bluuebunny/crossref_metadata_2025_split huggingface dataset:
Engineered lentivirus-derived nanoparticles (LVNPs) for delivery of CRISPR/Cas ribonucleoprotein complexes supporting base editing, prime editing and in vivo gene modification
Authors: Haldrup Jakob , Andersen Sofie , Labial Alexander Rafael LaVilla , Wolff Jonas Holst , Frandsen Frederik Plum , Skov Thomas Wisbech , Rovsing Anne Bruun , Nielsen Ian , Jakobsen Thomas Stax , Askou Anne Louise , Thomsen Martin K , Corydon Thomas J , Thomsen Emil Aagaard , Mikkelsen Jacob Giehm 
Published: September 2023

Abstract
Implementation of therapeutic in vivo gene editing using CRISPR/Cas relies on potent delivery of gene editing tools. Administration of ribonucleoprotein (RNP) complexes consisting of Cas protein and single guide RNA (sgRNA) offers short-lived editing activity and safety advantages over conventional viral and non-viral gene and RNA delivery approaches. By engineering lentivirus-derived nanoparticles (LVNPs) to facilitate RNP delivery, we demonstrate effective administration of SpCas9 as well as SpCas9-derived base and prime editors (BE/PE) leading to gene editing in recipient cells. Unique Gag/GagPol protein fusion strategies facilitate RNP packaging in LVNPs, and refinement of LVNP stoichiometry supports optimized LVNP yield and incorporation of therapeutic payload. We demonstrate near instantaneous target DNA cleavage and complete RNP turnover within 4 days. As a result, LVNPs provide high on-target DNA cleavage and lower levels of off-target cleavage activity compared to standard RNP nucleofection in cultured cells. LVNPs accommodate BE/sgRNA and PE/epegRNA RNPs leading to base editing with reduced bystander editing and prime editing without detectable indel formation. Notably, in the mouse eye, we provide the first proof-of-concept for LVNP-directed in vivo gene disruption. Our findings establish LVNPs as promising vehicles for delivery of RNPs facilitating donor-free base and prime editing without formation of double-stranded DNA breaks.
PL02.3.A NRG ONCOLOGY STUDY BN007: RANDOMIZED PHASE II/III TRIAL OF IPILIMIUMAB (IPI) PLUS NIVOLUMAB (NIVO) VS. TEMOZOLOMIDE (TMZ) IN MGMT-UNMETHYLATED (UMGMT) NEWLY DIAGNOSED GLIOBLASTOMA (NGBM)
Authors: Lassman A B , Polley M C , Iwamoto F M , Sloan A E , Wang T J C , Aldape K D , Wefel J S , Gondi V , Gutierrez A N , Manasawala M , Gilbert M R , Sulman E P , Wolchok J D , Greene R M , Neil E C , Lukas R V , Goldlust S A , Snuderl M , Dignam J J , Won M , Movsas B , Mehta M P 
Published: September 2023

Abstract

BACKGROUND
New therapies are especially needed for uMGMT nGBM. NRG Oncology BN002 (phase I) demonstrated safety and preliminary efficacy of Ipi+Nivo for nGBM, leading to BN007 as phase II/III.

METHODS
Adults with uMGMT nGBM (WHO 2016) and KPS ≥ 70 were randomized to RT and concurrent and adjuvant Ipi+Nivo or TMZ, stratified by glioma-recursive partitioning analysis class (RPA), intent to use tumor-treating fields (NCT04396860). Phase II primary endpoint was progression-free survival (PFS), powered 95% to detect a hazard ratio (HR) ≤0.58 with 1-sided 0.15 significance after 100 events. If p&lt;0.15, then phase III would accrue with overall survival (OS) as primary endpoint. Corticosteroids were disallowed at Ipi+Nivo start. Histology, biomarkers, and PFS were assessed centrally.

