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The Journal of Toxicological Sciences Apr 2015The effects of the peroxisome proliferator, dehydroepiandrosterone sulfate (DHEAS), and the typical cytochrome P450 (CYP) inducers phenobarbital (PB) and...
The effects of the peroxisome proliferator, dehydroepiandrosterone sulfate (DHEAS), and the typical cytochrome P450 (CYP) inducers phenobarbital (PB) and 3-methylcholanthrene (3-MC) on fatty liver were examined in rats. Treating rats with orotic acid caused marked accumulation of lipid droplets in the liver. This effect of orotic acid was almost eradicated by co-treatment with DHEAS and PB. While DHEAS or PB alone also alleviated fatty liver, treatment with 3-MC caused little effect on a reduction in lipid droplets. Histopathological examinations revealed numerous peroxisomes in the liver of rats treated with DHEAS. In addition, a significant increase in the expression on hepatic CYPs was observed in rats the fatty liver of which was attenuated. Regarding other enzymes associated with hepatic fatty acid oxidation, the expression levels of sirtuin 1, sirtuin 6, and carnitine palmitoyltransferase 1 were also upregulated most markedly by treatment with DHEAS alone. Thus, the attenuation in fatty liver observed in the present study is likely due to peroxisome proliferation and the induction of fatty acid-metabolizing enzymes by DHEAS and typical CYP inducers.
Topics: Animals; Cytochrome P-450 Enzyme Inducers; Cytochrome P-450 Enzyme System; Dehydroepiandrosterone Sulfate; Drug Therapy, Combination; Fatty Acids; Fatty Liver; Liver; Male; Methylcholanthrene; Orotic Acid; Oxidation-Reduction; Peroxisomes; Phenobarbital; Rats, Sprague-Dawley; Sirtuin 1
PubMed: 25786523
DOI: 10.2131/jts.40.181 -
Nature Communications Sep 2017The analysis of neoantigen-specific CD8 T cells in tumour-bearing individuals is challenging due to the small pool of tumour antigen-specific T cells. Here we show that...
The analysis of neoantigen-specific CD8 T cells in tumour-bearing individuals is challenging due to the small pool of tumour antigen-specific T cells. Here we show that mass cytometry with multiplex combinatorial tetramer staining can identify and characterize neoantigen-specific CD8 T cells in mice bearing T3 methylcholanthrene-induced sarcomas that are susceptible to checkpoint blockade immunotherapy. Among 81 candidate antigens tested, we identify T cells restricted to two known neoantigens simultaneously in tumours, spleens and lymph nodes in tumour-bearing mice. High-dimensional phenotypic profiling reveals that antigen-specific, tumour-infiltrating T cells are highly heterogeneous. We further show that neoantigen-specific T cells display a different phenotypic profile in mice treated with anti-CTLA-4 or anti-PD-1 immunotherapy, whereas their peripheral counterparts are not affected by the treatments. Our results provide insights into the nature of neoantigen-specific T cells and the effects of checkpoint blockade immunotherapy.Immune checkpoint blockade (ICB) therapies can unleash anti-tumour T-cell responses. Here the authors show, by integrating MHC tetramer multiplexing, mass cytometry and high-dimensional analyses, that neoantigen-specific, tumour-infiltrating T cells are highly heterogeneous and are subjected to ICB modulations.
Topics: Animals; Antigens, Neoplasm; Antineoplastic Agents, Immunological; CD8-Positive T-Lymphocytes; CTLA-4 Antigen; Immunophenotyping; Immunotherapy; Lymphocytes, Tumor-Infiltrating; Methylcholanthrene; Mice; Programmed Cell Death 1 Receptor; Sarcoma, Experimental
PubMed: 28916749
DOI: 10.1038/s41467-017-00627-z -
Cancer Immunology Research Feb 2017Antibody blockade of programmed death-1 (PD-1) or its ligand, PD-L1, has led to unprecedented therapeutic responses in certain tumor-bearing individuals, but PD-L1...
