Project description:To explore the possible changes of gene expression induced by a carcinogen, we treated wild-type and Dicer1-KO mice with one dose of 120 mg/kg N-ethyl-N-nitrosourea (ENU), a model genotoxic carcinogen, and vehicle control. The gene expression profiles were assessed in the mouse livers in wild-type and Dicer1-KO mice design. Total RNA were isolated from the livers at days 15 after the treatment and their expression was determined using Gene Array. Gene expression in treated wild-type and Dicer1-KO mice was measured at 15 days after exposure to one dose of 120 mg/kg N-ethyl-N-nitrosourea (ENU). Each treatment duplex ,Drug-ko-a,Drug-ko-b,Drug-wt-a,Drug-wt-b,Control-ko-a,Control-ko-b,Control-wt-a,Control-wt-b.
Project description:To explore the possible changes of gene expression induced by a carcinogen, we treated wild-type and Dicer1-KO mice with one dose of 120 mg/kg N-ethyl-N-nitrosourea (ENU), a model genotoxic carcinogen, and vehicle control. The gene expression profiles were assessed in the mouse livers in wild-type and Dicer1-KO mice design. Total RNA were isolated from the livers at days 15 after the treatment and their expression was determined using Gene Array.
Project description:Dysregulated expression of microRNA (miRNA) has been extensively detected in human cancer tissues and has shown promise in defining tumor status. It, however, is little known whether and when expression of miRNAs can be changed in normal tissues after carcinogen exposure. To explore possible time-course changes of miRNA expression induced by carcinogens, we treated mice with one dose of 120 mg/kg body weight model genotoxic carcinogen N-ethyl-N-nitrosourea (ENU) and vehicle control. The miRNA expression profiles were determined in the mouse livers in a time-course manner. MiRNAs were isolated from the livers of ENU-treated and control mice at days 1, 3, 7, 15, 30 and 120 after the treatment. The miRNA expressions were determined using RT2-mouse miRNA PCR Array. Principal component analysis of the gene expression profiles showed that miRNA expression at post-treatment days 7 and 15 were different from those at the other time points and the controls. The numbers of the dysregulated miRNAs changed with time, being 3, 5, 14, 32, 5 and 5 at post-treatment days 1, 3, 7, 15, 30 and 120, respectively. Functional analysis of the differentially expressed miRNA at post-treatment days 7 and 15 indicated that the major functions of these ENU-induced dysregulated miRNAs were mainly associated with DNA repair and tumorigenesis, suggesting the microRNA expression is related to genotoxicity of ENU. These results propose that one to two weeks after ENU exposure is the best time for miRNA expression sampling; and that a large number of miRNAs whose expression is dysregulated after carcinogen exposure could be an indicator for carcinogenic damage. Series type: Non-coding RNA profiling by RT-PCR
Project description:Dynamic changes in the mouse liver DNA methylome associated with short (1 day) and prolonged (7, 28 and 91 days) exposure to the rodent liver non-genotoxic carcinogen (NGC), phenobarbital (PB). Full expression dataset (all time points: 1, 7, 28, 91 days) Replicated control vs. pb treated study
Project description:To further our investigations for early biomarkers of non-genotoxic carcinogenesis, groups of mice were treated by gavage with a prototypic non-genotoxic carcinogen: Phenobarbital (PB, CAS: 57-30-7), for a period of 28 and 90d and liver tissue harvested for expression profiling. Control groups were treated with appropriate vehicle (0.5% Methylcellulose).
Project description:Rapidly increasing number of man-made chemicals urges the development of reliable time- and cost-effective approaches for the carcinogen detection and identification. Considering this, the utility of high throughput microarray gene expression profiling for the identification of genotoxic and non-genotoxic carcinogens in vitro was investigated. Human terminally differentiated hepatic HepaRG cells were treated with model liver carcinogens, genotoxic carcinogen aflatoxin B1 (AFB1) and non-genotoxic carcinogen methapyrilene, at IC10 and IC25 concentrations for 72 hours, and transcriptomic profiles were determined. Treatment of HepaRG cells with IC10 and IC25 concentrations of AFB1 resulted in altered expression of 538 and 3033 genes (p-value ≤0.01 and fold change ≥2.0), respectively, and treatment of HepaRG cells with methapyrilene at the IC10 and IC25 concentrations altered the expression of 1255 and 1861 genes, respectively. Pathway analysis of transcriptomic signatures in HepaRG cells treated with minimally cytotoxic IC10 concentrations of AFB1 and methapyrilene demonstrated a strong enrichment in genes involved in key carcinogen-associated pathways, including receptor-mediated effects, detoxification response, cell death and apoptosis, cell proliferation and survival, oxidative stress and inflammation. Importantly, DNA damage and repair, cell cycle progression, and cell cycle checkpoint control pathways were uniquely activated in AFB1-treated HepaRG cells, whereas receptor-mediated signaling detoxification response pathway was predominantly altered in methapyrilene-treated HepaRG cells. In summary, high throughput microarray gene expression approach identifies specific carcinogen-exposure-associated transcriptomic responses and identifies affected molecular pathways, and categorize pathways associated with carcinogen exposure in a short-term in vitro test.
