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Glial-lineage malignancies (gliomas) recurrently mutate and/or delete the master regulators of apoptosis p53 and/or p16/CDKN2A, undermining apoptosis-intending (cytotoxic) treatments. By contrast to disrupted p53/p16, glioma cells are live-wired with the master transcription factor circuits that specify and drive glial lineage fates: these transcription factors activate early-glial and replication programs as expected, but fail in their other usual function of forcing onward glial lineage-maturation-late-glial genes have constitutively "closed" chromatin requiring chromatin-remodeling for activation-glioma-genesis disrupts several epigenetic components needed to perform this work, and simultaneously amplifies repressing epigenetic machinery instead. Pharmacologic inhibition of repressing epigenetic enzymes thus allows activation of late-glial genes and terminates glioma self-replication (self-replication = replication without lineage-maturation), independent of p53/p16/apoptosis. Lineage-specifying master transcription factors therefore contrast with p53/p16 in being enriched in self-replicating glioma cells, reveal a cause-effect relationship between aberrant epigenetic repression of late-lineage programs and malignant self-replication, and point to specific epigenetic targets for noncytotoxic glioma-therapy.

Includes the legends for Suppl. Table S1-S5.

Suppl. Table S4 shows "MAPKi combinations chosen based on low estimated IC50s and pharmaceutical company in consideration of future clinical studies".

Suppl. Figure S1 shows "Initial MAPKi screen using metabolic activity as readout". Suppl. Figure S2 shows "Western blot validation of MAPK pathway alterations in HEK293T cells". Suppl. Figure S3 shows "Dose-response curves of MAPKi combination treatment in DKFZ-BT66 pDIPZ-CMV cells". Suppl. Figure S4 shows "Dose response curves of MAPKi combination treatment in BT 40 pDIPZ CMV cells". Suppl. Figure S5 shows "Isobolograms of MAPKi combination treatment in DKFZ-BT66 pDIPZ-CMV and BT-40 pDIPZ-CMV cells"

Synergistic effects of trametinib and RG7388 treatment.

Mutant IDH1 reduces expansion of stem cells in vivo

Uni-and multivariate Analysis of IL1B and SASP in PA cohort

Solid papillary carcinoma with reverse polarity (SPCRP) is a rare breast cancer subtype with an obscure etiology. In this study, we sought to describe its unique histopathologic features and to identify the genetic alterations that underpin SPCRP using massively parallel whole-exome and targeted sequencing. The morphologic and immunohistochemical features of SPCRP support the invasive nature of this subtype. Ten of 13 (77%) SPCRPs harbored hotspot mutations at R172 of the isocitrate dehydrogenase IDH2, of which 8 of 10 displayed concurrent pathogenic mutations affecting PIK3CA or PIK3R1. One of the IDH2 wild-type SPCRPs harbored a TET2 Q548* truncating mutation coupled with a PIK3CA H1047R hotspot mutation. Functional studies demonstrated that IDH2 and PIK3CA hotspot mutations are likely drivers of SPCRP, resulting in its reversed nuclear polarization phenotype. Our results offer a molecular definition of SPCRP as a distinct breast cancer subtype. Concurrent IDH2 and PIK3CA mutations may help diagnose SPCRP and possibly direct effective treatment. Cancer Res; 76(24); 7118–29. ©2016 AACR.

Supplemental Table Legend

IGFBP1 mRNA expression after treatment with trametinib or IGFBP1 knockdown.

Maintenance of RG7388 resistance after withdrawal of permanent RG7388 exposure.

Document containing figures illustrating results of Sanger sequencing, DNA methylation profiling of SPCRPs, the analysis of IDH2 expression in non-malignant breast epithelial cells and its downstream effects, and tables describing the antibodies used for immunohistochemical analysis, the alterations surveyed by the SNaPshot genotyping assay, Sanger sequencing primers, and statistics and results of the massively parallel sequencing analyses.

Document containing methods on whole exome and targeted massively parallel sequencing analysis, 2-hydroxyglutarate (2HG) assay of cell lines, methylation profiling, and supplementary references.

IGFBP1 expression in glioblastoma cell lines and after occurrence of RG7388 resistance.

Effects of short-term RG7388 treatment in glioblastoma cell lines.

Legends for Supplementary Figures S1-S5

Supplementary Methods

In vivo toxicity and on-target efficacy. 