Antibody blockade of programmed death-1 (PD-1) or its ligand, PD-L1, has led to unprecedented therapeutic responses in certain tumor-bearing individuals, but PD-L1 expression's prognostic value in stratifying cancer patients for such treatment remains unclear. Reports conflict on the significance of correlations between PD-L1 on tumor cells and positive clinical outcomes to PD-1/PD-L1 blockade. We investigated this issue using genomically related, clonal subsets from the same methylcholanthrene-induced sarcoma: a highly immunogenic subset that is spontaneously eliminated in vivo by adaptive immunity and a less immunogenic subset that forms tumors in immunocompetent mice, but is sensitive to PD-1/PD-L1 blockade therapy. Using CRISPR/Cas9-induced loss-of-function approaches and overexpression gain-of-function techniques, we confirmed that PD-L1 on tumor cells is key to promoting tumor escape. In addition, the capacity of PD-L1 to suppress antitumor responses was inversely proportional to tumor cell antigenicity. PD-L1 expression on host cells, particularly tumor-associated macrophages (TAM), was also important for tumor immune escape. We demonstrated that induction of PD-L1 on tumor cells was IFNγ-dependent and transient, but PD-L1 induction on TAMs was of greater magnitude, only partially IFNγ dependent, and was stable over time. Thus, PD-L1 expression on either tumor cells or host immune cells could lead to tumor escape from immune control, indicating that total PD-L1 expression in the immediate tumor microenvironment may represent a more accurate biomarker for predicting response to PD-1/PD-L1 blockade therapy, compared with monitoring PD-L1 expression on tumor cells alone. Cancer Immunol Res; 5(2); 106-17. ©2017 AACR.
Topics: Animals; B7-H1 Antigen; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Female; Gene Expression; Gene Knockout Techniques; Genes, MHC Class I; Humans; Male; Mice; Mutation; Neoplasms; Sarcoma; Tumor Burden; Tumor Escape; Tumor Microenvironment
PubMed: 28073774
DOI: 10.1158/2326-6066.CIR-16-0391 -
Molecular Carcinogenesis Jan 2017Adenocarcinoma accounts for ∼40% of lung cancer, equating to ∼88 500 new patients in 2015, most of who will succumb to this disease, thus, the public health burden...
Adenocarcinoma accounts for ∼40% of lung cancer, equating to ∼88 500 new patients in 2015, most of who will succumb to this disease, thus, the public health burden is evident. Unfortunately, few early biomarkers as well as effective therapies exist, hence the need for novel targets in lung cancer treatment. We previously identified epiregulin (Ereg), an EGF-like ligand, as a biomarker in several mouse lung cancer models. In the present investigation we used a primary two-stage initiation/promotion model to test our hypothesis that Ereg deficiency would reduce lung tumor promotion in mice. We used 3-methylcholanthrene (initiator) or oil vehicle followed by multiple weekly exposures to butylated hydroxytoluene (BHT; promoter) in mice lacking Ereg (Ereg ) and wildtype controls (BALB/ByJ; Ereg ) and examined multiple time points and endpoints (bronchoalveolar lavage analysis, tumor analysis, mRNA expression, ELISA, wound assay) during tumor promotion. At the early time points (4 and 12 wk), we observed significantly reduced amounts of inflammation (macrophages, PMNs) in the Ereg mice compared to controls (Ereg ). At 20 wk, tumor multiplicity was also significantly decreased in the Ereg mice versus controls (Ereg ). IL10 expression, an anti-inflammatory mediator, and downstream signaling events (Stat3) were significantly increased in the Ereg mice in response to BHT, supporting both reduced inflammation and tumorigenesis. Lastly, wound healing was significantly increased with recombinant Ereg in both human and mouse lung epithelial cell lines. These results indicate that Ereg has proliferative potential and may be utilized as an early cancer biomarker as well as a novel potential therapeutic target. © 2016 Wiley Periodicals, Inc.
Topics: Adenocarcinoma; Adenocarcinoma of Lung; Animals; Butylated Hydroxytoluene; Carcinogenesis; Epiregulin; Gene Deletion; Gene Expression Regulation, Neoplastic; Humans; Inflammation; Lung; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C
PubMed: 26894620
DOI: 10.1002/mc.22475 -
Lipids in Health and Disease Nov 2019A healthy gastric mucosal epithelium exhibits tumor-suppressive properties. Gastric epithelial cell dysfunction contributes to gastric cancer development. Oxysterols...
