Project description:Since xenobiotics enter the organism via the liver, hepatocytes must cope with numerous perturbations. In particular, exposure to hepatotoxic agents resulting in liver injury triggers a strong alteration in gene expression. The contribution of these transcriptional regulatory networks to the propagation of injury (i.e. by modulation of metabolic pathways, inflammation, proliferation) are not fully understood. Therefore, we conducted a time-resolved gene array study on mouse liver after exposure to a single intraperitoneal injection of the hepatotoxic compound carbon tetrachloride (CCl4). This model induces a transient injury which reaches its maximum between 2 to 3 days after injection, followed by a precise regenerative response. The experiment included early time points (i.e. 2 and 8h) and late time points (1 to 16 days) to cover the initial events induced by CCl4 metabolization and cell stress, and the regenerative phase between 2-6 days after intoxicaiton. C57BL/6N male mice (8-12 weeks old) were obtained from Charles Rivers (Sulzfeld, Germany). The local Ethics committee approved the experiments. 4-5 mice were used for each time point. Mice received a single intraperitoneal injection of CCl4 (1.6 g/kg body weight) dissolved in 0.5 ml olive oil. The liver tissue was collected after 2h, 8h, and 1, 2, 4, 6, 8 and 16 days following CCl4 administration. As control, mice received 0.5 ml of olive oil intraperitonealy for 1 or 8 days. Healthy liver was collected from untreated mice. At the indicated time points, mice were anesthetized and blood was collected from the heart with a 25 gauge needle, using EDTA as anticoagulant, for analysis of the liver transaminases GOT and GPT in serum. Afterwards, the liver was resected, washed in ice cold PBS and sectioned for further analysis. Liver tissue sections of about 0.5 cm2 were snap frozen in liquid nitrogen and stored at -80ﾰC for subsequent isolation of proteins or RNA. RNA was isolated from mouse liver tissue using the Phenol/Chloroform method (Trizolﾮ, Qiagen, Hilden, Germany) according to the manufacturerﾒs instructions. RNA concentration and integrity were determined spectrophotometrically in a Nanodropﾮ2000 (ThermoScientific, Waltham MA, USA) and in a Bioanalyzerﾮ (Agilent, Waldbronn, Germany), respectively.

Project description:It is well-known that isolation and cultivation of primary hepatocytes causes major gene expression alterations. In the present genome-wide, time resolved study of cultivated human and mouse hepatocytes, we made the observation that expression changes in culture strongly resemble alterations in liver diseases. Hepatocytes of both species were cultivated in collagen sandwich and in monolayer conditions. Genome-wide data were also obtained from human NAFLD, cirrhosis, HCC, and hepatitis B virus infected tissue as well as mouse livers after partial hepatectomy, CCl4 intoxication, obesity, HCC and LPS. A strong similarity between cultivation and disease induced expression alterations was observed. For example, expression changes in hepatocytes induced by one day cultivation and one day CCl4 exposure in vivo correlated with R=0.615 (P<0.001). Interspecies comparison identified predominantly similar responses in human and mouse hepatocytes but also a minority of genes that responded differently. Unsupervised clustering of altered genes identified three main clusters: (1) downregulated genes corresponding to mature liver functions, (2) upregulation of an inflammation/RNA-processing cluster, (3) upregulated migration/cell-cycle associated genes. Gene regulatory network analysis highlights overrepresented and deregulated HNF4 and CAR (cluster 1), KrÃ¼ppel-like factors MafF and ELK1 (cluster 2) as well as ETF (cluster 3) among the interspecies conserved key regulators of expression changes. Interventions ameliorating but by far not abrogating cultivation-induced responses include removal of non-parenchymal cells, generation of the hepatocytesâ own matrix in spheroids, supplementation with bile salts and siRNA mediated suppression of key transcription factors. In conclusion, the study shows that gene regulatory network alterations of cultivated hepatocytes resemble those of inflammatory liver diseases and should therefore be considered and exploited as disease models.

