Abstract Background & aims Constitutive activation of the β-catenin pathway is a determining feature in the pathogenesis of two primary liver cancers, namely HCC and hepatoblastoma (HB). Activating alterations in CTNNB1 gene and, to a lesser extent, inhibiting alterations in APC gene are observed in 30 to 40% of HCC cases and 80 to 90% of HB cases. For both tumours, therapeutic management is far from optimal. Therefore, relevant experimental models are needed to increase our knowledge and test new therapeutic approaches. Methods Organoids and tumouroids were established from APC Δhep and βcat Δex3 mouse models, which are clinically relevant models for β-catenin-activated HCC and mesenchymal HB. We developed a new methodological approach based on a dynamic suspension culture in a rotating bioreactor. Morphological and molecular characteristics and sensitivity to WNTinib, a treatment already successfully tested on human HCC and HB tumouroids, were evaluated by histology, immunohistochemistry, immunofluorescence, and RT-qPCR. Results This easy-to-implement methodology allows for the rapid generation of a large number of organoids and tumouroids that are uniform in size and show no signs of cell death in their core. The robustness of the methodology is illustrated by the maintenance of the histological architecture, cell diversity and gene expression in organoids and tumouroids in comparison with the native liver tissues. In addition, the value of the HCC-derived tumouroids for evaluating cancer treatment was assessed based on their responsiveness to the β-catenin antagonist WNTinib. Conclusions The organoids and tumouroids that we present here are new reliable in vitro cancer models, recapitulating the main features of β-catenin-driven HCC and mesenchymal HB. They can be integrated into an appropriate platform for drug screening and could enable the development of “à la carte” therapies that are urgently needed for these indications. Impact and implications This study addresses the critical need for representative in vitro models to investigate β-catenin-driven liver cancers. The organoids and tumouroids developed here are particularly valuable for researchers seeking robust, reproducible models that accurately reflect the cellular diversity and gene expression profiles of native liver tumours. These findings have practical applications in exploring cancer mechanisms, screening new drugs, optimizing personalized treatment strategies, and reducing reliance on animal models, which ultimately benefits patients. Highlights Easy and rapid generation of mouse liver organoids and tumouroids from β-catenin activated tumours using culture in a bioreactor Tumouroids preserve histology, cell diversity, and gene expression of native tissue HCC-derived tumouroids respond to β-catenin inhibitor WNTinib These reliable 3D models reduce reliance on animal experiments for drug testing

Acyl coenzyme A binding protein (ACBP encoded by diazepam binding inhibitor DBI) is involved in non-malignant liver diseases. Here, we show that DBI mRNA and circulating ACBP/DBI levels are increased in patients with hepatocellular carcinoma (HCC). We investigated its role in hepatocarcinogenesis in mice, inhibiting ACBP/DBI by three methods: (1) inducible whole-body or liver-specific knockout of DBI, (2) a point mutation of the ACBP/DBI receptor (GABRG2), and (3) induction of autoantibodies neutralizing ACBP/DBI. ACBP/DBI plays a major pro-carcinogenic role in HCC induced by intrahepatic transplantation of HCC cell lines, transgenic co-expression of the two oncogenes Myc and Ctnnb1, and chronic challenge with a Western-style diet together with either carbon tetrachloride (CCl4) or diethylnitrosamine. ACBP/DBI inhibition normalizes HCC-associated gene expression, reducing oncogenic alterations in cell cycle-, immunomodulatory-, and ferroptosis-regulatory genes. ACBP/DBI inhibition increases HCC responses to PD-1 blockade and sensitizes HCC to the therapeutic induction of ferroptosis. Hence, ACBP/DBI constitutes an actionable target involved in HCC pathogenesis.

The insulin receptor (INSR) exists in two isoforms, INSR-A and INSR-B, resulting from alternative splicing of the INSR pre-mRNA. INSR-B mediates the metabolic and mitogenic effects of insulin in the adult liver, while INSR-A is expressed during development. Recently, INSR-A has been detected in pathological murine and human livers. Here, we develop an in vivo CRISPR/Cas9 strategy to assess the impact of INSR-A on mouse liver homeostasis and susceptibility to carcinogenesis. We find that INSR-A expression in hepatocytes leads to the spontaneous development of liver tumours and also increases tumour initiation in a context of β-catenin-driven liver carcinogenesis. Mechanistically, this is attributed to the higher intrinsic capacity of INSR-A expressing hepatocytes to enter apoptosis, rendering the microenvironment more inflammatory, thus making way for the proliferation of preneoplastic cells. Collectively, our data highlight a novel function for INSR-A in promoting liver cancer via non-cell autonomous mechanisms.

