bluuebunny/crossref_metadata_2025 huggingface dataset:
MPK3/MPK6-mediated phosphorylation of ERF72 positively regulates resistance to Botrytis cinerea through directly and indirectly activating the transcription of camalexin biosynthesis enzymes
Authors: Li Yihao , Liu Kun , Tong Ganlu , Xi Chao , Liu Jin , Zhao Heping , Wang Yingdian , Ren Dongtao , Han Shengcheng
Published: September 2021

Ethylene response factor (ERF) Group VII members generally function in regulating plant growth and development, abiotic stress responses, and plant immunity in Arabidopsis; however, the details of the regulatory mechanism by which Group VII ERFs mediate plant immune responses remain elusive. Here, we characterized one such member, ERF72, as a positive regulator that mediates resistance to the necrotrophic pathogen Botrytis cinerea. Compared with the wild-type (WT), the erf72 mutant showed lower camalexin concentration and was more susceptible to B. cinerea, while complementation of ERF72 in erf72 rescued the susceptibility phenotype. Moreover, overexpression of ERF72 in the WT promoted camalexin biosynthesis and increased resistance to B. cinerea. We identified the camalexin-biosynthesis genes PAD3 and CYP71A13 and the transcription factor WRKY33 as target genes of ERF72. We also determined that MPK3 and MPK6 phosphorylated ERF72 at Ser151 and improved its transactivation activity, resulting in increased camalexin concentration and increased resistance to B. cinerea. Thus, ERF72 acts in plant immunity to coordinate camalexin biosynthesis both directly by regulating the expression of biosynthetic genes and indirectly by targeting WRKK33.
The Flowers in The Muses Garland
Authors: Blayney Peter W M
Published: September 2021

A recent publication has laid the groundwork for future studies of printers’ flowers. This paper begins by using the evidence of flowers to show that two seemingly unrelated printed fragments in the Beinecke Library come from a single book. An attempt to identify the printer then reveals the largely unexplored extent to which London printers’ ornaments migrated to Scotland in the 1590s and came back in 1603, and that leads in turn to some new biographical facts about the printer Robert Waldegrave.

An appendix looks at some later copies of Robert Granjon’s best-known six-part combinable flower, which have too often been mistaken for the originals.
The origin of Galactic cosmic rays as revealed by their composition
Authors: Tatischeff Vincent , Raymond John C , Duprat Jean , Gabici Stefano , Recchia Sarah
Published: September 2021

Galactic cosmic rays (GCRs) are thought to be accelerated in strong shocks induced by massive star winds and supernova explosions sweeping across the interstellar medium. But the phase of the interstellar medium from which the CRs are extracted has remained elusive until now. Here, we study in detail the GCR source composition deduced from recent measurements by the AMS-02, Voyager 1, and SuperTIGER experiments to obtain information on the composition, ionization state, and dust content of the GCR source reservoirs. We show that the volatile elements of the CR material are mainly accelerated from a plasma of temperature ≳ 2 MK, which is typical of the hot medium found in Galactic superbubbles energized by the activity of massive star winds and supernova explosions. Another GCR component, which is responsible for the overabundance of 22Ne, most likely arises from acceleration of massive star winds in their termination shocks. From the CR-related gamma-ray luminosity of the Milky Way, we estimate that the ion acceleration efficiency in both supernova shocks and wind termination shocks is of the order of 10−5. The GCR source composition also shows evidence for a preferential acceleration of refractory elements contained in interstellar dust. We suggest that the GCR refractories are also produced in superbubbles, from shock acceleration and subsequent sputtering of dust grains continuously incorporated into the hot plasma through thermal evaporation of embedded molecular clouds. Our model explains well the measured abundances of all primary and mostly primary CRs from H to Zr, including the overabundance of 22Ne.
Emission line galaxies in the SHARDS Frontier Fields – I. Candidate selection and the discovery of bursty Hα emitters
Authors: Griffiths Alex , Conselice Christopher J , Ferreira Leonardo , Ceverino Daniel , Rosa-González Daniel , Huertas-Company Marc , Pampliega Belén Alcalde , Pérez-González Pablo G , Sanchez Helena Dominguez , Vega Olga
Published: September 2021

Emission line galaxies provide a crucial tool for the study of galaxy formation and evolution, providing a means to trace a galaxy’s star formation history or metal enrichment, and to identify galaxies at a range of stellar masses. In this paper, we present a study of emission line galaxies in the Survey for High-z Absorption Red and Dead Sources (SHARDS) Frontier Fields (FF) medium-band survey. Through detailed flux calibrations we combine the first results of the SHARDS-FF survey with existing Hubble Frontier Field data to select 1098 candidate emission line galaxies from the Hubble Frontier Filed clusters Abell 370 and MACS J1149.5+2223. Furthermore, we implement this deep medium-band imaging to update photometric redshift estimates and stellar population parameters and discover 38 predominantly low-mass Hα emitters at redshifts 0.24 < z < 0.46. Overall, 27 of these sources have corresponding ultraviolet (UV) data from the Hubble Space Telescope that allow us to distinguish these sources and investigate the burstiness of their star formation histories. We find that more than 50 per cent of our sample shows an enhancement in Hα over UV, suggesting recent bursts in star formation on time-scales of a few to tens of Myr. We investigate these sources and find that they are typically low-mass discy galaxies with normal sizes. Their structures and star formation suggest that they are not undergoing mergers but are bursting due to alternative causes, such as gas accretion.
MetaPlatanus: a metagenome assembler that combines long-range sequence links and species-specific features
Authors: Kajitani Rei , Noguchi Hideki , Gotoh Yasuhiro , Ogura Yoshitoshi , Yoshimura Dai , Okuno Miki , Toyoda Atsushi , Kuwahara Tomomi , Hayashi Tetsuya , Itoh Takehiko
Published: September 2021

