Cross-Species Comparison Identifies Proneural specific patterns of genetic alterations in Glioblastoma
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE36940 | GEO | 2014/01/17
SECONDARY ACCESSION(S): PRJNA157131
REPOSITORIES: GEO
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Project description:The determinants of the genetic complexity of Glioblastoma are poorly understood. We generated murine Glioblastomas by transforming glial progenitors in the adult brain with PDGF expression and PTEN deletion +/- p53 deletion. PDGF+PTEN-/- tumors developed additional deletions of specific genes in up to 100% of the tumors, whereas PDGF+PTEN-/-p53-/- tumors did not. Cross-species comparison with data from tCGA database and published in Verhaak, 2010, showed that consistent genetic deletions observed in mouse tumors were specific to human Proneural Glioblastoma. These findings show that the genetic alterations that accumulate during tumor progression are determined by the initiating genetic alterations and by the cellular context in which they occur. Murine gliomas were induced in vivo by retroviral mediated PDGF overexpression, PTEN deletion with or without p53 deletion using Cre/lox system. Tumors were subsequently harvested for sequencing and aCGH analysis. Paired liver DNA was used for hybridization. For PDGF+PTEN-/- tumors, different timepoints were obtained including 21, 35 days post tumor induction, as well as endstage tumors.
2014-01-17 | E-GEOD-36940 | biostudies-arrayexpress
Project description:In order to understand the relationships between the human non-GCIMP glioblastoma subgroups, we performed computational analysis of human genomic data to predict the temporal sequence in which the driver events arise during tumorigenesis. The order of evolutionary events for non-GCIMP GBM is 1) chr 7 gain and loss of chr 10, followed by 2) CDKN2A loss and/or TP53 mutation, and 3) alterations canonical for specific subtypes such as NF1 loss or focal amplification of PDGFRα or EGFR. We then developed a computational methodology to identify the drivers of broad copy number changes, identifying PDGF-A (chr 7) and PTEN (chr 10) as driving the initial non-disjunction events. These predictions were validated using mouse modeling, showing PDGF-A is sufficient to induce PN-like gliomas that are enhanced by loss of Ink4a-Arf, Tp53 or Pten. Additional Nf1 loss converts PN to the MES subtype. Our findings suggest non-GCIMP GBMs arise as, and evolve from, a common proneural-like precursor.
2014-04-03 | GSE45874 | GEO
Project description:In order to understand the relationships between the human non-GCIMP glioblastoma subgroups, we performed computational analysis of human genomic data to predict the temporal sequence in which the driver events arise during tumorigenesis. The order of evolutionary events for non-GCIMP GBM is 1) chr 7 gain and loss of chr 10, followed by 2) CDKN2A loss and/or TP53 mutation, and 3) alterations canonical for specific subtypes such as NF1 loss or focal amplification of PDGFRα or EGFR. We then developed a computational methodology to identify the drivers of broad copy number changes, identifying PDGF-A (chr 7) and PTEN (chr 10) as driving the initial non-disjunction events. These predictions were validated using mouse modeling, showing PDGF-A is sufficient to induce PN-like gliomas that are enhanced by loss of Ink4a-Arf, Tp53 or Pten. Additional Nf1 loss converts PN to the MES subtype. Our findings suggest non-GCIMP GBMs arise as, and evolve from, a common proneural-like precursor. hGBM_sphere: Three different human GBM sphere lines expressing two different NF1-shRNAs or empty shRNA-control were generated by a lentiviral infection with the relevant pLKO.1 vectors. The total RNAs were obtained from the GBM sphere lines and the gene expression profile of the NF1-shRNA cells was then compared to the control cells. hGBM_rapamycin: Two human GBM