down-regulating HNF4α-3'UTR activity.

CONCLUSIONS

Collectively, an HNF4α-NF-κB feedback circuit including miR-124, miR-7, and miR-21 was identified in HCC, and the combination of HNF4α and NF-κB exhibited more powerful predictive efficiency of patient prognosis. These findings broaden the knowledge of hepatic inflammation and cancer initiation/progression, and also provide novel prognostic biomarkers and therapeutic targets for HCC.

Abstract 134: HNF4α inhibits liver cancer metastasis via suppression of NF-кB activity

BACKGROUND & AIMS: Hepatocyte nuclear factor 4α (HNF4α) is a liver enriched transcription factor and is indispensable for liver development. However, the role of HNF4α in hepatocellular carcinoma (HCC) metastasis remains largely unknown.

METHODS: 429 HCC tissues were involved in the correlation analysis of HNF4α levels with tumor features and patient outcomes. Effect of HNF4α on HCC metastasis was monitored through in vivo imaging system. Expression of HNF4α, RelA(p65) or microRNAs in human HCCs was determined by Real-time PCR, western blot or immunohistochemistry. Point mutation and ChIP assay were performed to detect the interaction of HNF4α with the promoter of target microRNA. 3’UTR reporter assay was conducted to determine the regulation of RelA by microRNAs.

RESULTS: Reduced HNF4α expression correlated well with the aggressive clinicopathological characteristics of HCC and predicted poor prognosis of patients. HNF4α levels were even lower in metastatic HCCs, and ectopic HNF4α expression suppressed the metastasis of hepatoma cells both in vitro and in vivo. HNF4α suppressed HCC metastasis through inhibiting RelA expression and NFκB activity. miR-7 and miR-124, which were transcriptionally up-regulated by HNF4α, repressed RelA expression via interaction with RelA-3’UTR. Herein, HNF4α suppresses NF-κB activity and RelA expression via a miR-7 and miR-124-dependent manner. Moreover, combination of HNF4α and NF-κB exhibited more powerful predictive efficiency of patient prognosis.

CONCLUSIONS: Considering the importance of HNF4α and NF-κB in chronic liver disease, the suppression of NF-κB by HNF4α is not only essential in connecting hepatic inflammation and tumorigenesis, but also indicates novel strategy in HCC prevention and therapy.

Citation Format: Bei-Fang Ning, Jiao Liu, Wen-Ping Xu, Chuan Yin, Xin Zhang, Wei-Fen Xie. HNF4α inhibits liver cancer metastasis via suppression of NF-кB activity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 134. doi:10.1158/1538-7445.AM2014-134

Abstract 2463: Suppression of hepatocyte nuclear factor 4α by nuclear factor κB in hepatoma cells

BACKGROUND & AIMS: HCC predominantly arises from cirrhotic liver where there usually has been repeated wound-healing response upon chronic inflammation. However, the mechanistic link between hepatic inflammation and carcinogenesis remains largely unknown.

METHODS: Expression of HNF4α, RelA(p65) or microRNAs in human HCCs was determined by Real-time PCR, western blot or immunohistochemistry. 3′UTR reporter assay was conducted to determine the regulation of HNF4α by microRNAs. The recombinant adenoviruses carrying HNF4α gene were injected into diethylinitrosamine(DEN)-administrated Wistar rats through tail vein. Tissue microarray was utilized to assess the expression of HNF4α and RelA HCC tissues.

RESULTS: Overexpression or interference of RelA remarkably decreased or increased HNF4α expression in hepatoma cells respectively, suggesting a negative regulation of HNF4α by NF-κB. Interestingly, ecotopic RelA expression dramatically reduced the activation of HNF4α-3′UTR indicating microRNA could be involved in the feedback regulation. MiR-21 was predicted to be regulated by NF-κB using Targetscan analysis, and overexpression of RelA evidently enhanced the miR-21 expression. Delivery of miR-21 mimic notably suppressed HNF4α-3′UTR activity and HNF4α expression. Moreover, treatment of miR-21 inhibitor increased HNF4α levels and attenuated the down-regulation of HNF4α by RelA. Consistently, downregulation of HNF4α and upregulation of RelA was detected during DEN-induced rat hepatocarcingenesis, negative correlation of HNF4α and RelA was also observed in human HCCs. CONCLUSIONS: These findings not only broaden the knowledge on hepatic inflammation and cancer initiation, but also indicates novel strategy in HCC prevention.