BACKGROUND
A healthy gastric mucosal epithelium exhibits tumor-suppressive properties. Gastric epithelial cell dysfunction contributes to gastric cancer development. Oxysterols provided from food or cholesterol oxidation in the gastric epithelium may be further sulfated by hydroxysteroid sulfotransferase 2B1 (SULT2B1), which is highly abundant in the gastric epithelium. However, the effects of SULT2B1 on gastric epithelial function and gastric carcinogenesis are unclear.
METHODS
A mouse gastric tumor model was established using carcinogenic agent 3-methylcholanthrene (3-MCA). A SULT2B1 deletion (SULT2B1) human gastric epithelial line GES-1 was constructed by CRISPR/CAS9 genome editing system.
RESULTS
The gastric tumor incidence was higher in the SULT2B1 mice than in the wild-type (WT) mice. In gastric epithelial cells, adenovirus-mediated SULT2B1b overexpression reduced the levels of oxysterols, such as 24(R/S),25-epoxycholesterol (24(R/S),25-EC) and 27-hydroxycholesterol (27HC). This condition also increased PI3K/AKT signaling to promote gastric epithelial cell proliferation, epithelization, and epithelial development. However, SULT2B1 deletion or SULT2B1 knockdown suppressed PI3K/AKT signaling, epithelial cell epithelization, and wound healing and induced gastric epithelial cell malignant transition upon 3-MCA induction.
CONCLUSIONS
The abundant SULT2B1 expression in normal gastric epithelium might maintain epithelial function via the PI3K/AKT signaling pathway and suppress gastric carcinogenesis induced by a carcinogenic agent.
Topics: Animals; Base Sequence; CRISPR-Cas Systems; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Cholesterol; Gastric Mucosa; Gene Editing; Gene Expression Regulation, Neoplastic; Humans; Hydroxycholesterols; Methylcholanthrene; Mice; Mice, Knockout; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Signal Transduction; Stomach Neoplasms; Sulfotransferases; Survival Analysis
PubMed: 31757214
DOI: 10.1186/s12944-019-1149-6 -
Tumour Biology : the Journal of the... 2023Epithelial-mesenchymal transition (EMT) is associated with altered cellular adhesion. We previously demonstrated that cellular adhesion influences Low-dose...
BACKGROUND
Epithelial-mesenchymal transition (EMT) is associated with altered cellular adhesion. We previously demonstrated that cellular adhesion influences Low-dose Hyper-Radiosensitivity (HRS) in a variety of tumor cells. However, the relationship of low-dose HRS with the phenotypic plasticity incurred by EMT during the neoplastic transformation remains to be elucidated.
OBJECTIVE
To investigate whether acquisition of EMT phenotype during progressive neoplastic transformation may affect low-dose radiation sensitivity.
METHODS
Primary thyroid cells obtained from a human cystic thyroid nodule were first subjected to nutritional stress. This yielded immortalized INM-Thy1 cell strain, which was further treated with either multiple γ-radiation fractions (1.5 Gy each) or repetitive cycles of 3-methylcholanthrene and phorbol-12-myristate-13-acetate, yielding two progressive transformants, viz., INM-Thy1R and INM-Thy1C. Morphological alterations, chromosomal double-minutes, cell adhesion proteins, anchorage dependency, tumorigenicity in nude mice and cellular radiosensitivity were studied in these strains.
RESULTS
Both transformants (INM-Thy1R, INM-Thy1C) displayed progressive tumorigenic features, viz., soft agar colony growth and solid tumor growth in nude mice, coupled with features of epithelial-mesenchymal transition and activated Wnt pathway. Incidentally, the chemical-induced transformant (INM-Thy1C) displayed a prominent HRS (αs/αr = 29.35) which remained unaffected at high cell density. However, the parental (INM-Thy1) cell line as well as radiation-induced transformant (INM-Thy1R) failed to show this hypersensitivity.
CONCLUSION
The study shows that induction of EMT in thyroid follicular cells may accompany increased susceptibility to low-dose ionizing radiation, which was attenuated by adaptive resistance acquired during radiation-induced transformation.
Topics: Animals; Mice; Humans; Cell Adhesion; Epithelial-Mesenchymal Transition; Mice, Nude; Thyroid Epithelial Cells; Carcinogenesis
PubMed: 37742670
DOI: 10.3233/TUB-220027 -
Biology Open Sep 2019Recently, several promising treatments for high-grade gliomas (HGGs) failed to provide significant benefit when translated from the preclinical setting to patients....
