P53 constrains progression to anaplastic thyroid carcinoma in a Braf-mutant mouse model of papillary thyroid cancer.
ABSTRACT: Anaplastic thyroid carcinoma (ATC) has among the worst prognosis of any solid malignancy. The low incidence of the disease has in part precluded systematic clinical trials and tissue collection, and there has been little progress in developing effective therapies. BRAF and TP53 mutations co-occur in a high proportion of ATC, particularly those associated with a precursor papillary thyroid carcinoma (PTC). In order to develop an adult-onset model of BRAF-mutant anaplastic thyroid carcinoma, we generated a novel thyroid-specific CreER transgenic mouse. We utilize a Cre-regulated BrafV600E mouse and a conditional Trp53 allelic series to demonstrate that p53 constrains progression from papillary to anaplastic thyroid carcinoma. Gene expression and immunohistochemical analyses of murine tumors identified the cardinal features of human ATC including loss of differentiation, local invasion, distant metastasis and rapid lethality. We employed small animal ultrasound imaging to monitor autochthonous tumors, and show that treatment with the selective BRAF inhibitor PLX4720 improved survival, but did not lead to tumor regression or suppress signaling through the MAPK pathway. Combination of PLX4720 and the MEK inhibitor PD0325901 more completely suppressed MAPK pathway activation in mouse and human ATC cell lines, and improved the structural response and survival of ATC-bearing animals. This model expands the limited repertoire of autochthonous models of clinically aggressive thyroid cancer, and these data suggest that small molecule MAPK pathway inhibitors hold clinical promise in the treatment of advanced thyroid carcinoma. Total RNA from five murine papillary thyroid carcinoma (PTC) tumors and five murine anaplastic thyroid carcinoma (ATC) tumors was analyzed.
Project description:A comparison of profiles of normal thryoid tissue (NT), papillary thyroid carcinoma tissue (PTC) and anaplastic thyroid carcinoma tissue (ATC) was carried out to identify expression patterns specifically associated with analplastic thyroid carcinoma Keywords: Expression profile survey of normal tissue and tumor subtypes Overall design: RNA from each of the 4 normal thyroids, 10 papillary thryoid carcinomas and 5 analplastic thryoid carcinomas was labeled (Cy5) and co-hybridized with RNA from a pool of throid cancer cell lines to an array of immobilized PCR products representing the inserts of human cDNA clones
Project description:We profiled the gene expression of 11 anaplastic thyroid carcinomas (ATC), 49 papillary thyroid carcinomas (PTC) and 45 normal thyroids (N) We hibridized a series of anaplastic thyroid carcinomas (ATC) and papillary thyroid carcinomas (PTC) onto Affymetrix U133 Plus 2.0 arrays. ATCs were obtained from different hospitals in France and Belgium. Paired RNA samples of PTCs and non-tumoral thyroid tissues were obtained from Ukraine via the Chernobyl Tissue Bank (www.chernobyltissuebank.com). Diagnoses were confirmed by the members of the International Pathology Panel of the Chernobyl Tissue Bank.
Project description:This SuperSeries is composed of the following subset Series: GSE30429: Gene Array Analyzer (GAA): Alternative usage of gene arrays to study alternative splicing events (MoGene array) GSE32998: Gene Array Analyzer (GAA): Alternative usage of gene arrays to study alternative splicing events (MoEx array) Refer to individual Series
Project description:The latest version of microarrays released by Affymetrix, the GeneChip Gene 1.0 ST Arrays (gene arrays), are designed in a similar fashion as exon arrays, which enables to identify differentially expressed exons, rather than only the expression level of whole transcripts. Here, we propose an extension, Gene Array Analyzer (GAA), to our previously published Exon Array Analyzer (EAA). GAA enables to analyse gene arrays on exon level and therefore supports to identify alternative splicing with gene arrays. To show the applicability of GAA, we used gene arrays to profile alternative splice events during the development of the heart. Further re-analysis of published gene arrays could show, that some of these splice events reoccur under pathological conditions. The web interface of GAA is user friendly, functional without set up and freely available at http://GAA.mpi-bn.mpg.de. Alternative splicing and gene expression analysis during development of the heart and cardiomyoyte differentiation.
