Project description:Malignant peripheral nerve sheath tumors (MPNSTs) are the leading cause of premature death for patients with Neurofibromatosis type 1 and no approved targeted therapies are available. Benign plexiform neurofibromas have been successfully treated with selumetinib, a MEK inhibitor, but after progression to MPNST, MEK inhibition alone is not effective. Frequently, adaptive responses to single agent targeted inhibitors invokes alterations in receptor tyrosine kinase expression and feedback regulation that leads to inhibitor bypass. Here, the effects of SHP099, an inhibitor of the protein-tyrosine phosphatase SHP2 (encoded by the PTPN11 gene) was tested alone and in combination with trametinib (MEKi) in an NF1 MPNST patient derived xenograft model (PDX4) treated with SHP099, hydroxychloroquine (HCQ) or the combination. Kinase enrichment proteomic analysis was performed using tumor tissue treated with SHP099, hydroxychloroquine (HCQ) or the combination to evaluate the effects on the functional kinome.
Project description:Malignant peripheral nerve sheath tumors (MPNSTs) are the leading cause of premature death for patients with Neurofibromatosis type 1 and no approved targeted therapies are available. Benign plexiform neurofibromas have been successfully treated with selumetinib, a MEK inhibitor, but after progression to MPNST, MEK inhibition alone is not effective. Frequently, adaptive responses to single agent targeted inhibitors invokes alterations in receptor tyrosine kinase expression and feedback regulation that leads to inhibitor bypass. Here, the effects of SHP099, an inhibitor of the protein-tyrosine phosphatase SHP2 (encoded by the PTPN11 gene) was tested alone and in combination with trametinib (MEKi) in an orthotopic implantation murine model of NF1 MPNST with defined genotype (NP, Nf1-/-;Trp53-/-). Kinase enrichment proteomic analysis was performed using tumor tissue from vehicle, SHP099, trametinib, or trametinib and SHP099 in combination for 5 or 21 days to evaluate the effects on the functional kinome.
Project description:Malignant peripheral nerve sheath tumors (MPNSTs) are the leading cause of premature death for patients with Neurofibromatosis type 1 and no approved targeted therapies are available. Benign plexiform neurofibromas have been successfully treated with selumetinib, a MEK inhibitor, but after progression to MPNST, MEK inhibition alone is not effective. Frequently, adaptive responses to single agent targeted inhibitors invokes alterations in receptor tyrosine kinase expression and feedback regulation that leads to inhibitor bypass. Here, the effects of SHP099, an inhibitor of the protein-tyrosine phosphatase SHP2 (encoded by the PTPN11 gene) was tested alone and in combination with trametinib (MEKi) in an orthotopic implantation murine model of NF1 MPNST with defined gentotype (NI, Nf1-/-;Ink4a/Arf-/-). Kinase enrichment proteomic analysis was performed using tumor tissue from vehicle, SHP099, or trametinib and SHP099 in combination for 5, 15, or 28 days to evaluate the effects on the functional kinome.
Project description:<p>Malignant peripheral nerve sheath tumors (MPNSTs) are a group of highly aggressive soft tissue sarcomas that may occur sporadically, in association with neurofibromatosis type I (NF1-associated), or after radiotherapy (RT-associated). We utilized comprehensive genomic approaches and identified recurrent loss-of-function somatic alterations in the Polycomb repressive complex 2 (PRC2) core components EED or SUZ12. Genetic loss of either of these two genes results in complete loss of H3K27me3 and aberrant transcriptional programming in the affected tumors.</p>
Project description:Understanding biological pathways critical for common neurofibromatosis type 1 (NF1) peripheral nerve tumors is essential, as tumor biomarkers, prognostic factors and therapeutics are all lacking. We used gene expression profiling to define transcriptional changes between primary normal Schwann cells (n = 10), NF1-derived primary benign neurofibroma Schwann cells (n = 22), malignant peripheral nerve sheath tumor (MPNST) cell lines (n = 13), benign neurofibromas (n = 26) and MPNST (n = 6). Dermal and plexiform neurofibromas were indistinguishable. A prominent theme in the analysis was aberrant differentiation. Neurofibromas repressed gene programs normally active in Schwann cell precursors and immature Schwann cells. MPNST signatures strongly differed; genes upregulated in the sarcomas were significantly enriched for genes activated in neural crest cells. We validated differential expression of 82 genes including the neural crest transcription factor SOX9 and SOX9 predicted targets. SOX9 immunoreactivity was robust in neurofibroma and MPSNT tissue sections and targeting SOX9 - strongly expressed in NF1-related tumors - caused MPNST cell death. SOX9 is a biomarker of neurofibroma and MPNST, and possibly a therapeutic target in NF1. Keywords: tumor stage 86 microarrays, consisting of 77 samples and 9 batch reference samples: NHSC (10), dNFSC (11), pNFSC (11), MPNST cell lines (13), dNF (13), pNF (13), MPNST (6)
Project description:The goal of this study was to determine the distribution of H3K27me3 in rat peripheral nerve, which is formed by PRC2, polycomb repressive complex 2.
