Nrf2 activation does not affect adenoma development in a mouse model of colorectal cancer.
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ABSTRACT:
SUBMITTER: Knatko EV
PROVIDER: S-EPMC8443638 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Nrf2 is a transcription factor that regulates cellular stress response and irinotecan-metabolising pathways. Its aberrant activity has been reported in a number of cancers, although relatively few studies have explored a role for Nrf2 in colorectal cancer (CRC). This study assessed the expression of Nrf2 in patient CRC tissues and explored the effect of Nrf2 modulation alone, or in combination with irinotecan, in human (HCT116) and murine (CT26) cell lines in vitro and in an orthotopic syngeneic mouse model utilising bioluminescent imaging. Using a tissue microarray, Nrf2 was found to be overexpressed (p<0.01) in primary CRC and metastatic tissue relative to normal colon, with a positive correlation between Nrf2 expression in matched primary and metastatic samples. In vitro experiments in CRC cell lines revealed that Nrf2 siRNA and brusatol, which is known to inhibit Nrf2, decreased viability and sensitised cells to irinotecan toxicity. Furthermore, brusatol effectively abrogated CRC tumour growth in subcutaneously and orthotopically-allografted mice, resulting in an average 8-fold reduction in luminescence at the study end-point (p=0.02). Our results highlight Nrf2 as a promising drug target in the treatment of CRC.
| S-EPMC6007465 | biostudies-literature
Project description:Patients with KRAS mutated colorectal cancer (CRC) represent a cohort with unmet medical needs, with limited options of FDA-approved therapies. Representing 40-45% of all CRC patients, they are considered ineligible to receive anti-EGFR monoclonal antibodies that have added a significant therapeutic benefit for KRAS wild type CRC patients. Although several mouse models of CRC have been developed during the past decade, one genetically resembling the KRAS mutated CRC is yet to be established. In this study C57 BL/6 mice with truncated adenomatous polyposis coli (APC) floxed allele was crossed with heterozygous KRAS floxed outbred mice to generate an APCf/f KRAS+/f mouse colony. In another set of breeding, APC floxed mice were crossed with CDX2-Cre-ERT2 mice and selected for APCf/f CDX2-Cre-ERT2 after the second round of inbreeding. The final model of the disease was generated by the cross of the two parental colonies and viable APC f/f KRAS +/f CDX2-Cre-ERT2 (KPC: APC) were genotyped and characterized. The model animals were tamoxifen (TAM) induced to generate tumors. Micro-positron emission tomography (PET) scan was used to detect and measure tumor volume and standard uptake value (SUV). Hematoxylin and eosin (H&E) staining was performed to establish neoplasm and immunohistochemistry (IHC) was performed to determine histological similarities with human FFPE biopsies. The MSI/microsatellite stable (MSS) status was determined. Finally, the tumors were extensively characterized at the molecular level to establish similarities with human CRC tumors. The model KPC: APC animals are conditional mutants that developed colonic tumors upon induction with tamoxifen in a dose-dependent manner. The tumors were confirmed to be malignant within four weeks of induction by H&E staining and higher radioactive [18F] fluoro-2-deoxyglucose (FDG) uptake (SUV) in micro-PET scan. Furthermore, the tumors histologically and molecularly resembled human colorectal carcinoma. Post tumor generation, the KPC: APC animals died of cachexia and rectal bleeding. Implications: This model is an excellent preclinical platform to molecularly characterize the KRAS mutated colorectal tumors and discern appropriate therapeutic strategies to improve disease management and overall survival.