RESULTS
Among 374 patients screened, 159 were randomized in phase II (79 Ipi+Nivo, 80 TMZ). Demographics (age median 60 years, range 28-79; male 66%, white 88%, not Hispanic/Latino 89%), KPS (90-100 61%), extent of resection (gross total 65% per local PI), and RPA (III 10%, IV 73%, V 17%) were well-balanced between arms. After 100 PFS events, the pre-planned phase II analysis demonstrated no improvement for Ipi+Nivo vs. TMZ [median 7.7 (95% CI: 6.5, 8.5) vs. 8.5 (95% CI: 7.1, 10.4) months; HR 1.47 (95% CI: 0.98-2.2); 1-sided p=0.96]. OS is immature (&gt;50% alive, 13.7 months median follow-up) but without observed difference between arms [median ~13 months each; HR 0.95 (95% CI: 0.61-1.49); 1-sided p=0.36]. On the Ipi+Nivo arm, treatment-related grade 3, 4, and 5 events were reported in 26 (33.3%), 4 (5.1%), and 2 (2.6%; colitis and autoimmune disorder, n=1 each) patients.

CONCLUSION
Ipi+Nivo did not improve PFS for uMGMT nGBM. Accrual permanently closed after phase II. No new safety signals were identified. Molecular analyses and survival follow-up are ongoing. Funded by NCI Grants U10CA180868, U10CA180822, U24CA196067 (NRG Oncology Operations, SDMC, Specimen Bank).
KS01.5.A LATE BREAKING ABSTRACT: LONG-TERM FOLLOW-UP OF PATIENTS WITH NEWLY DIAGNOSED IDH-MUTANT ASTROCYTOMA AFTER IDH1-VAC TREATMENT
Authors: Bunse L , Lindner K , Wick A , Poschke I , Freitag A , Edelmann D , Lanz L , Breckwoldt M , Sahm F , Schmitt A , Schnell O , Hense J , Misch M , Krex D , Denk M , Steinbach J , von Deimling A , Schmitt M , Tabatabai G , Bendszus M , Wick W , Platten M 
Published: September 2023

Abstract

BACKGROUND
The Neurooncology Working Group of the German Cancer Society trial 16 (NOA16), a multicenter, single-arm, open-label, first-in-human phase I trial, met its primary endpoints in demonstrating safety and immunogenicity of a long peptide vaccine targeting IDH1(R132H) (IDH1-vac) added to standard of care in 32 patients with newly diagnosed World Health Organization (WHO) Grade 3 (n=21) and 4 (n=11) IDH1(R132H)+ astrocytomas (ClinicalTrials.gov identifier NCT02454634).

MATERIAL AND METHODS
Here, we report on the clinical and immunological long-term follow-up of NOA16. Data cut-off was May 2023.

RESULTS
Six-year progression-free and survival rates of patients in the safety data set were 0.47 (CI: 0.29 - 0.63) and 0.66 (CI: 0.46 - 0.79), respectively. Six-year progression-free and survival rates in the Grade 3 population were 0.52 (CI: 0.30 - 0.71) and 0.67 (CI: 0.43 - 0.83), respectively. Six-year progression-free and survival rates in the Grade 4 population were 0.55 (CI: 0.23 - 0.78) and 0.62 (CI: 0.28 - 0.84), respectively. Six-year progression-free and survival rates in patients with complete resection (n=17) were 0.82 (CI: 0.55 - 0.94) and 0.88 (CI: 0.61 - 0.97), respectively. Calculated via the Simon-Makuch method, patients in the immunogenicity dataset (n=30) with immune responses (IR) had six-year progression-free and survival rates of 0.46 (0.26 - 0.64) and 0.75 (CI: 0.55 - 0.87), respectively. Two patients without IR showed progressive disease (PD) within two years of first diagnosis and died within 3 years of first diagnosis. In one-year landmark analyses, best mutation-specific B cell response at the time point of last vaccination or later was associated with a favorable clinical course, suggesting a relevant but differential response to repetitive therapeutic vaccination regimes.