Recently, several promising treatments for high-grade gliomas (HGGs) failed to provide significant benefit when translated from the preclinical setting to patients. Improving the animal models is fundamental to overcoming this translational gap. To address this need, we developed and comprehensively characterized a new model based on the orthotopic implantation of CT-2A cells cultured in neurospheres (NS/CT-2A). Murine CT-2A methylcholanthrene-induced HGG cells (C57BL/6 background) were cultured in monolayers (ML) or NS and orthotopically inoculated in syngeneic animals. ML/CT-2A and NS/CT-2A tumors' characterization included the analysis of tumor growth, immune microenvironment, glioma stem cells (GSCs), vascularization and metabolites. The immuno-modulating properties of NS/CT-2A and ML/CT-2A cells on splenocytes were tested Mice harboring NS/CT-2A tumors had a shorter survival than those harboring ML/CT-2A tumors (=0.0033). Compared to standard ML/CT-2A tumors, NS/CT-2A tumors showed more abundant GSCs (=0.0002 and 0.0770 for Nestin and CD133, respectively) and regulatory T cells (Tregs, =0.0074), and a strong tendency towards an increased vascularization (=0.0503). There were no significant differences in metabolites' composition between NS/ and ML/CT-2A tumors. , NS were able to drive splenocytes towards a more immunosuppressive status by reducing CD8 T cells (=0.0354) and by promoting Tregs (=0.0082), macrophages (MF, =0.0019) and their M2 subset (=0.0536). Compared to standard ML/CT-2A tumors, NS/CT-2A tumors show a more aggressive phenotype with increased immunosuppression and GSCs proliferation. Because of these specific features, the NS/CT-2A model represents a clinically relevant platform in the search for new HGG treatments aimed at reducing immunosuppression and eliminating GSCs.
PubMed: 31511246
DOI: 10.1242/bio.044552 -
Frontiers in Cellular and Infection... 2021The opportunistic pathogen is one of the few intestinal bacteria that has been consistently linked to colorectal cancer (CRC). This study aimed to identify novel...
OBJECTIVE
The opportunistic pathogen is one of the few intestinal bacteria that has been consistently linked to colorectal cancer (CRC). This study aimed to identify novel -induced pathways in colon epithelial cells that could further explain how contributes to CRC development.
DESIGN AND RESULTS
Transcription profiling of cultured CRC cells that were exposed to revealed the specific induction of oxidoreductase pathways. Most prominently, and genes that encode phase I biotransformation enzymes were responsible for the detoxification or bio-activation of toxic compounds. A common feature is that these enzymes are induced through the Aryl hydrocarbon receptor (AhR). Using the specific inhibitor CH223191, we showed that the induction of was dependent on the AhR both using multiple CRC cell lines as using wild-type C57bl6 mice colonized with . Furthermore, we showed that CYP1 could also be induced by other intestinal bacteria and that a yet unidentified diffusible factor from the secretome (SGS) induces CYP1A enzyme activity in an AhR-dependent manner. Importantly, priming CRC cells with SGS increased the DNA damaging effect of the polycyclic aromatic hydrocarbon 3-methylcholanthrene.
CONCLUSION
This study shows that gut bacteria have the potential to modulate the expression of biotransformation pathways in colonic epithelial cells in an AhR-dependent manner. This offers a novel theory on the contribution of intestinal bacteria to the etiology of CRC by modifying the capacity of intestinal epithelial or (pre-)cancerous cells to (de)toxify dietary components, which could alter intestinal susceptibility to DNA damaging events.
Topics: Animals; Biotransformation; Colorectal Neoplasms; Cytochrome P-450 CYP1A1; Epithelial Cells; Mice; Mice, Inbred C57BL; Receptors, Aryl Hydrocarbon; Streptococcus gallolyticus
PubMed: 34778104
DOI: 10.3389/fcimb.2021.740704 -
British Journal of Cancer Jan 2018We investigated the role of prostaglandin receptors (e.g. prostaglandin E2 receptor 2 (EP2), EP4) and the efficacy of celecoxib in urothelial tumourigenesis and cancer...
BACKGROUND
We investigated the role of prostaglandin receptors (e.g. prostaglandin E2 receptor 2 (EP2), EP4) and the efficacy of celecoxib in urothelial tumourigenesis and cancer progression.
