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The Journal of Biological Chemistry Nov 2023Wilm's tumor 1-associating protein (WTAP), a regulatory protein of the mA methyltransferase complex, has been found to play a role in regulating various physiological...
Wilm's tumor 1-associating protein (WTAP), a regulatory protein of the mA methyltransferase complex, has been found to play a role in regulating various physiological and pathological processes. However, the in vivo role of WTAP in the pathogenesis of hepatocellular carcinoma (HCC) is unknown. In this study, we have elucidated the crucial role of WTAP in HCC progression and shown that hepatic deletion of Wtap promotes HCC pathogenesis through activation of multiple signaling pathways. A single dose of diethylnitrosamine injection causes more and larger HCCs in hepatocyte-specific Wtap knockout (Wtap-HKO) mice than Wtap mice fed with either normal chow diet or a high-fat diet. Elevated CD36, IGFBP1 (insulin-like growth factor-binding protein 1), and chemokine (C-C motif) ligand 2 (CCL2) expression leads to steatosis and inflammation in the Wtap-HKO livers. The hepatocyte proliferation is dramatically increased in Wtap-HKO mice, which is due to higher activation of extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription-3 signaling pathways. Hepatic deletion of Wtap activates the ERK signaling pathway by increasing the protein stability of GRB2 and ERK1/2, which is due to the decreased expression of proteasome-related genes. Restoring PSMB4 or PSMB6 (two key components of the proteasome) leads to the downregulation of GRB2 and ERK1/2 in Wtap-HKO hepatocytes. Mechanistically, WTAP interacts with RNA polymerase II and H3K9ac to maintain expression of proteasome-related genes. These results demonstrate that hepatic deletion of Wtap promotes HCC progression through activating GRB2-ERK1/2-mediated signaling pathway depending on the downregulation of proteasome-related genes especially Psmb4 and Psmb6.
Topics: Animals; Mice; Carcinoma, Hepatocellular; Cell Proliferation; Down-Regulation; Extracellular Signal-Regulated MAP Kinases; Hepatocytes; Liver Neoplasms; Mice, Knockout; Proteasome Endopeptidase Complex; Mice, Inbred C57BL
PubMed: 37777158
DOI: 10.1016/j.jbc.2023.105301 -
Mutation Research. Genetic Toxicology... Oct 2023N-Nitrosodiethylamine (NDEA), a well-studied N-nitrosamine, was tested in rats to compare the dose-response relationship of three genotoxicity endpoints. Mutant /...
Comparison of the transgenic rodent mutation assay, error corrected next generation duplex sequencing, and the alkaline comet assay to detect dose-related mutations following exposure to N-nitrosodiethylamine.
N-Nitrosodiethylamine (NDEA), a well-studied N-nitrosamine, was tested in rats to compare the dose-response relationship of three genotoxicity endpoints. Mutant / mutation frequencies were determined using the transgenic rodent (TGR) gene mutation assay and error corrected next generation sequencing (ecNGS) (i.e., duplex sequencing (DS)), and genetic damage was detected by the alkaline comet assay. Big Blue® (cII Locus) animals (n = 6 per dose group) were administered doses of 0.001, 0.01, 0.1, 1, 3 mg/kg/day NDEA by oral gavage. Samples were collected for cII mutation and DS analyses following 28-days of exposure and 3 days recovery. In a separate study, male Sprague-Dawley (SD) rats (n = 6 per dose group) were administered the same doses by oral gavage for two consecutive days and then samples collected for the alkaline comet assay. A dose-related increase in mutant / mutation frequencies of the liver but not duodenum was observed using the TGR assay and DS with DS resulting in a slightly more sensitive response, with a lower benchmark dose (BMD). In addition, a dose-related increase in percent tail DNA was observed in the liver using the alkaline comet assay. Therefore, DS and comet assays showed good utility for hazard identification and dose-response analysis of a representative N-nitrosamine comparable to the TGR gene mutation assay.
Topics: Rats; Animals; Male; Comet Assay; Diethylnitrosamine; Rodentia; Rats, Sprague-Dawley; Mutation; Animals, Genetically Modified; DNA Damage; High-Throughput Nucleotide Sequencing; Nitrosamines; Mutagenicity Tests; Dose-Response Relationship, Drug
PubMed: 37770142
DOI: 10.1016/j.mrgentox.2023.503685 -
International Journal of Molecular... Sep 2023Overconsumption of high-fat foods increases the risk of fatty liver disease (FLD) and liver cancer with long pathogenic cycles. It is also known that the intake of the...