Background & Aims Tumor development and progression are mainly driven by oncogenic mutations but are also regulated by physical factors, such as applied forces or microenvironment stiffness. Through its structural and transcriptional functions, ßcatenin is a key factor that acts on both aspects to promote liver tumorigenesis, leading to hepatocellular carcinoma (HCC) development. However, the mechanisms by which these two functions regulate downstream targets remain poorly understood. Herein, we describe Rnd3, also called RhoE, an atypical member of the Rho GTPase family, as a common target of both functions of ß-catenin. We previously demonstrated that RND3 expression is downregulated in HCC, which correlates with intrahepatic metastasis. Yet, a molecular understanding of how Rnd3 expression is dysregulated in cancer is largely missing. Approach & Results Using human HCC samples and cultured cell lines, we demonstrate that Rnd3 expression is regulated by ß-catenin pathways, regardless of their mutational status. Both the transcriptional and the structural activity of ß-catenin repress the expression of RND3 . Indeed, we found that wild-type ß-catenin suppresses RND3 transcription through the Hippo pathway, whereas oncogenic ß-catenin downregulates RND3 expression through miRNA targeting its 3’UTR. Conclusion Rnd3 may constitute a key protein involved in the transcriptional program driven by oncogenic ß-catenin in HCC and as a mediator of the mechanosensitive response associated with cell-cell adhesion. ### Competing Interest Statement The authors have declared no competing interest. * GS : Glutamine Synthetase HCC : hepatocellular carcinoma Fondation ARC pour la Recherche sur le Cancer, https://ror.org/0489qz649, Post-doc fellowship Association Française pour l’Etude du Foie, https://ror.org/04fh21g11 La Ligue Contre le Cancer, https://ror.org/00rkrv905 Institut National du Cancer, PLBIO-INCa2014-182

BACKGROUND:The mesenchymal subtype of colorectal cancer (CRC), associated with poor prognosis, is characterized by abundant expression of the cellular prion protein PrPC, which represents a candidate therapeutic target. How PrPC is induced in CRC remains elusive. This study aims to elucidate the signaling pathways governing PrPC expression and to shed light on the gene regulatory networks linked to PrPC. METHODS:We performed in silico analyses on diverse datasets of in vitro, ex vivo and in vivo models of mouse CRC and patient cohorts. We mined ChIPseq studies and performed promoter analysis. CRC cell lines were manipulated through genetic and pharmacological approaches. We created mice combining conditional inactivation of Apc in intestinal epithelial cells and overexpression of the human prion protein gene PRNP. Bio-informatic analyses were carried out in two randomized control trials totalizing over 3000 CRC patients. RESULTS:In silico analyses combined with cell-based assays identified the Wnt-β-catenin and glucocorticoid pathways as upstream regulators of PRNP expression, with subtle differences between mouse and human. We uncover multiple feedback loops between PrPC and these two pathways, which translate into an aggravation of CRC pathogenesis in mouse. In stage III CRC patients, the signature defined by PRNP-CTNNB1-NR3C1, encoding PrPC, β-catenin and the glucocorticoid receptor respectively, is overrepresented in the poor-prognosis, mesenchymal subtype and associates with reduced time to recurrence. CONCLUSIONS:An unleashed PrPC-dependent vicious circle is pathognomonic of poor prognosis, mesenchymal CRC. Patients from this aggressive subtype of CRC may benefit from therapies targeting the PRNP-CTNNB1-NR3C1 axis.