CONCLUSION
This data supports a randomized clinical trial of IDH-vac in patients with newly diagnosed IDH-mutant gliomas. A booster treatment regime should be considered as continuous source of IDH1R132H-reactive T cells.
JS09.6.A ASSESSMENT OF RESPONSE TO REGORAFENIB IN RECURRENT GLIOMA PATIENTS USING FET PET AND MRI INCLUDING ADC VALUES
Authors: Werner J , Lohmann P , Kabbasch C , Wollring M M , Tscherpel C , Stoffels G , Goldbrunner R , Langen K , Fink G R , Galldiks N 
Published: September 2023

Abstract

BACKGROUND
The phase 2 REGOMA trial suggested that glioblastoma patients treated with the multikinase inhibitor regorafenib at first progression have significantly longer overall survival than patients treated with lomustine. Here, we evaluated the value of O-(2-[18F]fluoroethyl)-L-tyrosine (FET) PET and MRI for the evaluation of response to regorafenib in recurrent glioma patients.

MATERIAL AND METHODS
Twenty patients (age range, 30-72 years) with CNS WHO grade 3 or 4 gliomas (glioblastoma, 85%) at recurrence were treated according to the REGOMA trial with regorafenib at 160 mg/d for the first three weeks of each 4-week cycle, with individual dose adjustment according to toxicity. FET PET and MRI were performed at baseline and follow-up after the second cycle. Static FET PET parameters comprised tumor-to-brain ratios (TBR) and metabolic tumor volumes (MTV). Parameters derived from dynamic FET PET acquisition were time-to-peak and slope. MRI response assessment was based on RANO criteria. Additionally, mean and minimum apparent diffusion coefficients (ADC) were obtained from diffusion-weighted MRI. FET PET parameters and ADC thresholds were defined using ROC analyses to predict an overall survival of ≥ 6 months. The predictive values of FET PET parameters, ADC values, and RANO criteria were subsequently evaluated using univariate and multivariate survival estimates.

RESULTS
Patients received a median of three regorafenib cycles (range, 2-10 cycles). After treatment initiation, the median follow-up was 8.6 months (range, 3.2-27.3 months). The median number of previous treatment lines was two (range, 1-4 lines). At the time of data analysis, 17 patients (85%) had died. After two cycles of regorafenib, a regorafenib-induced reduction of mean TBR values by ≥ 10% predicted a longer overall survival (9.9 vs. 5.3 months; P=0.023). Interestingly, absolute mean TBR values ≤ 2.0 at follow-up were prognostic and associated with longer OS (10.6 vs. 4.5 months; P=0.007). In contrast, MTV, dynamic PET parameters, RANO criteria, and ADC values were not predictive for response or prognostic (all P&gt;0.05). Multivariate survival analyses revealed that relative mean TBR changes were most potent in predicting response to regorafenib (P=0.038; HR, 0.246) and absolute mean TBR values for prognostication (P&lt;0.001; HR, 0.005).

CONCLUSION
Data suggest that FET PET parameters are clinically valuable for identifying responders to regorafenib early after treatment initiation and helpful for prognostication. MRI parameters, including ADC values, do not appear to add valuable information in this context.
P01.05.A COGNITIVE OUTCOMES IN ADULT MENINGIOMA PATIENTS AFTER SURGERY WITH OR WITHOUT RADIOTHERAPY
Authors: De Roeck L , Coolkens L , De Vleeschouwer S , Sleurs C , Lambrecht M 
Published: September 2023

Abstract

BACKGROUND
Meningioma patients often report cognitive complaints after therapy, profoundly impacting health-related quality of life. However, prevalence of these cognitive sequelae is inconsistent across trials. Moreover, meningioma patients often suffer from severe anxiety after treatment compared to healthy controls, possibly adversely affecting cognition.

MATERIAL AND METHODS
In this cohort study, 41 adult WHO grade 1 and 2 meningioma patients underwent comprehensive cognitive testing, covering the domains of memory, executive functioning, visuomotor functioning, attention, and language. Cognitive scores were transformed into z-scores using normative data adjusted for age, education, and sex. Patients were categorized as cognitively impaired if at least 2 tests scores differed ≥ - 1.5 SD or if at least 1 test score differed ≥ - 2.0 SD from the reference mean. Moreover, all patients filled out an online self-report inventory, assessing anxiety. Anxiety, age at diagnosis and treatment modality were included as predictors in a linear regression model per cognitive domain. Bonferroni correction was applied to correct for multiple testing.