Lists of primers, antibodies, miR and survival, Supplemental Table 1.

Synergistic effects of RG7388 treatment and radiotherapy on inhibition of proliferation.

Human astrocytomas and oligodendrogliomas are defined by mutations of the metabolic enzymes isocitrate dehydrogenase (IDH) 1 or 2, resulting in the production of the abnormal metabolite D-2 hydroxyglutarate. Here, we studied the effect of mutant IDH on cell proliferation and apoptosis in a glioma mouse model. Tumors were generated by inactivating Pten and p53 in forebrain progenitors and compared with tumors additionally expressing the Idh1 R132H mutation. Idh-mutant cells proliferated less in vitro and mice with Idh-mutant tumors survived significantly longer compared with Idh-wildtype mice. Comparison of miRNA and RNA expression profiles of Idh-wildtype and Idh-mutant cells and tumors revealed miR-183 was significantly upregulated in IDH-mutant cells. Idh-mutant cells were more sensitive to endoplasmic reticulum (ER) stress, resulting in increased apoptosis and thus reduced cell proliferation and survival. This was mediated by the interaction of miR-183 with the 5′ untranslated region of semaphorin 3E, downregulating its function as an apoptosis suppressor. In conclusion, we show that mutant Idh1 delays tumorigenesis and sensitizes tumor cells to ER stress and apoptosis. This may open opportunities for drug treatments targeting the miR-183–semaphorin axis.Significance:The pathologic metabolite 2-hydroxyglutarate, generated by IDH-mutant astrocytomas, sensitizes tumor cells to ER stress and delays tumorigenesis.

Figure S1: Markers of OIS in murine PA model Figure S2: Viability of DKFZ-BT66 cells under rIL1B treatment Figure S3: SASP factor protein levels in primary PAs Figure S4: Treatments of astrocytes with senolytic agents and combinations treatments of ABT-737 in DKFZ-BT66 cells

Background Dendritic cells (DC), the most potent professional antigen presenting cells capable of effective cross-presentation, have been demonstrated to license T helper cells to induce antitumor immunity in solid tumors. Specific DC subtypes are recruited to the injured brain by microglial chemokines, locally adapting to distinct transcriptional profiles. In isocitrate dehydrogenase (IDH) type 1 mutant gliomas, monocyte-derived macrophages have recently been shown to display an attenuated intratumoral antigen presentation capacity as consequence of the local accumulation of the oncometabolite R-2-hydroxyglutarate. The functionality and the contribution of DC to the IDH-mutant tumor microenvironment (TME) remains unclear. Methods Frequencies and intratumoral phenotypes of human DC in IDH-wildtype (IDHwt) and -mutant high-grade gliomas are comparatively assessed by transcriptomic and proteomic profiling. DC functionality is investigated in experimental murine glioblastomas expressing the model antigen ovalbumin. Single-cell sequencing-based pseudotime analyses and spectral flow cytometric analyses are used to profile DC states longitudinally. Results DC are present in primary and recurrent high-grade gliomas and interact with other immune cell types within the TME. In murine glioblastomas, we find an IDH-status-associated major histocompatibility class I-restricted cross-presentation of tumor antigens by DC specifically in the tumor but not in meninges or secondary lymphoid organs of tumor-bearing animals. In single-cell sequencing-based pseudotime and longitudinal spectral flow cytometric analyses, we demonstrate an IDH-status-dependent differential, exclusively microenvironmental education of DC. Conclusions Glioma-associated DCs are relevantly abundant in human IDHwt and mutant tumors. Glioma IDH mutations result in specifically educated, dysfunctional DCs via paracrine reprogramming of infiltrating monocytes, providing the basis for combinatorial immunotherapy concepts against IDH mutant gliomas.

