Project description:The classical sacrococcygeal chordoma tumor presents with a typical morphology of lobulated myxoid tumor tissue with cords, strands and nests of tumor cells consisting of small non-vacuolated cells, intermediate cells with a wide range of vacuolization and large heavily vacuolated (physaliferous) cells. Because of its rare incidence, lack of suited model systems and technical limitations analysis was only performed on bulk tumor mass neglecting its heterogeneous composition. We aimed at elucidating the differences between small non-vacuolated and large physaliferous cells on the genomic and transcriptomic level. Secondly, we intended to clarify whether the observed cell types are derived from genetically distinct clones or rather represent different phenotypes. Using the chordoma cell line MUG-Chor1 we monitored morphological changes via time lapse experiments. We isolated pure fractions of each phenotype by means of laser microdissection or micromanipulation allowing phenotype-specific analysis. Pools of 100 cells each were genetically profiled after whole genome amplification by array comparative genomic hybridization. For expression analysis 20 cells each were subjected to whole transcriptom amplification, forwarded to RNA microarray analysis and qRT-PCR. Time lapse analysis unveiled small non-vacuolated cells to develop into large physaliferous cells via intermediate cells containing an increasing amount of vacuoles. Furthermore, we showed small and large physaliferous cells to proliferate at the same rate but intermediate cells to be the most proliferating cell phenotype. Small non-vacuolated and large physaliferous cells showed identical copy number variations. Despite their obvious morphological disparities we detected only modest changes in over all gene expression. However, verification of candidate genes yielded significant up-regulation of ALG11 (700-fold), PPP2CB (18.6-fold), and UCHL3 (18.7-fold) in large physaliferous cells. Of two different cell types (large and small MUG-Chor1 cells) we analysed each in triplicates. In total 6 cell pools were analysed.
Project description:The classical sacrococcygeal chordoma tumor presents with a typical morphology of lobulated myxoid tumor tissue with cords, strands and nests of tumor cells consisting of small non-vacuolated cells, intermediate cells with a wide range of vacuolization and large heavily vacuolated (physaliferous) cells. Because of its rare incidence, lack of suited model systems and technical limitations analysis was only performed on bulk tumor mass neglecting its heterogeneous composition. We aimed at elucidating the differences between small non-vacuolated and large physaliferous cells on the genomic and transcriptomic level. Secondly, we intended to clarify whether the observed cell types are derived from genetically distinct clones or rather represent different phenotypes. Using the chordoma cell line MUG-Chor1 we monitored morphological changes via time lapse experiments. We isolated pure fractions of each phenotype by means of laser microdissection or micromanipulation allowing phenotype-specific analysis. Pools of 100 cells each were genetically profiled after whole genome amplification by array comparative genomic hybridization. For expression analysis 20 cells each were subjected to whole transcriptom amplification, forwarded to RNA microarray analysis and qRT-PCR. Time lapse analysis unveiled small non-vacuolated cells to develop into large physaliferous cells via intermediate cells containing an increasing amount of vacuoles. Furthermore, we showed small and large physaliferous cells to proliferate at the same rate but intermediate cells to be the most proliferating cell phenotype. Small non-vacuolated and large physaliferous cells showed identical copy number variations. Despite their obvious morphological disparities we detected only modest changes in over all gene expression. However, verification of candidate genes yielded significant up-regulation of ALG11 (700-fold), PPP2CB (18.6-fold), and UCHL3 (18.7-fold) in large physaliferous cells.
Project description:Patient-derived xenografts retain the genotype of the parent tumors more readily than tumor cells maintained in culture. The two reported clival chordoma xenografts are derived from recurrent tumors after radiation. In order to study the genetics of clival chordoma in the absence of prior radiation we sought to establish a patient-derived xenograft at primary resection of a clival chordoma.
Project description:Skull base chordoma is a primary rare malignant bone-origin tumor showing relatively slow growth pattern and locally destructive lesions, which can only be characterized by histologic components. There is no available prognostic or therapeutic biomarker to predict clinical outcome or treatment response and the molecular mechanisms underlying chordoma development still remain unexplored. Therefore, we sought out to identify novel somatic variations that are associated with chordoma progression and potentially employed as therapeutic targets. Thirteen skull base chordomas were subjected for whole-exome and/or whole-transcriptome sequencing. In process, we have identified chromosomal aberration in 1p, 7, 10, 13 and 17q, high frequency of functional germline SNP of the T gene, rs2305089 (P = 0.0038) and several recurrent alterations including MUC4, NBPF1, NPIPB15 mutations and novel gene fusion of SAMD5-SASH1 for the first time in skull base chordoma.
Project description:Identifying the spectrum of genes required for cancer cell survival can reveal essential cancer circuitry and therapeutic targets, but such a map remains incomplete for many cancer types. We apply genome-scale CRISPR-Cas9 loss-of-function screens to map the landscape of selectively essential genes in chordoma, a bone cancer with few validated targets. This approach confirms a known chordoma dependency, TBXT (T; brachyury), and identifies a range of additional dependencies, including PTPN11, ADAR, PRKRA, LUC7L2, SRRM2, SLC2A1, SLC7A5, FANCM, and THAP1. CDK6, SOX9, and EGFR, genes previously implicated in chordoma biology, are also recovered. We find genomic and transcriptomic features that predict specific dependencies, including interferon-stimulated gene expression, which correlates with ADAR dependence and is elevated in chordoma. Validating the therapeutic relevance of dependencies, small-molecule inhibitors of SHP2, encoded by PTPN11, have potent preclinical efficacy against chordoma. Our results generate an emerging map of chordoma dependencies to enable biological and therapeutic hypotheses.
Project description:The prognostic factors of skull base chordoma associated with outcomes of patients after surgical resection remain poorly defined. This project aimed to identify a novel prognostic factor for patients with skull base chordoma. Using a proteomics approach, we screened tumor biomarkersthat upregulated in the rapid-recurrence group of chordoma, narrowed down by bioinformatics analysis, and finally potential biomarker was chosen for validation by immunohistochemistry using tissue microarray.
Project description:Chromatin profiling of chordoma collected by the Broad chordoma target discovery project paired end ATAC-Seq profiling in the UCH2 and MUGCHOR chordoma cell lines