Project description:The aim of this study was to compare the gene expression profile changes of DMBA-induced rat breast tumors after treatment with hydroxytyrosol (a natural compound from virgin olive oil). To this end, a cDNA microarray experiment was performed (Affymetrix’s Rat Genome 230 2.0 array). This gene expression study was carried out on the tumor biopsy samples prior to hydroxytyrosol treatment, and compared with matched tumor biopsy samples after completion of the hydroxytyrosol treatment schedule. The result of this study was the identification of several genes related to apoptosis, cell cycle arrest, proliferation, differentiation, survival and transformation-related genes. Breast tumors were induced with a single oral dose of 7,12-dimethylbenz(alpha)anthracene (100 mg/kg body weight) in female Sprague-Dawley rats to test the antitumor power of orally administrated hydroxytyrosol (0.5 mg/kg body weight 5 days/week for 6 weeks). Gene expression analysis was performed in paired samples as follows: HT final trucut tumor vs initial trucut tumor (HT final vs basal). For this assay, 5 samples were chosen according to histopathologic criteria (Bloom-Richardson grade II). Gene expression profiling was carried out using Affymetrix’s GeneChip technology, using the Rat Genome 230 v2.0 array from this provider. All the protocols and apparatus were recommended by Affymetrix. Total RNA from frozen mammary tumors was extracted by RNeasy Mini kit and homogenized by QIAshredder columns according to manufacturer’s instructions. The quality and quantity of the obtained RNA was checked out through agarose electrophoresis and later spectrophotometry at 260/280 nm. Biotinylated cRNA was synthesized following the IVT labeling kit from Affymetrix and purified by the GeneChip Sample Cleanup Module from Affymetrix. The quality and quantity of the obtained cRNA was again checked out through agarose electrophoresis and posterior spectrophotometry at 260/280 nm. After hybridization, slides were washed and scanned following the manufacturer’s standard protocol. Intensity values were normalized by Robust Multichip Average method and subsequently these were filtered to remove the control sequences and those with a hybridization signal close to background. The spike controls were: BioB, BioC, BioD and Cre; because BioB was the least abundant in the samples, it was used to estimate the sensitivity of the experiment. The housekeeping control was GAPDH. After non-supervised clustering using Pearson correlation coefficient, statistical significance of gene expression was estimated by Student’s T test for paired samples using GeneSpring GX 7.3 software (Agilent).

Project description:The aim of this study was to compare the gene expression profile changes of DMBA-induced rat breast tumors after treatment with adriamycin. To this end, a cDNA microarray was performed (Affymetrix’s Rat Genome 230 2.0 array). This gene expression study was carried out on the tumor biopsy samples prior to adriamycin treatment, and compared with matched tumor biopsy samples after completion of the adriamycin treatment schedule. Breast tumors were induced with a single oral dosage of 7,12-dimethylbenz(alpha)anthracene (100 mg/kg body weight) in female Sprague-Dawley rats and subsequently treated with adriamycin (1 mg/kg body weight/week for 6 weeks) intravenously through lateral tail vein. Gene expression analysis was performed in paired samples as follows: ADR final trucut tumor vs initial trucut tumor (ADR final vs basal). For this assay, 5 samples were chosen according to histopathologic criteria (Bloom-Richardson grade II). Gene expression profiling was carried out using Affymetrix’s GeneChip technology, using the Rat Genome 230 2.0 array from this provider. All the protocols and apparatus were recommended by Affymetrix. Total RNA from frozen mammary tumors was extracted by RNeasy Mini kit and homogenized by QIAshredder columns according to manufacturer’s instructions. The quality and quantity of the obtained RNA was checked out through agarose electrophoresis and later spectrophotometry at 260/280 nm. Biotinylated cRNA was synthesized following the IVT labeling kit from Affymetrix and purified by the GeneChip Sample Cleanup Module from Affymetrix. The quality and quantity of the obtained cRNA was again checked out through agarose electrophoresis and posterior spectrophotometry at 260/280 nm. After hybridization, slides were washed and scanned following the manufacturer’s standard protocol. Intensity values were normalized by Robust Multichip Average method and subsequently these were filtered to remove the control sequences and those with a hybridization signal close to background. The spike controls were: BioB, BioC, BioD and Cre; because BioB was the least abundant in the samples, it was used to estimate the sensitivity of the experiment. The housekeeping control was GAPDH. After non-supervised clustering using Pearson correlation coefficient, statistical significance of gene expression was estimated by Student’s T test for paired samples, using GeneSpring GX 7.3 software (Agilent).

Project description:The aim of this study was to compare the gene expression profile changes of DMBA-induced rat breast tumors from an initial stage to the moment of sacrifice. To this end, a cDNA microarray was performed (Affymetrix’s Rat Genome 230 2.0 array). This gene expression study was carried out on the umor biopsy samples and compared with matched tumor biopsy samples once the study ended (7 weeks after initial biopsy). Breast tumors were induced with a single oral dosage of 7,12-dimethylbenz(alpha)anthracene (100 mg/kg body weight) in female Sprague-Dawley rats. Gene expression analysis was performed in paired samples as follows: DMBA final trucut tumor vs initial trucut tumor (DMBA final vs basal). For this assay, 5 samples were chosen according to histopathologic criteria (Bloom-Richardson grade II). Gene expression profiling was carried out using Affymetrix’s GeneChip technology, using the Rat Genome 230 2.0 array from this provider. All the protocols and apparatus were recommended by Affymetrix. Total RNA from frozen mammary tumors was extracted by RNeasy Mini kit and homogenized by QIAshredder columns according to manufacturer’s instructions. The quality and quantity of the obtained RNA was checked out through agarose electrophoresis and later spectrophotometry at 260/280 nm. Biotinylated cRNA was synthesized following the IVT labeling kit from Affymetrix and purified by the GeneChip Sample Cleanup Module from Affymetrix. The quality and quantity of the obtained cRNA was again checked out through agarose electrophoresis and posterior spectrophotometry at 260/280 nm. After hybridization, slides were washed and scanned following the manufacturer’s standard protocol. Intensity values were normalized by Robust Multichip Average method and subsequently these were filtered to remove the control sequences and those with a hybridization signal close to background. The spike controls were: BioB, BioC, BioD and Cre; because BioB was the least abundant in the samples, it was used to estimate the sensitivity of the experiment. The housekeeping control was GAPDH. After non-supervised clustering using Pearson correlation coefficient, statistical significance of gene expression was estimated by Student’s T test for paired samples, using GeneSpring GX 7.3 software (Agilent).

