scholarly journals DIPG-68. ALPHA-THALASSEMIA X-LINKED MENTAL RETARDATION PROTEIN (ATRX) LOSS-OF-FUNCTION IN A MOUSE MODEL OF DIFFUSE INTRINSIC PONTINE GLIOMA

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii300-iii300
Author(s):  
Chen Shen ◽  
David Picketts ◽  
Oren Becher
Keyword(s):  
Mouse Model ◽  
Pediatric Brain Tumor ◽  
High Grade Glioma ◽  
Genetic Alterations ◽  
Genetically Engineered ◽  
Tumor Incidence ◽  
Loss Of Function ◽  
Nestin Expression ◽  
Genetically Engineered Mouse Model ◽  
Clinical Cases

Abstract Diffuse Intrinsic Potine Glioma (DIPG) is a rare pediatric brain tumor for which no cure or efficacious therapies exist. Previous discoveries have revealed that, DIPG harbors distinct genetic alterations, when compared with adult high-grade glioma (HGG) or even with non-DIPG pediatric HGGs. ATRX alteration is found in 9% of clinical cases of DIPG, and significantly overlaps with H3.3K27M mutation and p53 loss, the two most common genetic changes in DIPG, found in 80% and 77% clinical cases, respectively. Here we developed genetically engineered mouse model of brainstem glioma using the RCAS-Tv-a system by targeting PDGF-B overexpression, p53 loss, H3.3K27M mutation and ATRX loss-of function to Nestin-expression brainstem progenitor cells of the neonatal mouse. Specifically, we used Nestin-Tv-a; p53 floxed; ATRX heterozygous female and Nestin-Tv-a; p53 floxed; ATRX floxed male breeders, generated offsprings with ATRX loss of function (n=18), ATRX heterozygous females (n=6), and ATRX WT (n=10). Median survial of the three groups are 65 days, 88 days and 51 days, respectively. Also, ATRX null mice is lower in tumor incidence (44.4%), compared with ATRX WT (80%). We evaluated the pathological features of DIPG with or without ATRX alteration, RNA-seq is performed to identify differentially expressed genes between ATRX WT and loss-of-function. In conclution, this study generated the first genetically modified mouse model studying ATRX loss-of-function in DIPG, and suggested that ATRX loss-of-function in DIPG may slow down tumorigenesis and decrease tumor incidence.

scholarly journals Genetically Engineered Mouse Model of Brainstem High-Grade Glioma

2020 ◽  
Vol 1 (3) ◽  
pp. 100165
Author(s):  
Fernando M. Nunez ◽  
Jessica C. Gauss ◽  
Flor M. Mendez ◽  
Santiago Haase ◽  
Pedro R. Lowenstein ◽  
...  
Keyword(s):  
Mouse Model ◽  
High Grade Glioma ◽  
Genetically Engineered ◽  
High Grade ◽  
Genetically Engineered Mouse Model

scholarly journals EPEN-20. EZHIP/CATACOMB COOPERATES WITH PDGF-A AND p53 LOSS TO GENERATE A GENETICALLY ENGINEERED MOUSE MODEL FOR POSTERIOR FOSSA A EPENDYMOMA

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii311-iii311
Author(s):  
Emily Kagan ◽  
Daniel Brat ◽  
Ali Shilatifard ◽  
Andrea Piunti ◽  
Oren Becher
Keyword(s):  
Median Survival ◽  
Critical Role ◽  
Pediatric Brain Tumor ◽  
Genetically Engineered ◽  
Rank Test ◽  
Loss Of Function ◽  
Wild Type ◽  
Term Survival ◽  
Log Rank Test ◽  
Genetically Engineered Mouse Model

