Polyphenic trait promotes liver cancer in a model of epigenetic instability in mice

Multi-Omics profiling identifies aldehyde dehydrogenase 2 as a critical mediator in the crosstalk between Treg-mediated immunosuppression microenvironment and hepatocellular carcinoma

Dysregulation of the aldehyde dehydrogenase (ALDH) family has been implicated in various pathological conditions, including cancer. However, a systematic evaluation of ALDH alterations and their therapeutic relevance in hepatocellular carcinoma (HCC) remains lacking. Herein, we found that 15 of 19 ALDHs were transcriptionally dysregulated in HCC tissues compared to normal liver tissues. A four gene signature, including ALDH2, ALDH5A1, ALDH6A1, and ALDH8A1, robustly predicted prognosis and defined a high-risk subgroup exhibiting immunosuppressive features like regulatory T cell (Tregs) infiltration. Single-cell profiling revealed selective overexpression of tumor necrosis factor receptor superfamily member 18 (TNFRSF18) on Tregs, upregulated in high-risk HCC patients. We identified ALDH2 as a tumor suppressor in HCC, with three novel phosphorylation sites mediated by protein kinase C zeta that enhanced enzymatic activity. Mechanistically, ALDH2 suppressed Tregs differentiation by inhibiting β-catenin/TGF-β1 signaling in HCC. Collectively, our integrated multi-omics analysis defines an ALDH-Tregs-TNFRSF18 axis that contributes to HCC pathogenesis and represents potential therapeutic targets for this aggressive malignancy.

Sex Dimorphic Effects of Bile Acid Metabolism in Liver Cancer in Mice

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is a male-dominant disease, but targeted sex hormone therapies have not been successful. Bile acids are a potential liver carcinogen and are biomolecules with hormone-like effects. A few studies highlight their potential sex dimorphism in physiology and disease. We hypothesized that bile acids could be a potential molecular signature that explains sex disparity in HCC.

METHODS & RESULTS

We used the farnesoid X receptor knockout (FxrKO) mouse model to study bile acid-dependent HCC. Temporal tracking of circulating bile acids determined more than 80% of FxrKO females developed spontaneous cholemia (ie, serum total bile acids ≥40 μmol/L) as early as 8 weeks old. Opposingly, FxrKO males were highly resistant to cholemia, with ∼23% incidence even when 26 weeks old. However, FxrKO males demonstrated higher levels of deoxycholate than females. Compared with males, FxrKO females had more severe cholestatic liver injury and further aberrancies in bile acid metabolism. Yet, FxrKO females expressed more detoxification transcripts and had greater renal excretion of bile acids. Intervention with CYP7A1 (rate limiting enzyme for bile acid biosynthesis) deficiency or taurine supplementation either completely or partially normalized bile acid levels and liver injury in FxrKO females. Despite higher cholemia prevalence in FxrKO females, their tumor burden was less compared with FxrKO males. An exception to this sex-dimorphic pattern was found in a subset of male and female FxrKO mice born with congenital cholemia due to portosystemic shunt, where both sexes had comparable robust HCC.

CONCLUSIONS

Our study highlights bile acids as sex-dimorphic metabolites in HCC except in the case of portosystemic shunt.

Developmental priming of cancer susceptibility

DNA mutations are necessary drivers of cancer, yet only a small subset of mutated cells go on to cause the disease. To date, the mechanisms that determine which rare subset of cells transform and initiate tumorigenesis remain unclear. Here, we take advantage of a unique model of intrinsic developmental heterogeneity (Trim28+/D9) and demonstrate that stochastic early life epigenetic variation can trigger distinct cancer-susceptibility 'states' in adulthood. We show that these developmentally primed states are characterized by differential methylation patterns at typically silenced heterochromatin, and that these epigenetic signatures are detectable as early as 10 days of age. The differentially methylated loci are enriched for genes with known oncogenic potential. These same genes are frequently mutated in human cancers, and their dysregulation correlates with poor prognosis. These results provide proof-of-concept that intrinsic developmental heterogeneity can prime individual, life-long cancer risk.