De novo metagenome assembly is effective in assembling multiple draft genomes, including those of uncultured organisms. However, heterogeneity in the metagenome hinders assembly and introduces interspecies misassembly deleterious for downstream analysis. For this purpose, we developed a hybrid metagenome assembler, MetaPlatanus. First, as a characteristic function, it assembles the basic contigs from accurate short reads and then iteratively utilizes long-range sequence links, species-specific sequence compositions, and coverage depth. The binning information was also used to improve contiguity. Benchmarking using mock datasets consisting of known bacteria with long reads or mate pairs revealed the high contiguity MetaPlatanus with a few interspecies misassemblies. For published human gut data with nanopore reads from potable sequencers, MetaPlatanus assembled many biologically important elements, such as coding genes, gene clusters, viral sequences, and over-half bacterial genomes. In the benchmark with published human saliva data with high-throughput nanopore reads, the superiority of MetaPlatanus was considerably more evident. We found that some high-abundance bacterial genomes were assembled only by MetaPlatanus as near-complete. Furthermore, MetaPlatanus can circumvent the limitations of highly fragmented assemblies and frequent interspecies misassembles obtained by the other tools. Overall, the study demonstrates that MetaPlatanus could be an effective approach for exploring large-scale structures in metagenomes.
PL03.1.A Surgery for glioblastomas in the elderly: an ANOCEF trial (CSA)
Authors: Laigle-Donadey F , Metellus P , Guyotat J , Menei P , Proust F , Dufour H , Chinot O , Honnorat J , Faillot T , Paquis P , Peruzzi P , Emery E , Guillamo J S , Carpentier A , Wager M , Lebbah S , Hajage D , Delattre J Y , Cornu P
Published: September 2021

BACKGROUND

The role of surgery for the treatment of malignant gliomas in patients 70 years of age or older is unsettled. We conducted a randomized trial that compared surgical resection of the tumor and biopsy only, both followed by standard therapy, in such patients.

MATERIAL AND METHODS

Patients aged 70 years and older, with a KPS of at least 50, presenting with a radiological suspicion of an operable glioblastoma (GBM) were randomly assigned between tumor resection and biopsy. Subsequently, they underwent standard radiotherapy during the first years of the trial (2008–2017), with the adjunction of concomitant and adjuvant temozolomide when this regimen became standard (2017–2019). The primary end point was survival; secondary endpoints were progression free survival (PFS), cognitive status (MMS), autonomy (KPS), quality of life (EORTC QLQ C30 and BN20), and perioperative morbidity/ mortality.

RESULTS

From 2008 to 2019, 107 patients from 9 centers were enrolled in the study, of whom 101 were evaluable for analysis because the diagnosis of GBM was histologically confirmed (50 patients in the “surgery” arm and 51 patients in the “biopsy” arm). There was no statistically significant difference of median survival between the “surgery” arm (9.37 mo) and the “biopsy” arms (8.96 mo, p=0.36). However, the surgery group had increased PFS (5.06 mo vs 4.02 mo; p=0.034; p=0.002 on multivariate analysis) and better QOL (e.g. physical and cognitive functioning, motor dysfunction, fatigue) and KPS score evolution as compared to the “biopsy” group. Surgery was not associated with increased mortality or morbidity.

CONCLUSION

This study suggests that optimal debulking surgery does not provide a significant survival benefit in elderly patients suffering from newly diagnosed malignant glioma, but resection improves QOL and autonomy with a significant though modest improvement of PFS.
PL03.2.A Radiotherapy is associated with a deletion signature that contributes to poor outcomes in glioma patients
Authors: Kocakavuk E , Anderson K J , Varn F S , Johnson K C , Amin S B , Sulman E P , Lolkema M P , Barthel F P , Verhaak R G W
Published: September 2021

BACKGROUND

Diffuse gliomas are highly aggressive brain tumors that invariably relapse despite treatment with chemo- and radiotherapy. Treatment with alkylating chemotherapy can drive tumors to develop a hypermutator phenotype. In contrast, the genomic effects of radiation therapy (RT) remain largely unknown.

MATERIAL AND METHODS

We analyzed the mutational spectra following treatment with RT in whole genome or exome sequencing data from 190 paired primary-recurrent gliomas from the Glioma Longitudinal Analysis (GLASS) dataset and 3693 post-treatment metastatic tumors from the Hartwig Medical Foundation (HMF).

RESULTS

We identified a significant increase in the burden of small deletions following radiation therapy that was independent of other factors (P = 3e-03, multivariable log-linear regression). These novel deletions demonstrated distinct characteristics when compared to pre-existing deletions present prior to RT-treatment and deletions in RT-untreated tumors. Radiation therapy-acquired deletions were characterized by a larger deletion size (GLASS and HMF, P = 1.5e-04 and P = 6e-16, respectively; Mann-Whitney U test), an increased distance to repetitive DNA elements (P < 2.2e-16, Kolmogorov-Smirnov test) and a lack of microhomology at breakpoints (P = 6.6e-05, paired Wilcoxon signed-rank test). Furthermore, mutational signature analysis confirmed the distinct genomic characteristics of RT-associated deletions when compared to deletions arising via homologous recombination deficiency or microsatellite instability.

These observations suggested that canonical non-homologous end joining (c-NHEJ) was the preferred pathway for DNA double strand break repair of RT-induced DNA damage. Furthermore, RT resulted in frequent chromosomal deletions and significantly increased frequencies of CDKN2A homozygous deletions in IDHmut glioma (P= 1.9e-05, Fisher’s exact test). Finally, a high burden of RT-associated deletions was associated with worse clinical outcomes (GLASS and HMF, P = 3.4e-02 and P < 1e-04, respectively; log-rank test).