Project description:The aim of this study was to compare the gene expression profile changes breast tumors after the treatment with Anthracyclines and Taxanes. To this end, an oligonucleotide microarray was performed (AffymetrixM-bM-^@M-^Ys HG-U133 Plus 2.0 array). This gene expression study was carried out on the biopsied tumor samples previous being treated with chemotherapy, and subsequently compared with themselves once treatment schedule ended. The post-chemotherapy biopsy was obtained from the surgical piece. The goal of this study was the finding of several genes related to apoptosis, proliferation, differentiation, survival and transformation-related genes and correlating their differences in expression with the degree of response to chemotherapy, determined by the Miller and Payne histological grading system. After informed consent, patients with a histologically confirmed diagnosis of breast cancer and scheduled chemotherapy treatment based on Anthracyclines and Taxanes (Treatment A: Epirubicin 90 mg/m2-Cyclophosphamide 600 mg/m2, 3 cycles bi-weekly and Taxol 150 mg/m2-Gemcitabine 2500 mg/m2, 6 cycles bi-weekly M-BM-1 weekly Herceptin 4 mg/Kg during the first week, 2 mg/Kg for the remaining 11 cycles; Treatment B: Doxorubicin 60 mg/m2-Pemetrexed 500 mg/m2, 4 cycles tri-weekly and Taxotere 100 mg/m2, 4 cycles tri-weekly; Treatment C: Doxorubicin 60 mg/m2-Cyclophosphamide 600 mg/m2, 4 cycles tri-weekly and Taxotere 100 mg/m2, 4 cycles tri-weekly) were recruited for this study. Pre-chemotherapy and post-chemotherapy biopsies were examined by a pathologist who determined the Miller & Payne grade for each patient. Matching pairs of pre-chemotherapy and post-chemotherapy samples were divided into 3 groups according to Miller & Payne grade: group of bad response (Miller & Payne grades 1 and 2), group of mid response (Miller & Payne grade 3) and group of good response (Miller & Payne grades 4 and 5). Gene expression analysis was performed in paired samples as follows: bad response group post-chemotherapy biopsy vs pre-chemotherapy biopsy (Bad Final vs Initial). For this assay were necessary 13 samples being chosen according to histopathologic criteria (Miller & Payne grades 4 and 5). Of them, 10 samples were paired and 3 pre-chemotherapy samples from patients that experienced a good response to chemotherapy were also included in this experimental series. Other comparisons in which this group of samples was involved include: Initial Bad vs Good, Initial Good vs Mid, Final Mid vs Good and Final Bad vs Good. This gene expression profiling was carried out making use of AffymetrixM-bM-^@M-^Ys GeneChip technology, with the AffymetrixM-bM-^@M-^Ys HG-U133 Plus 2.0 array from this provider. All the protocols and apparatus were recommended by Affymetrix. Total RNA from frozen mammary tumors was directly extracted by a RNeasy Mini kit and homogenized by QIAshredder columns under manufacturerM-bM-^@M-^Ys instructions. The quality and quantity of the obtained RNA, was checked out through agarose electrophoresis and later spectrophotometry at 260/280 nm. Biotinylated cRNA was synthesized following the IVT labeling kit from Affymetrix and purified by the GeneChip Sample Cleanup Module from Affymetrix. Once again, the quality and quantity of the obtained cRNA, was checked out through agarose electrophoresis and posterior spectrophotometry at 260/280 nm. After hybridization, slides were washed and scanned following the manufacturerM-bM-^@M-^Ys standard protocol. Intensity values were normalized by Robust Multichip Average method and subsequently these were filtered for remove the control sequences and those with a hybridization signal near to background. The spike controls were: BioB, BioC, BioD and Cre; because BioB was the less presented in the samples, it was used to estimate the sensitivity of the experiment. The housekeeping control was GAPDH. After non-supervised PCA analysis and clustering, gene expression statistical significances were identified by two regression models taking into account the pathologic response to chemotherapy and if the sample was obtained before or after chemotherapy treatment. Supervised PCA analysis and clustering were performed with processed data. Partek Genomics Suite v7.3.1 (Partek) software was employed for the statistic analysis and clustering.

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Microarray analysis of gene expression regulation in LS174T cells transduced with either ERK-dimerization inhibitory peptide or control

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