METHODS
We performed immunohistochemistry in bladder cancer (BC) tissue microarrays, in vitro transformation assay in a normal urothelial SVHUC line, and western blot/reverse transcription-polymerase chain reaction/cell growth assays in BC lines.
RESULTS
EP2/EP4 expression was elevated in BCs compared with non-neoplastic urothelial tissues and in BCs from those who were resistant to cisplatin-based neoadjuvant chemotherapy. Strong positivity of EP2/EP4 in non-muscle-invasive tumours or positivity of EP2/EP4 in muscle-invasive tumours strongly correlated with disease progression or disease-specific mortality, respectively. In SVHUC cells, exposure to a chemical carcinogen 3-methylcholanthrene considerably increased and decreased the expression of EP2/EP4 and phosphatase and tensin homologue (PTEN), respectively. Treatment with selective EP2/EP4 antagonist or celecoxib also resulted in prevention in 3-methylcholanthrene-induced neoplastic transformation of SVHUC cells. In BC lines, EP2/EP4 antagonists and celecoxib effectively inhibited cell viability and migration, as well as augmented PTEN expression. Furthermore, these drugs enhanced the cytotoxic activity of cisplatin in BC cells. EP2/EP4 and PTEN were also elevated and reduced, respectively, in cisplatin-resistant BC sublines.
CONCLUSIONS
EP2/EP4 activation correlates with induction of urothelial cancer initiation and outgrowth, as well as chemoresistance, presumably via downregulating PTEN expression.
Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cisplatin; Drug Resistance, Neoplasm; Heterografts; Humans; Immunohistochemistry; Male; Mice; Mice, Inbred NOD; Mice, SCID; Neoplasm Invasiveness; PTEN Phosphohydrolase; Receptors, Prostaglandin; Tissue Array Analysis; Urinary Bladder Neoplasms
PubMed: 29123257
DOI: 10.1038/bjc.2017.393 -
Drug Metabolism and Disposition: the... Sep 2018expression can be upregulated by the ligand-activated aryl hydrocarbon receptor (AHR). Based on prior observations with estrogen receptors and estrogen response...
expression can be upregulated by the ligand-activated aryl hydrocarbon receptor (AHR). Based on prior observations with estrogen receptors and estrogen response elements, we tested the hypothesis that single-nucleotide polymorphisms (SNPs) mapping hundreds of base pairs (bp) from xenobiotic response elements (XREs) might influence AHR binding and subsequent gene expression. Specifically, we analyzed DNA sequences 5 kb upstream and downstream of the gene for putative XREs. SNPs located ±500 bp of these putative XREs were studied using a genomic data-rich human lymphoblastoid cell line (LCL) model system. CYP1A1 mRNA levels were determined after treatment with varying concentrations of 3-methylcholanthrene (3MC). The rs2470893 (-1694G>A) SNP, located 196 bp from an XRE in the promoter, was associated with 2-fold variation in AHR-XRE binding in a SNP-dependent fashion. LCLs with the AA genotype displayed significantly higher AHR-XRE binding and CYP1A1 mRNA expression after 3MC treatment than did those with the GG genotype. Electrophoretic mobility shift assay (EMSA) showed that oligonucleotides with the AA genotype displayed higher LCL nuclear extract binding after 3MC treatment than did those with the GG genotype, and mass spectrometric analysis of EMSA protein-DNA complex bands identified three candidate proteins, two of which were co-immunoprecipitated with AHR. In conclusion, we have demonstrated that the rs2470893 SNP, which maps 196 bp from a promoter XRE, is associated with variations in 3MC-dependent AHR binding and expression. Similar "distant SNP effects" on AHR binding to an XRE motif and subsequent gene expression might occur for additional AHR-regulated genes.
Topics: 5' Untranslated Regions; Basic Helix-Loop-Helix Transcription Factors; Binding Sites; Cell Line, Tumor; Cytochrome P-450 CYP1A1; Cytochrome P-450 Enzyme Inducers; Enzyme Induction; Humans; Methylcholanthrene; Polymorphism, Single Nucleotide; Protein Binding; Receptors, Aryl Hydrocarbon; Response Elements; Transcription, Genetic; Xenobiotics
PubMed: 29980579
DOI: 10.1124/dmd.118.082164