| S-EPMC6888417 | biostudies-literature
Project description:Background & aimsActivation of the kelch-like ECH-associated protein 1 (Keap1)-nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway has been associated with metabolic reprogramming in many tumors, including hepatocellular carcinoma (HCC). However, the contribution of Nrf2 mutations in this process remains elusive. Here, we investigated the occurrence of Nrf2 mutations in distinct models of mouse hepatocarcinogenesis.MethodsHCCs were generated by experimental protocols consisting of the following: (1) a single dose of diethylnitrosamine (DEN), followed by repeated treatments with the nuclear-receptor agonist 1,4-bis-[2-(3,5-dichloropyridyloxy)]benzene; (2) repeated treatments with 1,4-bis-[2-(3,5-dichloropyridyloxy)]benzene alone; (3) a single dose of DEN followed by exposure to a choline-deficient L-amino acid-defined diet; and (4) a single dose of DEN with no further treatment. All of these protocols led to HCC development within 28-42 weeks. Activation of the Keap1-Nrf2 pathway was investigated by analyzing the presence of Nrf2 gene mutations, and the expression of Nrf2 target genes. Metabolic reprogramming was assessed by evaluating the expression of genes involved in glycolysis, the pentose phosphate pathway, and glutaminolysis.ResultsNo Nrf2 mutations were found in any of the models of hepatocarcinogenesis analyzed. Intriguingly, despite the described cooperation between β-catenin and the Nrf2 pathway, we found no evidence of Nrf2 activation in both early dysplastic nodules and HCCs, characterized by the presence of up to 80%-90% β-catenin mutations. No HCC metabolic reprogramming was observed either.ConclusionsThese results show that, unlike rat hepatocarcinogenesis, Nrf2 mutations do not occur in 4 distinct models of chemically induced mouse HCC. Interestingly, in the same models, metabolic reprogramming also was minimal or absent, supporting the concept that Nrf2 activation is critical for the switch from oxidative to glycolytic metabolism.
| S-EPMC8593617 | biostudies-literature
Project description:Despite advances in the modeling and understanding of colorectal cancer development, the dynamics of the progression from benign adenomatous polyp to colorectal carcinoma are still not fully resolved. To take advantage of adenoma size and prevalence data in the National Endoscopic Database of the Clinical Outcomes Research Initiative (CORI) as well as colorectal cancer incidence and size data from the Surveillance Epidemiology and End Results (SEER) database, we construct a two-type branching process model with compartments representing adenoma and carcinoma cells. To perform parameter inference we present a new large-size approximation to the size distribution of the cancer compartment and validate our approach on simulated data. By fitting the model to the CORI and SEER data, we learn biologically relevant parameters, including the transition rate from adenoma to cancer. The inferred parameters allow us to predict the individualized risk of the presence of cancer cells for each screened patient. We provide a web application which allows the user to calculate these individual probabilities at https://ccrc-eth.shinyapps.io/CCRC/. For example, we find a 1 in 100 chance of cancer given the presence of an adenoma between 10 and 20mm size in an average risk patient at age 50. We show that our two-type branching process model recapitulates the early growth dynamics of colon adenomas and cancers and can recover epidemiological trends such as adenoma prevalence and cancer incidence while remaining mathematically and computationally tractable.
| S-EPMC7001909 | biostudies-literature
Project description:Colorectal cancer (CRC) is the third most frequent cancer and the third leading cause of cancer deaths in the United States (American Cancer Society, Cancer facts and figures 2012, 20121). The major cause of death is metastasis and frequently, the target organ is the liver. Successful metastasis depends on acquired properties in cancer cells that promote invasion and migration, and on multiple interactions between tumors and host-derived cells in the microenvironment. These processes, however, occur asymptomatically, thus, metastasis remains poorly understood and often diagnosed only at the final stage. To facilitate the elucidation of the mechanisms underlying these processes and to identify the molecular regulators, particularly at the early stages, we developed a mouse model of hepatic metastasis of CRC by cecal implantation of a mouse adenocarcinoma cell line in an immune competent host that reliably recapitulates all steps of tumor growth and metastasis within a defined period. By in vivo selection, we isolated cells of varying metastatic potential. The most highly metastatic CT26-FL3 cells produced liver metastasis as early as 10 days after implantation in 90 % of host mice. These cells expressed elevated levels of genes whose products promote invasion, migration, and mobilization of bone marrow derived cells (BMDCs). Mice bearing tumors from CT26-FL3 had elevated serum levels of OPN, MMP9, S100A8, S100A9, SAA3, and VEGFA that promote invasion and BMDC mobilization, and showed enhanced BMDC recruitment to the liver where they established a pre-metastatic niche. This model provides an important platform to characterize metastatic cells and elucidate tumor-host interactions and mechanisms that drive liver metastasis of CRC.