CONCLUSION

Our results collectively suggest that effective repair of RT-induced DNA damage is detrimental to patient survival and that inhibiting c-NHEJ may be a viable strategy for improving the cancer-killing effect of radiotherapy. Furthermore, CDKN2A homozygous deletion at recurrence may be leveraged as a promising clinical biomarker of RT-resistance in IDHmut glioma. Taken together, the identified genomic scars as a result of RT reflect a more aggressive tumor with increased levels of resistance to follow up treatments.
OS02.6.A The TeloDIAG: How telomeric parameters can help in glioma rapid diagnosis and liquid biopsies approaches
Authors: Billard P , Guerriau C , Carpentier C , Juillard F , Grandin N , Lomonte P , Kantapareddy P , Barritault M , Rimokh R , Verrelle P , Maucort-Boulch D , Figarella-Branger D , Ducray F , Dehais C , Charbonneau M , Meyronet D , Poncet D A
Published: September 2021

BACKGROUND

The integration of molecular markers into the WHO 2016 classification has clarified the complex diagnosis of gliomas. Among these biomarkers, the TERT promoter mutation and the loss of ATRX (ATRX loss) are mutually exclusive alterations associated with re-activation of telomerase or alternative lengthening of telomeres (ALT), respectively. Strangely, 25% of gliomas display neither or both these alterations, a situation referred to as abnormal telomere maintenance mechanism (aTMM).

MATERIAL AND METHODS

To investigate the TMM actually involved in gliomas, the C-circle (CC) assay was adapted to tumor (FFPE and frozen) samples.

RESULTS

We constructed a CC-based algorithm able to identify the TMM of 284 gliomas with either TERT or ATRX alteration, with a sensitivity of 100% and a specificity of 97.3%, and succeeded in deciphering the TMM involved in 122 aTMM gliomas. Additionally, the combination of the TMM, the mutational status of the Isocitrate dehydrogenase 1/2 (IDH) gene, and the histological grading was used as base for a new classification: TeloDIAG. Six subtypes are defined in this classification: tOD, tLGA, tGBM_IDHmt, tGBM, and tAIV, corresponding to oligodendroglioma, IDHmt low grade astrocytoma, IDHmt glioblastoma, and IDHwt glioblastoma, respectively, the last class gathers ALT+ IDHwt glioma. The TeloDIAG diagnosis is 99% concordant with the WHO classification for glioma displaying typical molecular characteristics (N=312). It modified the classification of 38% (N=156) discordant tumors, such as IDHwt Astrocytoma, aTMM tumors, or gliomas with unexpected TMM (e.g. TERTwt oligodendroglioma, ATRX loss GBM). Interestingly, 20% (N=69) of TERTwt, ATRXwt, or IDHwt GBM were actually tAIV, which is remarkable as tAIV-glioma patients’ survival tended to be longer (21.2 months) than tGBM patients’ survival (16.5 months). Importantly, CC in blood sampled from IDHmt astrocytoma patients was detected with a sensitivity of 56% and a specificity of 95% (N = 206).

CONCLUSION

In sum, the TeloDIAG is a new, simple, and efficient tool helping in glioma diagnosis and a promising option for liquid biopsy
OS05.2.A MGMT promoter status in IDH1/2 mutant anaplastic astrocytoma patients assessed by DNA methylation profiling and qMS-PCR: a report from the EORTC Brain Tumor Group
Authors: Tesileanu C M S , French P J , Sanson M , Brandes A A , Wick W , Clement P M , Kros J M , Gorlia T , Golfinopoulos V , van den Bent M J
Published: September 2021

BACKGROUND

Temozolomide (TMZ) efficacy in high-grade glioma is related to O 6-methylguanine DNA methyltransferase promoter (MGMTp) methylation. We compared the prognostic and predictive effect of MGMTp between DNA methylation profiling (the MGMT-STP27 model) and quantitative methylation specific polymerase chain reaction (qMS-PCR) in isocitrate dehydrogenase 1 and 2 (IDH1/2) mutant (mt) anaplastic astrocytoma patients.

MATERIAL AND METHODS

The 2x2 factorial design phase III CATNON trial randomized 751 adult patients with newly diagnosed 1p/19q non-codeleted anaplastic glioma to 59.4 Gy radiotherapy (RT), RT with concurrent TMZ, RT with 12 cycles of adjuvant TMZ, or RT with concurrent and adjuvant TMZ. MGMTp methylation status was assessed with the MGMT-STP27 model using 850k EPIC data, and qMS-PCR. IDH1/2 mutation status was determined with a next-generation sequencing panel. Overall survival (OS) was measured from date of randomization.

