High specificity of BCL11B and GLG1 for EWSR1-FLI1 and EWSR1-ERG positive Ewing sarcoma

Ewing sarcoma (EwS) is an aggressive cancer displaying an undifferentiated small-round-cell histomorphology that can be easily confused with a broad spectrum of differential diagnoses. Using comparative transcriptomics and immunohistochemistry (IHC), we previously identified BCL11B and GLG1 as potential specific auxiliary IHC markers for EWSR1-FLI1-positive EwS. Herein, we aimed at validating the specificity of both markers in a far larger and independent cohort of EwS (including EWSR1-ERG-positive cases) and differential diagnoses. Furthermore, we evaluated their intra-tumoral expression heterogeneity. Thus, we stained tissue microarrays from 133 molecularly confirmed EwS cases and 320 samples from morphological mimics, as well as a series of patient-derived xenograft (PDX) models for BCL11B, GLG1, and CD99, and systematically assessed the immunoreactivity and optimal cut-offs for each marker. These analyses demonstrated that high BCL11B and/or GLG1 immunoreactivity in CD99-positive cases had a specificity of 97.5% and an accuracy of 87.4% for diagnosing EwS solely by IHC, and that the markers were expressed by EWSR1-ERG-positive EwS. Only little intra-tumoral heterogeneity in immunoreactivity was observed for differential diagnoses. These results indicate that BCL11B and GLG1 may help as specific auxiliary IHC markers in diagnosing EwS in conjunction with CD99, especially if confirmatory molecular diagnostics are not available.Barbara und Hubertus Trettner foundationDeutsche Forschungsgemeinschaft DFG 391665916Deutsche Stiftung fur junge Erwachsene mit KrebsDr. Leopold und Carmen Ellinger foundationDr. Rolf M. Schwiete foundationDr. Rudolf und Brigitte Zenner StiftungFriedrich-Baur foundationGerman Cancer Aid DKH-70112257German Cancer Aid DKH-108128German Cancer Aid DKH-70112018German Cancer Aid DKH-70113421

Endoglin and MMP14 contribute to Ewing sarcoma spreading by modulation of cell-matrix interactions

Endoglin (ENG) is a mesenchymal stem cell (MSC) marker typically expressed by active endothelium. This transmembrane glycoprotein is shed by matrix metalloproteinase 14 (MMP14). Our previous work demonstrated potent preclinical activity of first-in-class anti-ENG antibody-drug conjugates as a nascent strategy to eradicate Ewing sarcoma (ES), a devastating rare bone/soft tissue cancer with a putative MSC origin. We also defined a correlation between ENG and MMP14 expression in ES. Herein, we show that ENG expression is significantly associated with a dismal prognosis in a large cohort of ES patients. Moreover, both ENG/MMP14 are frequently expressed in primary ES tumors and metastasis. To deepen in their functional relevance in ES, we conducted transcriptomic and proteomic profiling of in vitro ES models that unveiled a key role of ENG and MMP14 in cell mechano-transduction. Migration and adhesion assays confirmed that loss of ENG disrupts actin filament assembly and filopodia formation, with a concomitant effect on cell spreading. Furthermore, we observed that ENG regulates cell-matrix interaction through activation of focal adhesion signaling and protein kinase C expression. In turn, loss of MMP14 contributed to a more adhesive phenotype of ES cells by modulating the transcriptional extracellular matrix dynamics. Overall, these results suggest that ENG and MMP14 exert a significant role in mediating correct spreading machinery of ES cells, impacting the aggressiveness of the disease.E.A.’s laboratory is supported by ISCIII-FEDER (PI20/00003), CIBERONC (CB16/12/00361), PAIDI-Junta de Andalucía (P18-RT-735), Fundación CRIS Contra el Cáncer, Asociación Candela Riera and Asociación Pablo Ugarte. A.T.A. is supported by Juan de la Cierva Incorporación fellowship (IJC-2018-036767-I); P.P.-C. is sponsored by the Fundación María García Estrada. J.O.-P is supported by Ph.D. Grant Plan Propio from the University of Seville. J.D.-M is supported by CIBERONC (CB16/12/00361). C.S.-A. is supported by the European Social Fund and the Junta de Andalucía (Talento Doctores 2020, DOC_01473). This work was supported by grants from the Consejería de Salud (Junta de Andalucía, grants No PI-0036-2017, PI-0040-2017, and PI-0061-2020) awarded to J.D.-M, A.T.A. and C. S.-A., respectively. This work was also supported by the GEIS-Fundación Mari Paz Jiménez Casado (IV beca trienal) granted to J.D.-M, the 13ª GEIS-Beca Buesa granted to A.T.A. and CRIS (Cancer Research Innovation Spain) granted to J.D.-M and E.A. The laboratory of T.G.P.G. is supported by the Barbara and Wilfried Mohr Foundation. The lab of J.A. is supported by the Instituto de Salud Carlos III (ISCIII), grant number PI20CIII/00020; Asociación Pablo Ugarte, grant numbers TRPV205/18, TPI-M 1149/13; Asociación Candela Riera; Asociación Todos Somos Iván & Fundación Sonrisa de Alex, grant reference: TVP333-19.S