sphere lines (TS543 and TS667) expressing the NF1-shRNAs were generated by a lentiviral infection with two different pLKO.1-NF1-shRNA vectors (two different target sequence; #2 and #5). The total RNAs were obtained from the NF1-shRNA lines treated with a 1nM rapamycin or 0.1% DMSO control for 5 hours and the gene expression profile was then compared between the both groups. Murine_gliomas: Murine brain tumors were generated by an injection of DF1 cells producing the relevant RCAS virus into newborn pups or adult mice brain. When mice presented any symptoms of disease, the mice were sacrificed and the brain tumor tissues were macroscopically dissected. Then total RNAs were extracted from the murine brain tumors or normal brain tissues and the gene expression profile was compared between various tumor types and/or normal brain tissues. In this study, two different RCAS-shNf1 (GR249 and GF249) and shp53 (R696 and mR696) was used for the generation of the murine brain tumors. Each RCAS vector has different structure but the target sequence against the Nf1 and p53 is same and similar knockdown effect was observed. Tumor grade were determined with the residual sections after a piece of tumor tissue were excised for the RNA extraction. The detail information of the experiment was described in the associated-publication. Murine_shere: Murine neurosphere lines were generated by a retroviral infection with the relevant RCAS viruses. The total RNAs were obtained from the murine neurosphere lines expressing the RCAS-shGL2, shNf1, shp53 or shNf1+shp53 and the gene expression profiles of the shNf1, shp53 or shNf1/p53 cells were then compared to the control shGL2 cells.
2014-04-03 | E-GEOD-45874 | biostudies-arrayexpress
Project description:Glioblastoma (GBM) is a highly lethal brain tumor presenting as one of two subtypes with distinct clinical histories and molecular profiles. The primary GBM subtype presents acutely as high-grade disease that typically harbors EGFR, PTEN and Ink4a/Arf mutations, and the secondary GBM subtype evolves from the slow progression of low-grade disease that classically possesses PDGF and p53 events1. Here, we show that concomitant CNS-specific deletion of p53 and Pten in the mouse CNS generates a penetrant acute-onset high-grade malignant glioma phenotype with striking clinical, pathological and molecular resemblance to primary GBM in humans. This genetic observation prompted p53 and PTEN mutational analysis in human primary GBM, demonstrating unexpectedly frequent inactivating mutations of p53 as well the expected PTEN mutations. Integrated transcriptomic profling, in silico promoter analysis and functional studies of murine neural stem cells (NSCs) established that dual, but not singular, inactivation of p53 and Pten promotes an undifferentiated state with high renewal potential and drives elevated c-Myc levels and its associated signature. Functional studies validated increased c-Myc activity as a potent contributor to the impaired differentiation and enhanced renewal of p53-Pten null NSCs as well as tumor neurospheres (TNSs) derived from this model. c-Myc also serves to maintain robust tumorigenic potential of p53-Pten null TNSs. These murine modeling studies, together with confirmatory transcriptomic/promoter studies in human primary GBM, validate a pathogenetic role of a common tumor suppressor mutation profile in human primary GBM and establish c-Myc as a key target for cooperative actions of p53 and Pten in the regulation of normal and malignant stem/progenitor cell differentiation, self-renewal and tumorigenic potential. We used microarrays to detail the gene expression difference of the p53-null and p53/Pten-doubly null neural stem cell after differentiation . Experiment Overall Design: transcriptome comparisons of 2 independent p53-null with 3 p53/Pten double-null murine NSCs at 1 day post exposure to the differentiation inducer.
