Project description:As the list of putative driver mutations in glioma grows, we are just beginning toAs the list of putative driver mutations in glioma grows, we are just beginning to elucidate the effects of dysregulated developmental signaling pathways on the transformation of neural cells. We have employed a postnatal, mosaic, autochthonous, glioma model that captures the first hours and days of gliomagenesis in more resolution than conventional genetically engineered mouse models of cancer. We provide evidence that disruption of the Nf1-Ras pathway in the ventricular zone at multiple signaling nodes uniformly results in rapid neural stem cell depletion, progenitor hyperproliferation, and gliogenic lineage restriction. Abolishing Ets subfamily activity, which is upregulated downstream of Ras, rescues these phenotypes and blocks glioma initiation. Thus, the Nf1-Ras-Ets axis might be one of the select molecular pathways that are perturbed for initiation and maintenance in glioma. Mouse Gene 1.0 ST Microarrays from Affimetryx were used for microarray analysis. For each experiment, total RNA was fluorescently labeled and hybridized. 3 cell lines derived from in vivo electroporated neural stem and progenitors were compared.
Project description:As the list of putative driver mutations in glioma grows, we are just beginning toAs the list of putative driver mutations in glioma grows, we are just beginning to elucidate the effects of dysregulated developmental signaling pathways on the transformation of neural cells. We have employed a postnatal, mosaic, autochthonous, glioma model that captures the first hours and days of gliomagenesis in more resolution than conventional genetically engineered mouse models of cancer. We provide evidence that disruption of the Nf1-Ras pathway in the ventricular zone at multiple signaling nodes uniformly results in rapid neural stem cell depletion, progenitor hyperproliferation, and gliogenic lineage restriction. Abolishing Ets subfamily activity, which is upregulated downstream of Ras, rescues these phenotypes and blocks glioma initiation. Thus, the Nf1-Ras-Ets axis might be one of the select molecular pathways that are perturbed for initiation and maintenance in glioma.
Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations. ChIP sequencing two transcription factors in PC3 cells, four transcription factors plus a FLAG control in RWPE-1 cells and input DNA sequencing from each cell line.
Project description:Tumor-associated macrophages/microglia (TAMs) are prominent microenvironment components in human glioblastoma (GBM) that are potential targets for anti-tumor therapy. However, TAM depletion by CSF1R inhibition showed mixed results in clinical trials. We hypothesized that GBM subtype-specific tumor microenvironment convey distinct sensitivities to TAM targeting.We generated syngeneic PDGFB-driven and RAS-driven GBM models that resemble proneural-like and mesenchymal-like gliomas, and determined the effect of TAM targeting by CSF1R inhibitor PLX3397 on glioma growth. We also investigated the co-targeting of TAMs and angiogenesis on PLX3397-resistant RAS-driven GBM. Using single-cell transcriptomic profiling, we further explored differences in tumor microenvironment cellular compositions and functions in PDGFB- and RAS-driven gliomas. We found that growth of PDGFB-driven tumors was markedly inhibited by PLX3397. In contrast, depletion of TAMs at the early phase accelerated RAS-driven tumor growth and had no effects on other proneural and mesenchymal GBM models. In addition, PLX3397-resistant RAS-driven tumors did not respond to PI3K signaling inhibition. Single-cell transcriptomic profiling revealed that PDGFB-driven gliomas induced expansion and activation of pro-tumor microglia, whereas TAMs in mesenchymal RAS-driven GBM were enriched in pro-inflammatory and angiogenic signaling. Co-targeting of TAMs and angiogenesis decreased cell proliferation and changed the morphology of RAS-driven gliomas.Our work identify functionally distinct TAM subpopulations in the growth of different glioma subtypes. Notably, we uncover a potential responsiveness of resistant mesenchymal-like gliomas to combined anti-angiogenic therapy and CSF1R inhibition. These data highlight the importance of characterization of the microenvironment landscape in order to optimally stratify patients for TAM-targeted therapy.
Project description:Since the NFI transcription factors have been shown to be key regulators of gliogenesis, we utilized this pathway to identify miRNAs involved in the regulation of the neurogenesis-to-gliogenesis switch by neural stem/progenitor cells (NSPCs). We focused on miRNAs with expression levels that were differentially regulated downstream of NFIA, and established a mouse embryonic stem cell (ESC) line that expresses NFIA in a doxycycline (Dox)-dependent manner. NFIA-overexpressing (OE) and control NSPCs (neurospheres) derived from ESCs were purified from their mixed cultures (primary neursphsres (PNs) or secondary neurospheres (SNs) ) by fluorescence activated cell sorting and subjected to miRNAarray analysis.
Project description:Since the NFI transcription factors have been shown to be key regulators of gliogenesis, we utilized this pathway to identify miRNAs involved in the regulation of the neurogenesis-to-gliogenesis switch by neural stem/progenitor cells (NSPCs). We focused on miRNAs with expression levels that were differentially regulated downstream of NFIA, and established a mouse embryonic stem cell (ESC) line that expresses NFIA in a doxycycline (Dox)-dependent manner. NFIA-overexpressing (OE) and control NSPCs (neurospheres) derived from ESCs were purified from their mixed cultures (primary neursphsres (PNs) or secondary neurospheres (SNs) ) by fluorescence activated cell sorting and subjected to the gene expression microrray analysis.
Project description:Since the NFI transcription factors have been shown to be key regulators of gliogenesis, we utilized this pathway to identify miRNAs involved in the regulation of the neurogenesis-to-gliogenesis switch by neural stem/progenitor cells (NSPCs). We focused on miRNAs with expression levels that were differentially regulated downstream of NFIA, and established a mouse embryonic stem cell (ESC) line that expresses NFIA in a doxycycline (Dox)-dependent manner.
Project description:Since the NFI transcription factors have been shown to be key regulators of gliogenesis, we utilized this pathway to identify miRNAs involved in the regulation of the neurogenesis-to-gliogenesis switch by neural stem/progenitor cells (NSPCs). We focused on miRNAs with expression levels that were differentially regulated downstream of NFIA, and established a mouse embryonic stem cell (ESC) line that expresses NFIA in a doxycycline (Dox)-dependent manner.
Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations.
Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations.