Loss of PATCHED (wechs-affy-mouse-512645)
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE12430 | GEO | 2009/02/09
SECONDARY ACCESSION(S): PRJNA113743
REPOSITORIES: GEO
Similar Datasets
Project description:We are examining the genes that control initiation and progression of murine medulloblastomas that result from loss of patched. Approximately 25% of human medulloblastomas have mutations in patched or in other elements of the sonic hedgehog pathway. However, the cells from which these tumors originate (neural progenitors or stem cells), the cells that are responsible for tumor propagation (cancer stem cells), and the genes that are required for tumor progression are poorly understood. To address these questions, we have developed conditional patched knockout mice in which the gene is deleted in neural stem cells or progenitors. In addition, we have isolated a population of tumor-propagating cells from these tumors. By studying these models we will gain insight into the mechanisms of tumorigenesis and identify new targets for therapy. To identify the molecular mechanisms that underlie tumor initiation and propagation, we will compare gene expression in tumors resulting from loss of patched in neural stem cells vs. progentors, and in cancer stem cells vs. non-cancer stem cells. We hypothesize that medulloblastomas initiated in neural stem cells (using GFAP-Cre) are more aggressive than those initiated in neural progenitors (using Math1-Cre), and will express more genes associated with self-renewal. In addition, we hypothesize that cancer stem cells (CD15+ cells) from a given tumor will express higher levels of self-renewal genes than non-stem cells (CD15- cells) from the same tumor. Cells from 5 GFAP-Cre tumors, 5 Math1-Cre tumors, and 5 conventional patched-knockout tumors will be isolated using enzymatic digestion and Percoll gradient centrifugation. These procedures have been found to result in 85-95% pure tumor cell populations. In addition, 5 tumors will be FACS-sorted to isolate CD15+ and CD15- populations. RNA will be prepared from each of these samples using an RNeasy kit from Qiagen. Samples of 2 micrograms will be resuspended in 10 microliters of RNase-free water, and sent to the Consortium for labeling, hybridization and analysis. Cells from the three types of tumors, and CD15+ and CD15- cells, will be compared to one another.
2009-02-21 | E-GEOD-12430 | biostudies-arrayexpress
Project description:Mice lacking p53 and one or two alleles of the cyclin D-dependent kinase inhibitor p18Ink4c are prone to medulloblastoma development. The tumor frequency is increased by exposing postnatal animals to ionizing radiation at a time when their cerebella are developing. In irradiated mice engineered to express a floxed p53 allele and a Nestin-Cre transgene, tumor development can be restricted to the brain. Analysis of these animals indicated that inactivation of one or both Ink4c alleles did not affect the time of medulloblastoma onset but increased tumor invasiveness. All such tumors exhibited complete loss of function of the Patched 1 (Ptc1) gene encoding the receptor for sonic hedgehog, and many exhibited other recurrent genetic alterations, including trisomy of chromosome 6, amplification of N-Myc, modest increases in copy number of the Ccnd1 gene encoding cyclin D1, and other complex chromosomal rearrangements. In contrast, medulloblastomas arising in Ptc1+/- mice lacking one or both Ink4c alleles retained p53 function and exhibited only limited genomic instability. Nonetheless, complete inactivation of the wild type Ptc1 allele was a universal event, and trisomy of chromosome 6 was again frequent. The enforced expression of N-Myc or cyclin D1 in primary cerebellar granule neuron precursors isolated from Ink4c-/-, p53-/- mice enabled the cells to initiate medulloblastomas when injected back into the brains of immunocompromised recipient animals. These engineered tumors exhibited gene expression profiles indistinguishable from those of medulloblastomas that arose spontaneously. These results underscore the functional interplay between a network of specific genes that recurrently contribute to medulloblastoma formation. Experiment Overall Design: 5 samples, 2 states