The CTNNB1 gene, encoding β-catenin, is frequently mutated in hepatocellular carcinoma (HCC, ∼30%) and in hepatoblastoma (HB, >80%), in which DLK1/DIO3 locus induction is correlated with CTNNB1 mutations. Here, we aim to decipher how sustained β-catenin activation regulates DLK1/DIO3 locus expression and the role this locus plays in HB and HCC development in mouse models deleted for Apc (ApcΔhep) or Ctnnb1-exon 3 (β-cateninΔExon3) and in human CTNNB1-mutated hepatic cancer cells. We identified an enhancer site bound by TCF-4/β-catenin complexes in an open conformation upon sustained β-catenin activation (DLK1-Wnt responsive element [WRE]) and increasing DLK1/DIO3 locus transcription in β-catenin-mutated human HB and mouse models. DLK1-WRE editing by CRISPR-Cas9 approach impaired DLK1/DIO3 locus expression and slowed tumor growth in subcutaneous CTNNB1-mutated tumor cell grafts, ApcΔhep HB and β-cateninΔExon3 HCC. Tumor growth inhibition resulted either from increased FADD expression and subsequent caspase-3 cleavage in the first case or from decreased expression of cell cycle actors regulated by FoxM1 in the others. Therefore, the DLK1/DIO3 locus is an essential determinant of FoxM1-dependent cell proliferation during β-catenin-driven liver tumorigenesis. Targeting the DLK1-WRE enhancer to silence the DLK1/DIO3 locus might thus represent an interesting therapeutic strategy to restrict tumor growth in primary liver cancers with CTNNB1 mutations.

The reprogramming of glutamine metabolism is a key event in cancer more generally and in hepatocellular carcinoma (HCC) in particular. Glutamine consumption supplies tumours with ATP and metabolites through anaplerosis of the tricarboxylic acid cycle, while glutamine production can be enhanced by the overexpression of glutamine synthetase. In HCC, increased glutamine production is driven by activating mutations in the CTNNB1 gene encoding β-catenin. Increased glutamine synthesis or utilisation impacts tumour epigenetics, oxidative stress, autophagy, immunity and associated pathways, such as the mTOR (mammalian target of rapamycin) pathway. In this review, we will discuss studies which emphasise the pro-tumoral or tumour-suppressive effect of glutamine overproduction. It is clear that more comprehensive studies are needed as a foundation from which to develop suitable therapies targeting glutamine metabolic pathways, depending on the predicted pro- or anti-tumour role of dysregulated glutamine metabolism in distinct genetic contexts.

Supplementary Figure 1 from Identification of the IFITM Family as a New Molecular Marker in Human Colorectal Tumors

Supplementary Materials and Methods from Identification of the IFITM Family as a New Molecular Marker in Human Colorectal Tumors

Background & Aims:β-catenin is a well-known effector of the Wnt pathway, and a key player in cadherin-mediated cell adhesion. Oncogenic mutations of β-catenin are very frequent in paediatric liver primary tumours. Those mutations are mostly heterozygous, which allows the co-expression of wild-type (WT) and mutated β-catenins in tumour cells. We investigated the interplay between WT and mutated β-catenins in liver tumour cells, and searched for new actors of the β-catenin pathway. Methods:Using an RNAi strategy in β-catenin-mutated hepatoblastoma (HB) cells, we dissociated the structural and transcriptional activities of β-catenin, which are carried mainly by WT and mutated proteins, respectively. Their impact was characterised using transcriptomic and functional analyses. We studied mice that develop liver tumours upon activation of β-catenin in hepatocytes (APCKO and β-cateninΔexon3 mice). We used transcriptomic data from mouse and human HB specimens, and used immunohistochemistry to analyse samples. Results:We highlighted an antagonistic role of WT and mutated β-catenins with regard to hepatocyte differentiation, as attested by alterations in the expression of hepatocyte markers and the formation of bile canaliculi. We characterised fascin-1 as a transcriptional target of mutated β-catenin involved in tumour cell differentiation. Using mouse models, we found that fascin-1 is highly expressed in undifferentiated tumours. Finally, we found that fascin-1 is a specific marker of primitive cells including embryonal and blastemal cells in human HBs. Conclusions:Fascin-1 expression is linked to a loss of differentiation and polarity of hepatocytes. We present fascin-1 as a previously unrecognised factor in the modulation of hepatocyte differentiation associated with β-catenin pathway alteration in the liver, and as a new potential target in HB. Impact and implications:The FSCN1 gene, encoding fascin-1, was reported to be a metastasis-related gene in various cancers. Herein, we uncover its expression in poor-prognosis hepatoblastomas, a paediatric liver cancer. We show that fascin-1 expression is driven by the mutated beta-catenin in liver tumour cells. We provide new insights on the impact of fascin-1 expression on tumour cell differentiation. We highlight fascin-1 as a marker of immature cells in mouse and human hepatoblastomas.