Note: This abstract was not presented at the meeting.

Citation Format: Bei-Fang Ning, Xin Zhang, Wei-Fen Xie. Suppression of hepatocyte nuclear factor 4α by nuclear factor κB in hepatoma cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2463. doi:10.1158/1538-7445.AM2014-2463

Perturbation of MicroRNA-370/Lin-28 homolog A/nuclear factor kappa B regulatory circuit contributes to the development of hepatocellular carcinoma

MicroRNA 370 (miR-370) is located within the DLK1/DIO3 imprinting region on human chromosome 14, which has been identified as a cancer-associated genomic region. However, the role of miR-370 in malignances remains controversial. Here, we report that miR-370 was repressed in human hepatocellular carcinoma (HCC) tissues and hepatoma cell lines. Using gain-of-function and loss-of-function experiments, we demonstrated that miR-370 inhibited the malignant phenotype of HCC cells in vitro. Overexpression of miR-370 inhibited growth and metastasis of HCC cells in vivo. Moreover, the RNA-binding protein, LIN28A, was identified as a direct functional target of miR-370, which, in turn, blocked the biogenesis of miR-370 by binding to its precursor. LIN28A also mediated the suppressive effects of miR-370 on migration and invasion of HCC cells by post-transcriptionally regulating RelA/p65, which is an important effector of the canonical nuclear factor kappa B (NF-κB) pathway. Interleukin-6 (IL-6), a well-known NF-κB downstream inflammatory molecule, reduced miR-370 but increased LIN28A levels in HCC. Furthermore, miR-370 levels were inversely correlated with LIN28A and IL-6 messenger RNA (mRNA) levels, whereas LIN28A mRNA expression was positively correlated with IL-6 expression in human HCC samples. Interestingly, reduction of miR-370 expression was associated with the development of HCC in rats, as well as with aggressive tumor behavior and short survival in HCC patients.

CONCLUSIONS

These data demonstrate the involvement of a novel regulatory circuit consisting of miR-370, LIN28A, RelA/p65 and IL-6 in HCC progression. Manipulating this feedback loop may have beneficial effect in HCC treatment.

Hepatocyte nuclear factor-4α reverses malignancy of hepatocellular carcinoma through regulating miR-134 in the DLK1-DIO3 region

Hepatocyte nuclear factor-4α (HNF4α) is a dominant transcriptional regulator of hepatocyte differentiation and hepatocellular carcinogenesis. There is striking suppression of hepatocellular carcinoma (HCC) by HNF4α, although the mechanisms by which HNF4α reverses HCC malignancy are largely unknown. Herein, we demonstrate that HNF4α administration to HCC cells resulted in elevated levels of 28 mature microRNAs (miRNAs) from the miR-379-656 cluster, which is located in the delta-like 1 homolog (DLK1) -iodothyronine deiodinase 3 (DIO3) locus on human chromosome 14q32. Consistent with the reduction of HNF4α, these miRNAs were down-regulated in human HCC tissue. HNF4α regulated the transcription of the miR-379-656 cluster by directly binding to its response element in the DLK1-DIO3 region. Interestingly, several miRNAs in this cluster inhibited proliferation and metastasis of HCC cells in vitro. As a representative miRNA in this cluster, miR-134 exerted a dramatically suppressive effect on HCC malignancy by down-regulating the oncoprotein, KRAS. Moreover, miR-134 markedly diminished HCC tumorigenicity and displayed a significant antitumor effect in vivo. In addition, inhibition of endogenous miR-134 partially reversed the suppressive effects of HNF4α on KRAS expression and HCC malignancy. Furthermore, a positive correlation between HNF4α and miR-134 levels was observed during hepatocarcinogenesis in rats, and decreases in miR-134 levels were significantly associated with the aggressive behavior of human HCCs.

CONCLUSION

Our data highlight the importance of the miR-379-656 cluster in the inhibitory effect of HNF4α on HCC, and suggest that regulation of the HNF4α-miRNA cascade may have beneficial effects in the treatment of HCC.