2008-06-14 | E-GEOD-6463 | biostudies-arrayexpress
Project description:SUMMARY; Medulloblastoma is the most common malignant brain tumor in children. It is thought to result from transformation of granule cell precursors (GCPs) in the developing cerebellum, but little is known about the early stages of the disease. Here we identify a pre-neoplastic stage of medulloblastoma in patched heterozygous mice, a model of the human disease. We show that pre-neoplastic cells are present in the majority of patched mutants, although only 16% of these mice develop tumors. Pre-neoplastic cells, like tumor cells, exhibit activation of the Sonic hedgehog pathway and constitutive proliferation. Importantly, they also lack expression of the wild-type patched allele, suggesting that loss of patched is an early event in tumorigenesis. While pre-neoplastic cells resemble GCPs and tumor cells in many respects, they have a distinct molecular signature. Genes that mark the pre-neoplastic stage include regulators of migration, apoptosis and differentiation, processes critical for normal development but previously unrecognized for their role in medulloblastoma. The identification and molecular characterization of pre-neoplastic cells provides insight into the early steps in medulloblastoma formation, and may yield important markers for early detection and therapy of this disease. ANIMALS; Patched heterozygous mice (Goodrich et al., 1997) were obtained from Matthew Scott's lab at Stanford, and maintained by breeding with 129X1/SvJ mice from Jackson Laboratories. Math1-GFP transgenic mice (Lumpkin et al., 2003) were provided by Jane Johnson at UT Southwestern Medical Center. Math1-GFP/patched+/- mice were generated by crossing patched heterozygotes with Math1-GFP mice, and then backcrossing to Math1-GFP mice three times before further analysis. All mice were maintained in the Cancer Center Isolation Facility at Duke University Medical Center. ISOLATION OF CELLS; Granule cell precursors (GCPs) were isolated from 7-day-old (P7) patched+/- mice; preneoplastic cells were obtained from 6 week-old patched mutants; and tumor cells were obtained from 10-25-week old patched mutants displaying physical and behavioral signs of medulloblastoma. Cells were isolated from each source using a protocol described in (Wechsler- Reya and Scott, 1999). Briefly, cerebella were digested in solution containing 10 U/ml papain Oliver et al. Pre-Neoplastic Stage of Medulloblastoma - 8 - (Worthington, Lakewood, NJ) and 250 U/ml DNase (Sigma) and triturated to obtain a cell suspension. This suspension was centrifuged through a step gradient of 35% and 65% Percoll (Amersham Biosciences, Piscataway, NJ), and cells were harvested from the 35%-65% interface. Cells were resuspended in serum-free culture medium consisting of Neurobasal containing B27 supplement, sodium pyruvate, L-glutamine, and penicillin/streptomycin (all from Invitrogen, Carlsbad, California) and counted on a hemacytometer. Cells used for RNA isolation were centrifuged and flash frozen in liquid nitrogen. For proliferation assays or immunostaining, cells were plated on poly-D-lysine (PDL)-coated tissue culture vessels and incubated in serum-free culture medium. MICROARRAY HYBRIDIZATION AND ANALYSIS; RNA from GCPs, pre-neoplastic cells and tumor cells (isolated as described above, but not FACS-sorted) and from normal adult cerebellum (not dissociated) was converted to cDNA using the Superscript Choice cDNA kit (Invitrogen) and a T7-dT(24) primer (Genset/Proligo, Boulder, CO). cRNA was generated using a T7-transcription/labeling kit from Enzo Life Sciences and hybridized to Affymetrix U74Av2 chips (Affymetrix, Santa Clara, CA). Chips were scanned, and hybridization data were acquired using Affymetrix Suite 5.0 software. Affymetrix CEL files were normalized and quantified using Bioconductor software with the gcRMA model to quantify gene expression levels (Gentleman and Carey, 2002). Unsupervised principal components analysis (PCA) was used to identify the relationships among normal adult cerebellum, GCPs, pre-neoplastic cells and tumor cells based on expression profiles. To identify