Overconsumption of high-fat foods increases the risk of fatty liver disease (FLD) and liver cancer with long pathogenic cycles. It is also known that the intake of the chemical poison nitrosamine and its nanopreparations can promote the development of liver injuries, such as FLD, and hepatic fibrosis, and significantly shorten the formation time of the liver cancer cycle. The present work confirmed that the coexposure of a high-fat diet (HFD) and nano-diethylnitrosamine (nano-DEN) altered the tumor microenvironment and studied the effect of this coexposure on the progression of fatty liver malignant transformation into liver cancer. Gene transcriptomics and immunostaining were used to evaluate the tumor promotion effect of the coexposure in mice. After coexposure treatment, tumor nodules were obviously increased, and inflammation levels were elevated. The liver transcriptomics analysis showed that the expression levels of inflammatory, fatty, and fibrosis-related factors in the coexposed group were increased in comparison with the nano-DEN- and high-fat-alone groups. The Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that coexposure aggravated the high expression of genes related to the carcinomatous pathway and accelerated the formation of the tumor microenvironment. The immunohistochemical staining results showed that the coexposure significantly increased the abnormal changes in proteins related to inflammation, proliferation, aging, and hypoxia in mouse liver tissues. The coexposure of high fat and nano-DEN aggravated the process of steatosis and carcinogenesis. In conclusion, the habitual consumption of pickled foods containing nitrosamines in a daily HFD significantly increases the risk of liver pathology lesions progressing from FLD to liver cancer.
PubMed: 37762463
DOI: 10.3390/ijms241814162 -
Cancers Sep 2023MTBP is implicated in cell cycle progression, DNA replication, and cancer metastasis. However, the function of MTBP remains enigmatic and is dependent on cellular...
MTBP is implicated in cell cycle progression, DNA replication, and cancer metastasis. However, the function of MTBP remains enigmatic and is dependent on cellular contexts and its cellular localization. To understand the in vivo physiological role of MTBP, it is important to generate knockout mice. However, complete deletion of the gene in mice results in early embryonic lethality, while its heterozygous deletion shows modest biological phenotypes, including enhanced cancer metastasis. To overcome this and better characterize the in vivo physiological function of MTBP, we, for the first time, generated mice that carry an hypomorphic allele () in which Mtbp protein is expressed at approximately 30% of that in the wild-type allele. We treated wild-type, , and mice with a liver carcinogen, diethylnitrosamine (DEN), and found that the mice showed worse overall survival when compared to the wild-type mice. Consistent with previous reports using human liver cancer cells, mouse embryonic fibroblasts (MEFs) from the mice showed an increase in the nuclear localization of p-Erk1/2 and migratory potential. Thus, mice and cells from mice are valuable to understand the in vivo physiological role of Mtbp and validate the diverse functions of MTBP that have been observed in human cells.
PubMed: 37760565
DOI: 10.3390/cancers15184596 -
Biomolecules Aug 2023N-nitrosodiethylamine (NDEA) is a potential carcinogen known to cause liver tumors and chronic inflammation, diabetes, cognitive problems, and signs like Alzheimer's...
Metformin Prevents NDEA-Induced Memory Impairments Associated with Attenuating Beta-Amyloid, Tumor Necrosis Factor-Alpha, and Interleukin-6 Levels in the Hippocampus of Rats.
N-nitrosodiethylamine (NDEA) is a potential carcinogen known to cause liver tumors and chronic inflammation, diabetes, cognitive problems, and signs like Alzheimer's disease (AD) in animals. This compound is classified as probably carcinogenic to humans. Usual sources of exposure include food, beer, tobacco, personal care products, water, and medications. AD is characterized by cognitive decline, amyloid-β (Aβ) deposit, tau hyperphosphorylation, and cell loss. This is accompanied by neuroinflammation, which involves release of microglial cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin 1β (IL-1β), by nuclear factor kappa B (NF-κB) upregulation; each are linked to AD progression. Weak PI3K/Akt insulin-signaling inhibits IRS-1 phosphorylation, activates GSK3β and promotes tau hyperphosphorylation. Metformin, an antihyperglycemic agent, has potent anti-inflammatory efficacy. It reduces proinflammatory cytokines such as IL-6, IL-1β, and TNF-α via NF-κB inhibition. Metformin also reduces reactive oxidative species (ROS) and modulates cognitive disorders reported due to brain insulin resistance links. Our study examined how NDEA affects spatial memory in Wistar rats. We found that all NDEA doses tested impaired memory. The 80 µg/kg dose of NDEA increased levels of Aβ1-42, TNF-α, and IL-6 in the hippocampus, which correlated with memory loss. Nonetheless, treatment with 100 mg/kg of metformin attenuated the levels of pro-inflammatory cytokines and Aβ1-42, and enhanced memory. It suggests that metformin may protect against NDEA-triggered memory issues and brain inflammation.
