Project description:The MEK inhibitor selumetinib induces objective responses and provides clinical benefit in children with neurofibromatosis type 1 (NF1) and inoperable plexiform neurofibromas (PNs). To evaluate whether similar outcomes were possible in adult patients, in whom PN growth is generally slower than in pediatric patients, an open-label phase 2 study of selumetinib in adults with NF1 PNs was conducted. Correlative analysis included extraction of RNA followed by sequencing. Samples include paired specimens collected before and on treatment.
Project description:The MEK inhibitor selumetinib induces objective responses in children with neurofibromatosis type 1 (NF1) and inoperable plexiform neurofibromas (PNs). We conducted an open-label phase 2 study of selumetinib in 33 adults with PNs (NCT02407405). The objective response rate was 72.7% (24/33 patients). Median tumor volume decrease at best response was 23.6% at data cut-off with 19 patients continuing to receive study treatment. Acneiform rash was the most common adverse event (AE, 33/33 patients, 15 grade ≥2); acneiform rash and increases of ALT, AST, CPK, and lipase were the only grade 3/4 AEs to occur in more than 1 patient. Patients report improved pain levels and quality of life. Phosphorylation of ERK1/2 decreased significantly in paired biopsies (P≤0.0003) without compensatory phosphorylation of AKT1/2/3 (P =0.0697-0.9587). Selumetinib can induce sustained tumor volume decreases in adults with inoperable PNs and is well tolerated, while paired biopsies reveal novel pharmacodynamic insights. Kinase enrichment proteomic analysis was performed using patient pre-treatment/baseline and on-treatment specimens when sufficient material was obtained, with detectable on-target loss of binding of selumetinib targets MEK2 and MEK1 in treated samples.
Project description:To define alterations early in tumor formation, we studied nerve tumors in neurofibromatosis 1 (NF1), a tumor predisposition syndrome in which affected individuals develop plexiform neurofibroma (PN). These benign tumors are driven by NF1 loss in Schwann cells (SC). By comparing normal nerve cells to PN cells using single cell and bulk RNA sequencing, we identified changes in five SC populations, including a de novo Schwann cell progenitor-like population. Long after Nf1 loss, SC populations developed PN-specific expression of Dcn, Postn, and CD74, and showed dramatic expansion of immune and stromal cell populations; in human PN, immune and stromal cells comprised 90% of cells. Label transfer enabled verification of each SC population and predicted tumor unique patterns of cell-cell communication in each SC population. We identified PROS-AXL, FGF-FGFR, and MIF-CD74 and its effector pathway NFkB as deregulated in NF1 SC populations, including SCP-like cells. Each receptor-ligand pair was predicted to influence surrounding cells in mouse and human. These findings highlight remarkable changes in all PN cells driven by loss of NF1 in multiple types of SCs and identify therapeutic targets for PN.
Project description:Neurofibromatosis type 1 (NF1) is the most common autosomal dominant disorder, affecting 1 in 3,500 individuals worldwide and predisposing to cancer. Germline mutations in the NF1 gene, encoding the p21Ras GTPase-activating protein (GAP) neurofibromin, are the underlying cause for NF1. Somatic inactivation of the wild type copy of NF1 leads to deregulated Ras signaling. Clinical manifestations are diverse for NF1 patients, but the predominant lesions are plexiform neurofibroma (PNF), arising from the Schwann cell (SC) lineage. While PNF are generally benign, approximately 10% of patients will experience PN progression to highly aggressive malignant peripheral nerve sheath tumors (MPNST) with poor prognosis. There are currently no approved targeted therapies for PNF or MPNST. In this study, we used a conditional mouse model of NF1, test the multi-receptor tyrosine kinase inhibitor, cabozantinib (XL184). Mice were treated with vehicle or with cabozantinib for 3 or 7 days. Tissue was harvested, lysates prepared, and the lysate was used for kinome profiling. From cell lines or tumor tissue, protein lysates are prepared and passed over an affinity matrix consisting of Sepharose beads covalently coupled to a mixture of linker-adapted Type I kinase inhibitors. Kinase capture is reproducible and is a function of affinity for kinases for the immobilized inhibitors, expression level of the kinase, as well as the activation state of the kinase. Following affinity purification, kinases are identified and their multiplexed kinase inhibitor bead binding quantified by mass spectrometry (MIB/MS). Our goal is to identify the kinome changes in NF1 plexiform neurofibroma induced by cabozantinib treatment.