Biology-driven targeted therapy of pediatric soft-tissue and bone tumors: current opportunities and future challenges

Recent advances in the understanding of the biological basis of pediatric soft-tissue and bone tumors, especially owing to the advent of “omics” technologies, have led to an exponential increase in the current knowledge on the genetic and cellular patho-mechanisms that drive these diseases. This offers the unprecedented opportunity to develop and implement targeted therapies such as monoclonal antibodies, small molecules, oncolytic viruses, and immunotherapies in standard and/or personalized treatment regimens. However, to date only a few examples document a successful translation of discoveries from the bench to the bedside. Recent international expert congresses such as the “Pediatric Cancer Translational Genomics” conference (Phoenix, Arizona, 2012), the ESF-EMBO workshop on “Molecular Biology and Innovative Therapies in Sarcomas” (Pultusk, Poland, 2012), and the AACR special meeting on “Pediatric Cancer at the Crossroads – Translating Discovery into Improved Outcomes” (San Diego, California, 2013) further emphasize the urgent need for a more rapid and especially more successful translational process. Hence, we strongly believe that a Frontiers Research Topic aiming at this aspect would fit just in time and that it would have great potential to receive numerous contributions of outstanding experts of the field. The proposed Frontiers Research Topic shall provide a platform for active and interdisciplinary discussion, summarize current state-of-the-art knowledge on all basic research and translational aspects in pediatric soft-tissue and bone tumors, and offer new perspectives of how to further promote and accelerate the translational process. We welcome high-quality original research articles, brief reports, as well as opinion, hypothesis, and review articles, and especially encourage submissions from early-career scientists

Transcriptional Programs Define Intratumoral Heterogeneity of Ewing Sarcoma at Single-Cell Resolution

EWSR1-FLI1, the chimeric oncogene specific for Ewing sarcoma (EwS), induces a cascade of signaling events leading to cell transformation. However, it remains elusive how genetically homogeneous EwS cells can drive the heterogeneity of transcriptional programs. Here, we combine independent component analysis of single-cell RNA sequencing data from diverse cell types and model systems with time-resolved mapping of EWSR1-FLI1 binding sites and of open chromatin regions to characterize dynamic cellular processes associated with EWSR1-FLI1 activity. We thus define an exquisitely specific and direct enhancer-driven EWSR1-FLI1 program. In EwS tumors, cell proliferation and strong oxidative phosphorylation metabolism are associated with a well-defined range of EWSR1-FLI1 activity. In contrast, a subpopulation of cells from below and above the intermediary EWSR1-FLI1 activity is characterized by increased hypoxia. Overall, our study reveals sources of intratumoral heterogeneity within EwS tumors.ISSN:2666-3864ISSN:2211-124

High Specificity of BCL11B and GLG1 for EWSR1-FLI1 and EWSR1-ERG Positive Ewing Sarcoma

Ewing sarcoma (EwS) is an aggressive cancer displaying an undifferentiated small-round-cell histomorphology that can be easily confused with a broad spectrum of differential diagnoses. Using comparative transcriptomics and immunohistochemistry (IHC), we previously identified BCL11B and GLG1 as potential specific auxiliary IHC markers for EWSR1-FLI1-positive EwS. Herein, we aimed at validating the specificity of both markers in a far larger and independent cohort of EwS (including EWSR1-ERG-positive cases) and differential diagnoses. Furthermore, we evaluated their intra-tumoral expression heterogeneity. Thus, we stained tissue microarrays from 133 molecularly confirmed EwS cases and 320 samples from morphological mimics, as well as a series of patient-derived xenograft (PDX) models for BCL11B, GLG1, and CD99, and systematically assessed the immunoreactivity and optimal cut-offs for each marker. These analyses demonstrated that high BCL11B and/or GLG1 immunoreactivity in CD99-positive cases had a specificity of 97.5% and an accuracy of 87.4% for diagnosing EwS solely by IHC, and that the markers were expressed by EWSR1-ERG-positive EwS. Only little intra-tumoral heterogeneity in immunoreactivity was observed for differential diagnoses. These results indicate that BCL11B and GLG1 may help as specific auxiliary IHC markers in diagnosing EwS in conjunction with CD99, especially if confirmatory molecular diagnostics are not available

Search for the standard model Higgs boson in e+ e- collisions at s**(1/2) approximately = 192-GeV - 209-GeV

A search for the Standard Model Higgs boson has been performed with the OPAL detector at LEP based on the full data sample collected at sqrt(s) = 192-209 GeV in 1999 and 2000, corresponding to an integrated luminosity of approximately 426 pb-1. The data are examined for their consistency with the background-only hypothesis and various Higgs boson mass hypotheses. A lower bound of 109.7 GeV is obtained on the Higgs boson mass at the 95% confidence level. At higher masses, the data are consistent with both the background and the signal-plus-background hypotheses.Comment: 19 pages, 7 figures, Accepted by Physics Letters