Topics: Animals; Rats; Alzheimer Disease; Amyloid beta-Peptides; Carcinogens; Cytokines; Diethylnitrosamine; Hippocampus; Interleukin-6; Memory Disorders; Metformin; NF-kappa B; Phosphatidylinositol 3-Kinases; Rats, Wistar; Tumor Necrosis Factor-alpha
PubMed: 37759689
DOI: 10.3390/biom13091289 -
Biology Aug 2023Hepatocellular carcinoma (HCC) is the second-largest cause of death among all cancer types. Many drugs have been used to treat the disease for a long time but have been...
Hepatocellular carcinoma (HCC) is the second-largest cause of death among all cancer types. Many drugs have been used to treat the disease for a long time but have been mostly discontinued because of their side effects or the development of resistance in the patients with HCC. The administration of DZ orally is a great focus to address the clinical crisis. Daidzein (DZ) is a prominent isoflavone polyphenolic chemical found in soybeans and other leguminous plants. It has various pharmacological effects, including anti-inflammatory, antihemolytic, and antioxidant. This present study investigates the protective effect of DZ on chemically induced HCC in rat models. The DZ was administered orally four weeks before HCC induction and continued during treatment. Our study included four treatment groups: control (group 1, without any treatment), HCC-induced rats (group II), an HCC group treated with DZ at 20 mg/kg (group III), and an HCC group treated with DZ at 40 mg/kg (group IV). HCC rats showed elevation in all the HCC markers (AFP, GPC3, and VEGF), liver function markers (ALP, ALT, and AST), inflammatory markers (IL-6, TNF-α, and CRP), and lipid markers concomitant with a decrease in antioxidant enzymes and protein. However, groups III and IV demonstrated dose-dependent alleviation in the previous parameters resulting from HCC. In addition, the high dose of DZ reduces many hepatological changes in HCC rats. All study parameters improved with DZ administration. Due to its antioxidant and anti-inflammatory characteristics, DZ is a promising HCC treatment option for clinical use.
PubMed: 37759583
DOI: 10.3390/biology12091184 -
Frontiers in Oncology 2023Phenobarbital (PB) is an archetypal substance used as a mouse hepatocellular carcinoma (HCC) promotor in established experimental protocols. Our previous results showed...
Phenobarbital (PB) is an archetypal substance used as a mouse hepatocellular carcinoma (HCC) promotor in established experimental protocols. Our previous results showed CAR is the essential factor for PB induced HCC promotion. Subsequent studies suggested Gadd45β, which is induced by PB through CAR activation, is collaborating with CAR to repress TNF-α induced cell death. Here, we used Gadd45β null mice (Gadd45β KO) treated with N-diethylnitrosamine (DEN) at 5 weeks of age and kept the mice with PB supplemented drinking water from 7 to 57 weeks old. Compared with wild type mice, Gadd45β KO mice developed no HCC in the PB treated group. Increases in liver weight were more prominent in wild type mice than KO mice. Microarray analysis of mRNA derived from mouse livers found multiple genes specifically up or down regulated in wild type mice but not null mice in DEN + PB groups. Further qPCR analysis confirmed two genes, Tgfbr2 and irisin/Fndc5, were up-regulated in PB treated wild type mice but no significant increase was observed in Gadd45β KO mice. We focused on these two genes because previous reports showed that hepatic Irisin/Fndc5 expression was significantly higher in HCC patients and that irisin binds to TGF-β receptor complex that includes TGFBR2 subunit. Our results revealed irisin peptide in cell culture media increased the growth rate of mouse hepatocyte-derived AML12 cells. Microarray analysis revealed that irisin-regulated genes in AML12 cells showed a significant association with the genes in the TGF-β pathway. Expression of irisin/Fndc5 and Tgfbr2 induced growth of human HCC cell line HepG2. Thus, Gadd45β plays an indispensable role in mouse HCC development regulating the irisin/Fndc5 and Tgfbr2 genes.
PubMed: 37746289
DOI: 10.3389/fonc.2023.1217847 -
Frontiers in Immunology 2023Tumor-initiating cells (TICs) are rare, stem-like, and highly malignant. Although intravenous hepatitis B and C immunoglobulins have been used for HBV and HCV...
INTRODUCTION
Tumor-initiating cells (TICs) are rare, stem-like, and highly malignant. Although intravenous hepatitis B and C immunoglobulins have been used for HBV and HCV neutralization in patients, their tumor-inhibitory effects have not yet been examined. Hepatitis B immunoglobulin (HBIG) therapy is employed to reduce hepatocellular carcinoma (HCC) recurrence in patients after living donor liver transplantations (LDLT).
HYPOTHESIS
We hypothesized that patient-derived intravenous immunoglobulin (IVIG) binding to HCC associated TICs will reduce self-renewal and cell viability driven by β-CATENIN-downstream pathways. β-CATENIN activity protected TICs from IVIG effects.
METHODS
The effects of HBIG and HCIG binding to TICs were evaluated for cell viability and self-renewal.