Abstract BACKGROUND PFA ependymoma is a pediatric brain tumor with only 30% long-term survival. Recently a gene called CXORF67/EZHIP/CATACOMB (henceforward: CATACOMB) was found to be overexpressed in PFA ependymoma. CATACOMB’s mechanism of action has been found to be analogous to that of the H3K27M mutation as its expression reduces H3K27me3 via inhibition of PRC2 catalytic activity. METHODS We infected NESTIN- or GFAP-expressing neonatal hindbrain progenitors with wild-type CATACOMB or a loss of function (LOF) point mutant (M406K), alone, with PDGFA, and with and without p53 deletion. RESULTS CATACOMB overexpression alone or with p53 loss was insufficient to induce tumorigenesis. CATACOMB overexpression with PDGFA and p53 loss was sufficient to induce tumorigenesis using either the LOF mutant (M406K) or the wild-type CATACOMB in both cells-of-origin. The histology appeared more ependymoma-like when CATACOMB was expressed in GFAP-expressing progenitors. Median survival for the model initiated in NESTIN progenitors was 99.5 days for the CATACOMB mutant (n=26) group and 61 days for the CATACOMB wild-type (n=28; log-rank test p=0.0033). Median survival for the model initiated in GFAP progenitors were 144 days for the CATACOMB mutant (n=19) group and 65 days for the CATACOMB wild-type (n=21; log-rank test is P<0.0013). Immunohistochemistry for H3K27me3 demonstrated that CATACOMB wild-type tumors had reduced H3K27me3 compared to CATACOMB mutant tumors. CONCLUSIONS Disrupting CATACOMB inhibitory activity toward PRC2 significantly increases survival in mice in both models, suggesting this activity plays a critical role in accelerating tumorigenesis. Ependymoma-like histology was more commonly observed in the model initiated in the GFAP-expressing progenitors.

scholarly journals IDH1-R132H acts as a tumor suppressor in glioma via epigenetic up-regulation of the DNA damage response

2019 ◽  
Vol 11 (479) ◽  
pp. eaaq1427 ◽  
Author(s):  
Felipe J. Núñez ◽  
Flor M. Mendez ◽  
Padma Kadiyala ◽  
Mahmoud S. Alghamri ◽  
Masha G. Savelieff ◽  
...  
Keyword(s):  
Dna Damage ◽  
Tumor Suppressor ◽  
Mouse Model ◽  
Dna Damage Response ◽  
Genetically Engineered ◽  
Low Grade ◽  
Loss Of Function ◽  
Genetically Engineered Mouse Model ◽  
Damage Response ◽  
Inactivating Mutations

Patients with glioma whose tumors carry a mutation in isocitrate dehydrogenase 1 (IDH1R132H) are younger at diagnosis and live longer. IDH1 mutations co-occur with other molecular lesions, such as 1p/19q codeletion, inactivating mutations in the tumor suppressor protein 53 (TP53) gene, and loss-of-function mutations in alpha thalassemia/mental retardation syndrome X-linked gene (ATRX). All adult low-grade gliomas (LGGs) harboring ATRX loss also express the IDH1R132H mutation. The current molecular classification of LGGs is based, partly, on the distribution of these mutations. We developed a genetically engineered mouse model harboring IDH1R132H, TP53 and ATRX inactivating mutations, and activated NRAS G12V. Previously, we established that ATRX deficiency, in the context of wild-type IDH1, induces genomic instability, impairs nonhomologous end-joining DNA repair, and increases sensitivity to DNA-damaging therapies. In this study, using our mouse model and primary patient-derived glioma cultures with IDH1 mutations, we investigated the function of IDH1R132H in the context of TP53 and ATRX loss. We discovered that IDH1R132H expression in the genetic context of ATRX and TP53 gene inactivation (i) increases median survival in the absence of treatment, (ii) enhances DNA damage response (DDR) via epigenetic up-regulation of the ataxia-telangiectasia–mutated (ATM) signaling pathway, and (iii) elicits tumor radioresistance. Accordingly, pharmacological inhibition of ATM or checkpoint kinases 1 and 2, essential kinases in the DDR, restored the tumors’ radiosensitivity. Translation of these findings to patients with IDH1132H glioma harboring TP53 and ATRX loss could improve the therapeutic efficacy of radiotherapy and, consequently, patient survival.

scholarly journals Wild-Type Hras Suppresses the Earliest Stages of Tumorigenesis in a Genetically Engineered Mouse Model of Pancreatic Cancer

PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0140253 ◽  
Author(s):  
Jamie D. Weyandt ◽  
Benjamin L. Lampson ◽  
Sherry Tang ◽  
Matthew Mastrodomenico ◽  
Diana M. Cardona ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Mouse Model ◽  
Genetically Engineered ◽  
Wild Type ◽  
Genetically Engineered Mouse Model

P2-066 A genetically engineered mouse model with an enhanced beta-secretase substrate exhibits increased amyloid generation