Project description:Neurofibromatosis type 1 (NF1) is the most common autosomal dominant disorder, affecting 1 in 3,500 individuals worldwide and predisposing to cancer. Germline mutations in the NF1 gene, encoding the p21Ras GTPase-activating protein (GAP) neurofibromin, are the underlying cause for NF1. Somatic inactivation of the wild type copy of NF1 leads to deregulated Ras signaling. Clinical manifestations are diverse for NF1 patients, but the predominant lesions are plexiform neurofibroma (PNF), arising from the Schwann cell (SC) lineage. While PNF are generally benign, approximately 10% of patients will experience PN progression to highly aggressive malignant peripheral nerve sheath tumors (MPNST) with poor prognosis. There are currently no approved targeted therapies for PNF or MPNST. In this study, we used a conditional mouse model of NF1, test the multi-receptor tyrosine kinase inhibitor, cabozantinib (XL184). Mice were treated with vehicle or with cabozantinib for 3 or 7 days. Tissue was harvested, lysates prepared, and the lysate was used for kinome profiling. From cell lines or tumor tissue, protein lysates are prepared and passed over an affinity matrix consisting of Sepharose beads covalently coupled to a mixture of linker-adapted Type I kinase inhibitors. Kinase capture is reproducible and is a function of affinity for kinases for the immobilized inhibitors, expression level of the kinase, as well as the activation state of the kinase. Following affinity purification, kinases are identified and their multiplexed kinase inhibitor bead binding quantified by mass spectrometry (MIB/MS). Our goal is to identify the kinome changes in NF1 plexiform neurofibroma induced by cabozantinib treatment.
Project description:Schwann cells and macrophages were dissociated from normal DRGs and 1- and 7-month-old neurofibroma. Schwann cells from neurofibroma have Nf1-/- phenotypes. All macrophages have Nf1+/+ phenotypes. We used microarrays (Affymetrix MoGene 2.0 ST GeneChip) to detect transcriptomal changes between 7-month-old neurofibroma Schwann cells (or macrophages) versus 1-month-old wild-type (or neurofibroma) Schwann cells (or macrophages). Expression data of three sets of cells: (1)Schwann cells and macrophages from 1-month-old wild-type mouse dorsal root ganglia, (2) Schwann cells (Nf1-/-) and macrophages (Nf1+/+) from 1-month-old neurofibroma, (3) Schwann cells (Nf1-/-) and macrophages (Nf1+/+) from 7-month-old neurofibroma We chopped mouse DRG/neurofibromas into 1-3 mm^3 pieces and plated them in dissociation medium containing 20mL L-15 (Mediatech), 0.5 mg/mL collagenase type 1 (Worthington; Lakewood, NJ), and 2.5 mg/mL dispase protease type II (Cambrex; East Rutherford, NJ) at 37°C for 4-6 hours with shaking. The dissociation reaction was stopped by adding DMEM +10%FBS. Undigested DRG/tumors were excluded by 100µM cell strainer. Cells were collected by centrifugation. For each microarrays (Schwann cell, macrophage), Affymetrix GeneChip Command Console (v4.0.0) was used to create .chp files. All the probe sets on Affymetrix Mouse Gene 2.0 ST array (Mogene-2_0-st-v1.na33.2.mm10) were summarized by Affymetix Expression Console program using robust multi-chip average (RMA) method . After preprocessing steps, data from two batches were combined and their batch effects were corrected using ComBat method Please note that [1] all MP samples are Nf1+/+ (no mutation on Nf1 gene) and the only difference is their ages (1month, 7month) and [2] the 'nf1' in sample title reperesents "neurofibroma type1 disease", not "Nf1 gene".
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. Transformation from Nf1-null benign plexiform neurofibromas is driven by the loss of the Cdkn2a (Arf) locus. Here, genetically engineered mouse models with combined Nf1 flox/flox and Arf flox/flox alleles were used (crossed with Postn-Cre+ mice). Tissue from MPNSTs that form in the Nf1-/-;Arf-/- setting were used for mRNA sequencing and compared to benign plexiform neurofibroma tissue (Nf1-/- from Nf1 flox/flox; Postn-Cre+ mice, GSE213789) to identify transcriptome signatures from MPNST and compare them to benign plexiform neurofibroma.
Project description:Analysis of the effect of NF1 second hit mutation to the reading of the whole human genome by comparing the gene expression profiles of neurofibroma derived Schwann cell cultures representing two different NF1 genotypes (NF1+/- and NF1-/-).
Project description:Plexiform neurofibroma is a major contributor to morbidity in Neurofibromatosis type I (NF1) patients. Macrophages and mast cells infiltrate neurofibroma, and data from mouse models implicate these leukocytes in neurofibroma development. Anti-inflammatory therapy targeting these cell populations has been suggested as a means to prevent neurofibroma development. Here, we compare gene expression in inflamed nerves from NF1 models which invariably form neurofibroma to those with inflammation driven by EGFR overexpression which rarely progresses to neurofibroma. We find that the chemokine Cxcl10 is uniquely up-regulated in NF1 mice that invariably develop neurofibroma. Global deletion of the Cxcl10 receptor Cxcr3 prevented neurofibroma development in these neurofibroma-prone mice. Cxcr3 expression localized to T cells and dendritic cells (DCs) in both inflamed nerves and neurofibromas. These data support a heretofore unappreciated role for T cells/DCs in neurofibroma initiation.