Background and aims One-third of hepatocellular carcinomas (HCCs) have mutations that activate the β-catenin pathway with mostly CTNNB1 mutations. Mouse models using Adenomatous polyposis coli ( Apc ) loss-of-functions (LOF) are widely used to mimic β-catenin-dependent tumorigenesis. Considering the low prevalence of APC mutations in human HCCs we aimed to generate hepatic tumors through CTNNB1 exon 3 deletion (β cat Δex3 ) and to compare them to hepatic tumors with Apc LOF engineered through a frameshift in exon 15 ( Apc fs-ex15 ). Methods We used hepatic-specific and inducible Cre-lox mouse models as well as a hepatic-specific in vivo CRISPR/Cas9 approach using AAV vectors, to generate Apc fs-ex15 and βcat Δex3 hepatic tumors harboring activation of the β-catenin pathway. Tumors generated by the Cre-lox models were analyzed phenotypically using immunohistochemistry and were selected for transcriptomic analysis using RNA-sequencing. Mouse RNAseq data were compared to human RNAseq data (normal tissues (8), HCCs (48) and hepatoblastomas (9)) in an integrative analysis. Tumors generated via CRISPR were analyzed using DNA sequencing and immunohistochemistry. Results Mice with βcat Δex3 alteration in hepatocytes developed liver tumors. Generated tumors were indistinguishable from those arising in Apc fs-ex15 mice. Both Apc fs-ex15 and βcat Δex3 mouse models induced two phenotypically distinct tumors (differentiated or undifferentiated). Integrative analysis of human and mouse tumors showed that mouse differentiated tumors are close to human well differentiated CTNNB1 -mutated tumors, while undifferentiated ones are closer to human mesenchymal hepatoblastomas, and are activated for YAP signaling. Conclusion Apc fs-ex15 and βcat Δex3 mouse models similarly induce tumors transcriptionally close to either well differentiated β-Catenin activated human HCCs or mesenchymal hepatoblastomas.

Background & Aims: The NKG2D system is a potent immuno-surveillance mechanism in cancer, wherein the activating NK cell receptor (NKG2D) on immune cells recognises its cognate ligands on tumour cells. Herein, we evaluated the expression of NKG2D ligands in hepatocellular carcinoma (HCC), in both humans and mice, taking the genomic features of HCC tumours into account. Methods: The expression of NKG2D ligands (MICA, MICB, ULBP1 and ULBP2) was analysed in large human HCC datasets by Fluidigm TaqMan and RNA-seq methods, and in 2 mouse models (mRNA and protein levels) reproducing the features of both major groups of human tumours. Results: We provide compelling evidence that expression of the MICA and MICB ligands in human HCC is associated with tumour aggressiveness and poor patient outcome. We also found that the expression of ULBP1 and ULBP2 was associated with poor patient outcome, and was downregulated in CTNNB1-mutated HCCs displaying low levels of inflammation and associated with a better prognosis. We also found an inverse correlation between ULBP1/2 expression levels and the expression of beta-catenin target genes in patients with HCC, suggesting a role for beta-catenin signalling in inhibiting expression. We showed in HCC mouse models that beta-catenin signalling downregulated the expression of Rae-1 NKG2D ligands, orthologs of ULBPs, through TCF4 binding. Conclusions: We demonstrate that the expression of NKG2D ligands is associated with aggressive liver tumorigenesis and that the downregulation of these ligands by beta-catenin signalling may account for the less aggressive phenotype of CTNNB1-mutated HCC tumours. Lay summary: The NKG2D system is a potent immuno-surveillance mechanism in cancer. However, its role in hepato-cellular carcinoma development has not been widely investigated. Herein, we should that the expression of NKG2D ligands by tumour cells is associated with a more aggressive tumour subtype. (C) 2021 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