Fermented Stevia Improves Alcohol Poisoning Symptoms Associated with Changes in Mouse Gut Microbiota

We previously found that the continuous feeding of ethanol caused mice dysbiosis, in which the cecal microbiota were significantly altered, as compared with those in the non-feeding control group, especially in some bacterial genera involved in gut inflammation. In the present study, we have found that the fermented extract of stevia (Stevia rebaudiana) leaves with plant-derived lactic acid bacteria (LABs), Pediococcus pentosaceus LY45, improves the trimethylamine (TMA) productivity of cecal content, which can be used as an indicator of dysbiosis. The following animal experiment also shows that the LY45-fermented stevia extract represses the typical increase in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, which decreased from 1106 to 210 IU/L (p < 0.05) and from 591 to 100 IU/L (p < 0.05), respectively, together with the simultaneously latent TMA productivity (from 1356 to 745 μM, p < 0.05) of cecal content in the ethanol-fed mice. The microbiota analyses have shown that the observed increased alterations in pro-inflammatory genera putative SMB53 (family Clostridiaceae) and Dorea are restored by the fermented stevia extract. Our result indicates that the preliminary bioconversion of herbal medicinal precursors by fermentation with safe microorganisms like LABs is expected to be a hopeful method of producing specific metabolites that may contribute to the reconstruction of gut microbiota.

WDR4/TRIM28 is a novel molecular target linked to lenvatinib resistance that helps retain the stem characteristics in hepatocellular carcinomas

Hepatocellular carcinoma (HCC) is an aggressive malignancy with few effective treatment options. Lenvatinib is the first-line therapy for HCC but has only limited clinical benefit. Here, we explored the role and mechanism of the WD repeat domain 4 (WDR4) in lenvatinib resistance to improve clinical benefit. We found that lenvatinib-resistant HCC tissues/cells exhibited increased the N⁷-methylguanosine (m⁷G) modification and WDR4 expression. By a gain/loss of function experiment, we showed that WDR4 promoted HCC lenvatinib resistance and tumor progress both in vitro and in vivo. By proteomics analysis and RNA immunoprecipitation PCR, we found that tripartite motif protein 28 (trim28) was an important WDR4 target gene. WDR4 promoted TRIM28 expression, further affected target genes expression, and thus increased cell-acquired stemness and lenvatinib resistance. Clinical tissue data showed that TRIM28 expression was correlated with WDR4 levels, and the expression of both was positively correlated with poor prognosis. Our study provides new insight into the role of WDR4, suggesting a potential therapeutic target to enhance the lenvatinib sensitivity of HCC.

TRIM proteins in hepatocellular carcinoma

The tripartite motif (TRIM) protein family is a highly conserved group of E3 ligases with 77 members known in the human, most of which consist of a RING-finger domain, one or two B-box domains, and a coiled-coil domain. Generally, TRIM proteins function as E3 ligases to facilitate specific proteasomal degradation of target proteins. In addition, E3 ligase independent functions of TRIM protein were also reported. In hepatocellular carcinoma, expressions of TRIM proteins are both regulated by genetic and epigenetic mechanisms. TRIM proteins regulate multiple biological activities and signaling cascades. And TRIM proteins influence hallmarks of HCC. This review systematically demonstrates the versatile roles of TRIM proteins in HCC and helps us better understand the molecular mechanism of the development and progression of HCC.

Mechanism of Phellodendron and Anemarrhena Drug Pair on the Treatment of Liver Cancer Based on Network Pharmacology and Bioinformatics

Background

This study aims to explore the key targets and signaling pathways of the traditional Chinese medicine Phellodendron and Anemarrhena drug pair (PADP) for the treatment of liver cancer.

