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A polyphenotypic malignant paediatric brain tumour presenting a MN1-PATZ1 fusion, no epigenetic similarities with CNS High-Grade Neuroepithelial Tumour with MN1 Alteration (CNS HGNET-MN1) and related to PATZ1-fused sarcomas Central nervous system high-grade neuroepithelial tumour with I MN1 i alteration (CNS HGNET-MN1) is a brain tumour methylation class that has recently been identified, based on (epi)genetic profiles of a large CNS-PNETs cohort [1]. In addition, the tumour exhibited a polyphenotypic immunoprofile, a feature described in CNS HGNET-MN1 [4] but also pointing toward other tumour entities, such as atypical teratoid rhabdoid tumour or I CIC-NUTM1 i sarcoma [5]. [Extracted from the article]

Aims: DNA methylation‐based central nervous system (CNS) tumour classification has identified numerous molecularly distinct tumour types, and clinically relevant subgroups among known CNS tumour entities that were previously thought to represent homogeneous diseases. Our study aimed at characterizing a novel, molecularly defined variant of glioneuronal CNS tumour. Patients and methods: DNA methylation profiling was performed using the Infinium MethylationEPIC or 450 k BeadChip arrays (Illumina) and analysed using the 'conumee' package in R computing environment. Additional gene panel sequencing was also performed. Tumour samples were collected at the German Cancer Research Centre (DKFZ) and provided by multinational collaborators. Histological sections were also collected and independently reviewed. Results: Genome‐wide DNA methylation data from >25 000 CNS tumours were screened for clusters separated from established DNA methylation classes, revealing a novel group comprising 31 tumours, mainly found in paediatric patients. This DNA methylation‐defined variant of low‐grade CNS tumours with glioneuronal differentiation displays recurrent monosomy 14, nuclear clusters within a morphology that is otherwise reminiscent of oligodendroglioma and other established entities with clear cell histology, and a lack of genetic alterations commonly observed in other (paediatric) glioneuronal entities. Conclusions: DNA methylation‐based tumour classification is an objective method of assessing tumour origins, which may aid in diagnosis, especially for atypical cases. With increasing sample size, methylation analysis allows for the identification of rare, putative new tumour entities, which are currently not recognized by the WHO classification. Our study revealed the existence of a DNA methylation‐defined class of low‐grade glioneuronal tumours with recurrent monosomy 14, oligodendroglioma‐like features and nuclear clusters. [ABSTRACT FROM AUTHOR]

I. El Ayachi, N. Baeza, C. Fernandez, C. Colin, D. Scavarda, P. Pesheva and D. Figarella-Branger (2010) Neuropathology and Applied Neurobiology 36, 399–410 KIAA0510, the 3′-untranslated region of the tenascin-R gene, and tenascin-R are overexpressed in pilocytic astrocytomas Aims: Studying the molecules and signalling pathways regulating glioma invasiveness is a major challenge because these processes determine malignancy, progression, relapse and prognosis. We took advantage of our previous study focused on genes that were critical in tumour invasion to further study here an unknown sequence, referred to as KIAA0510, the chromosomal location of which was 1q25, described as a 5596-bp long mRNA and that we found to be significantly overexpressed in pilocytic astrocytomas compared with glioblastomas. Methods and results: Using in silico analysis as well as Polymerase chain reaction techniques, we decipher the full genomic characterization of the KIAA0510 sequence and demonstrate that KIAA0510 constitutes the 3′-untranslated region of tenascin-R gene. We have clearly confirmed the overexpression of tenascin-R in pilocytic astrocytomas vs. glioblastomas at mRNA and protein levels. We also analysed a large series of various brain tumours and found that in the group of astrocytic tumours, tenascin-R expression decreased with malignancy, whereas oligodendrogliomas sometimes retained a high level of tenascin-R even in high-grade tumours. Gangliogliomas strongly expressed tenascin-R too. In contrast, ependymomas and meningiomas were negative. In normal brain, tenascin-R was exclusively expressed by normal oligodendrocytes and subsets of neurones during post-natal development and in adulthood, where it could differentially affect cellular adhesiveness and/or differentiation. Conclusion: KIAA0510, the 3′-untranslated region of the tenascin-R gene, and tenascin-R are overexpressed in pilocytic astrocytomas. Gangliogliomas shared with pilocytic astrocytomas strong tenascin-R expression. Whether tenascin-R overexpression negatively influences brain invasion remains to be determined. [ABSTRACT FROM AUTHOR]

M. Civatte, C. Bartoli, N. Schleinitz, B. Chetaille, J. F. Pellissier and D. Figarella-Branger (2004)Neuropathology and Applied Neurobiology, doi: 10.1111/j.1365-2990.2004.00591.xExpression of theβ chemokines CCL3, CCL4, CCL5 and their receptors in idiopathic inflammatory myopathiesThe idiopathic inflammatory myopathies (IIM) are a group of autoimmune diseases characterized by chronic lymphocytic and macrophagic infiltration in muscle. Because the mechanism for recruitment of these cells probably involves chemokines, we focused on the study of the expression pattern of someβ chemokines and receptors because it may provide a basis for selective immunotherapy. The expression of CCL3 (MIP-1α), CCL4 (MIP-1β), CCL5 (RANTES) and their main receptors (CCR1 and CCR5) was studied by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry in a series of 16 IIM and five controls (four normal muscles and one tonsil). Except for CCL5, strong expression was observed by RT-PCR with all molecules in all IIM subtypes in comparison to control muscle. Immunohistochemistry revealed diffuse CCL4 expression in all vessels in dermatomyositis. In both polymyositis and sporadic inclusion body myositis (s-IBM) it was restricted to vessels in the vicinity of inflammatory exudates. CCL5 expression was low, restricted to a few inflammatory cells in all IIM; CCR1 expression was mainly restricted to macrophages and s-IBM endothelial cells, whereas CCR5 was localized in inflammatory cells invading non-necrotic muscle fibres. Expressions of both receptors were also recorded in few muscle fibres. In conclusion, the upregulation ofβ chemokines and receptors in IIM and their differential expression by various cells may contribute to chronic inflammation and to the peculiar distribution of inflammatory exudates in these diseases. [ABSTRACT FROM AUTHOR]