ABSTRACTBACKGROUND & AIMSß-catenin is a well-known effector of the Wnt pathway and a key player in cadherin-mediated cell adhesion. Oncogenic mutations of ß-catenin are highly frequent in pediatric liver primary tumors. Those mutations are mostly heterozygous allowing the co-expression of wild-type (WT) and mutated ß-catenins in tumor cells. We investigated the interplay between WT and mutated ß-catenins in liver tumor cells, and searched for new actors of the ß-catenin pathway.METHODSUsing an RNAi strategy in ß-catenin-mutated hepatoblastoma (HB) cells, we dissociated the structural and transcriptional activities of β-catenin, carried mainly by, respectively, WT and mutated proteins. Their impact was characterized using transcriptomic and functional analyses. We studied mice that develop liver tumors upon activation of ß-catenin in hepatocytes (APCKOand ß-cateninΔexon3mice). We made use of transcriptomic data from mouse and human HB specimens and analyzed samples by immunohistochemistry.RESULTSWe highlighted an antagonist role of WT and mutated ß-catenins on hepatocyte differentiation as attested by alteration of hepatocyte markers expression and bile canaliculi formation. We characterized Fascin-1 as a target of ß-catenin involved in hepatocyte differentiation. Using mouse models that allow the formation of two phenotypically distinct tumors (differentiated or undifferentiated), we found that Fascin-1 expression is higher in undifferentiated tumors. Finally, we found that Fascin-1 is a specific marker of the embryonal component in human HBs.CONCLUSIONSIn mice and human, Fascin-1 expression is linked to loss of differentiation and polarity of hepatocytes. Thus, we highlighted Fascin-1 as a new player in the modulation of hepatocyte differentiation associated to ß-catenin pathway alteration in the liver.Data Transparency Statementstudy materials will be made available to other researchers upon request.