Methods

Firstly, bioinformatics technology was used to analyze GSE62232 gene chip to obtain the differential genes of liver cancer. A network pharmacology technology was used to find the active components of PADP and their targets. Secondly, the differential genes were imported into STRING database to draw a PPI network, and network topology structure map combined with Cytoscape software. And the R language was used to identify differential gene targets and pathways through GO and KEGG pathway enrichment analysis. In addition, AutoDock Vina was used for molecular docking of core targets and core compounds. Moreover, GEPIA online analysis tool was used to perform survival analysis of the core target genes. Finally, RT-PCR was used to verify the changes of key target genes. CCK−8 assay was performed to detect cell proliferation. Flow cytometry was performed to detect the cell cycle and apoptotic. Transwell invasion assay was performed to detect cell invasion.

Results

Firstly, a total of 21,654 genes were obtained. After screening, 1019 differential genes were obtained, including 614 down-regulated genes and 405 up-regulated genes. Furthermore, after screening by ADME standards, 52 active ingredients were obtained, of which 37 were Phellodendron and 15 were Anemarrhena. And a total of 36 differential genes have been identified, including 13 up-regulated genes and 23 down-regulated genes. Moreover, through enrichment analysis, we found that PADP may treat liver cancer through multiple channels and multiple pathways including the p53 signaling pathway, IL-17 signaling pathway, TNF signaling pathway, Toll-like receptor signaling pathway and so on. Secondly, the molecular docking results showed that there was certain affinity between the core compounds and core target genes. In addition, GEPIA online analysis showed that ESR1, AR, CCNB1, CDK1, AKR1C3 and CCNA2 might become potential target genes for the survival and prognosis of PADP for the treatment of liver cancer. Finally, it was found that PADP could up regulate genes ESR1 and AR, down regulate genes CCNB1, CDK1, AKR1C3, and CCNA2. PADP could promote the apoptosis of liver cancer cells, shorten the cell cycle, and inhibit the proliferation and invasion of liver cancer cells.

Conclusion

PADP may treat liver cancer through multiple targets, multiple channels, and multiple pathways, thereby suppressing cancer cells and improving the living quality of patients.

Sex differences in white adipose tissue expansion: emerging molecular mechanisms

The escalating prevalence of individuals becoming overweight and obese is a rapidly rising global health problem, placing an enormous burden on health and economic systems worldwide. Whilst obesity has well described lifestyle drivers, there is also a significant and poorly understood component that is regulated by genetics. Furthermore, there is clear evidence for sexual dimorphism in obesity, where overall risk, degree, subtype and potential complications arising from obesity all differ between males and females. The molecular mechanisms that dictate these sex differences remain mostly uncharacterised. Many studies have demonstrated that this dimorphism is unable to be solely explained by changes in hormones and their nuclear receptors alone, and instead manifests from coordinated and highly regulated gene networks, both during development and throughout life. As we acquire more knowledge in this area from approaches such as large-scale genomic association studies, the more we appreciate the true complexity and heterogeneity of obesity. Nevertheless, over the past two decades, researchers have made enormous progress in this field, and some consistent and robust mechanisms continue to be established. In this review, we will discuss some of the proposed mechanisms underlying sexual dimorphism in obesity, and discuss some of the key regulators that influence this phenomenon.

Bile Acids and Microbiota: Multifaceted and Versatile Regulators of the Liver-Gut Axis

After their synthesis from cholesterol in hepatic tissues, bile acids (BAs) are secreted into the intestinal lumen. Most BAs are subsequently re-absorbed in the terminal ileum and are transported back for recycling to the liver. Some of them, however, reach the colon and change their physicochemical properties upon modification by gut bacteria, and vice versa, BAs also shape the composition and function of the intestinal microbiota. This mutual interplay of both BAs and gut microbiota regulates many physiological processes, including the lipid, carbohydrate and energy metabolism of the host. Emerging evidence also implies an important role of this enterohepatic BA circuit in shaping mucosal colonization resistance as well as local and distant immune responses, tissue physiology and carcinogenesis. Subsequently, disrupted interactions of gut bacteria and BAs are associated with many disorders as diverse as Clostridioides difficile or Salmonella Typhimurium infection, inflammatory bowel disease, type 1 diabetes, asthma, metabolic syndrome, obesity, Parkinson’s disease, schizophrenia and epilepsy. As we cannot address all of these interesting underlying pathophysiologic mechanisms here, we summarize the current knowledge about the physiologic and pathogenic interplay of local site microbiota and the enterohepatic BA metabolism using a few selected examples of liver and gut diseases.

