Project description:Despite histological similarity of ependymomas from throughout the neuraxis, the disease likely comprises multiple independent entities, each with a distinct molecular pathogenesis. Transcriptional profiling of two large independent cohorts of ependymomas reveals the existence of two demographically, transcriptionally, genetically and clinically distinct groups of posterior fossa (PF) ependymoma. Group A patients are younger, have laterally located tumors with a balanced genome, and are much more likely to exhibit recurrence, metastasis, and death as compared to Group B patients. Identification and optimization of immunohistochemical markers for PF ependymoma subgroups allowed validation of our findings on a third group of independent ependymomas using a human ependymoma tissue microarray, and provides a tool for prospective prognostication and stratification of PF ependymoma patients. This SuperSeries is composed of the following subset Series: GSE27283: Human ependymoma samples [expression] GSE27286: Human ependymoma samples, Subgrouping [aCGH - German Cancer Research Center human 33K BAC array] Refer to individual Series
Project description:Whole-genome transcriptional profiling of human ependymoma tumors. Subgrouping based on mRNA expression profile. Fresh frozen tumor material was collected during tumor resection. Gene expression profiles illustrate distinct expression pattern at diagnosis.
Project description:DNA Methylation profiles were generated for retrospective cases to support work into investigation of the immune environment in pediatric ependymoma. Samples were analyzed using the Illumina 450k beadchip and processed using the Heidelberg classifier (v11.2b and subsequently v12.3 for subgrouping/subtyping). The aim of the study was to better understand the immune-tumor microenvironment in pediatric ependymoma and the methylation profiles support the diagnoses of each case.
Project description:We analyzed DNA copy number alterations in 64 human gastric cancer samples and 8 gastric cancer cell lines using bacterial artificial chromosome (BAC) arrays based comparative genomic hybridisation (aCGH).
Project description:Whole-genome array comparative genomic hybridization (aCGH) of human ependymoma tumors. DOP-PCR products were spotted in triplicate onto NexterionTM Slide E epoxysilane-coated slides (PEQLAB, Erlangen, Germany) using a spotting robot (VersArray ChipWriterTM Pro system,BioRad, Munich, Germany) at 20C and 40% humidity. After spotting, slides were cross-linked,baked for 1 hr at 80C, and cross-linked again.
Project description:BACKGROUND: Array Comparative Genomic Hybridization (aCGH) is a rapidly evolving technology that still lacks complete standardization. Yet, it is of great importance to obtain robust and reproducible data to enable meaningful multiple hybridization comparisons. Special difficulties arise when aCGH is performed on archival formalin-fixed, paraffin-embedded (FFPE) tissue due to its variable DNA quality. Recently, we have developed an effective DNA quality test that predicts suitability of archival samples for BAC aCGH. METHODS: In this report, we first used DNA from a cancer cell-line (SKBR3) to optimize the aCGH protocol for automated hybridization, and subsequently optimized and validated the procedure for FFPE breast cancer samples. We aimed for highest throughput, accuracy, and reproducibility applicable to FFPE samples, which can also be important in future diagnostic use. RESULTS: Our protocol of automated array-CGH on archival FFPE ULS-labeled DNA showed very similar results compared with published data and our previous manual hybridization method. CONCLUSION: This report combines automated aCGH on unamplified archival FFPE DNA using non-enzymatic ULS labeling, and describes an optimized protocol for this combination resulting in improved quality and reproducibility.
Project description:Giant cell ependymoma (GCE), a rare ependymoma subtype, was only recently recognised as a separate diagnostic entity with variations both in malignant potential and in course of disease. The pathogenetic mechanisms behind ependymomas remain unknown. Only one karyotyped GCE has so far been reported. We present the first genomic characterisation of a supratentorial GCE using G-band karyotyping, DNA ploidy analysis and array comparative genomic hybridisation (aCGH). The G-banded karyotype was hypodiploid with multiple monosomies, a feature present also in the previously published case and, hence, probably characteristic of these tumours. We could also analyse cytogenetically a subsequent recurrent tumour, phenotypically an anaplastic ependymoma, but exhibiting a pattern of monosomies largely similar to that found in the primary tumour, allowing a first insight into the genetic events involved also in disease progression.