See Article, page 603–615 See Article, page 603–615 While one third of the world's population is overweight or obese, the impact of obesity as an epigenetic trait affecting not only people's health but also the health of unborn children is highly questionable. Obesity confers a higher risk of developing metabolic diseases, such as non-alcoholic fatty liver disease (NAFLD), and hepatocellular carcinoma (HCC).[1]Anstee Q.M. Reeves H.L. Kotsiliti E. Govaere O. Heikenwalder M. From NASH to HCC: current concepts and future challenges.Nat Rev Gastroenterol Hepatol. 2019; 16: 411-428Crossref PubMed Scopus (278) Google Scholar Besides that, the offspring of obese mothers are known to be more susceptible to NAFLD, but no relationship has been established between obesity in mothers and the risk of their progeny developing HCC.[2]Li J. Huang J. Li J.S. Chen H. Huang K. Zheng L. Accumulation of endoplasmic reticulum stress and lipogenesis in the liver through generational effects of high fat diets.J Hepatol. 2012; 56: 900-907Abstract Full Text Full Text PDF PubMed Scopus (99) Google Scholar There is abundant evidence for intergenerational inheritance of epigenetic states occurring in plants and animals.[3]Cavalli G. Heard E. Advances in epigenetics link genetics to the environment and disease.Nature. 2019; 571: 489-499Crossref PubMed Scopus (237) Google Scholar This inheritance presupposes an external stimulus — that can be metabolic — which stably modifies parental cell fate and can be transmitted from the parents to the fetus. When cellular memory is imprinted in the DNA of germ-line cells, cell reprogramming is stable over the generations, and becomes transgenerational. When affecting somatic cells of the mother, the inheritance of cell memory can be inter-generational, affecting only the immediate progeny. Maternal or paternal short RNAs have been implicated in inter- or trans-generational inheritance of epigenetic states.[4]Stuwe E. Toth K.F. Aravin A.A. Small but sturdy: small RNAs in cellular memory and epigenetics.Genes Dev. 2014; 28: 423-431Crossref PubMed Scopus (44) Google Scholar In this issue of Journal of Hepatology, Sun et al. proposed an inter-generational inheritance of HCC susceptibility in mice fed a high-fat-diet (HFD), revealing a new avenue for cancer research, at the crossroads of metabolism and epigenetics. Sun et al. addressed the role of a maternal multi-generational HFD exposure on the development of HCC in offspring.[5]Sun Y. Wang Q. Zhang Y. Geng M. Wei Y. Liu Y. et al.Multigenerational maternal obesity increases the incidence of HCC in offspring via miR-27a-3p.J Hepatol. 2020; 73: 603-615Abstract Full Text Full Text PDF Scopus (9) Google Scholar Male offspring were fed with a HFD and tumors were induced by diethylnitrosamine (DEN) – a widely used chemical carcinogen that induces chronic liver damage and liver carcinoma.[6]Tolba R. Kraus T. Liedtke C. Schwarz M. Weiskirchen R. Diethylnitrosamine (DEN)-induced carcinogenic liver injury in mice.Lab Anim. 2015; 49: 59-69Crossref PubMed Scopus (98) Google Scholar These mice were compared to mice fed with normal chow with and without DEN treatment. The analyses were performed over 3 generations. They identified a set of miRNAs which are differentially regulated. Specifically, they identified miR-27a-3p and its downstream targets Acsl1 (Acyl-CoA synthetase long chain family member 1) and Aldh2 (aldehyde dehydrogenase 2 family member) as important factors in fatty liver disease and subsequently HCC formation (Fig. 1). Interestingly maternal obesity due to HFD increased the susceptibility of the offspring to tumor formation and reduced survival in the second and third generation. RNA sequencing of liver tumors from these mice revealed alterations in genes responsible for the lipid and/or amino acid metabolism. The authors focused on the genes Acsl1 and Aldh2 which were gradually downregulated in the offspring; this downregulation has also been linked to poor survival in patients with liver cancer based on the TCGA database. Additional hepatic miRNA levels were examined by RNA sequencing to identify possible regulators. Several miRNAs were gradually altered in the offspring, including miR-27a-3p, which is suggested to decrease the survival rate of patients with HCC when expressed at elevated levels, according to the TCGA database. Bioinformatic analysis indicated that miR-27a-3p might regulate transcription of Acsl1 and Aldh2, which was verified by in vitro and in vivo analysis. The elevated level of miR-27a-3p in offspring assumes a transportation of miRNAs from the mother to the offspring by small extracellular vesicles (sEVs). The transport of miRNAs including miR-27a-3p by sEVs has previously been demonstrated. PMT (proneural-to-mesenchymal transition) is a common process in the progression of glioblastoma which results in increased radiotherapy resistance. PMT is triggered by tumor-associated macrophages releasing sEVs. These sEVs send miR-27a-3p, miR-22-3p and miR-221-3p to glioma stem cells promoting the mesenchymal phenotype via the RelB/p50 and STAT3 pathways.[7]Zhang Z. Xu J. Chen Z. Wang H. Xue H. Yang C. et al.Transfer of microRNA via macrophage-derived extracellular vesicles promotes proneural-to-mesenchymal transition in glioma stem cells.Cancer Immunol Res. 2020; https://doi.org/10.1158/2326-6066.CIR-19-0759Crossref Scopus (15) Google Scholar The interplay of the NF-κB pathway was also shown in the context of acute lung injury. miR-27a-3p targets NFKB1 and thereby functions as a regulator of M2 macrophage polarization. In this study, mesenchymal stem cell-derived sEVs alleviated acute lung injury through elevated levels of miR-27a-3p in alveolar macrophages, resulting in the promotion of M2 macrophages.[8]Wang J. Huang R. Xu Q. Zheng G. Qiu G. Ge M. et al.Mesenchymal stem cell-derived extracellular vesicles alleviate acute lung injury via Transfer of miR-27a-3p.Crit Care Med. 2020; 48: e599-e610PubMed Google Scholar sEVs are also reported to be involved in stem cell maintenance, self-renewal, and differentiation. sEV-derived miRNAs mimic the function of parental stem cells in regulating the maintenance and differentiation of stem cells, controlling the intercellular regulation of gene expression, and potentially even affecting cell fate. miR-27a-3p was highly expressed in human adipose tissue stromal/stem cells and is reported to be involved in the regulation of osteogenesis.