RESULTS

We identified 444 IDH1/2mt anaplastic astrocytoma patients of which MGMT-STP27 data was available for 440 patients (99.1%), qMS-PCR data for 361 patients (81.3%), and both for 357 patients (80.4%). MGMTp was methylated in 365 patients (83.0%) for the MGMT-STP27 model, and 168 patients (46.5%) for qMS-PCR. The agreement between the MGMT-STP27 model and qMS-PCR is 59.9% with a Cohen’s Kappa score of 0.229. At database lock, 289 patients with MGMT-STP27 data were still alive and 236 patients with qMS-PCR data. The median OS of MGMTp methylated glioma patients was 9.1 yrs [95 % confidence interval (CI) 7.5-not reached] for the MGMT-STP27 model, and not reached [95 % CI 9.1-not reached] for the qMS-PCR data. For MGMTp unmethylated glioma patients, the median OS was 6.9 yrs [95% CI 6.2-not reached] for the MGMT-STP27 model, and 6.8 yrs [95% CI 6.2–9.7] for the qMS-PCR data. The hazard ratio (HR) for OS based on MGMTp methylation was 0.88 [95% CI 0.58–1.31] for the MGMT-STP27 data, and 0.72 [95% CI 0.50–1.03]) for the qMS-PCR data. The HR for OS after RT with any TMZ vs RT alone for the MGMT-STP27 model was 0.53 [95% CI 0.37–0.78] for MGMTp methylated, and 0.54 [95% CI 0.25–1.18] for MGMTp unmethylated glioma patients; and for the MS-PCR data was 0.34 [95% CI 0.19–0.61] for MGMTp methylated, and 0.53 [95% CI 0.33–0.85] for MGMTp unmethylated glioma patients.

CONCLUSION

MGMTp methylation, regardless of assay, was neither prognostic nor predictive for outcome to temozolomide in IDH1/2mt anaplastic astrocytoma patients.
OS05.3.A Temporal muscle thickness as surrogate parameter of sarcopenia in newly diagnosed glioblastoma patients:translational imaging analysis of the CENTRIC EORTC 26071-22072 and CORE trials
Authors: Furtner J , Weller M , Weber M , Gorlia T , Nabors B , Reardon D , Tonn J , Stupp R , Preusser M
Published: September 2021

BACKGROUND

Temporal muscle thickness (TMT) was described as surrogate parameter of skeletal muscle mass. This study aimed to investigate the prognostic relevance of TMT in patients with newly diagnosed glioblastoma.

MATERIAL AND METHODS

TMT was assessed in cranial magnetic resonance images (MRI) of 755 pts enrolled in the CENTRIC EORTC 26071-22072 study (n=508) and CORE study (n=247). Predefined sex-specific TMT cutoff values were used to categorize “patients at risk of sarcopenia” and “patients with normal muscle status” at baseline. Furthermore, patients were categorized according to the extent of TMT loss over time. Cox models adjusted for other explanatory variables were used to evaluate the associations with progression-free survival (PFS) and overall survival (OS).

RESULTS

Overall, 510/755 (67.6%) patients were categorized as “at risk of sarcopenia” and 245/755 (32.4%) patients had normal muscle status at baseline. In both study cohorts patient at risk of sarcopenia at baseline had significantly higher risk of progression and death than patients with normal muscle status (CENTRIC: PFS = HR 0.16, 95% CI: 0.12, 0.21, p<0.001; OS = HR 0.341, 95% CI: 0.27, 0.44, p < 0.001; CORE: PFS = HR 0.29, 95% CI: 0.21, 0.39, p<0.001; OS = HR 0.365, 95% CI: 0.27, 0.49, p<0.001). In multivariate Cox models adjusted for other important prognostic parameters similar results were obtained. In patients at risk for sarcopenia the extent of TMT loss over time showed a significant inverse correlation with median OS times (CENTRIC: p < 0.001, CORE: p = 0.005, log-rank test), but not in patients with normal baseline muscle mass in both study cohorts (CENTRIC: p = 0.538, CORE: p = 0.28, log-rank test).

CONCLUSION

TMT identifies patients with newly diagnosed glioblastoma at risk for progressive sarcopenia and adverse outcomes. Early intervention for muscle mass preservation including exercise and resistance training as well as nutritional support may prevent skeletal muscle loss and improve patient outcome in this group of patients.
OS05.5.A Methylation analysis of matched primary and recurrent IDHmt astrocytoma; an update from the Glioma Longitudinal Analysis NL (GLASS-NL) consortium
Authors: Vallentgoed W R , Niers J M , van den Bent M J , Kouwenhoven M C M , Kros J M , Martin I , van Thuijl H F , van de Wiel M A , Wesseling P , French P J
Published: September 2021

BACKGROUND

The evolutionary processes that drive progression in patients with IDH-mutant astrocytoma remain unclear. The GLASS-NL consortium, as part of the larger worldwide GLASS consortium, was initiated to gain insight into the molecular mechanisms underlying glioma evolution and to identify markers of progression in IDH-mutant astrocytomas. Such markers can ultimately assist clinical decision making. Here, we present the first results of genome wide methylation profiling of samples included in the GLASS-NL study.

MATERIAL AND METHODS

110 adult patients were identified with an IDH-mutant astrocytoma at first diagnosis. All patients underwent a surgical resection of the tumor at least twice, separated by at least 6 months with a median of 40.9 months (IQR: 24.0, 64.7), in 37% and 18% of the cases, patients were treated with radiotherapy or chemotherapy respectively, before surgical resection of the recurrent tumor. Methylation profiling was done on (macro dissected) DNA isolated of 235 samples from 103 patients (102 1st, 101 2nd, 29 3rd, and 3 4th resection), using the Infinium MethylationEPIC BeadChip array. Copy number variations were also derived from these data. Methylation classes were determined according to Capper et al. (2018). Overall survival (OS) was measured from date of first surgery.

RESULTS

Of all primary tumors, the methylation-classifier assigned 85 (87%) to the A_IDH (‘low grade’) subclass and 10 (10%) to the A_IDH_HG (‘high grade’) subclass. The relative proportion of high grade tumors increased ~three-fold at tumor recurrence (32/101, 32%) and even further in the second recurrence (15/29, 52%). The overall DNA-methylation levels of recurrent samples was lower than that of primary samples. This difference is explained by the increased number of high grade samples at recurrence, since near identical DNA-methylation levels were observed in samples that remained low grade. In an unsupervised analysis, methylation data derived from first and second resections of individual patients mostly (79%) cluster together. This indicates that variability between tumors is larger than temporal heterogeneity within tumors. Recurrent samples that do not cluster with their primary tumor, form a separate cluster and have relatively low genome-wide DNA-methylation.

