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Gastroenterology May 2020The relationship between serum cholesterol level and development of hepatocellular carcinoma (HCC) remains unclear. We investigated the effects of serum cholesterol...
BACKGROUND AND AIMS
The relationship between serum cholesterol level and development of hepatocellular carcinoma (HCC) remains unclear. We investigated the effects of serum cholesterol level on development of liver tumors in mice.
METHODS
We performed studies with C57BL/6J mice, mice with disruption of the low-density lipoprotein receptor gene (Ldlrmice), and mice with conditional deletion of nature killer (NK) cells (NK mice). Some C57BL/6J and NK mice were given injections of diethylinitrosamine to induce liver tumor formation. Mice were placed on a normal diet (ND) or high-cholesterol diet (HCD) to induce high serum levels of cholesterol. We also studied mice with homozygous disruption of ApoE (ApoE mice), which spontaneously develop high serum cholesterol. C57BL/6J and NK mice on the ND or HCD were implanted with Hep1-6 (mouse hepatoma) cells and growth of xenograft tumors and lung metastases were monitored. Blood samples were collected from mice and analyzed by biochemistry and flow cytometry; liver and tumor tissues were collected and analyzed by histology, immunohistochemistry, and RNA-sequencing analysis. NK cells were isolated from mice and analyzed for cholesterol content, lipid raft formation, immune signaling, and changes in functions. We obtained matched tumor tissues and blood samples from 30 patients with HCC and blood samples from 40 healthy volunteers; levels of cholesterol and cytotoxicity of NK cells were measured.
RESULTS
C57BL/6J mice on HCD and ApoE mice with high serum levels of cholesterol developed fewer and smaller liver tumors and lung metastases after diethylinitrosamine injection or implantation of Hep1-6 cells than mice on ND. Liver tumors from HCD-fed mice and ApoE mice had increased numbers of NK cells compared to tumors from ND-fed mice. NK mice or mice with antibody-based depletion for NK cells showed similar tumor number and size in ND and HCD groups after diethylinitrosamine injection or implantation of Hep1-6 cells. NK cells isolated from C57BL/6J mice fed with HCD had increased expression of NK cell-activating receptors (natural cytotoxicity triggering receptor 1 and natural killer group 2, member D), markers of effector function (granzyme B and perforin), and cytokines and chemokines compared with NK cells from mice on ND; these NK cells also had enhanced cytotoxic activity against mouse hepatoma cells, accumulated cholesterol, increased lipid raft formation, and immune signaling activation. NK cells isolated from HCD-fed Ldlr mice did not have increased cholesterol content or cytotoxic activity against mouse hepatoma cells compared with ND-fed Ldlr mice. Serum levels of cholesterol correlated with number and activity of NK cells isolated from human HCCs.
CONCLUSIONS
Mice with increased serum levels of cholesterol due to an HCD or genetic disruption of ApoE develop fewer and smaller tumors after injection of hepatoma cells or a chemical carcinogen. We found cholesterol to accumulate in NK cells and activate their effector functions against hepatoma cells. Strategies to increase cholesterol uptake by NK cells can be developed for treatment of HCC.
Topics: Animals; Carcinoma, Hepatocellular; Cell Line, Tumor; Cholesterol; Diet, Atherogenic; Diethylnitrosamine; Disease Models, Animal; Female; Humans; Killer Cells, Natural; Liver Neoplasms; Lung Neoplasms; Male; Mice; Mice, Knockout, ApoE; Receptors, LDL
PubMed: 31972238
DOI: 10.1053/j.gastro.2020.01.028 -
Cellular and Molecular Gastroenterology... 2021Cancer-associated fibroblasts (CAFs) play a key role in the cancer process, but the research progress is hampered by the paucity of preclinical models that are essential...
BACKGROUND & AIMS
Cancer-associated fibroblasts (CAFs) play a key role in the cancer process, but the research progress is hampered by the paucity of preclinical models that are essential for mechanistic dissection of cancer cell-CAF interactions. Here, we aimed to establish 3-dimensional (3D) organotypic co-cultures of primary liver tumor-derived organoids with CAFs, and to understand their interactions and the response to treatment.