Project description:mRNA Expression in Quadriceps Muscle from Cofilin-2 Null Mice Compared to WT Littermates on Day 7 Quadriceps muscle resected on day 7 from cofilin-2 deficient mice and wildtype littermates were collected and mRNA was isolated. Expression changes were analyzed by microarray.
Project description:Embryonic development is tightly regulated by transcription factors and chromatin-associated proteins. H3K4me3 is associated with active transcription and H3K27me3 with gene repression, while the combination of both keeps genes required for development in a plastic state. Here we show that deletion of the H3K4me2/3 histone demethylase Jarid1b (Kdm5b/Plu1) results in major neonatal lethality due to respiratory failure. Jarid1b knockout embryos have several neural defects including disorganized cranial nerves, defects in eye development and increased incidences of exencephaly. Moreover, in line with an overlap of Jarid1b and Polycomb targets genes, Jarid1b knockout embryos display homeotic skeletal transformations typical for Polycomb mutants. Genome-wide analysis demonstrated that normally inactive genes encoding developmental regulators acquire aberrant H3K4me3 in early Jarid1b knockout embryos. H3K4me3 accumulates as embryonic development proceeds, leading to increased expression of neural master regulators in knockouts. Taken together, these results suggest that Jarid1b contributes to mouse development by protecting developmental genes from inappropriate acquisition of active histone modifications. * Lack of Jarid1b leads to major neonatal lethality and defects in neural systems * Jarid1b mutants display homeotic skeletal transformations * H3K4me3 is increased at inactive transcriptional regulators in Jarid1b-/- embryos * Chromatin changes are accompanied by elevated levels of key neural transcription factors RNA was extracted from heads of E8.5 embryos, three pools of 4 heads each were used per genotype
Project description:To try to investigate the mechanism behind the adaptive phenotypes observed in a mice model model of HD crossed with mGluR5 knockout, we analyzed whether mutated huntingtin (Htt) expression in a mGluR5 null background could be altering the expression of genes that might be involved in the pattern of Htt aggregation and HD-related locomotor alterations. In this data set, we include analysis of gene expression in striatum of mice with four different genotypes: HdhQ20/Q20/mGluR5+/+; HdhQ20/Q20/mGluR5-/- ; HdhQ111/Q111/mGluR5+/+ ; HdhQ111/Q111/mGluR5-/- 12 samples were analyzed. We used Partek Genomics Suite v6.5 (Partek, St. Louis, MO) to determine differences in gene expression levels. Genotype effects were considered significant based of the following criteria: (i) ANOVA p-values< 0.05 and (ii) 1.5 fold increase or decrease.
Project description:In immune responses, activated T cells migrate to B cell follicles and develop to T follicular helper (Tfh) cells, a new subset of CD4+ T cells specialized in providing help to B lymphocytes in the induction of germinal centers 1-3. Although Bcl6 has been shown to be essential in Tfh cell function, it may not regulate the initial migration of T cells 4 or the induction of Tfh program as exampled by CXCR5 upregulation 5. Here, we show that the Achaete-Scute homologue 2 (Ascl2) gene that encodes a basic helix-loop-helix (bHLH) transcription factor 6, is selectively upregulated in its expression in Tfh cells. Ectopic expression of Ascl2 uniquely upregulates CXCR5 but not Bcl6 and downregulates CCR7 expression in T cells in vitro and accelerates T cell migration to the follicles and Tfh cell development in vivo. Combined transcriptome profiling and genome-wide occupancy analysis indicate that Ascl2 directly regulates Tfh-related genes while inhibits expression of Th1 and Th17 genes. Acute deletion of Ascl2 as well as blockade of its function with the Id3 protein in peripheral CD4+ T cells results in a failure in Tfh cell development and the germinal center response. Conversely, mutation of Id3, known to cause antibody-mediated autoimmunity, greatly enhances Tfh cell generation. Thus, Ascl2 critically and directly initiates Tfh cell development. Decide gene expression patterns of CD4+ T cells with overexpressed Ascl2 or Tfh cells