genes that were differentially expressed among GCPs, pre-neoplastic cells and tumor cells, supervised analysis was carried out. A gene-by-gene ANOVA model with three groups (GCP, pre-neoplastic, tumor) was used to fit the log2-transformed intensities. To correct for multiple comparisons, the nominal p-value was adjusted using the false discovery rate (Benjamini and Hochberg, 1995). Genes were considered to be differentially expressed if they satisfied all of the following criteria: a difference in expression greater than 1.9-fold between any two groups, a maximum absolute intensity difference larger than 32 units, and an adjusted pvalue < 0.01. There were 118 genes that met these criteria. The identities of differentially expressed genes were verified by integrating data from the Affymetrix and Unigene databases. Gene functions were determined using information from Gene Ontology, Unigene, LocusLink and PubMed databases. Clustering was performed with Cluster and Treeview (Eisen et al., 1998). All statistical analysis was performed using R-1.7 software (Dalgaard, 2002). Results were visualized with Spotfire 6.0 (Somerville, MA). CORRESPONDING AUTHOR; Robert J. Wechsler-Reya*; Dept. of Pharmacology & Cancer Biology,; Duke University Medical Center Box 3813, Durham, NC 27710; Phone: 919-613-8754. Fax: 919-668-3556. Email: rw.reya@duke.edu; SUBMITTER_CITATION: Oliver TG, Read TA. Kessler JS, Mehmeti A, Wekks JF, Huynh TT, Lin SM, Wechsler-Reya RJ, Loss of patched and disruption of granule cell development in a pre-neoplastic stage of medulloblastoma, Development, 132, 2425-2439 (2005)
2007-08-31 | E-GEOD-2426 | biostudies-arrayexpress
Project description:The intermediate filament protein Nestin serves as a biomarker for stem cells and has been used to identify subsets of cancer stem-like cells. However, the mechanistic contributions of Nestin to cancer pathogenesis are not understood. Here we report that Nestin binds the hedgehog pathway transcription factor Gli3 to mediate the development of medulloblastomas of the hedgehog subtype. In a mouse model system, Nestin levels increased progressively during medulloblastoma formation resulting in enhanced tumor growth. Conversely, loss of Nestin dramatically inhibited proliferation and promoted differentiation. Mechanistic investigations revealed that the tumor-promoting effects of Nestin were mediated by binding to Gli3, a zinc finger transcription factor that negatively regulates hedgehog signaling. Nestin binding to Gli3 blocked Gli3 phosphorylation and its subsequent proteolytic processing, thereby abrogating its ability to negatively regulate the hedgehog pathway. Our findings show how Nestin drives hedgehog pathway-driven cancers and uncover in Gli3 a therapeutic target to treat these malignancies. Nestin+ and Nestin- GNPs (granule neuron precursors) were purified from Nestin-CFP/Math1-Cre/Ptch1-loxp cerebella at postnatal day 4 by FACs, and total RNA from these two cell populations were extracted, and then labeled and hybridized to Affymetrix Mouse Genome 430 2.0 arrays.
2016-08-09 | E-GEOD-84392 | biostudies-arrayexpress
Project description:SUMMARY Medulloblastoma is the most common malignant brain tumor in children. It is thought to result from transformation of granule cell precursors (GCPs) in the developing cerebellum, but little is known about the early stages of the disease. Here we identify a pre-neoplastic stage of medulloblastoma in patched heterozygous mice, a model of the human disease. We show that pre-neoplastic cells are present in the majority of patched mutants, although only 16% of these mice develop tumors. Pre-neoplastic cells, like tumor cells, exhibit activation of the Sonic hedgehog pathway and constitutive proliferation. Importantly, they also lack expression of the wild-type patched allele, suggesting that loss of patched is an early event in tumorigenesis. While pre-neoplastic cells resemble GCPs and tumor cells in many respects, they have a distinct molecular signature. Genes that mark the pre-neoplastic stage include regulators of migration, apoptosis and differentiation, processes critical for normal development but previously unrecognized for their