[9]Kaur S. Abu-Shahba A.G. Paananen R.O. Hongisto H. Hiidenmaa H. Skottman H. et al.Small non-coding RNA landscape of extracellular vesicles from human stem cells.Sci Rep. 2018; 8: 15503Crossref PubMed Scopus (26) Google Scholar A deregulation of metabolic pathways has been implicated in the onset and progression of HCCs. In a study by Zahid and colleagues, a gene signature coding for catabolic enzymes in patients with HCC identified ALDH2 and ADH1A (alcohol dehydrogenase 1A), both key regulators of alcohol metabolism, as key in the development of HCC. Using in silico analyses they claimed that ADH1A and ALDH2 were transcriptionally suppressed by HDAC1 (histone deacetylase 1) downstream of mTORC1 signaling, which was associated with poor survival and an aggressive disease state.[10]Zahid K.R. Yao S. Khan A.R.R. Raza U. Gou D. mTOR/HDAC1 crosstalk mediated suppression of ADH1A and ALDH2 links alcohol metabolism to hepatocellular carcinoma onset and progression in silico.Front Oncol. 2019; 9: 1000Crossref PubMed Scopus (8) Google Scholar It was also shown that ALDH2 mRNA and protein levels were significantly lower in tumor tissues than normal tissues and were also lower in tissues that exhibited increased migratory capacity. ALDH2 altered the redox status of cells by regulating acetaldehyde levels and stimulating the AMP-activated protein kinase signaling pathway.[11]Hou G. Chen L. Liu G. Li L. Yang Y. Yan H.X. et al.Aldehyde dehydrogenase-2 (ALDH2) opposes hepatocellular carcinoma progression by regulating AMP-activated protein kinase signaling in mice.Hepatology. 2017; 65: 1628-1644Crossref PubMed Scopus (25) Google Scholar Transgenic Aldh2-deficient mice were more susceptible to CCl4 and alcohol-induced liver fibrosis and subsequent HCC formation. Aldh2 deficiency results in increased amounts of harmful oxidized mitochondrial DNA transported via EVs, which can lead to the activation of oncogenic pathways in neighboring cells.[12]Seo W. Gao Y. He Y. Sun J. Xu H. Feng D. et al.ALDH2 deficiency promotes alcohol-associated liver cancer by activating oncogenic pathways via oxidized DNA-enriched extracellular vesicles.J Hepatol. 2019; 71: 1000-1011Abstract Full Text Full Text PDF PubMed Scopus (34) Google Scholar Several studies have demonstrated that ACSL1 is involved in aberrant lipid metabolism in liver cancer. HULC, a long noncoding RNA, modulates lipid metabolism by activating ACSL1.[13]Cui M. Xiao Z. Wang Y. Zheng M. Song T. Cai X. et al.Long noncoding RNA HULC modulates abnormal lipid metabolism in hepatoma cells through an miR-9-mediated RXRA signaling pathway.Cancer Res. 2015; 75: 846-857Crossref PubMed Scopus (232) Google Scholar Another modulator of lipid metabolism is miR205, which targets ACSL1;[14]Cui M. Wang Y. Sun B. Xiao Z. Ye L. Zhang X. MiR-205 modulates abnormal lipid metabolism of hepatoma cells via targeting acyl-CoA synthetase long-chain family member 1 (ACSL1) mRNA.Biochem Biophys Res Commun. 2014; 444: 270-275Crossref PubMed Scopus (65) Google Scholar NF-κB-ACSL1 signaling has also been suggested to be involved in abnormal lipid metabolism in liver cancer cells.[15]Yang G. Wang Y. Feng J. Liu Y. Wang T. Zhao M. et al.Aspirin suppresses the abnormal lipid metabolism in liver cancer cells via disrupting an NFkappaB-ACSL1 signaling.Biochem Biophys Res Commun. 2017; 486: 827-832Crossref PubMed Scopus (20) Google Scholar Consequently, ACSL1 was reported as a potential prognostic gene in HCC.[16]Yue C. Ren Y. Ge H. Liang C. Xu Y. Li G. et al.Comprehensive analysis of potential prognostic genes for the construction of a competing endogenous RNA regulatory network in hepatocellular carcinoma.Onco Targets Ther. 2019; 12: 561-576Crossref PubMed Scopus (32) Google Scholar These studies point to the fact that miR-27a-3p is not the only player upstream of Acsl1 and Aldh2. It is more likely part of a wider signaling network which ultimately influences susceptibility to HCC formation. Furthermore, Sun and colleagues analyzed the expression of miR-27a-3p/Acsl1/Aldh2 in patient samples. A small cohort of 27 fatty liver-associated HCCs and 27 non-fatty liver-associated HCCs and corresponding non-tumor tissues were analyzed by immunohistochemistry. In accordance with the reported HFD mouse model, similar results were reported in fatty liver-associated HCCs, suggesting that their mouse model is a powerful tool for the analyses of fatty liver disease and subsequent HCC development. The positive area for miR-27a-3p was increased in human HCC compared to non-tumor tissue. The miR-27a-3p positive area was increased in fatty liver-associated HCCs vs. non-fatty liver-associated HCCs, as well as in non-tumorous fatty liver tissue compared to non-fatty liver. Because of increased miR-27a-3p levels, the analyzed positive area of Acsl1 and Aldh2 was lower in liver tumors compared to non-tumor tissue. This effect was more dramatic in fatty liver-associated HCCs and also in the fatty liver itself. A more detailed analysis of a bigger patient cohort consisting of HCCs associated with different kinds of chronic liver disease would be of interest. It would also be interesting to know whether miR-27a-3p/Acsl1/Aldh2 levels differ depending on the etiology of fatty liver disease, or if this identified axis is a universal link in fatty liver and fatty liver-associated HCCs. This study provides new information on how maternal stress could influence progeny, with consequences for HCC development. The mode of inheritance is not a classical inter-generational one. It is multi-generational, as the susceptibility to HCC gradually increases over generations, requiring maintenance of HFD status in mothers over the generations to reach a sufficient level of miR-27a-3p to efficiently activate the miR-27a-3p/Acsl1/Aldh2 axis. However, several issues still remain. First, the mechanism of inheritance is unclear: In the mother, which cell type is responsible for miR-27a-3p synthesis and secretion? The transportation of miR-27a-3p from the mother to the fetus by sEVs also remains to be confirmed. Second, to what extent is the maternal transmission of the miR-27a-3p/Acsl1/Aldh2 axis conserved between mice and humans? If it is, there is further evidence for the need to prevent junk food consumption. This work was supported by the German Research Foundation (DFG/GRK 2254/C3-HEIST) to André Lechel, and by the Ligue Nationale Contre le Cancer to Sabine Colnot. SC and AL contributed equally to write the editorial. SC designed and realized the figure. The authors declare no conflicts of interest that pertain to this work. Please refer to the accompanying ICMJE disclosure forms for further details. Download .pdf (.15 MB) Help with pdf files disclosures.pdf Multigenerational maternal obesity increases the incidence of HCC in offspring via miR-27a-3pJournal of HepatologyVol. 73Issue 3PreviewObesity is an independent risk factor for malignancies, including hepatocellular carcinoma (HCC). However, it remains unknown whether maternal obesity affects the incidence of HCC in offspring. Thus, we aimed to investigate this association and its underlying mechanisms. Full-Text PDF