Hepatic transforming growth factor beta gives rise to tumor-initiating cells and promotes liver cancer development

Liver cirrhosis is a predominant risk factor for hepatocellular carcinoma (HCC). However, the mechanism underlying the progression from cirrhosis to HCC remains unclear. Herein we report the concurrent increase of liver progenitor cells (LPCs) and transforming growth factor-β (TGF-β) in diethylnitrosamine (DEN)-induced rat hepatocarcinogenesis and cirrhotic livers of HCC patients. Using several experimental approaches, including 2-acetylaminofluorene/partial hepatectomy (2-AAF/PHx) and 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-elicited murine liver regeneration, we found that activation of LPCs in the absence of TGF-β induction was insufficient to trigger hepatocarcinogenesis. Moreover, a small fraction of LPCs was detected to coexpress tumor initiating cell (T-IC) markers during rat hepatocarcinogenesis and in human HCCs, and TGF-β levels were positively correlated with T-IC marker expression, which indicates a role of TGF-β in T-IC generation. Rat pluripotent LPC-like WB-F344 cells were exposed to low doses of TGF-β for 18 weeks imitating the enhanced TGF-β expression in cirrhotic liver. Interestingly, long-term treatment of TGF-β on WB-F344 cells impaired their LPC potential but granted them T-IC properties including expression of T-IC markers, increased self-renewal capacity, stronger chemoresistance, and tumorigenicity in NOD-SCID mice. Hyperactivation of Akt but not Notch, signal transducer and activator of transcription 3 (STAT3), or mammalian target of rapamycin (mTOR) was detected in TGF-β-treated WB-F344 cells. Introduction of the dominant-negative mutant of Akt significantly attenuated T-IC properties of those transformed WB-F344 cells, indicating Akt was required in TGF-β-mediated-generation of hepatic T-ICs. We further demonstrate that TGF-β-induced Akt activation and LPC transformation was mediated by microRNA-216a-modulated phosphatase and tensin homolog deleted on chromosome 10 (PTEN) suppression.

CONCLUSION

Hepatoma-initiating cells may derive from hepatic progenitor cells exposed to chronic and constant TGF-β stimulation in cirrhotic liver, and pharmaceutical inhibition of microRNA-216a/PTEN/Akt signaling could be a novel strategy for HCC prevention and therapy targeting hepatic T-ICs.

Recombinant adenovirus carrying the hepatocyte nuclear factor-1alpha gene inhibits hepatocellular carcinoma xenograft growth in mice

Hepatocyte nuclear factor-1alpha (HNF1α) is one of the key transcription factors of the HNF family, which plays a critical role in hepatocyte differentiation. Substantial evidence has suggested that down-regulation of HNF1α may contribute to the development of hepatocellular carcinoma (HCC). Herein, human cancer cells and tumor-associated fibroblasts (TAFs) were isolated from human HCC tissues, respectively. A recombinant adenovirus carrying the HNF1α gene (AdHNF1α) was constructed to determine its effect on HCC in vitro and in vivo. Our results demonstrated that HCC cells and HCC tissues revealed reduced expression of HNF1α. Forced reexpression of HNF1α significantly suppressed the proliferation of HCC cells and TAFs and inhibited the clonogenic growth of hepatoma cells in vitro. In parallel, HNF1α overexpression reestablished the expression of certain liver-specific genes and microRNA 192 and 194 levels, with a resultant increase in p21 levels and induction of G(2)/M arrest. Additionally, AdHNF1α inhibited the expression of cluster of differentiation 133 and epithelial cell adhesion molecule and the signal pathways of the mammalian target of rapamycin and transforming growth factor beta/Smads. Furthermore, HNF1α abolished the tumorigenicity of hepatoma cells in vivo. Most interestingly, intratumoral injection of AdHNF1α significantly inhibited the growth of subcutaneous HCC xenografts in nude mice. Systemic delivery of AdHNF1α could eradicate the orthotopic liver HCC nodules in nonobese diabetic/severe combined immunodeficiency mice.

CONCLUSION

These results suggest that the potent inhibitive effect of HNF1α on HCC is attained by inducing the differentiation of hepatoma cells into mature hepatocytes and G(2)/M arrest. HNF1α might represent a novel, promising therapeutic agent for human HCC treatment. Our findings also encourage the evaluation of differentiation therapy for tumors of organs other than liver using their corresponding differentiation-determining transcription factor.

