Microarrays were used to analyse gene expression underlying early tumourigenesis in Eker rats. Distinct classes of up- and downregulated genes were identified in different preneoplasic lesion vs. microdissected normal (healthy) renal tubules.
Molecular characterization of preneoplastic lesions provides insight on the development of renal tumors.
Sex, Specimen part
View SamplesWe investigated an acute kidney injury (AKI) model in rats induced by cisplatin (Cp) administration. The cisplatin is widely used since its biochemical and histopathological characteristics are representative of drug-induced AKI in humans. Male Wistar rats were dosed once ip with 0, 1 and 3 mg/kg cisplatin. Tubular necorsis was observed histopathologically in all treated rats and war recovery on day 26. Gene expression profiling of the kidney cortex with microarrays 3, 5, 8, and 26 days after single administration of 3mg/kg Cp revealed a major profile pattern characterized by maximally increased and decreased mRNA levels on day 8, with clear changes already found 3 days after treatment for about half of the mRNAs. The mRNA expression pattern after administration of 1mg/kg Cp was overall similar, yet with a dose-dependent smaller fold-change. In summary we found 274 mRNAs showing significantly altered levels in the kidney of which 162 were increased and 112 decreased, respectively. Functional interpretation of the proteins encoded by these mRNAs revealed induction of a DNA damage response likely caused by the known molecular activity of Cp as DNA alkylating agent. Increased mRNAs associated with apoptosis (encoded by the corresponding genes like B-cell lymphoma 3-encoded protein, Bcl3; mouse double minute 2 homolog, Mdm2; p21/WAF1 also known as cyclin-dependent kinase inhibitor 1), cell cycle regulation (encoded by the corresponding genes like Cyclin-G1, Ccng1; B-cell translocation gene 2, Btg2) and stress response may have partly been induced by the DNA damage, but also by the kidney damage associated with Cp administration. Increased levels of mRNAs indicating regeneration (encoded by the corresponding genes like SPARC- related modular calcium-binding protein 2, Smoc2; Tenascin C, Tnc) and decreased levels of mRNAs coding for proteins related to kidney function, indicating dedifferentiation, are likely related to the observed kidney injury.
Comparison of the MesoScale Discovery and Luminex multiplex platforms for measurement of urinary biomarkers in a cisplatin rat kidney injury model.
Sex, Specimen part
View SamplesWe investigated a glomerulonephritis (GN) model in rats induced by nephrotoxic serum (NTS) which contains antibodies against the glomerular basement membrane (GBM). The anti-GBM GN model in rats is widely used since its biochemical and histopathological characteristics are similar to crescentic nephritis and Goodpasture's disease in humans. Male Wistar Kyoto (WKY) and Sprague Dawley (SD) rats were dosed once with 1, 2.5 and 5 ml/kg nephrotoxic serum (NTS) or 1.5 and 5 ml/kg NTS, respectively. GN and tubular damage were observed histopathologically in all treated rats after 14 days.
Glomerulonephritis-Induced Changes in Urinary and Kidney MicroRNA Profiles in Rats.
Sex, Specimen part
View SamplesThe carcinogenic potential of chemicals is currently evaluated with rodent life-time bioassays, which are time consuming, and expensive with respect to cost, number of animals and amount of compound required. Since the results of these 2-year bioassays are not known until quite late during development of new chemical entities, and since the short-term test battery to test for genotoxicity, a characteristic of genotoxic carcinogens, is hampered by low specificity, the identification of early biomarkers for carcinogenicity would be a big step forward. Using gene expression profiles from the livers of rats treated up to 14 days with genotoxic and non-genotoxic carcinogens we previously identified characteristic gene expression profiles for these two groups of carcinogens. We have now added expression profiles from further hepatocarcinogens and from non-carcinogens the latter serving as control profiles. We used these profiles to extract biomarkers discriminating genotoxic from non-genotoxic carcinogens and to calculate classifiers based on the support vector machine (SVM) algorithm. These classifiers then predicted a set of independent validation compound profiles with up to 88% accuracy, depending on the marker gene set. We would like to present this study as proof of the concept that a classification of carcinogens based on short-term studies may be feasible.
Cross-platform toxicogenomics for the prediction of non-genotoxic hepatocarcinogenesis in rat.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cross-platform toxicogenomics for the prediction of non-genotoxic hepatocarcinogenesis in rat.
Sex, Specimen part
View SamplesIn this study we performed microarray-based molecular profiling of liver samples from Wistar rats exposed to genotoxic carcinogens (GC), nongenotoxic carcinogens (NGC) or non-hepatocarcinogens (NC) for up to 14 days. In contrast to previous toxicogenomics studies aimed at the inference of molecular signatures for assessing the potential and mode of compound carcinogenicity, we considered multi-level omics data. Besides evaluating the predictive power of signatures observed on individual biological levels, such as mRNA, miRNA and protein expression, we also introduced novel feature representations which capture putative molecular interactions or pathway alterations by integrating expression profiles across platforms interrogating different biological levels.