| S-EPMC3836876 | biostudies-literature
Project description:BACKGROUND:There are still no absolute parameters predicting progression of adenoma into cancer. The present study aimed to characterize functional differences on the multistep carcinogenetic process from the adenoma-carcinoma sequence. METHODS:All samples were collected and mRNA expression profiling was performed by using Agilent Microarray high-throughput gene-chip technology. Then, the characteristics of mRNA expression profiles of adenoma-carcinoma sequence were described with bioinformatics software, and we analyzed the relationship between gene expression profiles of adenoma-adenocarcinoma sequence and clinical prognosis of colorectal cancer. RESULTS:The mRNA expressions of adenoma-carcinoma sequence were significantly different between high-grade intraepithelial neoplasia group and adenocarcinoma group. The biological process of gene ontology function enrichment analysis on differentially expressed genes between high-grade intraepithelial neoplasia group and adenocarcinoma group showed that genes enriched in the extracellular structure organization, skeletal system development, biological adhesion and itself regulated growth regulation, with the P value after FDR correction of less than 0.05. In addition, IPR-related protein mainly focused on the insulin-like growth factor binding proteins. CONCLUSION:The variable trends of gene expression profiles for adenoma-carcinoma sequence were mainly concentrated in high-grade intraepithelial neoplasia and adenocarcinoma. The differentially expressed genes are significantly correlated between high-grade intraepithelial neoplasia group and adenocarcinoma group. Bioinformatics analysis is an effective way to study the gene expression profiles in the adenoma-carcinoma sequence, and may provide an effective tool to involve colorectal cancer research strategy into colorectal adenoma or advanced adenoma.
| S-EPMC4483896 | biostudies-literature
Project description:In 100 primary colorectal carcinomas, we demonstrate by array comparative genomic hybridization (aCGH) that 33% show DNA copy number (DCN) loss involving PARK2, the gene encoding PARKIN, the E3 ubiquitin ligase whose deficiency is responsible for a form of autosomal recessive juvenile parkinsonism. PARK2 is located on chromosome 6 (at 6q25-27), a chromosome with one of the lowest overall frequencies of DNA copy number alterations recorded in colorectal cancers. The PARK2 deletions are mostly focal (31% approximately 0.5 Mb on average), heterozygous, and show maximum incidence in exons 3 and 4. As PARK2 lies within FRA6E, a large common fragile site, it has been argued that the observed DCN losses in PARK2 in cancer may represent merely the result of enforced replication of locally vulnerable DNA. However, we show that deficiency in expression of PARK2 is significantly associated with adenomatous polyposis coli (APC) deficiency in human colorectal cancer. Evidence of some PARK2 mutations and promoter hypermethylation is described. PARK2 overexpression inhibits cell proliferation in vitro. Moreover, interbreeding of Park2 heterozygous knockout mice with Apc(Min) mice resulted in a dramatic acceleration of intestinal adenoma development and increased polyp multiplicity. We conclude that PARK2 is a tumor suppressor gene whose haploinsufficiency cooperates with mutant APC in colorectal carcinogenesis.
| S-EPMC2930574 | biostudies-literature
Project description:PurposeThis study demonstrates that estradiol downregulates inflammation and inhibits colorectal cancer (CRC) development in azoxymethane/dextran sulfate sodium (AOM/DSS) mouse model.Materials and methodsAOM/DSS-treated male and female mice were sacrificed at weeks 2, 10, and 16, to assess estrogen effects on colitis and carcinogenesis. Macroscopic and histologic severity of colitis and Western blot and quantitative real-time polymerase chain reaction were evaluated, to measure inflammatory mediators and cytokines.ResultsCompared with AOM/DSS-treated male mice (M-AOM/DSS group), AOM/DSS-treated male mice with estradiol administration (M-AOM/DSS+estr group) displayed at week 2 significantly decreased severity of colitis. At weeks 10 and 16, AOM/DSS-treated female mice (F-AOM/DSS group) and the M-AOM/DSS+estr group showed significantly lower tumor multiplicity compared with the M-AOM/DSS group. At week 2, F-AOM/DSS group had a lower level of nuclear factor-κB (NF-κB) expression and higher level of nuclear factor erythroid 2-related factor 2 (Nrf2) expression, compared to the M-AOM/DSS group. At week 2, expression levels of NF-κB and its related mediators decreased in the M-AOM/DSS+estr group, while levels of Nrf2 and Nrf2-related anti-oxidant enzymes increased. In addition, estradiol significantly increased Nod-like receptor protein 3 (NLRP3) inflammasome expressions in AOM/DSS-treated male mice. In contrast, at weeks 10 and 16, Nrf2 and its-related anti-oxidant enzymes and NLRP3 inflammasome were highly expressed in M-AOM/DSS group and in F-AOM/DSS group, who developed cancer.ConclusionThe data suggest that estradiol inhibits the initiation of CRC by regulating Nrf2-related pathways. Moreover, these imply the dual role of Nrf2 and NLRP3 inflammasome, including promotion of tumor progression upon tumor initiation.