RESULTS
In this cohort, 26 out of 41 patients showed cognitive impairment (63,4%) and the same number reported to have higher anxiety levels compared to the norm. Patients performed worse than the norm in cognitive domains of language and visuomotor functioning. No significant differences were found in cognitive outcomes regarding therapy, being either surgery (n=31) or surgery followed by cranial radiotherapy (n=10). Age at time of diagnosis was the only significant predictor of language (p=.005) and attention (p=.015) performance, with worse performance in case of diagnosis at younger age. No impact of anxiety nor treatment modality was found in this study.

CONCLUSION
More than half of meningioma patients showed to be cognitively impaired after surgery with or without radiotherapy treatment, mostly in domains of language and visuomotor functioning. Younger patients could be affected more by language and attention difficulties in their daily lives. Given their more active stage in life, this can have an important impact. This effect was independent of emotional functioning. These findings will need to be validated in larger prospective longitudinal trials.
P02.06.B DIELECTRIC PROPERTIES OF INTRACRANIAL TUMORS
Authors: Proescholdt M , Haj A , Schebesch K , Doenitz C , Hoehne J , Schmidt N 
Published: September 2023

Abstract

BACKGROUND
Recently, tumor treating fields (TTFields) were established for the treatment of newly diagnosed glioblastoma (GBM). One of the most crucial parameters defining the treatment efficacy of TTFields is the electric field intensity, which depends on the dielectric properties of the tumor tissue. In this study we determined the dieclectric properties of brain tumors by analyzing resected tissue following a fast acquisition protocol. In GBM patients, histological analysis for cellularity, vascularization and myelin content was performed. In addition, sensitivity analyses for specific parameters (tissue hydration, temperature, and saline irrigation) were conducted.

MATERIAL AND METHODS
A cohort of 130 patients with tumors of different histology and malignancy grade have been recruited (meningioma: n=36; brain metastases n=29; low grade glioma n=7; anaplastic glioma = 12; other= 7; glioblastoma n=39, all treated with TTFields). Tissue samples were placed into a cylindrical cell with a known diameter. The impedance was recorded at frequencies 20Hz-1MHz using a software specifically developed for this study. The measured impedance was translated into dielectric properties of the sample (conductivity and relative permittivity) based on the parallel plate model. Myelin, which is the most powerful electric isolator in the brain, was assessed in GBM samples by luxol fast blue staining, and quantified in a three-tier scale. To assess the impact of tissue conditions on the measurements, probes were warmed to 35 degree Celsius, dehydrated or irrigated with 0.9% saline solution.

RESULTS
We found significant differences between the conductivity of different types of tumors with meningiomas showing the lowest and GBM tissue exhibiting the highest conductivity values. GBM samples with very high median conductivity values displayed a consistently lower myelin content. In addition, GBM patients with particularly high conductivity had a significantly shorter overall survival (log rank analysis, p = 0.024). While tissue temperature had no detectable effects on the dielectric properties in GBM, saline irrigation tissue hydration significantly affected the results.

CONCLUSION
The dielectric properties of intracranial tumors depend on histological class and malignancy grade. GBM patients with high conductivity values showed a significantly poorer prognosis, indicating this parameter as potential marker for TTF efficacy.
P02.20.B PLASMA MEMBRANE-ASSOCIATED 70 KDA HEAT SHOCK PROTEIN (HSP70) INVOLVED IN GLIOBLASTOMA CELLS INVASION AS A TARGET FOR TUMOR THERANOSTICS
Authors: Shevtsov M , Yudintceva N , Bobkov D , Tagaeva R , Samochernykh K , Kim A , Nechaeva A , Fedorov E , Fedorov V , Nazaralieva E , Ten A , Combs S E 
Published: September 2023

Abstract

BACKGROUND
Heat shock proteins (HSPs) represent a large family of highly conserved proteins serving as molecular chaperones that play an important role in intracellular homeostasis. Apart from their intracellular localization, members of various HSPs families such as HSP70 have been reported to be expressed on the plasma membrane of malignant cells, including glioblastoma multiforme (GBM). However, the role of the membrane-bound protein Hsp70 has not yet been investigated in the pathophysiology of GBM.