METHODS
Liver tumor organoids and CAFs were cultured from murine and human primary liver tumors. 3D co-culture models of tumor organoids with CAFs and Transwell culture systems were established in vitro. A xenograft model was used to investigate the cell-cell interactions in vivo. Gene expression analysis of CAF markers in our hepatocellular carcinoma cohort and an online liver cancer database indicated the clinical relevance of CAFs.
RESULTS
To functionally investigate the interactions of liver cancer cells with CAFs, we successfully established murine and human 3D co-culture models of liver tumor organoids with CAFs. CAFs promoted tumor organoid growth in co-culture with direct cell-cell contact and in a Transwell system via paracrine signaling. Vice versa, cancer cells secrete paracrine factors regulating CAF physiology. Co-transplantation of CAFs with liver tumor organoids of mouse or human origin promoted tumor growth in xenograft models. Moreover, tumor organoids conferred resistance to clinically used anticancer drugs including sorafenib, regorafenib, and 5-fluorouracil in the presence of CAFs, or the conditioned medium of CAFs.
CONCLUSIONS
We successfully established murine and human 3D co-culture models and have shown robust effects of CAFs in liver cancer nurturing and treatment resistance.
Topics: Animals; Antineoplastic Agents; Cancer-Associated Fibroblasts; Carcinoma, Hepatocellular; Coculture Techniques; Culture Media, Conditioned; Diethylnitrosamine; Drug Resistance, Neoplasm; Humans; Liver Neoplasms; Liver Neoplasms, Experimental; Mice; Organoids; Paracrine Communication; Primary Cell Culture; Tumor Cells, Cultured; Tumor Microenvironment; Xenograft Model Antitumor Assays
PubMed: 32932015
DOI: 10.1016/j.jcmgh.2020.09.003 -
Methods in Cell Biology 2021Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the third leading cause of cancer related mortality with a 10 year survival rate of merely... (Review)
Review
Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the third leading cause of cancer related mortality with a 10 year survival rate of merely 22-35%. Tumorigenesis frequently occurs in patients with chronic liver disease where continued liver cell damage, compensatory proliferation and inflammation provide the basis for tumor initiation, promotion and progression. Animal models of HCC are particularly useful to better understand molecular events underlying liver tumorigenesis. To this end, chemical carcinogenesis protocols based on the injection of genotoxic compounds such as diethylnitrosamine (DEN) are widely used to model liver tumorigenesis in rodents. DEN injection into 2 week old mice is sufficient to cause liver tumorigenesis after 8-10 months. When injected into older mice, DEN has to be combined with administration of tumor promoting agents such as phenobarbital or feeding high fat diet. Such protocols allow to dissect the different steps of tumor formation (i.e., tumor initiation and promotion) experimentally and to model liver pathologies in mice which frequently lead to HCC in human patients such as non-alcoholic fatty liver disease. Here, we review several established chemical carcinogenesis protocols based on DEN injection into mice and discuss their advantages as well as potential limitations.
Topics: Animals; Carcinogenesis; Carcinoma, Hepatocellular; Diethylnitrosamine; Humans; Liver; Liver Neoplasms; Mice; Mice, Inbred C57BL
PubMed: 33785162
DOI: 10.1016/bs.mcb.2020.08.006 -
Cell Reports. Medicine Sep 2023Inhibition of adenosine A2A receptor (A2AR) is a promising approach for cancer immunotherapy currently evaluated in several clinical trials. We here report that...
Inhibition of adenosine A2A receptor (A2AR) is a promising approach for cancer immunotherapy currently evaluated in several clinical trials. We here report that anti-obesogenic and anti-inflammatory functions of A2AR, however, significantly restrain hepatocellular carcinoma (HCC) development. Adora2a deletion in mice triggers obesity, non-alcoholic steatohepatitis (NASH), and systemic inflammation, leading to spontaneous HCC and promoting dimethylbenzyl-anthracene (DMBA)- or diethylnitrosamine (DEN)-induced HCC. Conditional Adora2a deletion reveals critical roles of myeloid and hepatocyte-derived A2AR signaling in restraining HCC by limiting hepatic inflammation and steatosis. Remarkably, the impact of A2AR pharmacological blockade on HCC development is dependent on pre-existing NASH. In support of our animal studies, low ADORA2A gene expression in human HCC is associated with cirrhosis, hepatic inflammation, and poor survival. Together, our study uncovers a previously unappreciated tumor-suppressive function for A2AR in the liver and suggests caution in the use of A2AR antagonists in patients with NASH and NASH-associated HCC.
