Project description:Ki-ras gene mutations are involved in the carcinogenesis of acute myeloid leukemia, melanoma and different carcinomas. In order to define potential mutation-specific therapeutic targets, expression profiling analyses were performed using stable transfected NIH3T3 cells carrying different ki-ras gene mutations. Maybe, this analysis allows the discorvery of ras-associated cellular mechanisms, which might lead to the identification of physiological targets for pharmacological interventions of the treatment of Ki-ras-associated human tumors. Keywords: cDNA microarray, murine fibroblast, ki-ras mutations, carcinogenesis 4 transfected murine fibroblast cell lines (mock, wt-kras, Asp, Val) were compared to non-transfected cell line. For each of the four comparison 4 chip experiments were performed including 2 dye swaps.
Project description:Antigen Ki-67 is a nuclear protein expressed in proliferating mammalian cells. It is widely used in cancer histopathology but its functions remain unclear. Here, we show that Ki-67 controls heterochromatin organisation. Altering Ki-67 expression levels did not significantly affect cell proliferation in vivo. Ki-67 mutant mice developed normally and cells lacking Ki-67 proliferated efficiently. Conversely, upregulation of Ki-67 expression in differentiated tissues did not inhibit cell cycle arrest. Ki-67 interactors included proteins involved in nucleolar processes and chromatin regulators. Ki-67 depletion disrupted nucleologenesis but did not inhibit pre-rRNA processing. In contrast, it altered gene expression. Ki-67 silencing also had wide-ranging effects on chromatin organisation, disrupting heterochromatin compaction and long-range genomic interactions. Trimethylation of histone H3K9 and H4K20 at heterochromatin was strongly reduced. Overexpression of human or Xenopus Ki-67 induced ectopic heterochromatin formation. Altogether, our results suggest that Ki-67 expression in proliferating cells spatially organises heterochromatin, thereby controlling gene expression.
Project description:Ki-ras gene mutations are involved in the carcinogenesis of acute myeloid leukemia, melanoma and different carcinomas. In order to define potential mutation-specific therapeutic targets, expression profiling analyses were performed using stable transfected NIH3T3 cells carrying different ki-ras gene mutations. Maybe, this analysis allows the discorvery of ras-associated cellular mechanisms, which might lead to the identification of physiological targets for pharmacological interventions of the treatment of Ki-ras-associated human tumors. Keywords: cDNA microarray, murine fibroblast, ki-ras mutations, carcinogenesis Overall design: 4 transfected murine fibroblast cell lines (mock, wt-kras, Asp, Val) were compared to non-transfected cell line. For each of the four comparison 4 chip experiments were performed including 2 dye swaps.
Project description:Transcriptional profiling of mouse cerebellar extract comparing SCA7 KI mice with wild type mice. Female mice were killed by decapitation on post natal days 10 and 22 and 11 weeks. Goal was to determine gene expression profiles differing between SCA7 KI mice and wild-type mice during post-natal developement of the cerebellum. Gene expression profiling was performed using RNA extracted from the cerebellum of KI and WT mice at P10 (5 WT and 5 KI), P22 (5 WT and 4 KI) and 11 wks (5WT and 6 KI). After labeling, RNAs were hybridized on dual-label G4122F Agilent® chips; a mix of all P10 samples was used as common reference (green channel). Quality control included visual control of the reconstructed image of the chip, M/A plot, corner intensities, outliers, positive and negative intensities, normalization factors. Normalization and statistical analyses were carried out by using BRB-array Tools developed by Dr. Richard Simon and the BRB-ArrayTools development team (Biometrics Research Branch, http://linus.nci.nih.gov/BRB-ArrayTools.html). Genes with less than 50% present calls or with low variability along the arrays (less than 20% of values with at least 2-fold change in either direction from the gene’s median value) were excluded from further analysis. For the 1905 remaining probes an interaction between time and genotype was analyzed by regression analysis of the time course of expression. In brief, probes for which variation over time differed for the genotype class were fitted to the following model: log expression ~ time + time**2 + genotype + genotype*time + genotype*time**2. A univiariate p-value < 0.001 (random variance model) was set for significant probes (genotype*time + genotype*time**2) and a False Discovery Rate (FDR) was calculated for each probe (Benjamini & Hochberg, 1995). Differences in profiles were identified with a Self Organisation Tree Algorithm (MultiplExperiment Viewer (MeV), (Saeed et al, 2006). Expression values were averaged by group and then clustered according to their profile as a function of time.
