Project description:Choroid plexus carcinoma (CPC) is a rare brain tumor that occurs most commonly in very young children, and has a dismal prognosis despite intensive therapy. Improved outcomes for CPC patients depend on a deeper understanding of the mechanisms underlying the disease. We developed transgenic models of CPCs by activating the Myc oncogene and deleting the Trp53 tumor suppressor gene in murine neural stem cells or progenitors. Murine CPCs resemble their human counterparts at a histological level, and like the hypodiploid subset of human CPCs, exhibit multiple whole-chromosome losses, particularly of chromosomes 8, 12 and 19. Analysis of murine and human CPC gene expression profiles and copy number changes reveals altered expression of genes involved in cell cycle, DNA damage response and cilium function. Finally, high throughput drug screening identifies small molecule inhibitors that decrease the viability of CPCs. These models will be valuable tools for understanding the biology of choroid plexus tumors and for testing novel approaches to therapy.
Project description:Atoh1-Cre; Myc/Myc mice developed choroid plexus papilloma and Atoh1-Cre; Myc/Myc; p53fl/fl mice developed choroid plexus carcinoma. By studying the gene expression profiles of normal choroid plexus, choroid plexus papilloma and choroid plexus carcinoma in mice, we aim to gain a better understanding of the biology of choroid plexus tumors
Project description:Tumor-associated hydrocephalus (TAH) is a common and lethal complication of brain metastases. Although other factors beyond mechanical obstructions have been suggested, the exact mechanisms are unknown. Using single-nucleus RNA-sequencing and spatial transcriptomics, we find that a distinct population of mast cells locate in the choroid plexus and dramatically increase during TAH. Genetic fate-tracing and intracranial mast cell-specific tryptase knockout showed that choroid plexus mast cells (CPMCs) disrupt cilia of choroid plexus epithelia via the tryptase-PAR2-FoxJ1 pathway and consequently increase cerebrospinal fluid production. Mast cells are also found in the human choroid plexus. Levels of tryptase in cerebrospinal fluid are closely associated with clinical severity of TAH. BMS-262084, an inhibitor of tryptase, can cross blood-brain-barrier, inhibits TAH in vivo and alleviates mast cell-induced damage of epithelial cilia in a human pluripotent stem cell-derived choroid plexus organoid model. Collectively, we uncover the function of CPMCs and provide an attractive therapy for TAH.
Project description:Choroid plexus carcinoma (CPC) is a rare brain tumor that occurs most commonly in very young children and has a dismal prognosis despite intensive therapy. Improved outcomes for patients with CPC depend on a deeper understanding of the mechanisms underlying the disease. Here we developed transgenic models of CPCs by activating the Myc oncogene and deleting the Trp53 tumor suppressor gene in murine neural stem cells or progenitors. Murine CPC resembled their human counterparts at a histologic level, and like the hypodiploid subset of human CPC, exhibited multiple whole-chromosome losses, particularly of chromosomes 8, 12, and 19. Analysis of murine and human CPC gene expression profiles and copy number changes revealed altered expression of genes involved in cell cycle, DNA damage response, and cilium function. High-throughput drug screening identified small molecule inhibitors that decreased the viability of CPC. These models will be valuable tools for understanding the biology of choroid plexus tumors and for testing novel approaches to therapy. SIGNIFICANCE: This study describes new mouse models of choroid plexus carcinoma and uses them to investigate the biology and therapeutic responsiveness of this highly malignant pediatric brain tumor.
Project description:Gene expression profiles generated from human tumor cells laser-microdissected from surgical samples of seven choroid plexus papillomas (Grade I WHO) as eight samples of epithelial cells lasermicrodissected from normal choroid plexus obtained at autopsy. Choroid plexus tumors are rare pediatric brain tumors derrived from the choroid plexus epithelium. Gene expression profiles of lasermicrodissected tumor cells from 7 individual choroid plexus tumor samples obtained at surgery were compared to gene expression profiles from non-neoplastic choroid plexus epithelial cells lasermicrodissected from normal non-neoplastic choroid plexus obtained at autopsy (Am J Surg Pathol. 2006 Jan;30(1):66-74.) in order to identfy genes differentially expressed in choroid plexus tumor cells.
Project description:Choroid plexus secretes cerebrospinal fluid important for brain development and homeostasis. The OTX2 homeoprotein is critical for choroid plexus development and remains highly expressed in adult choroid plexus. Through RNA sequencing analyses of constitutive and conditional knockdown adult mouse models, we reveal putative roles for OTX2 in choroid plexus function, including cell signaling and adhesion, and show that it regulates the expression of factors secreted into cerebrospinal fluid, notably transthyretin. We also show that Otx2 expression impacts choroid plexus immune and stress responses, and also affects splicing which leads to changes in mRNA isoforms of proteins implicated in oxidative stress response and DNA repair. Through mass spectrometry analysis of OTX2 protein partners in the choroid plexus, and in known non-cell autonomous target regions such as visual cortex and subventricular zone, we identified putative targets involved in cell adhesion, chromatin structure and RNA processing. Thus, OTX2 retains important roles in choroid plexus function and brain homeostasis throughout life.
Project description:Aggresome is a para nuclear inclusion body that functions as a storage compartment for misfolded proteins. Our previous work revealed the presence of aggresomes in pediatric choroid plexus tumors (CPT). CPTs are rare neoplasms comprised of three pathological subgroups; choroid plexus carcinoma (CPC), a grade III tumor, atypical choroid plexus papilloma (ACPP), a grade II tumor, and choroid plexus papilloma (CPP), a grade I tumor. In the current study, we aimed to investigate the prognostic value of aggresomes-positivity and its correlation to the pathological and molecular subtypes. The proteomics profiling of 21 CPT pediatric samples was investigated using ABSciex Triple TOF 5600+ mass spectrometer.