Purpose: Gliomas are intrinsic brain tumors with a high degree of constitutive and acquired resistance to standard therapeutic modalities such as radiotherapy and alkylating chemotherapy. Glioma subtypes are recognized by characteristic mutations. Some of these characteristic mutations have shown to generate immunogenic neoepitopes suitable for targeted immunotherapy. Experimental Design: Using peptide-based ELISpot assays, we screened for potential recurrent glioma neoepitopes in MHC-humanized mice. Following vaccination, droplet-based single-cell T-cell receptor (TCR) sequencing from established T-cell lines was applied for neoepitope-specific TCR discovery. Efficacy of intraventricular TCR-transgenic T-cell therapy was assessed in a newly developed glioma model in MHC-humanized mice induced by CRISPR-based delivery of tumor suppressor–targeting guide RNAs. Results: We identify recurrent capicua transcriptional repressor (CIC) inactivating hotspot mutations at position 215 CICR215W/Q as immunogenic MHC class II (MHCII)-restricted neoepitopes. Vaccination of MHC-humanized mice resulted in the generation of robust MHCII-restricted mutation-specific T-cell responses against CICR215W/Q. Adoptive intraventricular transfer of CICR215W-specific TCR-transgenic T cells exert antitumor responses against CICR215W-expressing syngeneic gliomas. Conclusions: The integration of immunocompetent MHC-humanized orthotopic glioma models in the discovery of shared immunogenic glioma neoepitopes facilitates the identification and preclinical testing of human leukocyte antigen (HLA)-restricted neoepitope-specific TCRs for locoregional TCR-transgenic T-cell adoptive therapy.

Glioblastoma is a highly aggressive brain tumor for which there is no cure. The metabolic enzyme 6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase 4 (PFKFB4) is essential for glioblastoma stem-like cell (GSC) survival but its mode of action is unclear. Understanding the role of PFKFB4 in tumor cell survival could allow it to be leveraged in a cancer therapy. Here, we show the importance of PFKFB4 for glioblastoma growth in vivo in an orthotopic patient derived mouse model. In an evaluation of patient tumor samples of different cancer entities, PFKFB4 protein was found to be overexpressed in prostate, lung, colon, mammary and squamous cell carcinoma, with expression level correlating with tumor grade. Gene expression profiling in PFKFB4-silenced GSCs revealed a downregulation of hypoxia related genes and Western blot analysis confirmed a dramatic reduction of HIF (hypoxia inducible factor) protein levels. Through mass spectrometric analysis of immunoprecipitated PFKFB4, we identified the ubiquitin E3 ligase, F-box only protein 28 (FBXO28), as a new interaction partner of PFKFB4. We show that PFKFB4 regulates the ubiquitylation and subsequent proteasomal degradation of HIF-1α, which is mediated by the ubiquitin ligase activity of FBXO28. This newly discovered function of PFKFB4, coupled with its cancer specificity, provides a new strategy for inhibiting HIF-1α in cancer cells. ispartof: ONCOGENESIS vol:11 issue:1 ispartof: location:United States status: published

The dynamics and phenotypes of intratumoral myeloid cells during tumor progression are poorly understood. Here we define myeloid cellular states in gliomas by longitudinal single-cell profiling and demonstrate their strict control by the tumor genotype: in isocitrate dehydrogenase (IDH)-mutant tumors, differentiation of infiltrating myeloid cells is blocked, resulting in an immature phenotype. In late-stage gliomas, monocyte-derived macrophages drive tolerogenic alignment of the microenvironment, thus preventing T cell response. We define the IDH-dependent tumor education of infiltrating macrophages to be causally related to a complex re-orchestration of tryptophan metabolism, resulting in activation of the aryl hydrocarbon receptor. We further show that the altered metabolism of IDH-mutant gliomas maintains this axis in bystander cells and that pharmacological inhibition of tryptophan metabolism can reverse immunosuppression. In conclusion, we provide evidence of a glioma genotype-dependent intratumoral network of resident and recruited myeloid cells and identify tryptophan metabolism as a target for immunotherapy of IDH-mutant tumors. Platten and colleagues find that tryptophan metabolism by myeloid cells contributes to immunosuppressive microenvironment uniquely in IDH-mutant gliomas, which can be overcome by inhibiting this pathway in murine tumor models.

Herein, the design and development of a new one-pot and metal-free oxidative C-H activation/aza-Prins type cyclization of alkynylamines is reported. The scope of this method was demonstrated by the preparation of ten new pyrido[2,1-a]isoquinolines in moderate to high yields (38-92%). Furthermore, a mechanistic proposal for the alkyne aza-Prins cyclization is described based on DFT calculations.

