Diabetes, Liver Cancer, and Cirrhosis: What Next?

Relationship between Intestinal Microflora and Hepatocellular Cancer Based on Gut-Liver Axis Theory

The intestinal microflora is a bacterial group that lives in the human digestive tract and has a long-term interdependence with the host. Due to the close anatomical and functional relationship between the liver and the intestine, the intestinal flora affects liver metabolism via the intestinal-hepatic circulation, thereby playing an extremely important role in the pathological process of liver inflammation, chronic fibrosis, and liver cancer. In recent years, the rapid development of technologies in high-throughput sequencing and genomics has opened up possibilities for a broader and deeper understanding of the crosstalk between the intestinal flora and the occurrence and development of liver cancer. This review aims to summarize the mechanisms by which the gut microbiota changes the body's metabolism, through the gut-liver axis, thereby affecting the occurrence and development of primary liver cancer. In addition, the potential regulation of intestinal microflora in the treatment of liver cancer is discussed.

Metformin suppresses interleukin-22 induced hepatocellular carcinoma by upregulating Hippo signaling pathway

BACKGROUND AND AIMS

Epidemiological studies have shown direct associations between type 2 diabetes and the risk of cancers. Accumulating evidence indicates that metformin is profoundly implicated in preventing tumor development. However, the exact mechanism underlying the antitumor effects of metformin in hepatocellular carcinoma (HCC) is still not clear.

METHODS

In this study, we investigated the effects of metformin on a mouse HCC model and interleukin-22 (IL-22)-associated carcinogenesis in vitro.

RESULTS

We found that metformin significantly suppressed the incidence and tumor burden of HCC in the diethyl-nitrosamine-induced HCC mouse model. As expected, the expression of IL-22, an important factor involved in HCC progression, was markedly reduced by metformin. Treatment of HCC cells with metformin inhibited IL-22 induced cell proliferation, migration, and invasion, and promoted cell apoptosis. Furthermore, ectopic expression of IL-22 makes HCC more aggressive, whereas metformin largely compromised it in vitro and in vivo. Mechanistically, the whole transcriptome analysis and functional analysis revealed that Hippo signaling pathway was involved in the antitumor ability of metformin. Consistent with this, metformin directly inhibited LATS1/2 and activated Mst1/2, phosphorylated YAP1 in vitro. After blocking the Hippo pathway by XMU-MP-1, the inhibitor of MST1/2, the inhibitory effects by metformin were dramatically attenuated as shown by in vitro study.

CONCLUSIONS

Collectively, our findings illuminate a new regulatory mechanism, metformin activates Hippo signaling pathway to regulate IL-22 mediated HCC progression and provide new insights into its tumor-suppressive roles.

Gut microbiota and human NAFLD: disentangling microbial signatures from metabolic disorders

Gut microbiota dysbiosis has been repeatedly observed in obesity and type 2 diabetes mellitus, two metabolic diseases strongly intertwined with non-alcoholic fatty liver disease (NAFLD). Animal studies have demonstrated a potential causal role of gut microbiota in NAFLD. Human studies have started to describe microbiota alterations in NAFLD and have found a few consistent microbiome signatures discriminating healthy individuals from those with NAFLD, non-alcoholic steatohepatitis or cirrhosis. However, patients with NAFLD often present with obesity and/or insulin resistance and type 2 diabetes mellitus, and these metabolic confounding factors for dysbiosis have not always been considered. Patients with different NAFLD severity stages often present with heterogeneous lesions and variable demographic characteristics (including age, sex and ethnicity), which are known to affect the gut microbiome and have been overlooked in most studies. Finally, multiple gut microbiome sequencing tools and NAFLD diagnostic methods have been used across studies that could account for discrepant microbiome signatures. This Review provides a broad insight into microbiome signatures for human NAFLD and explores issues with disentangling these signatures from underlying metabolic disorders. More advanced metagenomics and multi-omics studies using system biology approaches are needed to improve microbiome biomarkers.

Changing prevalence of aetiological factors and comorbidities among Australians hospitalised for cirrhosis

BACKGROUND

The rate of hospital admissions for cirrhosis increased 1.3-fold during 2008-2016 in Queensland. Alcohol misuse was a contributing factor for cirrhosis in 55% of admissions and 40% of patients had at least one comorbidity.

AIMS

To examine the temporal change in aetiology of liver disease and presence of comorbidity in patients admitted with cirrhosis.

METHODS

Population-based retrospective cohort study of all people treated in hospital for cirrhosis (10 254 patients) in Queensland during 2008-2016. Data were sourced from Queensland Hospital Admitted Patient Data Collection.

RESULTS

The commonest aetiology was alcohol (49.5%), followed by cryptogenic (unspecified cirrhosis; 28.5%), hepatitis C virus (19.3%), non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) (4.8%) and hepatitis B virus (HBV) (4.3%). The prevalence of alcohol-related (P = 0.41) and hepatitis C virus (P = 0.08) remained stable between 2008-2010 and 2014-2016, that of NAFLD/NASH, cryptogenic and HBV-cirrhosis increased by 67% (P < 0.00001), 27% (P < 0.00001) and 20% (P = 0.00019), respectively; 41.1% of patients had at least one comorbidity. The prevalence of type 2 diabetes nearly doubled (from 13.7% to 25.4%; P < 0.00001) between 2008-2010 and 2014-2016.

CONCLUSIONS

Alcohol misuse was the most important aetiology. The importance of NAFLD/NASH, cryptogenic and HBV-cirrhosis and the burden of comorbidity increased during 2008-2016. Ongoing alcohol misuse and the increasing prevalence of NAFLD/NASH, cryptogenic cirrhosis and comorbid type 2 diabetes among admissions for cirrhosis has implications for public health interventions to reduce the burden of unhealthy lifestyle and metabolic disorders.

Excess Body Weight and the Risk of Liver Cancer: Systematic Review and a Meta-Analysis of Cohort Studies

Objective: To update and expand the previous meta-analysis including all prospective studies on the issue of the associations between overweight, obesity, and liver cancer risk. We also performed a meta-regression to investigate a potential nonlinear and/or linear association between body mass index (BMI) and liver cancer risk.Methods: Literature search was conducted in four libraries from the beginning of indexing for each database to 1st September, 2018.Results: The summary risk estimate was statistically significant on the association between overweight and the risk of liver cancer incidence (relative ratio [RR] = 1.19). The RRs were significantly stronger in people with known liver disease with overweight than in the general population with overweight (RR = 1.50 vs. RR = 1.10; Pdifference = .02). The meta-analysis showed an increase by 87% on the risk of liver cancer incidence in obesity categories, relative to categories of normal BMI (RR = 1.87, P < .01). Moreover, the results showed that, overweight was associated with 9% increased and obesity with 66% increased for risk of liver cancer mortality. In linear model, the relative risks of liver cancer were 1.32 for continuous BMI per 5 kg/m2 increase.Conclusion: This meta-analysis supports the hypothesis that overweight, obesity may significantly increase liver cancer risk.

Activated TNF-α/RIPK3 signaling is involved in prolonged high fat diet-stimulated hepatic inflammation and lipid accumulation: inhibition by dietary fisetin intervention

Increasing evidence indicates that high-fat diet (HFD) is a predisposing factor for metabolic syndrome-associated systemic inflammation and nonalcoholic fatty liver disease (NAFLD).