CONCLUSION

Our data demonstrate that methylation profiling identifies a shift towards a higher grade at tumor progression coinciding with reduced genome-wide DNA-methylation levels.
OS06.2A Local immunotherapy of glioblastoma via AAV-mediated gene transfer of checkpoint inhibitors in combination with CAR-NK cells
Authors: Strecker M I , Wlotzka K , Strassheimer F , Reul J , Harter P N , Tonn T , Steinbach J P , Wels W S , Buchholz C J , Burger M C
Published: September 2021

BACKGROUND

Glioblastoma (GB) is the most common primary brain tumor which is characterized by low immunogenicity of tumor cells and prevalent immunosuppression in the tumor microenvironment (TME). Since expression of PD-L1 on GB cells has been described, immunotherapy with checkpoint inhibitors (CIs) may be a promising approach for GB treatment. However, systemic administration of CIs bears the risk of autoimmune-like side effects, while the intratumoral drug concentration reached may not be sufficient.

METHODS

We studied delivery of CIs through targeted Adeno-associated viral vectors (AAVs) encoding an anti PD-1 immunoadhesin (aPD-1) as a novel approach towards local immunotherapy in the syngeneic GL261-HER2 glioma model. Tumor cell-specific delivery was achieved by targeting HER2 via a specific designed ankyrin repeat protein (DARPin). We investigated the effects of this strategy alone and in combination with local injection of HER2-specific CAR-NK cells (NK-92/5.28.z), which have already shown efficacy in preclinical GB models and are currently under investigation in the CAR2BRAIN phase I clinical trial. Furthermore, aPD-1 functionality and cellular response to viral transduction as well as compatibility of both therapy approaches has been evaluated in various in vitro models.

RESULTS

HER2-AAV transduction efficacy of GB cells correlated with HER2 expression level, while target cells did not show anti-viral responses upon transduction. After transduction with aPD-1 HER2-AAVs, aPD-1 immunoadhesin was secreted in a time-dependent manner, bound its target on PD-1-expressing cells and was able to re-activate T-cells due to PD-1 blockade. AAV-transduction did not interfere with CAR-NK cell mediated tumor cell lysis. Biodistribution studies in mice revealed the presence of aPD-1 up to 10 days after a single HER2-AAV injection. In subcutaneous GL261-HER2 tumors, local treatment with HER2-AAVaPD-1 or HER2-AAVIgG-Fc+ NK-92/5.28.z therapy had no significant effect, whereas combination therapy profoundly delayed tumor growth.

CONCLUSIONS

Local therapy with aPD-1 encoding HER2-AAVs in combination with NK-92/5.28.z cells is a promising novel strategy for GB immunotherapy with the potential to enhance efficacy and reduce side effects.
OS06.3A LSD1-directed therapy curtails glioblastoma tumorigenicity by limiting the adaptation of tumor initiating cells to stressful environments
Authors: Faletti S , Osti D , Ceccacci E , Richichi C , Costanza B , Marotta G , Corà D , Pelicci G
Published: September 2021

BACKGROUND

Glioblastoma (GBM) is a fatal tumor whose aggressiveness, heterogeneity, therapy resistance and poor blood-brain-barrier penetration hinder the amelioration of the standard-of-care. Included in the GBM mass are the tumor initiating cells (TICs), representing the driver of GBM growth and relapse in virtue of their stem-like traits and therapy-resistance. Being constantly exposed to environmental stress, including nutrients deficiency, hypoxia and therapeutic insults, all GBM cells -and TICs in particular- have to be highly adaptive in order to survive. Thus, their ability to cope with stress could be targeted to curtail TICs maintenance and the whole GBM aggressiveness. The key of TICs adaptation relies, among the others, on their epigenetic plasticity, hence encouraging epigenetic drugs testing.

MATERIAL AND METHODS

By exploiting patient-derived GBM TICs and orthotopic xenograft models, we tested the antitumorigenic features of a novel, selective, orally bioavailable and brain-penetrant Lysine-specific histone demethylase 1 inhibitor (LSD1i). We confirmed the specificity of its effects by LSD1 genetic targeting. A combination of RNA-seq, Chromatin Immunoprecipitation(ChIP)-seq, Mass Spectrometry and reverse genetic experiments unraveled LSD1 molecular players in GBM TICs.

RESULTS

We identified LSD1 as a druggable target in human GBM: LSD1i treatment, mirrored by LSD1 genetic targeting, impairs growth, viability, stem-like traits and in vivo tumorigenicity of GBM TICs. Mechanistically, LSD1 is crucial for the expression of the activating transcription factor 4 (ATF4), which coordinates the integrated stress response (ISR) to manage stressful stimuli as nutrient deprivation and endoplasmic reticulum stress. By mimicking these stress cues in vitro, we found that LSD1i triggers a delayed but unabated ATF4 translation which provokes an over-lasting ISR, eventually culminating in GBM TICs apoptosis. Lastly, LSD1 demethylase activity is dispensable for ATF4 induction. Rather, LSD1i exerts its anti-tumorigenic potential by interfering with LSD1 scaffolding function in GBM TICs.

CONCLUSION

LSD1-directed therapy is likely a promising strategy to hinder GBM. By sensitizing GBM TICs to stress, LSD1i endangers the GBM TICs pool. The effectiveness of LSD1i administration in different patient-derived GBM TICs and xenografts, regardless of their molecular profile, places a strong rationale toward the clinical translation of this approach for GBM management.