Background Pilocytic astrocytoma (PA) is the most common pediatric brain tumor and a mitogen-activated protein kinase (MAPK)-driven disease. Oncogenic MAPK-signaling drives the majority of cells into oncogene-induced senescence (OIS). While OIS induces resistance to antiproliferative therapies, it represents a potential vulnerability exploitable by senolytic agents. Methods We established new patient-derived PA cell lines that preserve molecular features of the primary tumors and can be studied in OIS and proliferation depending on expression or repression of the SV40 large T antigen. We determined expression of anti-apoptotic BCL-2 members in these models and primary PA. Dependence of senescent PA cells on anti-apoptotic BCL-2 members was investigated using a comprehensive set of BH3 mimetics. Results Senescent PA cells upregulate BCL-XL upon senescence induction and show dependency on BCL-XL for survival. BH3 mimetics with high affinity for BCL-XL (BCL-XLi) reduce metabolic activity and induce mitochondrial apoptosis in senescent PA cells at nano-molar concentrations. In contrast, BH3 mimetics without BCL-XLi activity, conventional chemotherapy, and MEK inhibitors show no effect. Conclusions Our data demonstrate that BCL-XL is critical for survival of senescent PA tumor cells and provides proof-of-principle for the use of clinically available BCL-XL-dependent senolytics.

Pilocytic astrocytomas as well as other pediatric low-grade gliomas (pLGG) exhibit genetic events leading to aberrant activation of the MAPK pathway. The most common alterations are KIAA1549:BRAF fusions and BRAFV600E and NF1 mutations. Novel drugs targeting the MAPK pathway (MAPKi) are prime candidates for the treatment of these single-pathway diseases. We aimed to develop an assay suitable for preclinical testing of MAPKi in pLGGs with the goal to identify novel MAPK pathway–suppressing synergistic drug combinations. A reporter plasmid (pDIPZ) with a MAPK-responsive ELK-1–binding element driving the expression of destabilized firefly luciferase was generated and packaged using a lentiviral vector system. Pediatric glioma cell lines with a BRAF fusion (DKFZ-BT66) and a BRAFV600E mutation (BT-40) background, respectively, were stably transfected. Modulation of the MAPK pathway activity by MAPKi was measured using the luciferase reporter and validated by detection of phosphorylated protein levels. A screening of a MAPKi library was performed, and synergy of selected combinations was calculated. Screening of a MAPKi library revealed MEK inhibitors as the class inhibiting the pathway with the lowest IC50s, followed by ERK and next-generation RAF inhibitors. Combination treatments with different MAPKi classes showed synergistic effects in BRAF fusion as well as BRAFV600E mutation backgrounds. Here, we report a novel reporter assay for medium- to high-throughput preclinical drug testing in pLGG cell lines. The assay confirmed MEK, ERK, and next-generation RAF inhibitors as potential treatment approaches for KIAA1549:BRAF and BRAFV600E-mutated pLGGs. In addition, the assay revealed that combination treatments synergistically suppressed MAPK pathway activity.

Phytochemical investigation on the root wood of Erythrina sacleuxii (Leguminosae) led to the isolation of nine secondary metabolites (1-9). Compound 1 was isolated from the genus Erythrina for the first time. The pure compounds were identified on the basis of comprehensive spectroscopic and spectrometric analyses, while their absolute configurations were determined based on chiroptical measurements. Compounds 5 and 6 showed weak antifungal activity against Pyricularia oryzae with MIC values of 20 µg/mL. Bull. Chem. Soc. Ethiop. 2020, 34(1), 135-140. DOI: https://dx.doi.org/10.4314/bcse.v34i1.12