Gankyrin-mediated dedifferentiation facilitates the tumorigenicity of rat hepatocytes and hepatoma cells

Gankyrin is a critical oncoprotein overexpressed in human hepatocellular carcinoma (HCC). However, the mechanism underlying gankyrin-mediated hepatocarcinogenesis remains elusive. Herein, we provide evidence that gankyrin expression was progressively elevated in liver fibrosis, cirrhosis, and HCC. Levels of gankyrin expression were closely associated with the dedifferentiation status of hepatoma in patients. Decrease of hepatocyte characteristic markers and increase of cholangiocyte-specific markers were observed in rat primary hepatocytes with enforced gankyrin expression and diethylnitrosamine (DEN)-triggered rat hepatocarcinogenesis. Overexpression of gankyrin also attenuated the hepatic function of primary hepatocytes, which further suggests that gankyrin promotes the dedifferentiation of hepatocytes. Moreover, elevated expression of gankyrin closely correlated with the expression of HCC stem/progenitor cell markers in DEN-triggered hepatocarcinogenesis and human HCCs. Hepatoma cells derived from suspension-cultured spheroids exhibited a higher gankyrin level, and enforced gankyrin expression in hepatoma cells remarkably enhanced cluster of differentiation (CD)133, CD90, and epithelial cellular adhesion molecule expression, indicating a role of gankyrin in hepatoma cell dedifferentiation and the generation of hepatoma stem/progenitor cells. In contrast, down-regulation of gankyrin in hepatoma cells by lentivirus-mediated microRNA delivery significantly improved their differentiation status and attenuated malignancy. Interference of gankyrin expression in hepatoma cells also diminished the proportion of cancer stem/progenitor cells and their self-renewal capacity. Furthermore, gankyrin was found to bind hepatocyte nuclear factor 4α (HNF4α), which determines hepatocyte differentiation status and enhances proteasome-dependent HNF4α degradation in hepatoma cells. The inverse correlation of gankyrin and HNF4α was further confirmed in primary hepatocytes, DEN-induced hepatocarcinogenesis, and human HCCs.

CONCLUSION

Gankyrin-mediated dedifferentiation of hepatocytes and hepatoma cells via, at least partially, down-regulation of HNF4α facilitates HCC development, and interference of gankyrin expression could be a novel strategy for HCC prevention and differentiation therapy.

Sophocarpine alleviates non-alcoholic steatohepatitis in rats

BACKGROUND AND AIM

Non-alcoholic steatohepatitis (NASH) is one entity in the spectrum of non-alcoholic fatty liver disease (NAFLD). The aim of this study was to explore the prevention and therapeutic effect of sophocarpine on experimental rat NASH.

METHODS

Sophocarpine with the dosage of 20 mg/kg/day was injected into NASH rats. At the end of 12 weeks, all rats were killed to detect the degree of fatty degeneration, inflammation and fibrosis.

RESULTS

Sophocarpine intervention (in the pro-treated and treated groups) resulted in a significant decrease of liver weight, liver index, serum transaminase and serum lipids. Messenger RNA expressions of leptin, interleukin (IL)-6, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β1, procollagen-I and α-smooth muscle actin (SMA) and deposition of IL-6, TNF-α and TGF-β1 in liver decreased, whereas the messenger RNA expression of adiponectin increased significantly compared with that in the model group. Moreover, histological improvement was also observed in the sophocarpine intervention group. In addition, there was no significant difference in any detected indicator between the pro-treated and treated group.

CONCLUSIONS

Sophocarpine could decrease the level of serum transaminase, improve lipid metabolism, reduce synthesis of inflammatory cytokines TNF-α, TGF-β1 and IL-6, activate protective adipocytokine adiponectin, and might be selected as a promising agent for the clinical prevention and therapy of NASH.

Hepatocyte nuclear factor 4 alpha suppresses the development of hepatocellular carcinoma

Hepatocyte nuclear factor 4α (HNF4α) is a transcription factor that plays a key role in hepatocyte differentiation and the maintenance of hepatic function, but its role in hepatocarcinogenesis has yet to be examined. Here, we report evidence of a suppressor role for HNF4α in liver cancer. HNF4α expression was progressively decreased in the diethylinitrosamine-induced rat model of liver carcinogenesis. In human liver tissues, HNF4α expression was decreased in cirrhotic tissue and further decreased in hepatocarcinoma relative to healthy tissue. Notably, an inverse correlation existed with epithelial-mesenchymal transition (EMT). Enforced expression of HNF4α attenuated hepatocyte EMT during hepatocarcinogenesis, alleviated hepatic fibrosis, and blocked hepatocellular carcinoma (HCC) occurrence. In parallel, stem cell marker gene expression was inhibited along with cancer stem/progenitor cell generation. Further, enforced expression of HNF4α inhibited activation of β-catenin, which is closely associated with EMT and hepatocarcinogenesis. Taken together, our results suggest that the inhibitory effect of HNF4α on HCC development might be attributed to suppression of hepatocyte EMT and cancer stem cell generation through an inhibition of β-catenin signaling pathways. More generally, our findings broaden knowledge on the biological significance of HNF4α in HCC development, and they imply novel strategies for HCC prevention through the manipulation of differentiation-determining transcription factors in various types of carcinomas.