MATERIAL AND METHODS
mHsp70 expression as related to GBM cell invasive potential was analyzed in biopsies obtained from neurooncological patients using CellVoyager CQ1 Benchtop High-Content Analysis System (Yokogawa) and inverted confocal microscopy (Leica Microsystems). Application of membrane-associated chaperone for targeted therapies was assessed in the intracranial human NCH644, NCH421k, and U87 GBM models in immunodeficient mice employing various chaperone inhibitors (i.e., JG-98, MKT-077, pifithrin-μ (PES)) as a monotherapy or in combination with a single dose of stereotactic irradiation (10Gy) (SARRP).

RESULTS
Live-cell imaging of the patient-derived biopsies demonstrated the increased cellular density of mHsp70+ GBM cells particularly in the tissue along the tumor-brain margin. Time-lapse evaluation of the tumor sample further proved the migration of mHsp70+ cells into the surrounding normal brain tissues. Subsequent high-powered multiplex immunofluorescence analysis (Akoya Biosystems) confirmed significantly increased single-cell infiltration of mHsp70+ tumor cells (also positively stained for Nestin, Oct4, and SOX2) in the normal brain tissues. When mHsp70 inhibitors were applied in GBM animal models as a monotherapy or in combination with radiotherapy dramatic inhibition of tumor progression (as shown by MRI) and increased animal survival were observed.

CONCLUSION
Expression of the mHsp70 on the plasma membrane of GBM cells corresponds to the highly invasive potential of the tumor cells in neuro-oncological patients. Administration of the HSP70 small molecular inhibitors significantly decreased the GBM growth and invasion thus prolonging the overall survival of tumor-bearing mice. Further development of mHsp70-targeted agents represents a promising approach in treatment of multiforme glioblastoma.
P03.09.B LOW DOSE BATH FROM RADIOSURGERY TO SURROUNDING NORMAL BRAIN IN TREATMENT OF BRAIN METASTASES COULD STERILIZE BRAIN AND INHIBIT RECURRENCES
Authors: Mader T , Bhutto S , Tranter J , Martins Gomes L F , Hawkins M , Spyridonidis A , Baumert B G 
Published: September 2023

Abstract

BACKGROUND
Stereotactic radiosurgery and fractionated stereotactic radiotherapy (SRS/fSRT) are standard treatments for brain metastases. Each SRS/fSRT plan has a low-dose penumbra outside the high dose area, which multiplies if multiple metastases are irradiated and results in a low-dose bath in healthy brain tissue. We hypothesize that a certain dose of the low-dose bath can sterilize brain tissue and prevent local recurrences. We present first data of an ongoing project.

MATERIAL AND METHODS
Data of fifty-three patients with brain metastases treated with single fraction SRS or fractionated fSRT at our institute between 2020 and 2022 were reviewed retrospectively. All patients with at least one cranial follow-up MRI after 3 months were evaluated. Follow-up MRI scans were fused to the original treatment plans. New metastases in the isodose-volumes of 10 Gy-, 8 Gy-, 6 Gy-, 4 Gy-, and 2 - Gy were identified and evaluated. Mean doses, on the site of the new lesions, received from SRS/fSRT were tabulated summarized and analyzed.

RESULTS
Six of the 53 patients met the inclusion criteria. Five patients developed recurrent brain metastases out-of-field within 2-4 months of follow-up. One metastasis was observed outside the irradiation field. One patient developed no new metastases. With decreasing isodose levels an increasing number of new metastases were observed: In the reconstructed volume of 10Gy (V10Gy), V8Gy and V6Gy two metastases each, no metastases in the V4Gy and 5 metastases in the V2Gy. No toxicities were observed.