FUNDING

Italian association for Cancer Research (AIRC) and Italian Ministry of Health
OS08.6.A Glioblastoma treatment response machine learning monitoring biomarkers: a systematic review and meta-analysis
Authors: Booth T C , Chelliah A , Roman A , Al Busaidi A , Shuaib H , Luis A , Mirchandani A , Alparslan B , Mansoor N , Ashkan K , Ourselin S , Modat M , Grzeda M
Published: September 2021

BACKGROUND

The aim of the systematic review was to assess recently published studies on diagnostic test accuracy of glioblastoma treatment response monitoring biomarkers in adults, developed through machine learning (ML).

MATERIAL AND METHODS

PRISMA methodology was followed. Articles published 09/2018-01/2021 (since previous reviews) were searched for using MEDLINE, EMBASE, and the Cochrane Register by two reviewers independently. Included study participants were adult patients with high grade glioma who had undergone standard treatment (maximal resection, radiotherapy with concomitant and adjuvant temozolomide) and subsequently underwent follow-up imaging to determine treatment response status (specifically, distinguishing progression/recurrence from progression/recurrence mimics - the target condition). Risk of bias and applicability was assessed with QUADAS 2. A third reviewer arbitrated any discrepancy. Contingency tables were created for hold-out test sets and recall, specificity, precision, F1-score, balanced accuracy calculated. A meta-analysis was performed using a bivariate model for recall, false positive rate and area-under the receiver operator characteristic curve (AUC).

RESULTS

Eighteen studies were included with 1335 patients in training sets and 384 in test sets. To determine whether there was progression or a mimic, the reference standard combination of follow-up imaging and histopathology at re-operation was applied in 67% (13/18) of studies. The small numbers of patient included in studies, the high risk of bias and concerns of applicability in the study designs (particularly in relation to the reference standard and patient selection due to confounding), and the low level of evidence, suggest that limited conclusions can be drawn from the data. Ten studies (10/18, 56%) had internal or external hold-out test set data that could be included in a meta-analysis of monitoring biomarker studies. The pooled sensitivity was 0.77 (0.65–0.86). The pooled false positive rate (1-specificity) was 0.35 (0.25–0.47). The summary point estimate for the AUC was 0.77.

CONCLUSION

There is likely good diagnostic performance of machine learning models that use MRI features to distinguish between progression and mimics. The diagnostic performance of ML using implicit features did not appear to be superior to ML using explicit features. There are a range of ML-based solutions poised to become treatment response monitoring biomarkers for glioblastoma. To achieve this, the development and validation of ML models require large, well-annotated datasets where the potential for confounding in the study design has been carefully considered. Therefore, multidisciplinary efforts and multicentre collaborations are necessary.
OS10.5.A BrainWear: Longitudinal, objective assessment of physical activity in 42 HGG patients
Authors: Dadhania S , Pakzad-Shahabi L , Mistry S , Le-Calvez K , Saleem W , Mohammed W , Williams M
Published: September 2021

BACKGROUND

In patients with High Grade Glioma (HGG), QoL and physical function decline with progressive disease (PD). Objective assessment of physical functioning is challenging as patients spend most of their time away from the hospital. Wearable technology allows measurement of objective, continuous activity data in a non-obtrusive manner. BrainWear is a phase II feasibility study, collecting longitudinal physical activity (PA) data from patients with primary and secondary brain tumours.

MATERIAL AND METHODS

All agreed to wear an Axivity AX3 triaxial accelerometer and completed the EORTC QLQ C30 and BN20, the Montreal Cognitive Assessment (MoCA) and Multidimensional fatigue inventory (MFI) questionnaires. Accelerometers were changed at 14-day intervals, and PRO questionnaires completed at pre-specified study intervals. Age-sex matched controls were identified from the UK Biobank 7-day accelerometer study. Raw accelerometer data was processed using UK Biobank accelerometer software and inclusion of high-quality wear time selected as ≥72 hours of data in a 7-day data collection and data in each 1-hour period of a 24-hour cycle over multiple days. We analysed variation in activity by patient demographics and treatment days. The wilcoxin-signed rank test was used to compare participant activity between radiotherapy treatment days and non-treatment days, mixed effects models were used to evaluate longitudinal changes in activity and we used k-means clustering to characterise clusters of PA behaviours.

RESULTS

We have collected 3458 days of accelerometer data from 42 HGG patients with a median age of 59, 80% of which has been classified as high quality. Patients >60 years spend more time doing moderate activity compared to those <60 years (52 vs 33 minutes/day, p=0.012), and there are significant differences in mean vector magnitude (17.12 vs 16.85 mg, p=0.013) and walking (91 vs 72 minutes/day) between radiotherapy and non-radiotherapy days. In patients having a 6-week RT course, time spent in daily moderate activity falls 4-fold between week 1 and the second week after RT completion (70 minutes to 16 minutes/day). Comparing HGG patients to healthy controls shows a significant difference in time spent across all activities (p<0.05). K-means clustering analysis shows three distinct clusters, with 87% of HGG patients falling into the very inactive or moderately active groups.

CONCLUSION

Digital remote health monitoring is feasible and acceptable with 80% of data classified as high-quality wear-time suggesting good patient adherence. Triaxial accelerometer data collection captures objective evidence of a significant reduction in moderate daily activity at the time of expected peak RT side-effects and patients walk almost 30% less on non-RT treatment days. HGG patients show significantly lower levels of activity compared to matched healthy controls.
OS10.7.A Localization patterns of language errors during direct electrical brain stimulation: a systematic review
Authors: Collée E , Vincent A , Dirven C , Satoer D
Published: September 2021

BACKGROUND

Awake craniotomy with direct electrical stimulation (DES) is the standard treatment for patients with eloquent area gliomas. Language errors (paraphasias) are detected with DES and they indicate functional boundaries that need to be maintained to preserve quality of life. However, it is not fully clear in which brain locations paraphasias at different linguistic modalities and levels (production, comprehension, reading, writing, phonology, semantics, syntax) occur.