role in medulloblastoma. The identification and molecular characterization of pre-neoplastic cells provides insight into the early steps in medulloblastoma formation, and may yield important markers for early detection and therapy of this disease. ANIMALS Patched heterozygous mice (Goodrich et al., 1997) were obtained from Matthew Scott's lab at Stanford, and maintained by breeding with 129X1/SvJ mice from Jackson Laboratories. Math1-GFP transgenic mice (Lumpkin et al., 2003) were provided by Jane Johnson at UT Southwestern Medical Center. Math1-GFP/patched+/- mice were generated by crossing patched heterozygotes with Math1-GFP mice, and then backcrossing to Math1-GFP mice three times before further analysis. All mice were maintained in the Cancer Center Isolation Facility at Duke University Medical Center. ISOLATION OF CELLS Granule cell precursors (GCPs) were isolated from 7-day-old (P7) patched+/- mice; preneoplastic cells were obtained from 6 week-old patched mutants; and tumor cells were obtained from 10-25-week old patched mutants displaying physical and behavioral signs of medulloblastoma. Cells were isolated from each source using a protocol described in (Wechsler- Reya and Scott, 1999). Briefly, cerebella were digested in solution containing 10 U/ml papain Oliver et al. Pre-Neoplastic Stage of Medulloblastoma - 8 - (Worthington, Lakewood, NJ) and 250 U/ml DNase (Sigma) and triturated to obtain a cell suspension. This suspension was centrifuged through a step gradient of 35% and 65% Percoll (Amersham Biosciences, Piscataway, NJ), and cells were harvested from the 35%-65% interface. Cells were resuspended in serum-free culture medium consisting of Neurobasal containing B27 supplement, sodium pyruvate, L-glutamine, and penicillin/streptomycin (all from Invitrogen, Carlsbad, California) and counted on a hemacytometer. Cells used for RNA isolation were centrifuged and flash frozen in liquid nitrogen. For proliferation assays or immunostaining, cells were plated on poly-D-lysine (PDL)-coated tissue culture vessels and incubated in serum-free culture medium. MICROARRAY HYBRIDIZATION AND ANALYSIS RNA from GCPs, pre-neoplastic cells and tumor cells (isolated as described above, but not FACS-sorted) and from normal adult cerebellum (not dissociated) was converted to cDNA using the Superscript Choice cDNA kit (Invitrogen) and a T7-dT(24) primer (Genset/Proligo, Boulder, CO). cRNA was generated using a T7-transcription/labeling kit from Enzo Life Sciences and hybridized to Affymetrix U74Av2 chips (Affymetrix, Santa Clara, CA). Chips were scanned, and hybridization data were acquired using Affymetrix Suite 5.0 software. Affymetrix CEL files were normalized and quantified using Bioconductor software with the gcRMA model to quantify gene expression levels (Gentleman and Carey, 2002). Unsupervised principal components analysis (PCA) was used to identify the relationships among normal adult cerebellum, GCPs, pre-neoplastic cells and tumor cells based on expression profiles. To identify genes that were differentially expressed among GCPs, pre-neoplastic cells and tumor cells, supervised analysis was carried out. A gene-by-gene ANOVA model with three groups (GCP, pre-neoplastic, tumor) was used to fit the log2-transformed intensities. To correct for multiple comparisons, the nominal p-value was adjusted using the false discovery rate (Benjamini and Hochberg, 1995). Genes were considered to be differentially expressed if they satisfied all of the following criteria: a difference in expression greater than 1.9-fold between any two groups, a maximum absolute intensity difference larger than 32 units, and an adjusted pvalue < 0.01. There were 118 genes that met these criteria. The identities of differentially expressed genes were verified by integrating data from the Affymetrix and Unigene databases. Gene functions were determined using information from Gene Ontology, Unigene, LocusLink and PubMed databases. Clustering was performed with Cluster and Treeview (Eisen et al., 1998). All statistical analysis was performed using R-1.7 software (Dalgaard, 2002). Results were visualized with Spotfire 6.0 (Somerville, MA). CORRESPONDING AUTHOR Robert J. Wechsler-Reya* Dept. of Pharmacology & Cancer Biology, Duke University Medical Center Box 3813, Durham, NC 27710 Phone: 919-613-8754. Fax: 919-668-3556. Email: rw.reya@duke.edu Keywords = medulloblastoma Keywords = brain tumor Keywords = pre-neoplastic Keywords = patched Keywords = hedgehog Keywords = migration Keywords = differentiation
