Araştırma Çıktıları

Permanent URI for this communityhttps://hdl.handle.net/11443/931

Browse

Author: search.filters.author.Carrion-Grant, GeneiveHas files: Yes

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Integrated genomic characterization of IDH1-mutant glioma malignant progression
    (NATURE PUBLISHING GROUP, 2016-01-01) Bai, Hanwen; Harmanci, Akdes Serin; Erson-Omay, E. Zeynep; Li, Jie; Coskun, Sueleyman; Simon, Matthias; Krischek, Boris; Ozduman, Koray; Omay, S. Buelent; Sorensen, Eric A.; Turcan, Sevin; Bakirciglu, Mehmet; Carrion-Grant, Geneive; Murray, Phillip B.; Clark, Victoria E.; Ercan-Sencicek, A. Gulhan; Knight, James; Sencar, Leman; Altinok, Selin; Kaulen, Leon D.; Guelez, Burcu; Timmer, Marco; Schramm, Johannes; Mishra-Gorur, Ketu; Henegariu, Octavian; Moliterno, Jennifer; Louvi, Angeliki; Chan, Timothy A.; Tannheimer, Stacey L.; Pamir, M. Necmettin; Vortmeyer, Alexander O.; Bilguvar, Kaya; Yasuno, Katsuhito; Guenel, Murat
    Gliomas represent approximately 30\% of all central nervous system tumors and 80\% of malignant brain tumors(1). To understand the molecular mechanisms underlying the malignant progression of low-grade gliomas with mutations in IDH1 (encoding isocitrate dehydrogenase 1), we studied paired tumor samples from 41 patients, comparing higher-grade, progressed samples to their lower-grade counterparts. Integrated genomic analyses, including whole-exome sequencing and copy number, gene expression and DNA methylation profiling, demonstrated nonlinear clonal expansion of the original tumors and identified oncogenic pathways driving progression. These include activation of the MYC and RTK-RAS-PI3K pathways and upregulation of the FOXM1- and E2F2-mediated cell cycle transitions, as well as epigenetic silencing of developmental transcription factor genes bound by Polycomb repressive complex 2 in human embryonic stem cells. Our results not only provide mechanistic insight into the genetic and epigenetic mechanisms driving glioma progression but also identify inhibition of the bromodomain and extraterminal (BET) family as a potential therapeutic approach.
  • Thumbnail Image
    Item
    Somatic POLE mutations cause an ultramutated giant cell high-grade glioma subtype with better prognosis
    (OXFORD UNIV PRESS INC, 2015-01-01) Erson-Omay, E. Zeynep; Caglayan, Ahmet Okay; Schultz, Nikolaus; Weinhold, Nils; Omay, S. Bulent; Ozduman, Koray; Koksal, Yavuz; Li, Jie; Harmanci, Akdes Serin; Clark, Victoria; Carrion-Grant, Geneive; Baranoski, Jacob; Caglar, Caner; Barak, Tanyeri; Coskun, Suleyman; Baran, Burcin; Kose, Dogan; Sun, Jia; Bakircioglu, Mehmet; Gunel, Jennifer Moliterno; Pamir, M. Necmettin; Mishra-Gorur, Ketu; Bilguvar, Kaya; Yasuno, Katsuhito; Vortmeyer, Alexander; Huttner, Anita J.; Sander, Chris; Gunel, Murat
    Background. Malignant high-grade gliomas (HGGs), including the most aggressive form, glioblastoma multiforme, show significant clinical and genomic heterogeneity. Despite recent advances, the overall survival of HGGs and their response to treatment remain poor. In order to gain further insight into disease pathophysiology by correlating genomic landscape with clinical behavior, thereby identifying distinct HGG molecular subgroups associated with improved prognosis, we performed a comprehensive genomic analysis. Methods. We analyzed and compared 720 exome-sequenced gliomas (136 from Yale, 584 from The Cancer Genome Atlas) based on their genomic, histological, and clinical features. Results. We identified a subgroup of HGGs (6 total, 4 adults and 2 children) that harbored a statistically significantly increased number of somatic mutations (mean = 9257.3 vs 76.2, P = .002). All of these ``ultramutated{''} tumors harbored somatic mutations in the exonuclease domain of the polymerase epsilon gene (POLE), displaying a distinctive genetic profile, characterized by genomic stability and increased C-to-A transversions. Histologically, they all harbored multinucleated giant or bizarre cells, some with predominant infiltrating immune cells. One adult and both pediatric patients carried homozygous germline mutations in the mutS homolog 6 (MSH6) gene. In adults, POLE mutations were observed in patients younger than 40 years and were associated with a longer progression-free survival. Conclusions. We identified a genomically, histologically, and clinically distinct subgroup of HGGs that harbored somatic POLE mutations and carried an improved prognosis. Identification of distinctive molecular and pathological HGG phenotypes has implications not only for improved classification but also for potential targeted treatments.