Topics: Humans; Animals; Mice; Carcinoma, Hepatocellular; Non-alcoholic Fatty Liver Disease; Receptor, Adenosine A2A; Liver Neoplasms; Inflammation
PubMed: 37729873
DOI: 10.1016/j.xcrm.2023.101188 -
JHEP Reports : Innovation in Hepatology Apr 2022Hepatocellular carcinoma (HCC) is the predominant primary cancer arising from the liver and is one of the major causes of cancer-related mortality worldwide. The... (Review)
Review
Hepatocellular carcinoma (HCC) is the predominant primary cancer arising from the liver and is one of the major causes of cancer-related mortality worldwide. The cellular origin of HCC has been a topic of great interest due to conflicting findings regarding whether it originates in hepatocytes, biliary cells, or facultative stem cells. These cell types all undergo changes during liver injury, and there is controversy about their contribution to regenerative responses in the liver. Most HCCs emerge in the setting of chronic liver injury from viral hepatitis, fatty liver disease, alcohol, and environmental exposures. The injuries are marked by liver parenchymal changes such as hepatocyte regenerative nodules, biliary duct cellular changes, expansion of myofibroblasts that cause fibrosis and cirrhosis, and inflammatory cell infiltration, all of which may contribute to carcinogenesis. Addressing the cellular origin of HCC is the key to identifying the earliest events that trigger it. Herein, we review data on the cells of origin in regenerating liver and HCC and the implications of these findings for prevention and treatment. We also review the origins of childhood liver cancer and other rare cancers of the liver.
PubMed: 35243280
DOI: 10.1016/j.jhepr.2021.100416 -
Cellular and Molecular Gastroenterology... 2023Phosphoglycerate dehydrogenase (PHGDH), the rate-limiting enzyme of the de novo serine synthesis pathway (SSP), has been implicated in the carcinogenesis and metastasis...
BACKGROUND & AIMS
Phosphoglycerate dehydrogenase (PHGDH), the rate-limiting enzyme of the de novo serine synthesis pathway (SSP), has been implicated in the carcinogenesis and metastasis of hepatocellular carcinoma (HCC) because of its excessive expression and promotion of SSP. In previous experiments we found that SSP flux was diminished by knockdown of zinc finger E-box binding homeobox 1 (ZEB1), a stimulator of HCC metastasis, but the underlying mechanism remains largely unknown. Here, we aimed to determine how SSP flux is regulated by ZEB1 and the contribution of such regulation to carcinogenesis and progression of HCC.
METHODS
We used genetic mice with Zeb1 knockout in liver specifically to determine whether Zeb1 deficiency impacts HCC induced by the carcinogen diethylnitrosamine plus CCl. We explored the regulatory mechanism of ZEB1 in SSP flux using uniformly-labeled [C]-glucose tracing analyses, liquid chromatography-mass spectrometry, real-time quantitative polymerase chain reaction, luciferase report assay, and chromatin immunoprecipitation assay. We determined the contribution of the ZEB1-PHGDH regulatory axis to carcinogenesis and metastasis of HCC by cell counting assay, methyl thiazolyl tetrazolium (MTT) assay, scratch wound assay, Transwell assay, and soft agar assay in vitro, orthotopic xenograft, bioluminescence, and H&E assays in vivo. We investigated the clinical relevance of ZEB1 and PHGDH by analyzing publicly available data sets and 48 pairs of HCC clinical specimens.
RESULTS
We identified that ZEB1 activates PHGDH transcription by binding to a nonclassic binding site within its promoter region. Up-regulated PHGDH augments SSP flux to enable HCC cells to be more invasive, proliferative, and resistant to reactive oxygen species and sorafenib. Orthotopic xenograft and bioluminescence assays have shown that ZEB1 deficiency significantly impairs the tumorigenesis and metastasis of HCC, and such impairments can be rescued to a large extent by exogenous expression of PHGDH. These results were confirmed by the observation that conditional knockout of ZEB1 in mouse liver dramatically impedes carcinogenesis and progression of HCC induced by diethylnitrosamine/CCl, as well as PHGDH expression. In addition, analysis of The Cancer Genome Atlas database and clinical HCC samples showed that the ZEB1-PHGDH regulatory axis predicts poor prognosis of HCC.