The effects of epigenetic modification on the occurrence and progression of liver diseases and the involved mechanism

Introduction: Epigenetic modification is a type of gene expression and regulation that does not involve changes in DNA sequences. An increasing number of studies have proven that epigenetic modifications play an important role in the occurrence and progression of liver diseases through the gene regulation and protein expressions of hepatocellular lipid metabolism, inflammatory reaction, cell proliferation, and activation, etc.Areas covered: In this study, we elaborated and analyzed the underlying functional mechanism of epigenetic modification in alcoholic liver disease (ALD), nonalcoholic fatty liver disease (NAFLD), liver fibrosis (LF), viral hepatitis, hepatocellular carcinoma (HCC), and research progress of recent years.Expert opinion: The further understanding of epigenetic mechanisms that can regulate gene expression and cell phenotype leads to new insights in epigenetic control of chronic liver disease. Currently, hepatologists are exploring the role of DNA methylation, histone/chromatin modification, and non-coding RNA in specific liver pathology. These findings have led to advances in direct epigenetic biomarker testing of patient tissue or body fluid specimens, as well as quantitative analysis. Based on these findings, drug validation of some targets involved in the epigenetic mechanism of liver disease is gradually being carried out clinically.

TRIM28 protects CARM1 from proteasome-mediated degradation to prevent colorectal cancer metastasis

TRIM28 (Tripartite motif-containing protein 28), a member of TRIM family, is aberrantly expressed and reportedly has different functions in many types of human cancer. However, the biological roles of TRIM28 and related mechanism in colorectal cancer (CRC) remain unclear. Here, we showed that TRIM28 was downregulated in colorectal cancer compared with normal mucosa, especially at advanced stages, and acted as an independent prognostic factor of favorable outcome. Functional studies demonstrated that TRIM28 restrained CRC migration and invasion in vitro and in vivo. Mechanistically, we reported that CARM1 (co-activator-associated arginine methyltransferase1) was a critical player downstream of TRIM28. TRIM28 interacted with CARM1, and protected CARM1 from proteasome-mediated degradation through physical protein-protein interaction to suppress CRC metastasis. Further, TRIM28 suppressed the migration and invasion of CRC cells through inhibiting WNT/β-catenin signaling in a CARM1-dependent manner, but independent of CARM1's methyltransferase activity. The protein expression of CARM1 was positively correlated with TRIM28 in CRC tissues. Patients with high levels of TRIM28 and CARM1 had improved prognosis, whereas patients with low TRIM28 and CARM1 expression had the poor outcomes. Thus, our study reveals an inhibitory role of TRIM28 in CRC metastasis, which was achieved through a TRIM28-CARM1-WNT/β-catenin axis. This work provides potential prognostic and therapeutic targets for CRC treatment.

Epigenetic changes of the thioredoxin system in the tx-j mouse model and in patients with Wilson disease

Wilson disease (WD) is caused by mutations in the copper transporter ATP7B, leading to copper accumulation in the liver and brain. Excess copper inhibits S-adenosyl-L-homocysteine hydrolase, leading to variable WD phenotypes from widespread alterations in DNA methylation and gene expression. Previously, we demonstrated that maternal choline supplementation in the Jackson toxic milk (tx-j) mouse model of WD corrected higher thioredoxin 1 (TNX1) transcript levels in fetal liver. Here, we investigated the effect of maternal choline supplementation on genome-wide DNA methylation patterns in tx-j fetal liver by whole-genome bisulfite sequencing (WGBS). Tx-j Atp7b genotype-dependent differences in DNA methylation were corrected by choline for genes including, but not exclusive to, oxidative stress pathways. To examine phenotypic effects of postnatal choline supplementation, tx-j mice were randomized to one of six treatment groups: with or without maternal and/or continued choline supplementation, and with or without copper chelation with penicillamine (PCA) treatment. Hepatic transcript levels of TXN1 and peroxiredoxin 1 (Prdx1) were significantly higher in mice receiving maternal and continued choline with or without PCA treatment compared to untreated mice. A WGBS comparison of human WD liver and tx-j mouse liver demonstrated a significant overlap of differentially methylated genes associated with ATP7B deficiency. Further, eight genes in the thioredoxin (TXN) pathway were differentially methylated in human WD liver samples. In summary, Atp7b deficiency and choline supplementation have a genome-wide impact, including on TXN system-related genes, in tx-j mice. These findings could explain the variability of WD phenotype and suggest new complementary treatment options for WD.