2004 ◽  
Vol 25 ◽  
pp. S242 ◽  
Author(s):  
Adam J. Simon ◽  
Lin Chen ◽  
Eric A. Price ◽  
Min Xu ◽  
Adam Lucka ◽  
...  
Keyword(s):  
Mouse Model ◽  
Genetically Engineered ◽  
Beta Secretase ◽  
Genetically Engineered Mouse Model

scholarly journals IMMU-10. ESTABLISHING EFFECTIVE MODELS FOR IMMUNOTHERAPY IN GBM

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi121-vi121
Author(s):  
Daniel Zamler ◽  
Er-Yen Yen ◽  
Takashi Shingu ◽  
Jiangong Ren ◽  
Cynthia Kassab ◽  
...  
Keyword(s):  
Mouse Model ◽  
Cell Function ◽  
Genetically Engineered ◽  
Death Sentence ◽  
Immune Microenvironment ◽  
Knockout Mouse Model ◽  
Arginase 1 ◽  
Genetically Engineered Mouse Model ◽  
Human Gbm

Abstract The introduction of immunotherapies has been paradigm shifting for cancers that were previously a death sentence. However, preclinical/clinical studies on glioblastoma (GBM) have generated mixed outcomes in patients, likely due to its great heterogeneity of immune microenvironment, particularly the myeloid cell populations. Primary patient studies have been limited by a difficulty in performing longitudinal studies, uncontrolled environmental conditions, and genetic variability. There is also, unfortunately, a paucity of mouse models that effectively re-capitulate the immune microenvironment of the human disease. To address these difficulties, we have established the Qk/p53/Pten (QPP) triple knockout mouse model established in our lab. The QPP model uses a cre-lox system to induce Qk deletion on a Pten−/−; p53−/− background which helps NSCs maintain their stemness outside the SVZ in Nes-CreERT2;QkiL/L PtenL/L p53L/L mice, which develops glioblastoma with survival of ~105 days. We have preliminarily assessed the QPP tumors as a faithful model to study the immune response to GBM and found them to recapitulate human GBM with respect to differential response to checkpoint blockade therapy and myeloid and T-cells histopathologically, particularly regarding upregulation of Arginase-1 (Arg1). Arg1 is the canonical marker for tumor-associated macrophages (TAMs), which is a major population of myeloid cells that greatly infiltrate in human GBM, sometimes making up more than ~30% of all GBM cells. Given TAMs’ prevalence in the tumor microenvironment and their upregulation of Arg1 in both human GBM and our QPP model, we are testing whether manipulation of Arg1 will impact TAM function and influence GBM growth. We are also evaluating arginine metabolism in TAMs effect on T cell function in GBM. Lastly, we have developed a genetically engineered mouse model to study the role of Arg1 knockout in a GBM context in-vivo. Our studies suggest that Arg1 plays an important role in GBM immune interaction.

scholarly journals Nme1 and Nme2 genes exert metastasis-suppressor activities in a genetically engineered mouse model of UV-induced melanoma

2020 ◽  
Vol 124 (1) ◽  
pp. 161-165
Author(s):  
Nidhi Pamidimukkala ◽  
Gemma S. Puts ◽  
M. Kathryn Leonard ◽  
Devin Snyder ◽  
Sandrine Dabernat ◽  
...  
Keyword(s):  
Mouse Model ◽  
Suppressor Gene ◽  
Genetically Engineered ◽  
In Vivo Model ◽  
Metastasis Suppressor ◽  
Specific Context ◽  
Genetically Engineered Mouse Model ◽  
Metastatic Activity ◽  
First Time

AbstractNME1 is a metastasis-suppressor gene (MSG), capable of suppressing metastatic activity in cell lines of melanoma, breast carcinoma and other cancer origins without affecting their growth in culture or as primary tumours. Herein, we selectively ablated the tandemly arranged Nme1 and Nme2 genes to assess their individual impacts on metastatic activity in a mouse model (HGF:p16−/−) of ultraviolet radiation (UVR)-induced melanoma. Metastatic activity was strongly enhanced in both genders of Nme1- and Nme2-null mice, with stronger activity in females across all genotypes. The study ascribes MSG activity to Nme2 for the first time in an in vivo model of spontaneous cancer, as well as a novel metastasis-suppressor function to Nme1 in the specific context of UVR-induced melanoma.

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