2008-10-26 | E-GEOD-12694 | biostudies-arrayexpress
Project description:Mutations in the PTEN, TP53 and RB1 pathways are obligate events in the pathogenesis of human glioblastomas, the highest grade of astrocytoma. To investigate synergy between these tumor suppressors in mice, we induced various combinations of compound deletions conditionally in astrocytes and neural precursors in the mature brain. The resulting highly penetrant astrocytomas showed a spectrum of histopathological variation reminiscent of human tumors, and ranged from grade III to grade IV (glioblastoma). Secondary somatic mutations varied depending on the combination of initiating deletions and were relevant to human disease. Receptor tyrosine kinase amplifications were frequent in tumors initiated by combined conditional deletion of Pten and Tp53, but not when Rb, Pten and Tp53 were simultaneously deleted. Multiple mutations within PI3K and Rb pathways were acquired, however, Mapk activation was not consistently detected in astrocytomas. Gene expression profiling revealed striking similarities to previously described human astrocytoma subclasses. A subset of astrocytomas initiated outside of proliferative niches in the adult brain. Gene expression of 8 human brain samples including 2 normal brainstem and 6 brainstem low-grade gliomas were profiled using HG-U133 plus 2 arrays. Gene expression of 38 mouse tumor samples, including 24 Pten;p53 double knockout and 14 Pten;p53;Rb1 triple knockout, were profiled using Affymetrix Mouse Genome 430 v2 arrays. Copy number changes of 51 double knockout tumor samples were analysed using Roswell Park Cancer Institute 6.5k BAC arrays. Copy number changes of 21 triple knockout tumor samples were analysed using Agilent mouse genome CGH mocirarray 244A.
2011-03-23 | E-GEOD-22927 | biostudies-arrayexpress
Project description:Gene copy numbers of prostate tumors of G3 and G4 generations of LSL-mTert PB-Pten/p53 mouse model Prostate tumors were developed in G3 and G4 generations of LSL-mTert PB-Pten/p53 mice. These tumors were profiled with affy and aCGH. We used affy gene expression to correlate with the copy number alterations in the mouse prostate tumors.
2012-01-21 | E-GEOD-35247 | biostudies-arrayexpress
Project description:Glioblastoma (GBM) is a highly lethal brain tumor presenting as one of two subtypes with distinct clinical histories and molecular profiles. The primary GBM subtype presents acutely as high-grade disease that typically harbors EGFR, PTEN and Ink4a/Arf mutations, and the secondary GBM subtype evolves from the slow progression of low-grade disease that classically possesses PDGF and p53 events1. Here, we show that concomitant CNS-specific deletion of p53 and Pten in the mouse CNS generates a penetrant acute-onset high-grade malignant glioma phenotype with striking clinical, pathological and molecular resemblance to primary GBM in humans. This genetic observation prompted p53 and PTEN mutational analysis in human primary GBM, demonstrating unexpectedly frequent inactivating mutations of p53 as well the expected PTEN mutations. Integrated transcriptomic profling, in silico promoter analysis and functional studies of murine neural stem cells (NSCs) established that dual, but not singular, inactivation of p53 and Pten promotes an undifferentiated state with high renewal potential and drives elevated c-Myc levels and its associated signature. Functional studies validated increased c-Myc activity as a potent contributor to the impaired differentiation and enhanced renewal of p53-Pten null NSCs as well as tumor neurospheres (TNSs) derived from this model. c-Myc also serves to maintain robust tumorigenic potential of p53-Pten null TNSs. These murine modeling studies, together with confirmatory transcriptomic/promoter studies in human primary GBM, validate a pathogenetic role of a common tumor suppressor mutation profile in human primary GBM and establish c-Myc as a key target for cooperative actions of p53 and Pten in the regulation of normal and malignant stem/progenitor cell differentiation, self-renewal and tumorigenic potential. We used microarrays to detail the gene expression difference of the p53-null and p53/Pten-doubly null neural stem cell after differentiation . Keywords: cell type comparison
2008-10-01 | GSE12694 | GEO
Project description:WAP-Cre:Ptenf/f:p53lox.stop.lox_R270H composite mice were generated by genetic crossing. In these mice, Pten is deleted and a R270H p53 mutation in the DNA binding domain is induced upon expression of Cre recombinase in pregnancy-identified alveolar progenitors. Tumors were characterized by histology, marker analysis, various bioinformatics methods, high-throughput (HTP) FDA-drug screen as well as orthotopic injection to quantify tumor initiating cells (TICs) and tail-vein injection to identify lung-metastasis. Expression data comparing 2 types of Pten-deficient tumors (spindle and poorly differentiated) with other modles of mouse mammary tumors 2 types of Pten deletion plus p53-R270H mutation tumors (spindle and poorly differentiated) was compared with MMTV-Neu, Spindle Pten-p53-deficient tumors, and wild-type mammary gland cells.