The complexity of TRIM28 contribution to cancer

Since the first discovery in 1996, the engagement of TRIM28 in distinct aspects of cellular biology has been extensively studied resulting in identification of a complex nature of TRIM28 protein. In this review, we summarize core biological functions of TRIM28 that emerge from TRIM28 multi-domain structure and possessed enzymatic activities. Moreover, we will discuss whether the complexity of TRIM28 engagement in cancer biology makes TRIM28 a possible candidate for targeted anti-cancer therapy. Briefly, we will demonstrate the role of TRIM28 in regulation of target gene transcription, response to DNA damage, downregulation of p53 activity, stimulation of epithelial-to-mesenchymal transition, stemness sustainability, induction of autophagy and regulation of retrotransposition, to provide the answer whether TRIM28 functions as a stimulator or inhibitor of tumorigenesis. To date, number of studies demonstrate significant upregulation of TRIM28 expression in cancer tissues which correlates with worse overall patient survival, suggesting that TRIM28 supports cancer progression. Here, we present distinct aspects of TRIM28 involvement in regulation of cancer cell homeostasis which collectively imply pro-tumorigenic character of TRIM28. Thorough analyses are further needed to verify whether TRIM28 possess the potential to become a new anti-cancer target.

Targeted delivery of siRNA using RGDfC-conjugated functionalized selenium nanoparticles for anticancer therapy

Lack of biocompatible and effective delivery carriers is a significant shortcoming for siRNA-mediated cancer therapy. To overcome these limitations, selenium nanoparticles (SeNPs) have been proposed for siRNA transfection vehicles. In this study, we synthesized novel RGDfC peptide modified selenium nanoparticles (RGDfC-SeNPs) as a gene vehicle, which was expected to improve the tumor-targeted delivery activity. RGDfC-SeNPs were compacted with siRNAs (anti-Oct4) by electrostatic interaction, which was capable of protecting siRNA from degradation. RGDfC-SeNPs exhibited excellent ability to deliver siRNA into HepG2 cells. siRNA transfection assay showed that RGDfC-SeNPs presented a higher gene silencing efficacy than conventional lipofectamine 2000. The cytotoxicity of RGDfC-SeNPs/siRNA on normal cells was lower than that on tumor cells, indicating that RGDfC-SeNPs/siRNA exhibited selectivity between normal and cancer cells. Additionally, Oct4 knockdown mediated by the selenium nanoparticle transfection arrested HepG2 cells mainly at the G2/M phase and significantly induced HepG2 cell apoptosis. Western blotting results showed that RGDfC-SeNPs/siRNA might trigger Wnt/β-catenin signaling, and further activate a BCL-2 apoptosis-related signaling pathway to advance HepG2 cell apoptosis. In vivo biodistribution experiments indicated that RGDfC-SeNPs/siRNA nanoparticles were specifically targeted to the HepG2 tumors. Most importantly, RGDfC-SeNPs/siRNA inhibited tumor growth significantly and induced HepG2 cell apoptosis via silencing the Oct4 gene. In addition, the results of H&E staining demonstrated that RGDfC-SeNPs/siRNA had negligible toxicity on the major organs of mice. In a word, this study provides a novel strategy for the design of biocompatible and effective siRNA delivery vehicles in cancer therapy.