Project description:Many innovative techniques and scientific improvements are available to tackle societal concerns, like public health safety and confining the risk of cancerous exposure to chemicals, but have not been thoroughly tested and implicated yet. We investigated if microRNA and mRNA transcription profiles can be implemented in a short-term carcinogen classifier assay. Our study is additionally focusing on the drawbacks of present-day carcinogen screening strategies and also aims to contribute to a more ethical approach towards animal use and welfare within risk assessment. Since current in vitro and in silico assays are still not able to mimic the in vivo situation accurately we set out to develop an alternative short-term in vivo assay. Five genotoxic, seven non-genotoxic and five non-carcinogen exposure studies were used to investigate if murine hepatic microRNA and mRNA profiles after 7-day exposure are suitable tools to classify carcinogens. Classification analyses showed that a small transcript set, consisting of both microRNA and mRNA, is able to classify the genotoxic, non-genotoxic and non-carcinogens tested with 100% accuracy. The results indicate that microRNAs have the potential to be used as transcriptional classifiers and that a short-term transcriptional classifier assay in mice can be a powerful tool in carcinogenicity risk assessment. [microRNA profling] 68 hepatic samples in total, 3 control untreated samples, replicates per treated group n=3-4
Project description:The increasing number of man-made chemicals in the environment that may pose a carcinogenic risk emphasizes the need for the development of reliable time- and cost-effective approaches for carcinogen detection. To address this issue, we have investigated the utility of human hepatocytes for the in vitro identification of genotoxic and non-genotoxic carcinogens. Induced pluripotent stem cell (iPSC)-derived human hepatocytes were treated with the genotoxic carcinogens aflatoxin B1 (AFB1) and benzo[a]pyrene (B[a]P) and with the non-genotoxic liver carcinogen methapyrilene at non-cytotoxic concentrations for 7 days, and transcriptomic profile was examined. 1569 (892 protein-coding and 677 non-coding), 1693 (922 protein-coding and 771 non-coding), and 2061 (1462 protein-coding and 599 non-coding) differentially expressed genes were detected in cells treated with AFB1, B[a]P, and methapyrilene, respectively. Additionally, we examined the toxicogenomics response to AFB1, B[a]P, and methapyrilene exposure in human HepaRG cells and demonstrated that carcinogens had a less prominent effect on the cellular transcriptome as compared to that in human iPSC-derived hepatocytes. Overall, the results demonstrate that the prime non-genotoxic effect of exposure to carcinogens, regardless of their mode of action, in short-term in vitro testing is a profound global transcriptome response, indicating a greater value of toxicogenomics for rapid carcinogen screening in vitro.
Project description:Many innovative techniques and scientific improvements are available to tackle societal concerns, like public health safety and confining the risk of cancerous exposure to chemicals, but have not been thoroughly tested and implicated yet. We investigated if microRNA and mRNA transcription profiles can be implemented in a short-term carcinogen classifier assay. Our study is additionally focusing on the drawbacks of present-day carcinogen screening strategies and also aims to contribute to a more ethical approach towards animal use and welfare within risk assessment. Since current in vitro and in silico assays are still not able to mimic the in vivo situation accurately we set out to develop an alternative short-term in vivo assay. Five genotoxic, seven non-genotoxic and five non-carcinogen exposure studies were used to investigate if murine hepatic microRNA and mNA profiles after 7-day exposure are suitable tools to classify carcinogens. Classification analyses showed that a small transcript set, consisting of both microRNA and mRNA, is able to classify the genotoxic, non-genotoxic and non-carcinogens tested with 100% accuracy. The results indicate that microRNAs have the potential to be used as transcriptional classifiers and that a short-term transcriptional classifier assay in mice can be a powerful tool in carcinogenicity risk assessment. Since current in vitro and in silico assays are still not able to mimic the in vivo situation accurately we set out to develop an alternative short-term in vivo assay. Five genotoxic, seven non-genotoxic and five non-carcinogen exposure studies were used to investigate if murine hepatic microRNA and mNA profiles after 7-day exposure are suitable tools to classify carcinogens. Classification analyses showed that a small transcript set, consisting of both microRNA and mRNA, is able to classify the genotoxic, non-genotoxic and non-carcinogens tested with 100% accuracy. The results indicate that microRNAs have the potential to be used as transcriptional classifiers and that a short-term transcriptional classifier assay in mice can be a powerful tool in carcinogenicity risk assessment. [mRNA profling] 96 hepatic samples in total, 8 control untreated samples, replicates per treated group n=4-6