MATERIALS AND METHODS

A systematic review was conducted. We included 102 studies reporting on specific paraphasias and the corresponding brain locations during awake craniotomy with DES in adult glioma patients.

RESULTS

First, a wide distribution of brain locations for all paraphasias (n=930) was found, but patterns were observed. Cortically, paraphasias occurred most often in the precentral gyrus (22%), while subcortically, they occurred mainly at the inferior fronto-occipital fascicle (IFOF: 10%). Localization patterns for different paraphasia types and the corresponding language functions were also found: production/articulation (n=393)-precentral gyrus (41%), inferior frontal gyrus (9%), frontal aslant/striatal tract (4%), postcentral gyrus (3%); semantics (n=128)-IFOF (57%), superior temporal gyrus (9%); phonology (n=115)-arcuate fascicle (52%), superior longitudinal fascicle (10%), uncinate fascicle (3%); reading (n=25)-temporal lobe (48%), inferior longitudinal fascicle (32%); syntax (n=15)-inferior frontal gyrus (27%); speech initiation (n=9)-supplementary motor area (33%), frontal aslant tract (22%), frontal striatal tract (22%); writing (n=7)-superior parietal gyrus (71%). Second, 59% of all paraphasias occurred cortically, 40% subcortically and 1% at both levels.

CONCLUSION

The localization of most paraphasias are consistent with the assumed functionality of those brain locations as presented in the Dutch Linguistic Intraoperative Protocol model. However, new locations for production/articulation, phonology, reading and writing were found. This needs to be taken into consideration for future selection of pre, intra and postoperative language tasks at different language modalities and levels. Additionally, DES should always be applied at the subcortical level as a standard addition to the routine cortical mapping during awake craniotomy. In conclusion, this is the first systematic review on the localization of specific paraphasias during awake craniotomy. Based on the identified language localization patterns, language tasks could be selected more accurately. This could guide, and perhaps improve, pre, intra and postoperative language testing and monitoring, which in turn, may pave the way to a better postoperative language outcome. The possible relation between different intraoperative paraphasias and language outcome has yet to be determined.
OS12.6.A Combination therapy of CAR-NK-cells and anti-PD-1 results in high efficacy against advanced-stage glioblastoma in a syngeneic mouse model and induces protective anti-tumor immunity in vivo
Authors: Strassheimer F , Strecker M I , Alekseeva T , Macas J , Demes M C , Mildenberger I C , Tonn T , Wild P J , Sevenich L , Reiss Y , Harter P N , Plate K H , Wels W S , Steinbach J P , Burger M C
Published: September 2021

INTRODUCTION

Checkpoint inhibitors as well as adoptive cell therapy hold promise for cancer therapy and encouraging treatment responses have already been demonstrated in different cancer indications. Glioblastoma (GB) is the most common and aggressive primary brain tumor. Standard therapy has very limited efficacy in the majority of patients. Analysis of the GB microenvironment (TME) has shown prominent immunosuppressive features, including expression of PD-L1 on tumor cells and increased frequency of FOXP3-positive regulatory T cells. While the surrounding brain is HER2-negative, GB are frequently HER2-positive, suggesting HER2 as a promising target for adoptive immunotherapy. Previous results from mouse glioma models showed efficacy of CAR-NK cells (NK-92/5.28.z) targeted against HER2 as monotherapy with early stage but not with advanced-stage tumors.

MATERIALS AND METHODS

The murine glioma cell line GL261 was transfected with human HER2. Tumor cells were implanted either subcutaneously or orthotopically into C57BL/6 mice and treated either with HER2-specific NK-92/5.28.z cells alone or in combination with an anti-PD-1 antibody. Effects on tumor growth and survival were determined. Lymphocyte infiltration and immunosuppressive TME were characterized via highplex multi-color flow cytometry (FACS Symphony) and IHC (Phenoptics). Furthermore, gene expression profiles of tumor-infiltrating cells were determined via bulk RNAseq (NanoString).

RESULTS

Combined treatment with NK-92/5.28.z cells and anti-PD-1 checkpoint blockade resulted in synergistic effects, with tumor regression and long-term survival observed even in advanced-stage tumor bearing mice. Analysis of the TME showed changes in lymphocyte infiltration and increased expression of exhaustion markers in tumor and immune upon combined treatment with NK-92/5.28.z cells and anti-PD-1 antibody resulting in an altered TME. Both, PD-1 and Lag-3 expression are highly upregulated on tumor infiltrating T cells. Total infiltrating lymphocytes show a rather cytotoxic phenotype up combination treatment with NK-92/5.28.z cells and anti-PD-1 antibody

CONCLUSION

Our data demonstrate that efficacy of NK-92/5.28.z cells can be enhanced by combination with checkpoint blockade, resulting in successful treatment of advanced tumors refractory to NK-92/5.28.z monotherapy. Furthermore, the combination therapy induced a cytotoxic rather than immunosuppressive TME, leading to a primed immune system. To translate the concept of CAR-NK-cell therapy plus checkpoint inhibition to a clinical setting, we are adding a combination therapy cohort to our ongoing phase I clinical study (CAR2BRAIN; NCT03383978).
OS13.3.A Establishment of a novel system to specifically trace and ablate quiescent/slow cycling cells in high-grade glioma
Authors: Antonica F , Santomaso L , Aiello G , Pernici D , Miele E , Tiberi L
Published: September 2021

BACKGROUND

High-grade gliomas are the most common malignant brain tumors, with poor prognosis due to recurrence and tumor infiltration after surgical removal and chemotherapy. Quiescent/slow cycling stem cells have been proposed to be one of the main players of tumor relapse but their involvement in in the infiltration remain unclear. Despite they have been described in mouse models or after transcriptional profiling of human tumor samples, their direct visualization, targeting and ablation remains a challenge.