CONCLUSIONS
ZEB1 plays a crucial role in stimulating carcinogenesis and progression of HCC by activating PHGDH transcription and subsequent SSP flux, deepening our knowledge of ZEB1 as a transcriptional factor in fostering the development of HCC via reprogramming the metabolic pathway.
Topics: Humans; Animals; Mice; Carcinoma, Hepatocellular; Liver Neoplasms; Phosphoglycerate Dehydrogenase; Diethylnitrosamine; Cell Line, Tumor; Carcinogenesis; Zinc Finger E-box-Binding Homeobox 1
PubMed: 37331567
DOI: 10.1016/j.jcmgh.2023.06.006 -
Hepatology Communications Nov 2023O-GlcNAcylation is a post-translational modification catalyzed by the enzyme O-GlcNAc transferase, which transfers a single N-acetylglucosamine sugar from UDP-GlcNAc to...
BACKGROUND
O-GlcNAcylation is a post-translational modification catalyzed by the enzyme O-GlcNAc transferase, which transfers a single N-acetylglucosamine sugar from UDP-GlcNAc to the protein on serine and threonine residues on proteins. Another enzyme, O-GlcNAcase (OGA), removes this modification. O-GlcNAcylation plays an important role in pathophysiology. Here, we report that O-GlcNAcylation is essential for hepatocyte differentiation, and chronic loss results in fibrosis and HCC.
METHODS
Single-cell RNA-sequencing (RNA-seq) was used to investigate hepatocyte differentiation in hepatocyte-specific O-GlcNAc transferase-knockout (OGT-KO) mice with decreased hepatic O-GlcNAcylation and in O-GlcNAcase-KO mice with increased O-GlcNAcylation in hepatocytes. Patients HCC samples and the diethylnitrosamine-induced HCC model were used to investigate the effect of modulation of O-GlcNAcylation on the development of liver cancer.
RESULTS
Loss of hepatic O-GlcNAcylation resulted in disruption of liver zonation. Periportal hepatocytes were the most affected by loss of differentiation, characterized by dysregulation of glycogen storage and glucose production. O-GlcNAc transferase-KO mice exacerbated diethylnitrosamine-induced HCC development with increased inflammation, fibrosis, and YAP signaling. Consistently, O-GlcNAcase -KO mice with increased hepatic O-GlcNAcylation inhibited diethylnitrosamine-induced HCC. A progressive loss of O-GlcNAcylation was observed in patients with HCC.
CONCLUSIONS
Our study shows that O-GlcNAcylation is a critical regulator of hepatic differentiation, and loss of O-GlcNAcylation promotes hepatocarcinogenesis. These data highlight increasing O-GlcNAcylation as a potential therapy in chronic liver diseases, including HCC.
Topics: Humans; Mice; Animals; Carcinoma, Hepatocellular; Diethylnitrosamine; Liver Neoplasms; Cell Differentiation; Fibrosis
PubMed: 37930118
DOI: 10.1097/HC9.0000000000000283 -
Cancer Cell International Jun 2023Malignant transformation from hepatic fibrosis to carcinogenesis may be a therapeutic target for hepatocellular carcinoma (HCC). The aim of this study was to evaluate...
BACKGROUND
Malignant transformation from hepatic fibrosis to carcinogenesis may be a therapeutic target for hepatocellular carcinoma (HCC). The aim of this study was to evaluate anti-cancer efficacy of Pien-Tze-Huang (PZH), and to investigate the underlying mechanisms by integrating transcriptional regulatory network analysis and experimental validation.
METHODS
A diethylnitrosamine (DEN)-induced HCC model in rats was established and used to evaluate the anti-cancer efficacy of PZH. After detecting a transcriptomic profiling, the "disease-related gene-drug effective target" interaction network was constructed, and the candidate targets of PZH against malignant transformation from hepatic fibrosis to HCC were identified and verified in vitro.
