Introduction: Glioma stem cells isolated from human glioblastomas are resistant to radiation and cytotoxic chemotherapy and may drive tumor recurrence. Treatment efficacy may depend on the presence of glioma stem cells, expression of DNA repair enzymes such as methylguanine methyltransferase (MGMT), or transcriptome subtype. Methods: To model genetic alterations in the core signaling pathways of human glioblastoma, we induced conditional Rb knockout, Kras activation, and Pten deletion mutations in cortical murine astrocytes. Serial neurosphere culture, multi-lineage differentiation, and orthotopic transplantation were used to assess whether these mutations induced de-differentiation of cortical astrocytes into glioma stem cells. Efficacy of radiation and temozolomide was examined in vitro and in an allograft model in vivo. The effects of radiation on transcriptome subtype was examined by expression profiling. Results: G1/S-defective, Rb knockout astrocytes gained unlimited self-renewal and multi-lineage differentiation capacity, in both the presence and absence of Kras and Pten mutations. Only triple mutant astrocytes formed serially-transplantable glioblastoma allografts. Triple mutant astrocytes and allografts were sensitive to radiation, but expressed Mgmt and were resistant to temozolomide. Radiation induced a shift in transcriptome subtype of glioblastoma allografts from proneural to mesenchymal. Conclusion: A defined set of core signaling pathway mutations induces de-differentiation of cortical murine astrocytes into glioma stem cells. This non-germline genetically engineered mouse model mimics human proneural glioblastoma on histopathological, molecular, and treatment response levels. It may be useful in dissecting the genetic and cellular mechanisms of treatment resistance and developing more effective therapies. Overall design: Investigation of chromatin accessibility in astrocytes and glioblastoma cell lines
Core pathway mutations induce de-differentiation of murine astrocytes into glioblastoma stem cells that are sensitive to radiation but resistant to temozolomide.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Trichostatin A enhances vascular repair by injected human endothelial progenitors through increasing the expression of TAL1-dependent genes.
Treatment
View SamplesEndothelial colony-forming cells (ECFCs) have been reported as promising cells for regenerative medicine thanks to their angiorepair properties. Transcription factors are primary determinants of the functional capacity of the cells and TAL1 has been shown as a critical regulator of endothelial lineage in both development and adult life. However, only few (three) TAL1 targets have been identified so far in mouse and human endothelial cells. This microarray experiment, where TAL1 expression was knocked-down, was designed to identify TAL1-dependent genes in primary human endothelial stem/progenitor cells.
Trichostatin A enhances vascular repair by injected human endothelial progenitors through increasing the expression of TAL1-dependent genes.
Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Aneuploidy, oncogene amplification and epithelial to mesenchymal transition define spontaneous transformation of murine epithelial cells.
Sex, Specimen part
View SamplesHuman epithelial cancers are defined by a recurrent distribution of specific chromosomal aneuploidies. In our model system, mouse bladder and kidney epithelial cells spontaneously immortalize, transform and become tumorigenic after prolonged culture. We assessed genome and transcriptome alterations and found wide-spread aneuploidy, early transcriptional deregulation, and massive genomic dereguation of the cellular transcriptome.
Aneuploidy, oncogene amplification and epithelial to mesenchymal transition define spontaneous transformation of murine epithelial cells.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Norrin/Frizzled4 signalling in the preneoplastic niche blocks medulloblastoma initiation.
Specimen part
View SamplesMedulloblastoma (MB), a tumor of the cerebellum, is the most common malignant brain tumor in children. One third of all human MB exhibits a gene expression signature of Sonic hedgehog (Shh) signaling. Hedgehog (Hh) pathway inhibitors have shown efficacy in clinical trials for MB, however, tumors develop resistance to these compounds, highlighting the need to identify additional therapeutic targets for treatment. We have identified a role for Norrin signaling in tumor initiation in the Patched (Ptch) mouse model of MB. Norrin is a secreted factor that functions as an atypical Wnt by binding to the Frizzled4 (Fzd4) receptor on endothelial cells to activate canonical beta-catenin-mediated Wnt signaling pathway. In the cerebellum, activation of Norrin/Fzd4 signaling is required for the establishment and maintenance of the blood brain barrier (BBB). We have identified a role for Norrin signaling in the stroma as a potent tumor inhibitory signal. Inactivation of Norrin in Ptch+/- mice significantly shortens latency and increases MB incidence. This phenotype is associated with an increased frequency of pre-tumor lesions and their conversion to malignancy. In this context, loss of Norrin signalling in endothelial cells is associated with an accelerated transition to a pro-tumor stroma characterized by vascular permeability, inflammation and angiogenic remodelling. Accordingly, loss of Ndp significantly alters the stromal gene expression signature of established Ptch MB.
Norrin/Frizzled4 signalling in the preneoplastic niche blocks medulloblastoma initiation.
Specimen part
View SamplesMedulloblastoma (MB), a tumor of the cerebellum, is the most common malignant brain tumor in children. One third of all human MB exhibits a gene expression signature of Sonic hedgehog (Shh) signaling. Hedgehog (Hh) pathway inhibitors have shown efficacy in clinical trials for MB, however, tumors develop resistance to these compounds, highlighting the need to identify additional therapeutic targets for treatment. We have identified a role for Norrin signaling in tumor initiation in the Patched (Ptch) mouse model of MB. Norrin is a secreted factor that functions as an atypical Wnt by binding to the Frizzled4 (Fzd4) receptor on endothelial cells to activate canonical beta-catenin-mediated Wnt signaling pathway. In the cerebellum, activation of Norrin/Fzd4 signaling is required for the establishment and maintenance of the blood brain barrier (BBB). We have identified a role for Norrin signaling in the stroma as a potent tumor inhibitory signal. Inactivation of Norrin in Ptch+/- mice significantly shortens latency and increases MB incidence. This phenotype is associated with an increased frequency of pre-tumor lesions and their conversion to malignancy. In this context, loss of Norrin signalling in endothelial cells is associated with an accelerated transition to a pro-tumor stroma characterized by vascular permeability, inflammation and angiogenic remodelling. Accordingly, loss of Ndp significantly alters the stromal gene expression signature of established Ptch MB.
Norrin/Frizzled4 signalling in the preneoplastic niche blocks medulloblastoma initiation.
Specimen part
View SamplesProstate cancer is the most commonly diagnosed malignancy in the United States. While the majority of cases are cured with radiation or surgery, about 1/3 of patients will develop metastatic disease which there is no cure, and has a life expectancy of less than 5 years. Identification of antigens associated with this transition to metastatic disease is crucial for future therapies. One such antigen of interest is the SSX gene family, which are cancer/testis antigens that are associated with the epithelial to mesenchymal transition in other cancer types. Prior work has shown that, in prostate cancer, SSX expression was restricted to metastatic tissue and not primary tumor tissue which may indicate a role in disease progression. Some work has been done into the function of the SSX family, which revealed transcriptional regulator activity. But neither the targets of this activity or the function of SSX are known. Through a transcriptomics approach, we are seeking a better understanding of the different genes and pathways SSX regulates in the context of prostate cancer, and to determine if these pathways may contribute to disease progression.
SSX2 regulates focal adhesion but does not drive the epithelial to mesenchymal transition in prostate cancer.
Cell line
View SamplesWe performed NGS-based transcript profiling (RNA-seq) to profile transcripts that are expressed in MCF10A cells. 12,332 genes with FPKM>1 were considered as expressed in MCF10A cells. Overall design: mRNA profiles of MCF10A cells were generated by deep sequencing using Illumina Hiseq 2000.
Widespread genetic epistasis among cancer genes.
No sample metadata fields
View Samples