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Item Oligosarcomas, IDH-mutant are distinct and aggressive(SPRINGER, 2022-01-01) Suwala, Abigail K.; Felix, Marius; Friedel, Dennis; Stichel, Damian; Schrimpf, Daniel; Hinz, Felix; Hewer, Ekkehard; Schweizer, Leonille; Dohmen, Hildegard; Pohl, Ute; Staszewski, Ori; Korshunov, Andrey; Stein, Marco; Wongsurawat, Thidathip; Cheunsuacchon, Pornsuk; Sathornsumetee, Sith; Koelsche, Christian; Turner, Clinton; Le Rhun, Emilie; Muhlebner, Angelika; Schucht, Philippe; Ozduman, Koray; Ono, Takahiro; Shimizu, Hiroaki; Prinz, Marco; Acker, Till; Herold-Mende, Christel; Kessler, Tobias; Wick, Wolfgang; Capper, David; Wesseling, Pieter; Sahm, Felix; von Deimling, Andreas; Hartmann, Christian; Reuss, David E.Oligodendrogliomas are defined at the molecular level by the presence of an IDH mutation and codeletion of chromosomal arms 1p and 19q. In the past, case reports and small studies described gliomas with sarcomatous features arising from oligodendrogliomas, so called oligosarcomas. Here, we report a series of 24 IDH-mutant oligosarcomas from 23 patients forming a distinct methylation class. The tumors were recurrences from prior oligodendrogliomas or developed de novo. Precursor tumors of 12 oligosarcomas were histologically and molecularly indistinguishable from conventional oligodendrogliomas. Oligosarcoma tumor cells were embedded in a dense network of reticulin fibers, frequently showing p53 accumulation, positivity for SMA and CALD1, loss of OLIG2 and gain of H3K27 trimethylation (H3K27me3) as compared to primary lesions. In 5 oligosarcomas no 1p/19q codeletion was detectable, although it was present in the primary lesions. Copy number neutral LOH was determined as underlying mechanism. Oligosarcomas harbored an increased chromosomal copy number variation load with frequent CDKN2A/B deletions. Proteomic profiling demonstrated oligosarcomas to be highly distinct from conventional CNS WHO grade 3 oligodendrogliomas with consistent evidence for a smooth muscle differentiation. Expression of several tumor suppressors was reduced with NF1 being lost frequently. In contrast, oncogenic YAP1 was aberrantly overexpressed in oligosarcomas. Panel sequencing revealed mutations in NF1 and TP53 along with IDH1/2 and TERT promoter mutations. Survival of patients was significantly poorer for oligosarcomas as first recurrence than for grade 3 oligodendrogliomas as first recurrence. These results establish oligosarcomas as a distinct group of IDH-mutant gliomas differing from conventional oligodendrogliomas on the histologic, epigenetic, proteomic, molecular and clinical level. The diagnosis can be based on the combined presence of (a) sarcomatous histology, (b) IDH-mutation and (c) TERT promoter mutation and/or 1p/19q codeletion, or, in unresolved cases, on its characteristic DNA methylation profile.Item Molecular modelling of the FOXO4-TP53 interaction to design senolytic peptides for the elimination of senescent cancer cells(ELSEVIER, 2021-01-01) Le, Hillary H.; Cinaroglu, Suleyman S.; Manalo, Elise C.; Ors, Aysegul; Gomes, Michelle M.; Sahbaz, Burcin Duan; Bonic, Karla; Marmolejo, Carlos A. Origel; Quentel, Arnaud; Plaut, Justin S.; Kawashima, Taryn E.; Ozdemir, E. Sila; Malhotra V, Sanjay; Ahiska, Yavuz; Sezerman, Ugur; Akcapinar, Gunseli Bayram; Saldivar, Joshua C.; Timucin, Emel; Fischer, Jared M.Background: Senescent cells accumulate in tissues over time as part of the natural ageing process and the removal of senescent cells has shown promise for alleviating many different age-related diseases in mice. Cancer is an age-associated disease and there are numerous mechanisms driving cellular senescence in cancer that can be detrimental to recovery. Thus, it would be beneficial to develop a senolytic that acts not only on ageing cells but also senescent cancer cells to prevent cancer recurrence or progression. Methods: We used molecular modelling to develop a series of rationally designed peptides to mimic and target FOXO4 disrupting the FOXO4-TP53 interaction and releasing TP53 to induce apoptosis. We then tested these peptides as senolytic agents for the elimination of senescent cells both in cell culture and in vivo. Findings: Here we show that these peptides can act as senolytics for eliminating senescent human cancer cells both in cell culture and in orthotopic mouse models. We then further characterized one peptide, ES2, showing that it disrupts FOXO4-TP53 foci, activates TP53 mediated apoptosis and preferentially binds FOXO4 compared to TP53. Next, we show that intratumoural delivery of ES2 plus a BRAF inhibitor results in a significant increase in apoptosis and a survival advantage in mouse models of melanoma. Finally, we show that repeated systemic delivery of ES2 to older mice results in reduced senescent cell numbers in the liver with minimal toxicity. Interpretation: Taken together, our results reveal that peptides can be generated to specifically target and eliminate FOXO4+ senescent cancer cells, which has implications for eradicating residual disease and as a combination therapy for frontline treatment of cancer. Funding: This work was supported by the Cancer Early Detection Advanced Research Center at Oregon Health \& Science University. (C) 2021 The Authors. Published by Elsevier B.V.Item Lack of hotspot mutations other than TP53 R249S in aflatoxin B1 associated hepatocellular carcinoma(WALTER DE GRUYTER GMBH, 2020-01-01) Akyerli, Cemaliye B.; Yuksel, Sirin K.; Yakicier, M. CengizObjective: Despite the recent advances in diagnosis and treatment of hepatocellular carcinoma (HCC), it is still a major health problem. Therefore, understanding the molecular mechanism is very important. Our aim is to investigate the molecular basis of aflatoxin B1 (AFB1) induced HCC other than the hotspot TP53 p.Arg249Ser (c.747G>T) (R249S) mutation. Methods: 525 genes previously reported to be involved in carcinogenesis with mutations in different cancer types were analyzed by next generation sequencing for 525 cancer-gene panel (Roche/NimbleGen) in one tumor sample (T29) and one cell line (MAHLAVU) carrying TP53 R249S mutation. Additionally, ARID2 and BCORL1 genes were analyzed by Sanger sequencing for MAHLAVU and Primary Liver Carcinoma/Poliomyelitis Research Foundation/5 (PLC/PRF/5) cell lines. Results: No other common gene mutations were found in the analyzed T29 and MAHLAVU samples and also no genetic variation possibly associated with AFB1 was detected in PLC/PRF/5 cell line and 68 COSMIC HCC samples. Likewise, no pathogenic mutation was detected in ARID2 and BCORL1 genes of MAHLAVU and PLC/PRF/5 cell lines. Conclusion: No fingerprint mutations were detected in the analyzed genes. To the best of our knowledge, other hotspot mutations appear to be absent if not at a very low frequency in HCC carrying TP53 R249S mutation.