Project description:Microarrays were used to examine gene expression changes between bone marrow isolated haematopoeietic cell populations (LSK cells: Lin-Sca1+cKit+) populations of control and mutant (LysM-KI) mice. The LysM-KI mouse is a murine model which expresses an Idh1 (isocitrate dehydrogenase 1) mutation (Idh1-R132H) in cells of the myeloid lineage. Mutations in IDH1 (and IDH2) in humans are commonly found in cytogenetically normal acute myeloid leukemia as well as glioblastomas. The current study was initiated to understand how these mutations may affect leukemogenesis and myeloid cell development. Total RNA obtained from bone marrow sorted LSK cells of mutant LysM-KI and control individual mice.
Project description:As an oncogene, use of HER2 vaccines in humans requires the development of HER2 immunotherapies with maximal immunologic potential, but minimal oncologic potential. To address these issues, we developed a recombinant adenoviral vector expressing a mutated HER2 inactivated for kinase function (Ad-HER2-ki). Ad-HER2-ki was highly expressed, but non-phosphorylated and elicited minimal transcription dysregulation in primary cells. In contrast, Ad-HER2-wt elicited a strong oncogenic signature associated with tumorigenesis. Overall design: Early Passage Human Mammary Epithelial cells (HMECs) were serum starved for 36hrs. and infected at a MOI of 150 with either Ad-GFP, Ad-HER2-wt, or Ad-HER2-ki vectors. At 18 hpi, RNA was extracted and transcriptomes evaluated by microarray. Five samples were infected per virus treatment, each a completely separate biologic replicate.
Project description:Transcriptional profiling of embryonic DRG neurons from TrkAC-KI and wild type mice. Overall design: Two-condition experiment, TrkAC-KI vs. Wild type. Three independent biological replicates, each containing DRGs from 6-8 embryos from multiple litters, were prepared for each genotype.
Project description:PECs from wild-type, NF-IL6KO and KI(LAP) mice were stimulated with or without LPS+IFN-gamma for 12h. We used microarrays to check the difference of gene induction among wild type, KO and KI mice. Experiment Overall Design: Peritoneal macrophages were collected for RNA extraction and hybridization on Affymetrix microarrays.
Project description:The RET gene has been identified previously as a target of activated ALK at the mRNA level in both human neuroblastoma cell lines and primary tumors as well as in murine tumors driven by mutated Alk and MYCN. Moreover, it has been shown that tumor growth of murine TH-MYCN/KI Alkmut tumors was impaired upon Ret inhibition by the vandetanib inhibitor, suggesting RET as a therapeutic target in ALK mutated neuroblastoma. To further demonstrate the crucial role of RET in ALK mutated driven neuroblastoma oncogenesis, transgenic TH-MYCN mice were bred with KI RetM919T tumors. We document an oncogenic cooperation between activated Ret and MYCN overexpression in neuroblastoma formation. We used microarrays to analyze the global programme of gene expression of MYCN/RetM919T tumors and compare these profiles with profiles of MYCN/Alkmut tumors (GSE46583). Altogether, our data show that MYCN/RetM919T tumors present with expression profiles close to MYCN/Alkmut tumors. Overall design: We selected 6 murine neuroblastoma tumors from MYCN/RetM919T mice for RNA extraction and hybridization on Affymetrix microarrays