| S-EPMC6473282 | biostudies-literature
Project description:Gut microbiome is gaining interest because of its links with several diseases, including colorectal cancer (CRC), as well as the possibility of being used to obtain non-intrusive predictive disease biomarkers. Here we performed a meta-analysis of 1042 fecal metagenomic samples from seven publicly available studies. We used an interpretable machine learning approach based on functional profiles, instead of the conventional taxonomic profiles, to produce a highly accurate predictor of CRC with better precision than those of previous proposals. Moreover, this approach is also able to discriminate samples with adenoma, which makes this approach very promising for CRC prevention by detecting early stages in which intervention is easier and more effective. In addition, interpretable machine learning methods allow extracting features relevant for the classification, which reveals basic molecular mechanisms accounting for the changes undergone by the microbiome functional landscape in the transition from healthy gut to adenoma and CRC conditions. Functional profiles have demonstrated superior accuracy in predicting CRC and adenoma conditions than taxonomic profiles and additionally, in a context of explainable machine learning, provide useful hints on the molecular mechanisms operating in the microbiota behind these conditions.
| S-EPMC8748837 | biostudies-literature
Project description:BACKGROUND:Circulating microRNAs (miRNAs) are emerging as promising biomarkers for cancer. The objective of the current study was to investigate the potential of circulating cell-free miRNAs as biomarkers for colorectal cancer (CRC) and its precursor lesion, colorectal adenoma. METHODS:The serum levels of 800 miRNAs were assessed in a discovery set of 21 patients with CRC, 19 patients with adenoma, and 21 healthy controls using the NanoString miRNA analysis platform. Significantly differentially expressed miRNAs were examined further in a validation cohort of 34 patients with CRC, 33 patients with adenoma, and 35 healthy controls using Fluidigm quantitative polymerase chain reaction assays. RESULTS:The ratios between the expression values of the differentially expressed miRNAs were computed. Three miRNA ratios (miR-17-5p/miR-135b, miR-92a-3p/miR135b, and miR-451a/miR-491-5p) were validated for discriminating patients with adenoma and those with CRC from the healthy control group, and 5 miRNA ratios (let-7b/miR-367-3p, miR-130a-3p/miR-409-3p, miR-148-3p/miR-27b, miR-148a-3p/miR-409-3p, and miR-21-5p/miR-367-3p) were validated for discriminating patients with CRC from those with adenoma and healthy controls. The area under the receiver operating characteristic curve values for the 3 miRNA ratios in discriminating patients with adenoma from healthy controls were 0.831 and 0.735, respectively, in the discovery and validation sets. The area under the receiver operating characteristic curve values for the 5 miRNA ratios in discriminating patients with CRC from those with adenoma were 0.797 and 0.732, respectively, in the discovery and validation sets. Pathway analysis revealed that target genes regulated by the miRNAs from the miRNA ratios were enriched mainly in metabolism-related and inflammation-related pathways. CONCLUSIONS:The data from the current study suggest that circulating miRNAs can distinguish patients with CRC and those with adenoma and may represent novel biomarkers for the early, noninvasive detection of CRC. Cancer 2018;124:785-96. © 2017 American Cancer Society.
| S-EPMC5801195 | biostudies-literature