Biology subjects

Capper, D.

Publications and source records attributed to Capper, D..

3 recordsLinked to original sources

bioRxiv2021

Distribution of GOPC:ROS1 and other ROS1 fusions in glioma types

The ROS proto-oncogene 1 (ROS1) gene is rearranged in various cancers. The translated fusion protein presents an attractive therapeutic target, since specific inhibitors have been approved for several tumor types. In glioma, ROS1 fusions are frequent within infantile hemispheric glioma, and single case reports on occurrences in other glioma types exist. However, a comprehensive analysis spanning the full width of glioma types and subtypes is lacking. We here assessed the spectrum and distribution of ROS1 fusions by screening >20,000 glioma cases for typical chromosomal alterations, with subsequent RNA-sequencing for confirmation of candidate cases. ROS1 fusions were identified in 16 cases, from low grade pilocytic astrocytoma WHO grade 1 to glioblastoma, IDH wildtype WHO grade 4. Thus, despite being enriched in some tumor types, ROS1 fusions are not pathognomonic for specific glioma types and may consitute a relevant target in a variety of cases.

genomics↗

bioRxiv2021

Recurrent fusions in PLAGL1 define a distinct subset of pediatric-type supratentorial ependymoma

Ependymomas encompass a heterogeneous group of central nervous system (CNS) neoplasms that occur along the entire neuroaxis. In recent years, extensive (epi-)genomic profiling efforts have identified several molecular groups of ependymoma that are characterized by distinct molecular alterations and/or patterns. Based on unsupervised visualization of a large cohort of genome-wide DNA methylation data, we identified a highly distinct group of pediatric-type tumors (n = 40) forming a cluster separate from all established CNS tumor types, of which a high proportion were histopathologically diagnosed as ependymoma. RNA sequencing revealed recurrent fusions involving the pleomorphic adenoma gene-like 1 (PLAGL1) gene in 19 of 20 of the samples analyzed, with the most common fusion being EWSR1:PLAGL1 (n = 13). Five tumors showed a PLAGL1:FOXO1 fusion and one a PLAGL1:EP300 fusion. High transcript levels of PLAGL1 were noted in these tumors, with concurrent overexpression of the imprinted genes H19 and IGF2, which are regulated by PLAGL1. Histopathological review of cases with sufficient material (n = 16) demonstrated a broad morphological spectrum of largely ependymoma-like tumors. Immunohistochemically, tumors were GFAP-positive and OLIG2- and SOX10-negative. In 3/16 of the cases, a dot-like positivity for EMA was detected. Consistent with other fusion-positive ependymal groups, all tumors in our series were located in the supratentorial compartment. Median age of the patients at the time of diagnosis was 6.2 years. Analysis of time to progression or recurrence revealed survival times comparable to those of patients with ZFTA:RELA-fused ependymoma. In summary, our findings suggest the existence of a novel group of supratentorial ependymomas that are characterized by recurrent PLAGL1 fusions and enriched for pediatric patients.

cancer biology↗

bioRxiv2020

An Integrative Genetic, Epigenetic and Proteomic Characterization of Pancreatic Neuroendocrine Neoplasms (PanNENs) defines Distinct Molecular Features of α- and β-cell like Subgroups

Pancreatic Neuroendocrine Carcinomas (PanNECs) are high-grade, poorly-differentiated tumors grouped together with Pancreatic Neuroendocrine Tumors (PanNETs) and placed within the Pancreatic Neuroendocrine Neoplasms (PanNENs) WHO tumor classification. Despite recent studies suggesting the endocrine origin of low-grade PanNETs, high-grade PanNEC origin remains unknown. DNA methylation analysis using the Illumina 850K beadchip array was conducted on 57 PanNEN samples, including 14 PanNECs. Distinct methylation profiles separated PanNEN samples into two major groups, clearly distinguishing high-grade PanNECs from other PanNETs including high-grade NETG3. DNA mutations, copy number changes and Immunohistochemistry of pancreatic cell-type markers PDX1, ARX and SOX9 were utilized to further characterize PanNECs and their hierarchical cell of origin in the pancreas. Phylo-epigenetic and cell-type signature features using methylation data from normal alpha, beta, acinar and ductal adult cells indicate an exocrine cell of origin for PanNECs, thus separating them in cell lineage from other PanNENs of endocrine origin. Our study provides a robust and clinically relevant method relying on methylation profiles to clearly distinguish PanNECs from PanNETG3s to improve patient stratification and treatment.

cancer biology↗