CONCLUSION
Our data suggest a trend towards a benefit that the low-dose bath as part of the penumbra of stereotactic radiotherapy sterilizes brain tissue. Especially, brain regions receiving doses of 4 Gy or more had fewer new lesions compared to regions that received less than 4 Gy. This should be further validated prospectively in larger patient populations, in clinical trials with combination of CNS-accessible immunotherapy like Osimertinib. Indications for whole brain radiotherapy could be further reduced. Low dose spillage with manageable risks might be sufficient to treat microscopic brain metastases in the future.
P03.16.A ROLE OF BRD9 IN REGULATING RADIOTHERAPY INDUCED CHANGES IN CHROMATIN ARCHITECTURE OF GBM
Authors: Celikkol S A , Pinarbasi-Değirmenci N , Bagci-Onder T 
Published: September 2023

Abstract
Glioblastoma (GBM) is the most common, formidable, and aggressive type of adult brain tumor, with a poor prognosis. The standard treatment strategies are surgical resection, followed by radiotherapy and accompanying chemotherapy. However, 90% of patients suffer from recurrence of the disease due to the radiation resistance and chemotherapy resistance of glioblastoma cells, which exacerbate the success of the treatment, and thus, resistance remains one of the most important obstacles to overcome. The advances in molecular biology revealed that therapy resistance is related with alterations in DNA repair pathways as well as epigenetic changes governed by histone modifications and chromatin remodeling. Therefore, understanding the underlying epigenetic mechanisms that are involved in the DNA damage response has the potential to develop effective therapeutic strategies. In this manner, an epigenetic drug screen is conducted to identify novel epigenetic modifiers and their inhibitors as radiosensitizers. Bromodomain containing 9 (BRD9) was selected as target modifier while iBRD9 is selected as the radiosensitizer. Inhibition of BRD9 with a common probe, iBRD9 reduced cell viability and colony formation when combined with different doses of radiotherapy. Also, as an acetylated histone reader, inhibition of BRD9 increased the number of acetylated histones as shown by Western Blotting; where Belinostat treatment served as positive control. Currently, our efforts are directed towards understanding which genes are directly targeted by BRD9 in the presence and absence of radiotherapy. To this end, we have ectopically expressed Flag-tagged BRD9 and confirmed its expression by Western Blots. We showed that BRD9 was mainly localized to nucleus. Using this tool, we will perform ChIP sequencing and reveal radiotherapy induced changes in BRD9 binding sites.
P04.04.A GENOME-WIDE CRISPR/CAS9 KNOCKOUT SCREENS REVEAL EPIGENETIC REGULATORS AS DRUGGABLE TARGETS FOR SONIC HEDGEHOG MEDULLOBLASTOMA
Authors: Tsiami F , Piccioni F , Root D , Bandopadhayhay P , Segal R , Tabatabai G , Merk D 
Published: September 2023

Abstract

BACKGROUND
Sonic hedgehog medulloblastoma (SHH-MB) is a malignant pediatric brain tumor that accounts for 30% of all MBs and is characterized by constitutive activation of the SHH signaling pathway. Besides the standard-of-care therapies, current therapies are targeting Smoothened (SMO) receptor, in order to inhibit the pathway. However, acquired or de novo resistance against SMO inhibition limits its efficacy. Therefore, our aim is to unravel novel therapeutic targets for SHH-MB, potentially beyond the SHH pathway.

MATERIAL AND METHODS
We performed genome-wide CRISPR/Cas9 knockout screens, in order to decipher cancer dependencies and synthetic lethal interactors for SHH-MB. The hits identified were first validated genetically and pharmacologically in in vitro assays, while further molecular analyses including RNAseq and differential methylation were also conducted. Moreover, the identified hits were evaluated in in vivo mouse models representing normal cerebellar, as well as SHH-MB development.

RESULTS
Functional genomics identified members of the epigenetic machinery, such as Dnmt1 and Smarca5 as context-specific dependencies for SHH-MB. We prove that DNMT1 inhibition is efficacious against SMO-resistant and sensitive SHH-MB cell lines, by inhibiting SHH pathway output, as shown via RNAseq. A further knockout drug screen unraveled novel synthetic lethal interactors for DNMT1 inhibitors. Genetic ablation and pharmacological inhibition of epigenetic regulators prolongs survival of established mouse models of SHH-MB.

CONCLUSION
Summarizing, our data indicate inhibitors of epigenetic regulators as novel therapeutic targets for SHH-MB irrespective of mutational drivers within the SHH pathway. We further propose combinatorial treatment approaches for this tumor entity that involve DNMT1 inhibitors.