2005-03-22 | GSE2426 | GEO
Project description:Mice lacking p53 and one or two alleles of the cyclin D-dependent kinase inhibitor p18Ink4c are prone to medulloblastoma development. The tumor frequency is increased by exposing postnatal animals to ionizing radiation at a time when their cerebella are developing. In irradiated mice engineered to express a floxed p53 allele and a Nestin-Cre transgene, tumor development can be restricted to the brain. Analysis of these animals indicated that inactivation of one or both Ink4c alleles did not affect the time of medulloblastoma onset but increased tumor invasiveness. All such tumors exhibited complete loss of function of the Patched 1 (Ptc1) gene encoding the receptor for sonic hedgehog, and many exhibited other recurrent genetic alterations, including trisomy of chromosome 6, amplification of N-Myc, modest increases in copy number of the Ccnd1 gene encoding cyclin D1, and other complex chromosomal rearrangements. In contrast, medulloblastomas arising in Ptc1+/- mice lacking one or both Ink4c alleles retained p53 function and exhibited only limited genomic instability. Nonetheless, complete inactivation of the wild type Ptc1 allele was a universal event, and trisomy of chromosome 6 was again frequent. The enforced expression of N-Myc or cyclin D1 in primary cerebellar granule neuron precursors isolated from Ink4c-/-, p53-/- mice enabled the cells to initiate medulloblastomas when injected back into the brains of immunocompromised recipient animals. These engineered tumors exhibited gene expression profiles indistinguishable from those of medulloblastomas that arose spontaneously. These results underscore the functional interplay between a network of specific genes that recurrently contribute to medulloblastoma formation. Keywords: disease state analysis
2007-03-15 | GSE6463 | GEO
Project description:Patients with medulloblastoma are typically treated with a narrow range of therapies, but may experience widely divergent outcomes; 80-90% become long-term survivors while 20% develop incurable recurrence. Transcriptomic profiling has identified four subgroups with different recurrence risks, but outcomes remain variable for individual patients within each subgroup. To gain new insight into why patients with similar-appearing tumors have variable outcomes, we examined how the timing of tumor initiation effects medulloblastomas triggered by a single, common driver mutation. We genetically-engineered mice to express an oncogenic Smo allele starting early in development in the broad lineage of neural stem cells, or later, in the more committed lineage of cerebellar granule neuron progenitors. Both groups developed medulloblastomas and no other tumors. We compared medulloblastoma progression, response to therapy, gene expression profile and cellular heterogeneity, determined by single cell transcriptomic analysis (scRNA-seq). The average transcriptomic profiles of the tumors were similar. However, stem cell-triggered medulloblastomas progressed faster, contained more OLIG2-expressing tumor stem cells, and consistently showed radioresistance. In contrast, progenitor-triggered MBs progressed slower, lost stem cell character over time and were radiosensitive. Progenitor-triggered medulloblastomas also contained more diverse stromal populations, including tumor-associated macrophages, indicating that the timing of oncogenesis affected the subsequent interactions between the tumor and microenvironment. Our findings show that developmental events in tumorigenesis may be impossible to infer from transcriptomic profile, but while remaining cryptic can nevertheless influence tumor composition and the outcome of therapy. Precise understanding of medulloblastoma pathogenesis and prognosis requires supplementing transcriptomic data with biomarkers of cellular heterogeneity.