Chromatin remodelers are found highly mutated in cancer including hepatocellular carcinoma. These mutations frequently occur in ARID (AT-rich Interactive Domain) genes, encoding subunits of the ATP-dependent SWI/SNF remodelers. The increasingly prevalent complexity that surrounds the functions and specificities of the highly modular BAF (BG1/BRM-associated factors) and PBAF (polybromo-associated BAF) complexes, including ARID1A/B or ARID2, is baffling. The involvement of the SWI/SNF complexes in diverse tissues and processes, and especially in the regulation of gene expression, multiplies the specific outcomes of specific gene alterations. A better understanding of the molecular consequences of specific mutations impairing chromatin remodelers is needed. In this review, we summarize what we know about the tumor-modulating properties of ARID2 in hepatocellular carcinoma.

Erythropoietin (EPO) is a key regulator of erythropoiesis. The embryonic liver is the main site of erythropoietin synthesis, after which the kidney takes over. The adult liver retains the ability to express EPO, and we discovered here new players of this transcription, distinct from the classical hypoxia-inducible factor pathway. In mice, genetically invalidated in hepatocytes for the chromatin remodeler Arid1a, and for Apc, the major silencer of Wnt pathway, chromatin was more accessible and histone marks turned into active ones at the Epo downstream enhancer. Activating β-catenin signaling increased binding of Tcf4/β-catenin complex and upregulated its enhancer function. The loss of Arid1a together with β-catenin signaling, resulted in cell-autonomous EPO transcription in mouse and human hepatocytes. In mice with Apc-Arid1a gene invalidations in single hepatocytes, Epo de novo synthesis led to its secretion, to splenic erythropoiesis and to dramatic erythrocytosis. Thus, we identified new hepatic EPO regulation mechanism stimulating erythropoiesis.