2015-12-15 | E-GEOD-75989 | biostudies-arrayexpress
Project description:Primary glioblastoma, representing over 90% of adult glioblastoma, develop rapidly without preexisting lower-grade glioma. We have generated a mouse model of primary glioblastoma driven by a single p53 mutation. These p53-mutant gliomas lose the syntenic region of human chromosome 10q, which is mapped to mouse chr19 and chr7. Loss of mouse chr19, containing Pten, activates PI3K/Akt signaling. Using serial MRI/3D-reconstruction, whole-genome sequencing and spectral karyotyping-based single-cell phylogenetic tree building, we showed two distinct types of tumor evolution in p53-mutant driven mouse models. Malignant gliomas/GBMs grew as a single mass (Type 1) and multifocal masses (Type 2), respectively, despite both exhibiting loss of Pten/chromosome 19 (chr19) and PI3K/Akt activation with sub-tetraploid/4N genomes. Analysis of early biopsied and multi-segment tumor tissues revealed no evidence of less proliferative diploid/2N lesions in Type 1 tumors. Strikingly, CA-derived relatively quiescent tumor precursors with ancestral diploid/2N genomes and normal Pten/chr19 were observed in the subventricular zone (SVZ), but was distantly segregated from multi-focal Type 2 tumors. Importantly, PI3K/Akt inhibition by Rictor/mTORC2 deletion blocked distant dispersal, restricting glioma growth in the SVZ.
2020-06-10 | GSE152071 | GEO
Project description:To model the effect of Pten loss on breast cancer, we deleted Pten using a floxed allele and the deleter lines MMTV-Cre(NLST), which targets stem/bi-potent progenitor cells, and WAP-Cre, which targets CD24-positive, pregnancy-identified stem cells/alveolar progenitors. Mammary tumors were detected in WAP-Cre:Ptenf/f females with a latency of 15.2 months. By 18 months, nearly all mice had succumbed to cancer. MMTV-Cre:Ptenf/f mice developed mammary tumors after a longer latency of 26.4 months and reduced penetrance (70%) compared to WAP-Cre:Ptenf/f mice. Tumors from both models were heterogeneous, consisting primarily of differentiated adenocarcinoma (adenomyoepithelioma; ~70%) and adenosquamous carcinoma (20-25%). In addition, a small fraction of tumors was classified as acinar and poorly differentiated adenocarcinoma (4-7%) and adenosarcoma (3-4%). To test the consequences of combined Pten and p53 gene mutation on breast cancer, we deleted both genes via MMTV-Cre or WAP-Cre. Kaplan-Meier tumor free survival curves revealed that WAP-Cre:Ptenf/f:p53f/f and MMTV-Cre:Ptenf/f:p53f/f females developed tumors with reduced latency of 11.3 and 9.8 months, compared with 15.2, 26.4, and 16.9 months for single-mutant WAP-Cre:Ptenf/f, MMTV-Cre:Ptenf/f or MMTV-Cre:p53f/f mice, respectively. In contrast to the heterogeneity of Pten tumors and small percentage of adenosarcomas in these mice, ~70% of Pten:p53 lesions were histologically classified as adeno-sacrcomatoid-like or mesenchymal-like breast cancer, with the rest exhibiting mixed mesenchymal plus adenocarcinomas and differentiated adenocarcinomas. The adeno-sacrcomatoid-like tumors expressed the mesenchymal markers vimentin, K5, SMA, N-cadherin and desmin but not ER, as well as islands of luminal-like K18 expressing cells surrounded by a layer of K14-positive cells. We used microarrays to detect differentially expressed genes in the Pten:p53 double-knock-out vs Pten or p53 single deletions Total RNA was extracted from tumors developed by double Trizol method and hybridized on Affymetrix microarrays.
2012-08-08 | E-GEOD-39955 | biostudies-arrayexpress