2020-08-01 | GSE155471 | GEO
Project description:Medulloblastomas (MBs) are cerebellar tumors that can be classified into molecularly distinct subgroups that differ in pathology and prognosis. The mechanisms that underlie subgroup specification are largely unknown. While human SHH MBs express MYCN, Group3 (G3) MBs are associated with c-MYC (MYC) overexpression and often show metastasis that confers a poor prognosis. Although MYC proteins are thought to be functionally exchangeable, ectopic expression of Myc or N-myc in Trp53-/-;Cdkn2c-/- cerebellar granule neuron progenitors (GNPs) induces G3 and SHH MBs, respectively, demonstrating that each Myc protein has distinct biological properties. We now show that Myc and N-myc differ in their affinity to Miz1 and that Myc, but not N-myc, effectively recruits Miz1 to its target sites on chromatin. The interaction of Myc with Miz1 is required for the genesis of G3 MB. Myc suppresses ciliogenesis and âreprogramsâ the transcriptome of SHH-dependent GNPs to stem-like cells by repressing genes highly expressed in SHH MB via Miz1. Consistently, target genes of Myc/Miz1 are repressed in human G3 MBs but not in other MB subgroups. Collectively, the data show that the interaction of Myc with Miz1 is a defining hallmark of G3 MB development. In this study, we show that Myc and N-myc differ in their affinity for Miz1, and Myc/Miz1 interaction is required for Group3 medulloblastoma (MB). The gene expression profiles of these tumors were compared to our previously published Group3 MB model as well as SHH model of MB (Kawachi et al., 2012, Cancer Cell). Cerebellar granule neuron progenitors (GNPs) [dka220-222] from postnatal (P) 6 Math1-GFP;Trp53-/-;Cdkn2c-/-. For SHH medulloblastomas, [dka204-206] and [blm015-017 or dka050-dka051], spontaneous medulloblastomas from Cdkn2c-/-;Trp53Fl/Fl;Nestin-Cre (Kawachi et al., 2012, Cancer Cell) and Ptch1+/-;Cdkn2c-/- (Uziel et al., 2005, Genes Dev) were used, respectively. Myc- [dka201-203] and MycV394D (termed MycVD thereafter)- [bvo017-bvo023] tumors were from Trp53-/-;Cdkn2c-/- cerebella of P6-P7 pups. Myc/ÎPOZ tumors [bvo002-bvo006] were obtained from Trp5Fl/Fl;Miz1ÎPOZ/POZ;Nestin-Cre cerebella of P6-P7 pups.
2016-01-21 | E-GEOD-66093 | biostudies-arrayexpress
Project description:This dataset includes the raw single-cell RNAseq data from Math1-Cre;SmoM2 and Math1-Cre;SmoM2;Piezo2 fl/fl mouse medulloblastoma model. In this project, we focused on transcriptomic alteration caused by Piezo2 knockout in Sox2 positive MB initiation cells.
2022-09-22 | GSE197402 | GEO
Project description:We examined the transformation susceptibility of different cerebellar stem/progenitors by developing several new Group3 medulloblastoma murine models using orthotopic transplantation and in utero electroporation (EP)-based in vivo gene transfer with Cre/LoxP-mediated conditional Myc gene activation and loss of Trp53 function. We used microarrays to compared the transcriptome of these novel Group3 medulloblastoma mouse models to existing mouse models of medulloblastoma subgroups and used cross-species analysis to compare these models to human medulloblastoma subgroups This study aimed to investigate the cell of origin of Group3 MB using our orthotopical MYC model followed by a novel electroporation approach. Orthotopic cell-lineage specific MYC tumors were generated by enforced Myc expression in P6 GNPs isolated from P0-1 tamoxifen treated [Atoh1-CreER;Trp53fl/-] and [Prom1-CreER;Trp53fl/-] mice followed by cortical implants in immunocompromised mice. These tumors are referred to as Atoh1ER-MYC [dka072-075], Prom1-CreER [dka077-081]. The first Group3 MB models in which tumors developed in situ were generated by electroporation of plasmids containing Myc and dominant negative Trp53 flanked by loxP sites into the fourth ventricle of E13.5 Blbp-Cre [dka081, 087, 089, 090, 091 and blm121], Gad2-IRES-Cre [blm128-130 and blm134] and Ptf1a-Cre [blm135-137] mouse embryos. The gene expression profile of these tumors were compared to our previously published Group3 MB model as well as SHH and WNT models of medulloblastoma. For SHH subgroup medulloblastoma, [dka001-005, 009, 033 and 034] and [dka050-057], spontaneous medulloblastomas from [Cdkn2c-/-; Trp53Fl/Fl; Nestin-Cre] and [Cdkn2c-/-; Ptch1+/-] (Uziel et al.,2005 Genes Dev) were used, respectively. For Group3 medulloblastomas, [dka013-16, 049 and 065-067], in which Myc was overexpressed in Cdkn2c-/-, Trp53-/- cerebellar cells and implanted into the cortices of immunocompromised nude mice prior to tumor isolation. For WNT subgroup medulloblastomas [pgr003, 016 and 066], spontaneously developed tumors from CTNNB1+/lox (ex3); BLBP-Cre; Trp53Fl/Fl (Gibson et al., 2010, Nature) were removed for RNA extraction.
2015-02-13 | E-GEOD-65888 | biostudies-arrayexpress