Purpose Isocitrate dehydrogenase 1 (IDH1) mutations are associated with improved survival in gliomas. Depending on the IDH1 status, TERT promoter mutations affect prognosis. IDH1 mutations are associated with alpha-thalassemia/mental retardation syndrome X-linked (ATRX) mutations and alternative lengthening of telomeres (ALT), suggesting an interaction between IDH1 and telomeres. However, little is known how IDH1 mutations affect telomere maintenance. Methods We analyzed cell-specific telomere length (CS-TL) on a single cell level in 46 astrocytoma samples (WHO II-IV) by modified immune-quantitative fluorescence in situ hybridization, using endothelial cells as internal reference. In the same samples, we determined IDH1/TERT promoter mutation status and ATRX expression. The interaction of IDH1R132H mutation and CS-TL was studied in vitro using an IDH1R132H doxycycline-inducible glioma cell line system. Results Virtually all ALTpositive astrocytomas had normal TERT promoter and lacked ATRX expression. Further, all ALTpositive samples had IDH1R132H mutations, resulting in a significantly longer CS-TL of IDH1R132H gliomas, when compared to their wildtype counterparts. Conversely, TERT promotor mutations were associated with IDHwildtype, ATRX expression, lack of ALT and short CS-TL. ALT, TERT promoter mutations, and CS-TL remained without prognostic significance, when correcting for IDH1 status. In vitro, overexpression of IDHR132H in the glioma cell line LN319 resulted in downregulation of ATRX and rapid TERT-independent telomere lengthening consistent with ALT. Conclusion ALT is the major telomere maintenance mechanism in IDHR132H mutated astrocytomas, while TERT promoter mutations were associated with IDHwildtype glioma. IDH1R132H downregulates ATRX expression in vitro resulting in ALT, which may contribute to the strong association of IDH1R132H mutations, ATRX loss, and ALT.

Chitin is a highly abundant polysaccharide in nature and linked to immune recognition of fungal infections and asthma in humans. Ubiquitous in fungi and insects, chitin is absent in mammals and plants and, thus, represents a microbe-associated molecular pattern (MAMP). However, the highly polymeric chitin is insoluble, which potentially hampers recognition by host immune sensors. In plants, secreted chitinases degrade polymeric chitin into diffusible oligomers, which are ‘fed to’ innate immune receptors and co-receptors. In human and murine immune cells, a similar enzymatic activity was shown for human chitotriosidase (CHIT1) and oligomeric chitin is sensed via an innate immune receptor, Toll-like receptor (TLR) 2. However, a complete system of generating MAMPs from chitin and feeding them into a specific receptor/co-receptor-aided sensing mechanism has remained unknown in mammals. Here, we show that the secreted chitinolytic host enzyme, CHIT1, converts inert polymeric chitin into diffusible oligomers that can be sensed by TLR1-TLR2 co-receptor/receptor heterodimers, a process promoted by the lipopolysaccharide binding protein (LBP) and CD14. Furthermore, we observed that Chit1 is induced via the β-glucan receptor Dectin-1 upon direct contact of immortalized human macrophages to the fungal pathogen Candida albicans, whereas the defined fungal secreted aspartyl proteases, Sap2 and Sap6, from C. albicans were able to degrade CHIT1 in vitro. Our study shows the existence of an inducible system of MAMP generation in the human host that enables contact-independent immune activation by diffusible MAMP ligands with striking similarity to the plant kingdom. Moreover, this study highlights CHIT1 as a potential therapeutic target for TLR2-mediated inflammatory processes that are fueled by oligomeric chitin.

Background Targeted immunotherapies are of growing interest in the treatment of various cancers. B7 homolog 3 protein (B7-H3), a member of the co-stimulatory/-inhibitory B7-family, exerts immunosuppressive and pro-tumorigenic functions in various cancer types and is under evaluation in ongoing clinical trials. Unfortunately, interaction partner(s) remain unknown which restricts the druggability. Methods Aiming to identify potential binding partner(s) of B7-H3, a yeast two-hybrid and a mass spectrometry screen were performed. Potential candidates were evaluated by bimolecular fluorescence complementation (BiFC) assay, co-immunoprecipitation (co-IP), and functionally in a 3H-thymidine proliferation assay of Jurkat cells, a T-cell lineage cell line. Prognostic value of angio-associated migratory cell protein (AAMP) and B7-H3 expression was evaluated in isocitrate dehydrogenase 1 wildtype (IDH1wt) glioblastoma (GBM) patients from The Cancer Genome Atlas (TCGA)-GBM cohort. Results Of the screening candidates, CD164, AAMP, PTPRA, and SLAMF7 could be substantiated via BiFC. AAMP binding could be further confirmed via co-IP and on a functional level. AAMP was ubiquitously expressed in glioma cells, immune cells, and glioma tissue, but did not correlate with glioma grade. Finally, an interaction between AAMP and B7-H3 could be observed on expression level, hinting toward a combined synergistic effect. Conclusions AAMP was identified as a novel interaction partner of B7-H3, opening new possibilities to create a targeted therapy against the pro-tumorigenic costimulatory protein B7-H3.