MATERIAL AND METHODS

Tumors were induced over-expressing oncogenic forms of MET and p53 in the subventricular zone (SVZ) of P2 mouse brain as well as human forebrain organoids. The co-expression with specific cell cycle sensors as well as lineage specific CreERT2 under control of stem cells promoters allowed to visualize and target glioma stem cells.

RESULTS

Here, we used a fluorescent cell cycle sensor to visualize quiescent tumor cells in mouse brain cancer and human cancer organoids. In particular, we characterized them within the tumor revealing the invasiveness capacity of slow cycling tumor cells. Furthermore, we generated a new system to specifically trace and ablate such cells. Indeed, lineage tracing experiments allowed to trace quiescent Prom1 progeny in the tumors after temozolomide treatment. In addition, the selective ablation of qProm1 in mouse brain cancer reduced tumor infiltration. Finally, time-lapse experiments showed that slow cycling cells are also able to infiltrate co-cultured human brain cancer organoids.

CONCLUSION

Overall, our data show that quiescent/slow cycling cells are key driver of tumor invasiveness, the major malignant feature of high-grade brain cancer.
P02.01 A strategy to personalize the use of radiation in patients with brain metastasis based on S100A9-mediated resistance
Authors: Miarka L , Monteiro C , Dalmasso C , Yebra N , Fustero-Torre C , Hegarty A , Keelan S , Goy Y , Mohme M , Caleiras E , Vareslija D , Young L , Soffietti R , Fernández-Alén J , Blasco G , Alcázar L , Sepúlveda J , Pérez A , Lain A , Siegfried A , Wikman H , Cohen-Jonathan Moyal E , Valiente M
Published: September 2021

BACKGROUND

Finding effective treatment options for patients with brain metastasis remains an unmet need. Given the limitations imposed by the blood-brain-barrier for systemic approaches, radiotherapy offers a superior ability to access the brain. While clinical practice recently adapted the use of stereotactic radiosurgery (SRS), Whole-Brain-Radiotherapy (WBRT) continuous to be an important treatment option, since many patients present with multifocal lesions or bad performance scores, rendering them ineligible for SRS. Unfortunately, overall survival of patients remains unaffected by radiotherapy. Despite this clinical data, the molecular mechanisms that allow metastatic cells to resist radiotherapy in the brain is unknown.

MATERIAL AND METHODS

We have applied WBRT to experimental brain metastasis from lung and breast adenocarcinoma and validated their resistance in vivo.

RESULTS

An unbiased search to identify potential mediators of resistance identified the S100A9-RAGE-NFκB-JunB pathway. Targeting this pathway genetically reverts the resistance to radiotherapy and increases therapeutic benefits in vivo. In two independent cohorts of brain metastasis from lung and breast adenocarcinoma patients, levels of S100A9 correlate with the response to radiotherapy, offering a novel approach to stratify patients according to their expected benefit. In order to make this biomarker also available for brain metastasis patients receiving palliative WBRT without preceding surgery, we complemented our tumor-specimen based approach with the less invasive detection of S100A9 from liquid biopsies. Here, serum S100A9 also correlated with a worse response to WBRT in brain metastasis patients. Furthermore, we have validated the use of a blood-brain-barrier permeable RAGE inhibitor to restore radio-sensitivity in experimental brain metastasis models in vivo and in patient-derived organotypic cultures of radio-resistant brain metastasis ex vivo.

CONCLUSION

We identified S100A9 as a major mediator of radio-resistance in brain metastasis and offer the molecular framework to personalize radiotherapy by exploiting it as a biomarker and as a therapeutic target, thus maximizing the benefits for the patient.
P03.06 Boolean logic puzzles as a neurosurgical mapping tool to preserve programming skill
Authors: Donders-Kamphuis M , Miller K J , van der Kallen B F W , Broekman M L D
Published: September 2021

BACKGROUND

In glioma surgery, awake craniotomy with Direct Electrical Stimulation (DES) is increasingly becoming the gold standard treatment to preserve language, cognition and motor function and to optimize extent of resection. Computer programming is historically seen as an integration of cognition, language, and mathematics but an intraoperative task to monitor computer programming does not exist yet. In this study we describe a new task for intraoperative monitoring, using visual Boolean Logic Puzzles.

MATERIAL AND METHODS

We describe a computer programmer who underwent awake craniotomy to resect an anaplastic astrocytoma in the left superior frontal gyrus. At the request of the patient we tested programming language. We developed a new task and set of logic puzzle visual stimuli to monitor underlying cognitive function used for programming language. This test was used during preoperative functional MRI (fMRI), direct electrical stimulation (DES) and ongoing monitoring during resection.

RESULTS

In fMRI this task showed bilateral activation in Brodmann area 6 and 8 and for left hemisphere in Brodmann area 10. These areas are below and lateral of the tumor. Monitoring of language, motor skills and Boolean mapping was performed during DES and while resection was performed. No deficits in programming ability could be identified intra- and postoperatively.

CONCLUSION

Boolean Logic Puzzles may be a useful intraoperative task to preserve programming skills.