24 research outputs found

    The transcriptional landscape of Shh medulloblastoma

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    © The Author(s) 2021. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Sonic hedgehog medulloblastoma encompasses a clinically and molecularly diverse group of cancers of the developing central nervous system. Here, we use unbiased sequencing of the transcriptome across a large cohort of 250 tumors to reveal differences among molecular subtypes of the disease, and demonstrate the previously unappreciated importance of non-coding RNA transcripts. We identify alterations within the cAMP dependent pathway (GNAS, PRKAR1A) which converge on GLI2 activity and show that 18% of tumors have a genetic event that directly targets the abundance and/or stability of MYCN. Furthermore, we discover an extensive network of fusions in focally amplified regions encompassing GLI2, and several loss-of-function fusions in tumor suppressor genes PTCH1, SUFU and NCOR1. Molecular convergence on a subset of genes by nucleotide variants, copy number aberrations, and gene fusions highlight the key roles of specific pathways in the pathogenesis of Sonic hedgehog medulloblastoma and open up opportunities for therapeutic intervention.info:eu-repo/semantics/publishedVersio

    Failure of human rhombic lip differentiation underlies medulloblastoma formation

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    Medulloblastoma (MB) comprises a group of heterogeneous paediatric embryonal neoplasms of the hindbrain with strong links to early development of the hindbrain 1–4. Mutations that activate Sonic hedgehog signalling lead to Sonic hedgehog MB in the upper rhombic lip (RL) granule cell lineage 5–8. By contrast, mutations that activate WNT signalling lead to WNT MB in the lower RL 9,10. However, little is known about the more commonly occurring group 4 (G4) MB, which is thought to arise in the unipolar brush cell lineage 3,4. Here we demonstrate that somatic mutations that cause G4 MB converge on the core binding factor alpha (CBFA) complex and mutually exclusive alterations that affect CBFA2T2, CBFA2T3, PRDM6, UTX and OTX2. CBFA2T2 is expressed early in the progenitor cells of the cerebellar RL subventricular zone in Homo sapiens, and G4 MB transcriptionally resembles these progenitors but are stalled in developmental time. Knockdown of OTX2 in model systems relieves this differentiation blockade, which allows MB cells to spontaneously proceed along normal developmental differentiation trajectories. The specific nature of the split human RL, which is destined to generate most of the neurons in the human brain, and its high level of susceptible EOMES +KI67 + unipolar brush cell progenitor cells probably predisposes our species to the development of G4 MB

    Management of adjuvant settings for Stage III melanoma patients in France prior to checkpoint inhibitors: epidemiological data from the RIC-Mel database

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    International audienceBackground: Targeted therapies such as BRAF and MEK inhibitors and immunotherapies have been made available to treat melanoma.Objectives: To provide an overview of the management of the French Stage III melanoma population after complete lymph node resection prior to new adjuvant therapies.Materials and methods: A subgroup data analysis.Results: Data from 1,835 patients were analysed (15.58% Stage IIIA, 39.24% Stage IIIB, 43.92% Stage IIIC and 1.25% Stage IIID). Superficial spreading melanoma was the most frequent (70.98% in Stage IIIA for whom mutation analysis was performed; BRAF mutation was identified in up to 62% Stage IIIA patients). Sentinel lymph node biopsy was performed in 88.46% of Stage IIIA patients, 42.36% of Stage IIIB, 53.97% of Stage IIIC and 34.78% of Stage IIID. Up to 80% of Stage IIIA patients had no adjuvant treatment follow-up. Ulceration (p = 0.004; RR: 2.98; 95% CI: 1.4-6.3) and age at diagnosis (p = 0.0002; RR: 1.04; 95% CI: 1.02-1.06) were significant predictive factors for survival. Adjuvant interferon-α was administered in up to 13.04% of Stage IIID patients.Conclusion: Only a small number of Stage III melanoma patients were treated with interferon-α in adjuvant settings. New adjuvant therapies are currently having an effect on clinical practice in France, increasing survival and decreasing cost

    Multiwinner Approval Rules as Apportionment Methods

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    We establish a link between multiwinner elections and apportionment problems by showing how approval-based multiwinner election rules can be interpreted as methods of apportionment. We consider several multi-winner rules and observe that some, but not all, of them induce apportionment methods that are well established in the literature and in the actual practice of proportional representation. For instance, we show that Proportional Approval Voting induces the D'Hondt method and that Monroe's rule induces the largest remainder method. We also consider properties of apportionment methods and exhibit multiwinner rules that induce apportionment methods satisfying these properties

    Multiwinner approval rules as apportionment methods

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    International audienceDuring the first round of the 2012 French presidential election, participants in an in situ experiment were invited to vote according to “evaluative voting”, which involves rating the candidates using a numerical scale. Various scales were used: (0,1), (-1,0,1), (0,1,2), and (0,1,
,20). The paper studies scale calibration effects, i.e., how individual voters adapt to the scale, leading to possibly different election outcomes. The data show that scales are not linearly equivalent, even if individual ordinal preferences are not inconsistent. Scale matters, notably because of the symbolic power of negative grades, which does not affect all candidates uniformly
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