Project description:Notch dependent gene expression in T6E cell line Transcription profiles of Notch signaling active, inactive and recovered were compared
Project description:Loss or damage to the mandible due to trauma, treatment of oral malignancies, and other diseases is currently treated using bone grafting techniques that suffer from numerous shortcomings and contraindications. Zebrafish naturally heal large injuries to their mandibular bone, and thus offer an opportunity to understand how to boost intrinsic healing ability. Using a novel her6:mCherry Notch reporter, we show that canonical Notch signaling is induced during the initial stages of cartilage callus formation in both mesenchymal cells and chondrocytes. We also show that modulation of Notch signaling during the initial postoperative period results in lasting changes to regenerate bone quantity one month later. Notch signaling is required for mandibular bone healing, as pharmacological inhibition of Notch signaling blocks cartilage callus formation and results in non-union. Conversely, conditional transgenic activation of Notch signaling accelerates regenerative ossification. Mechanistically, we report that postoperative Notch signaling regulates multiple phases of chondroid regeneration and patterns callus metabolic landscape. Given conserved functions of Notch signaling in bone repair across vertebrates, we propose that targeted activation of Notch signaling during the early phases of bone healing may have therapeutic value.
Project description:Soft tissue sarcomas (STS) are a heterogeneous group of tumors associated with poor clinical outcome. While a subset of STS are characterized by simple karyotypes and recurrent chromosomal translocations, the mechanisms driving cytogenetically complex sarcomas are largely unknown. Clinical evidence led us to partially inactivate Pten and p53 in the smooth muscle lineage of mice, which developed high-grade undifferentiated pleomorphic sarcomas (HGUPS), leiomyosarcomas (LMS) and carcinosarcomas (CS) that widely recapitulate the human disease, including the aberrant karyotype and metastatic behavior. Pten was found haploinsufficient whereas the wild-type allele of p53 invariably gained point mutations. Gene expression profile showed upregulated Notch signaling in PtenM-bM-^HM-^F/+p53M-bM-^HM-^F/+ tumors compared to Pten+/+p53M-bM-^HM-^F/+. Consistently, Pten silencing exacerbated the clonogenic and invasive potential of p53-deficient bone marrow-derived mouse mesenchymal stem cells and tumor cells, while activating the Notch pathway. Moreover, the increased oncogenic behavior of PtenM-bM-^HM-^F/+p53M-bM-^HM-^F/+ and shPten-transduced Pten+/+p53M-bM-^HM-^F/+ tumor cells was counteracted by treatment with a gamma secretase inhibitor (GSI), suggesting that the aggressiveness of those tumors can be attributed, at least in part, to enhanced Notch signaling. This study demonstrates a cooperative role for Pten and p53 suppression in complex karyotype sarcomas while establishing Notch as an important functional player in the crosstalk of these pathways during tumor progression. Our results highlight the importance of molecularly subclassifying high-grade sarcoma patients for targeted treatments. Compare PtenM-bM-^HM-^F/+p53M-bM-^HM-^F/+ to Pten+/+p53M-bM-^HM-^F/+ high-grade undifferentiated pleomorphic sarcomas (HGUPS) 4 PtenM-bM-^HM-^F/+p53M-bM-^HM-^F/+ were compared to 5 Pten+/+p53M-bM-^HM-^F/+ Keywords: Differential gene expression.
Project description:Soft tissue sarcomas (STS) are a heterogeneous group of tumors associated with poor clinical outcome. While a subset of STS are characterized by simple karyotypes and recurrent chromosomal translocations, the mechanisms driving cytogenetically complex sarcomas are largely unknown. Clinical evidence led us to partially inactivate Pten and p53 in the smooth muscle lineage of mice, which developed high-grade undifferentiated pleomorphic sarcomas (HGUPS), leiomyosarcomas (LMS) and carcinosarcomas (CS) that widely recapitulate the human disease, including the aberrant karyotype and metastatic behavior. Pten was found haploinsufficient whereas the wild-type allele of p53 invariably gained point mutations. Gene expression profile showed upregulated Notch signaling in Pten∆/+p53∆/+ tumors compared to Pten+/+p53∆/+. Consistently, Pten silencing exacerbated the clonogenic and invasive potential of p53-deficient bone marrow-derived mouse mesenchymal stem cells and tumor cells, while activating the Notch pathway. Moreover, the increased oncogenic behavior of Pten∆/+p53∆/+ and shPten-transduced Pten+/+p53∆/+ tumor cells was counteracted by treatment with a gamma secretase inhibitor (GSI), suggesting that the aggressiveness of those tumors can be attributed, at least in part, to enhanced Notch signaling. This study demonstrates a cooperative role for Pten and p53 suppression in complex karyotype sarcomas while establishing Notch as an important functional player in the crosstalk of these pathways during tumor progression. Our results highlight the importance of molecularly subclassifying high-grade sarcoma patients for targeted treatments. Compare Pten∆/+p53∆/+ to Pten+/+p53∆/+ high-grade undifferentiated pleomorphic sarcomas (HGUPS)
Project description:Dysregulation of the Notch-RBPJ signaling pathway has been found associated with various human diseases including cancers; however, precisely how this key signaling pathway is fine-tuned via its interactors and modifications is still largely unknown. In this study, using a proteomic approach, we identified FBXO42 as a novel RBPJ interactor. FBXO42 promotes RBPJ polyubiquitination on lysine (K) 175 via K63 linkage, which enhances the association of RBPJ with chromatin remodeling complexes and induces a global chromatin relaxation. Genetically depleting FBXO42 or pharmacologically targeting its E3 ligase activity attenuates the Notch signaling-related leukemia development in vivo. Taken together, our findings not only revealed FBXO42 as a critical regulator of the Notch pathway by modulating RBPJ-dependent global chromatin landscape changes, but also provide insights into the therapeutic intervention of the Notch pathway for leukemia treatment.