Hepatocyte nuclear factor 4 alpha suppresses the development of hepatocellular carcinoma

Hepatocyte nuclear factor 4α (HNF4α) is a transcription factor that plays a key role in hepatocyte differentiation and the maintenance of hepatic function, but its role in hepatocarcinogenesis has yet to be examined. Here, we report evidence of a suppressor role for HNF4α in liver cancer. HNF4α expression was progressively decreased in the diethylinitrosamine-induced rat model of liver carcinogenesis. In human liver tissues, HNF4α expression was decreased in cirrhotic tissue and further decreased in hepatocarcinoma relative to healthy tissue. Notably, an inverse correlation existed with epithelial-mesenchymal transition (EMT). Enforced expression of HNF4α attenuated hepatocyte EMT during hepatocarcinogenesis, alleviated hepatic fibrosis, and blocked hepatocellular carcinoma (HCC) occurrence. In parallel, stem cell marker gene expression was inhibited along with cancer stem/progenitor cell generation. Further, enforced expression of HNF4α inhibited activation of β-catenin, which is closely associated with EMT and hepatocarcinogenesis. Taken together, our results suggest that the inhibitory effect of HNF4α on HCC development might be attributed to suppression of hepatocyte EMT and cancer stem cell generation through an inhibition of β-catenin signaling pathways. More generally, our findings broaden knowledge on the biological significance of HNF4α in HCC development, and they imply novel strategies for HCC prevention through the manipulation of differentiation-determining transcription factors in various types of carcinomas.

Inhibition of extracellular signal-regulated kinase 1 by adenovirus mediated small interfering RNA attenuates hepatic fibrosis in rats

Extracellular signal-regulated kinase 1 (ERK1) is a critical part of the mitogen-activated protein kinase signal transduction pathway, which is involved in hepatic fibrosis. However, the effect of down-regulation of ERK1 on hepatic fibrosis has not been reported. Here, we induced hepatic fibrosis in rats with dimethylnitrosamine administration or bile duct ligation. An adenovirus carrying small interfering RNA targeting ERK1 (AdshERK1) was constructed to determine its effect on hepatic fibrosis, as evaluated by histological and immunohistochemical examination. Our results demonstrated that AdshERK1 significantly reduced the expression of ERK1 and suppressed proliferation and levels of fibrosis-related genes in hepatic stellate cells in vitro. More importantly, selective inhibition of ERK1 remarkably attenuated the deposition of the extracellular matrix in fibrotic liver in both fibrosis models. In addition, both hepatocytes and biliary epithelial cells were proven to exert the ability to generate the myofibroblasts depending on the insults of the liver, which were remarkably reduced by AdshERK1. Furthermore, up-regulation of ERK1 paralleled the increased expression of transforming growth factor beta1 (TGF-beta1), vimentin, snail, platelet-derived growth factor-BB (PDGF-BB), bone morphogenetic protein 4 (BMP4), and small mothers against decapentaplegic-1 (p-Smad1), and was in reverse correlation with E-cadherin in the fibrotic liver. Nevertheless, inhibition of ERK1 resulted in the increased level of E-cadherin in parallel with suppression of TGF-beta1, vimentin, snail, PDGF-BB, BMP4, and p-Smad1. Interestingly, AdshERK1 treatment promoted hepatocellular proliferation.

CONCLUSION

Our study provides the first evidence for AdshERK1 suppression of hepatic fibrosis through the reversal of epithelial-mesenchymal transition of both hepatocytes and biliary epithelial cells without interference of hepatocellular proliferation. This suggests that ERK1 is implicated in hepatic fibrogenesis and selective inhibition of ERK1 by small interfering RNA may present a novel option for hepatic fibrosis treatment.