Cross-platform toxicogenomics for the prediction of non-genotoxic hepatocarcinogenesis in rat.
Sex, Specimen part
View SamplesWe investigated a drug-induced liver injury (DILI) model in rats induced by methapyrilene (MPy) administration. MPy, a former antihistamine and anticholinergic drug, was withdrawn in the 1970ties due to its ability to initiate hepatocarcinogenesis and is now used to induce hepatobiliary injury and biliary epithelial cell hyperplasia. Male Wistar rats (810 weeks old, weighing 170200 g) were randomly assigned to three dosing groups (n=6 per group and time-point) and dosed with MPy at 0, 30 and 80 mg/kg/day by oral gavage. After 4, 8 or 15 days, or after 14 days followed by a recovery period of 10 days (day 24) rats were sacrificed. Increased levels of ALAT, ASAT, AP and -GT as well as bili-t and total bile acids indicated liver damage (AP and GT indicating biliary effects). They were detectable on day 7 at the high dose of 80 mg/kg MPy and persisted until day 15 at end of treatment. Histopathologically, vacuolation and necrosis of the hepatocytes (predominantly in the periportal region) were seen starting on day 3 - especially in animals treated with 80 mg/kg MPy. These findings were accompanied by periportal mononuclear inflammatory cell filtration. Bile duct proliferation, bile duct hyperplasia and increased numbers of mitoses of hepatocytes were evident at all treatment time points. The frequency and severity of these findings increased with dose and duration of the treatment. Gene expression analysis in liver tissues revealed highly significant transcriptional changes in the high dose group, detectable on day 4 and intensifying over time. Besides genes associated with apoptosis (CASP4, CASP12), detoxification (CYB4B) and proliferation (p21, CCNG1) several were related to bile acid metabolism or transport. For example, bile acid exporters OATP1, NTCP, OATP4 and MOAT1/ OATPB as well as the putative bile acid metabolizing enzymes AMACR, BAAT and ACOX2 were found down regulated in response to MPy treatment. In contrast, mRNAs encoding putative bile acid importers MRP2 and ABCC4 / MRP4 were found up regulated. Most of the deregulated levels returned to control values during the recovery phase except OATP1, MOAT1/ OATPB, which remained slightly elevated. Interestingly, OATP4 followed an inverse trend of deregulation after 10 days of recovery, presumably due to overcompensation. Overall, the expression changes found associated with bile acid metabolism or transport could be linked to detected bile acid level alterations in liver and plasma.
Quantitative targeted bile acid profiling as new markers for DILI in a model of methapyrilene-induced liver injury in rats.
Sex, Specimen part
View SamplesAt present, substantial efforts are focused on the development of in vitro assays coupled with omics technologies for the identification of carcinogenic substances as an alternative to the classical 2-year rodent carcinogenicity bioassay. A prerequisite for the eventual regulatory acceptance of such assays, however, is the in vivo relevance of the observed in vitro findings.
Comparison of hepatocarcinogen-induced gene expression profiles in conventional primary rat hepatocytes with in vivo rat liver.
Specimen part
View SamplesBackground: Obesity is a risk factor for breast cancer in postmenopausal women and is associated with decreased survival and less favorable clinical characteristics such as greater tumor burden, higher grade, and poor prognosis, regardless of menopausal status. Despite the negative impact of obesity on clinical outcome, molecular mechanisms through which excess adiposity influences breast cancer etiology are not well-defined.
Effect of obesity on molecular characteristics of invasive breast tumors: gene expression analysis in a large cohort of female patients.
Disease stage
View SamplesHuman cytotrophoblast organoid cultures were established from the villous trophoblast of first trimester placentas. We analyzed the global expression profile of the cytotrophoblast organoids (CTB-ORG) and compared to the profile of the tissue of origin i.e. villous cytotrophoblast (vCTB) as well as to differentiated syncytiotrophoblast (STB) and placental fibroblasts (FIB). Overall design: We employed QuantSeq method to analyzed the global expression profile of the cytotrophoblast organoids (4 replicates, CTB-ORG 1-4) and compared to the profile of the tissue of origin i.e. villous cytotrophoblast (3 replicates, vCTB 1-3) as well as to in vitro differentiated syncytiotrophoblast (3 replicates, STB1-3) and placental fibroblasts (2 replicates, FIB 1-2).
Self-Renewing Trophoblast Organoids Recapitulate the Developmental Program of the Early Human Placenta.
Specimen part, Subject
View Samples