RESULTS
PZH effectively alleviated the pathological changes of hepatic fibrosis and cirrhosis, and inhibited tumor formation and growth in DEN-induced HCC rats. Additionally, the administration of PZH reduced the levels of various hepatic function-related serological indicators significantly. Mechanically, a ferroptosis-related SLC7A11-GSH-GPX4 axis might be one of potential targets of PZH against malignant transformation from hepatic fibrosis to HCC. Especially, high SLC7A11 expression may be associated with poor prognosis of HCC patients. Experimentally, the administration of PZH markedly increased the trivalent iron and ferrous ion, suppressed the expression levels of SLC7A11 and GPX4 proteins, and reduced the GSH/GSSG ratio in the liver tissues of DEN-induced HCC rats.
CONCLUSIONS
Our data offer an evidence that PZH may effectively improve the hepatic fibrosis microenvironment and prevent the occurrence of HCC through promoting ferroptosis in tumor cells via inhibiting the SLC7A11-GSH-GPX4 axis, implying that PZH may be a potential candidate drug for prevention and treatment of HCC at an early stage.
PubMed: 37280673
DOI: 10.1186/s12935-023-02946-2 -
Oncogene Oct 2023The Carbohydrate Response Element (ChoRE) Binding Protein (ChREBP) and its binding partner Max-like protein X (MLX) mediate transcription of lipogenic genes under...
The Carbohydrate Response Element (ChoRE) Binding Protein (ChREBP) and its binding partner Max-like protein X (MLX) mediate transcription of lipogenic genes under glucose-rich conditions. Dysregulation of glucose and lipid metabolism frequently occurs in cancers, including Hepatocellular Carcinomas (HCCs). However, it is currently unclear whether the glucose-induced lipogenic program plays a role in the development of HCCs. Here, we show that MLX expression is elevated in HCC specimens and downregulation of MLX expression inhibits proliferation of HCC cells. In mice, liver-specific knockout of Mlx results in dramatic decrease in the expression of lipogenic genes and lipid levels in circulation. Interestingly, in the absence of Mlx, the development of tumors in multiple HCC models, such as diethylnitrosamine (DEN) treatment and hydrodynamic injection of oncogenes (AKT/RAS or CTNNB1/RAS), is robustly blocked. However, a high-fat diet can partially restore tumorigenesis in Mlx-deficient livers, indicating a critical role of lipid synthesis in HCC development. In addition, liver-specific expression of a dominant negative MLX (dnMLX) via adeno-associated virus effectively blocks tumorigenesis in mice. Thus, the glucose-induced lipogenic program is required in the development of HCC, and the ChREBP: MLX transcription factors serve as a potential target for cancer therapies.
PubMed: 37684408
DOI: 10.1038/s41388-023-02831-2 -
The Journal of Biological Chemistry Oct 2023Circadian rhythms are controlled at the cellular level by a molecular clock consisting of several genes/proteins engaged in a transcription-translation-degradation...
Circadian rhythms are controlled at the cellular level by a molecular clock consisting of several genes/proteins engaged in a transcription-translation-degradation feedback loop. These core clock proteins regulate thousands of tissue-specific genes. Regarding circadian control in neoplastic tissues, reports to date have demonstrated anomalous circadian function in tumor models and cultured tumor cells. We have extended these studies by analyzing circadian rhythmicity genome-wide in a mouse model of liver cancer, in which mice treated with diethylnitrosamine at 15 days develop liver tumors by 6 months. We injected tumor-bearing and control tumor-free mice with cisplatin every 2 h over a 24-h cycle; 2 h after each injection mice were sacrificed and gene expression was measured by XR-Seq (excision repair sequencing) assay. Rhythmic expression of several core clock genes was observed in both healthy liver and tumor, with clock genes in tumor exhibiting typically robust amplitudes and a modest phase advance. Interestingly, although normal hepatic cells and hepatoma cancer cells expressed a comparable number of genes with circadian rhythmicity (clock-controlled genes), there was only about 10% overlap between the rhythmic genes in normal and cancerous cells. "Rhythmic in tumor only" genes exhibited peak expression times mainly in daytime hours, in contrast to the more common pre-dawn and pre-dusk expression times seen in healthy livers. Differential expression of genes in tumors and healthy livers across time may present an opportunity for more efficient anticancer drug treatment as a function of treatment time.
Topics: Animals; Mice; Carcinoma, Hepatocellular; Circadian Rhythm; Liver; Liver Neoplasms; Male; Excision Repair; CLOCK Proteins; Gene Ontology
PubMed: 37714462
DOI: 10.1016/j.jbc.2023.105251