WOS

Permanent URI for this collectionhttps://hdl.handle.net/11443/932

Browse

Author: search.filters.author.Pamir, M. NecmettinSubject: search.filters.subject.glioblastoma

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    MEOX2 homeobox gene promotes growth of malignant gliomas
    (OXFORD UNIV PRESS INC, 2022-01-01) Schoenrock, Anna; Heinzelmann, Elisa; Steffl, Bianca; Demirdizen, Engin; Narayanan, Ashwin; Krunic, Damir; Baehr, Marion; Park, Jong-Whi; Schmidt, Claudia; Oezduman, Koray; Pamir, M. Necmettin; Wick, Wolfgang; Bestvater, Felix; Weichenhan, Dieter; Plass, Christoph; Taranda, Julian; Mall, Moritz; Turcan, Sevin
    Background Glioblastoma (GBM) is an aggressive tumor that frequently exhibits gain of chromosome 7, loss of chromosome 10, and aberrantly activated receptor tyrosine kinase signaling pathways. Previously, we identified Mesenchyme Homeobox 2 (MEOX2), a gene located on chromosome 7, as an upregulated transcription factor in GBM. Overexpressed transcription factors can be involved in driving GBM. Here, we aimed to address the role of MEOX2 in GBM. Methods Patient-derived GBM tumorspheres were used to constitutively knockdown or overexpress MEOX2 and subjected to in vitro assays including western blot to assess ERK phosphorylation. Cerebral organoid models were used to investigate the role of MEOX2 in growth initiation. Intracranial mouse implantation models were used to assess the tumorigenic potential of MEOX2. RNA-sequencing, ACT-seq, and CUT\&Tag were used to identify MEOX2 target genes. Results MEOX2 enhanced ERK signaling through a feed-forward mechanism. We identified Ser(155) as a putative ERK-dependent phosphorylation site upstream of the homeobox-domain of MEOX2. S155A substitution had a major effect on MEOX2 protein levels and altered its subnuclear localization. MEOX2 overexpression cooperated with p53 and PTEN loss in cerebral organoid models of human malignant gliomas to induce cell proliferation. Using high-throughput genomics, we identified putative transcriptional target genes of MEOX2 in patient-derived GBM tumorsphere models and a fresh frozen GBM tumor. Conclusions We identified MEOX2 as an oncogenic transcription regulator in GBM. MEOX2 increases proliferation in cerebral organoid models of GBM and feeds into ERK signaling that represents a core signaling pathway in GBM.
  • 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.