RESULTS
Inhibition of β-CATENIN pathway(s) augmented TIC susceptibility to HBIG- and HCIG-immunotherapy. HBV X protein (HBx) upregulates both β-CATENIN and NANOG expression. The co-expression of constitutively active β-CATENIN with NANOG promotes self-renewal ability and tumor-initiating ability of hepatoblasts. HBIG bound to HBV+ cells led to growth inhibition in a TIC subset that expressed hepatitis B surface antigen. The HBx protein transformed cells through β-CATENIN-inducible lncRNAs and . Co-expression of constitutively active β-CATENIN with NANOG promoted self-renewal ability of TICs through EGLN3 induction. β-CATENIN-induced lncRNAs stabilized HIF2 to maintain self-renewal of TICs. Targeting of resulted in destabilization of EZH2-dependent β-CATENIN activity and synergized cell-killing of TICs by HBIG or HCIG immunotherapy.
DISCUSSION
Taken together, WNT and stemness pathways induced HIF2 of TICs via cooperating lncRNAs resulting in resistance to cancer immunotherapy. Therefore, therapeutic use of IVIG may suppress tumor recurrence through inhibition of TICs.
Topics: Humans; beta Catenin; Carcinoma, Hepatocellular; Immunoglobulins, Intravenous; Immunotherapy; Liver Neoplasms; Liver Transplantation; Living Donors; Neoplasm Recurrence, Local; RNA, Long Noncoding
PubMed: 37744383
DOI: 10.3389/fimmu.2023.1204907 -
Nature Communications Sep 2023CSCs (Cancer stem cells) with distinct metabolic features are considered to cause HCC (hepatocellular carcinoma) initiation, metastasis and therapeutic resistance. Here,...
CSCs (Cancer stem cells) with distinct metabolic features are considered to cause HCC (hepatocellular carcinoma) initiation, metastasis and therapeutic resistance. Here, we perform a metabolic gene CRISPR/Cas9 knockout library screen in tumorspheres derived from HCC cells and find that deletion of SCARB2 suppresses the cancer stem cell-like properties of HCC cells. Knockout of Scarb2 in hepatocytes attenuates HCC initiation and progression in both MYC-driven and DEN (diethylnitrosamine)-induced HCC mouse models. Mechanistically, binding of SCARB2 with MYC promotes MYC acetylation by interfering with HDCA3-mediated MYC deacetylation on lysine 148 and subsequently enhances MYC transcriptional activity. Screening of a database of FDA (Food and Drug Administration)-approved drugs shows Polymyxin B displays high binding affinity for SCARB2 protein, disrupts the SCARB2-MYC interaction, decreases MYC activity, and reduces the tumor burden. Our study identifies SCARB2 as a functional driver of HCC and suggests Polymyxin B-based treatment as a targeted therapeutic option for HCC.
Topics: Animals; Mice; Carcinoma, Hepatocellular; Liver Neoplasms; Neoplastic Stem Cells; Polymyxin B; Humans
PubMed: 37739936
DOI: 10.1038/s41467-023-41593-z -
Cell Death & Disease Sep 2023Hepatocarcinogenesis is initiated by repeated hepatocyte death and liver damage, and the underlying mechanisms mediating cell death and the subsequent carcinogenesis...
Hepatocarcinogenesis is initiated by repeated hepatocyte death and liver damage, and the underlying mechanisms mediating cell death and the subsequent carcinogenesis remain to be fully investigated. Immunoresponsive gene 1 (IRG1) and its enzymatic metabolite itaconate are known to suppress inflammation in myeloid cells, and its expression in liver parenchymal hepatocytes is currently determined. However, the potential roles of IRG1 in hepatocarcinogenesis are still unknown. Here, using the diethylnitrosamine (DEN)-induced hepatocarcinogenesis mouse model, we found that IRG1 expression in hepatocytes was markedly induced upon DEN administration. The DEN-induced IRG1 was then determined to promote the intrinsic mitochondrial apoptosis of hepatocytes and liver damage, thus enhancing the subsequent hepatocarcinogenesis. Mechanistically, the mitochondrial IRG1 could associate and trap anti-apoptotic MCL-1 to inhibit the interaction between MCL-1 and pro-apoptotic Bim, thus promoting Bim activation and downstream Bax mitochondrial translocation, and then releasing cytochrome c and initiating apoptosis. Thus, the inducible mitochondrial IRG1 promotes hepatocyte apoptosis and the following hepatocarcinogenesis, which provides mechanistic insight and a potential target for preventing liver injury and HCC.
Topics: Animals; Mice; Apoptosis; Carcinogenesis; Carcinoma, Hepatocellular; Hepatocytes; Liver Neoplasms; Myeloid Cell Leukemia Sequence 1 Protein
PubMed: 37737207
DOI: 10.1038/s41419-023-06155-7