bluuebunny/crossref_metadata_2025 huggingface dataset:
The Vulnerability of Indonesian Smallholder Oil Palm Farmers in the Times of Global Crisis
Authors: Novira Nina
Published: June 2023

Since 2010, Indonesia has overtaken Malaysia as the biggest palm oil producer in the world. From around 12,7 million hectares of oil palm plantation spread across the country (2017), more than one third belonged to smallholder farmers. Almost all of those smallholder farmers do not possess any processing skill, thus they are dependent on oil palm mills to sell the fruit bunch. The export-oriented nature of palm oil resulted in the price fluctuation that follows global dynamics. With case studies in four villages in Labuhan Batu Utara Regency, this paper seeks to explore the awareness of how such conditions could impact the economic resilience of oil palm smallholder farmers during the global crisis and explore the near-future strategy to overcome it. The study used a qualitative approach using the in-depth interview to interview smallholder oil palm farmers, village officials, oil palm fruit middlemen, and related local government agency officials. The results show that smallholder oil palm farmers are most vulnerable in multiple aspects. The understanding of the relation of the price fluctuation to the global political and economical dynamics is gained through literature study. The lack of processing skills of farmers do not allow any possibility for an added value to the oil palm fruit, hence selling the fresh fruit immediately after harvest is the only option. Since selling is the only option, while on the other hand they do not hold any power to determine the price, little can be done when price slumps due to global dynamics. The farmers as well as the local leaders and government agency officials do not aware of the threat this may pose. Therefore, no agenda is currently set yet to strengthen the farmers’ resilience or in the near future.
Economic valuation of cattle farm development in Mondokan Sub-district, Sragen Regency
Authors: Irawan Sunu W J B , Sutrisno Djoko , Setyono Prabang
Published: June 2023

Agricultural development in Mondokan Sub-district encounters water scarcity which limits access to clean water for consumption and cultivation. This problem is exacerbated by shifting seasons due to global warming. The limited supply of water affects the cropping patterns of the community. Rice is planted in the rainy season and corn is planted inshifting between the dry and rainy season. Meanwhile, during the dry season, the field is abandoned. This cropping pattern has an impact on the economic level of the community. The dependence on cultivation as the main livelihood of the community needs to be solved through other alternatives, including animal husbandry. Cattle farm development in Mondokan Sub-district is supported by the environmental capacity of up to 9 million livestock units. However, the large capacity requires support in the livestock economy. The cattle farm development requires an economic valuation to obtain more significant benefits than cultivation. The economic valuation for the development of cattle farms employed the cost-benefit analysis method. The samples were farmers from Pare Village of Mondokan Sub-district who already have livestocks. The valuation assessment used the breeding system. The results of the economic valuation based on benefit and cost analysis indicate that cattle farming in Mondokan Sub-district is feasible.
Aquifer zone identification using VES method for agricultural irrigation in the southern part of Sukoharjo
Authors: Koesuma Sorja , Maulana Rahma
Published: June 2023

One of Indonesia’s regencies known for its agricultural land is Sukoharjo. The shortage of irrigation water has caused many problems in past years. The purpose of the research was to better understand the subsurface structure to increase the effectiveness of drilling in deep groundwater. Schlumberger’s configuration with a deep aquifer irrigation target zone was used to conduct the investigation. The track’s length is between 275 and 300 meters. Information obtained about the depth of the aquifer zone in the southern part of Sukoharjo is estimated to range from 4.83 to 155.79 meters. In the southern part of Sukoharjo, most of the ground cover consists of layers of sediment, limestone, and sandy clay.
Class-Room
Authors: Lawrence D. H.
Published: June 2023

A school-day was drawing to a close. In the class-room the last lesson was in progress, peaceful and still. It was elementary botany. The desks were littered with catkins, hazel and willow, which the children had been sketching. But the sky had come...
Totem
Authors: Lawrence D. H.
Published: June 2023

In the morning Gerald woke late. He had slept heavily. Pussum was still asleep, sleeping childishly and pathetically. There was something small and curled up and defenceless about her, that roused an unsatisfied flame of passion in the young man’s blood, a devouring avid...
Breadalby
Authors: Lawrence D. H.
Published: June 2023

Breadalby was a Georgian house with Corinthian pillars, standing among the softer, greener hills of Derbyshire, not far from Cromford. In front, it looked over a lawn, over a few trees, down to a string of fish-ponds in the hollow of the silent park....
Water-Party
Authors: Lawrence D. H.
Published: June 2023

Every year Mr Crich gave a more or less public water-party on the lake. There was a little pleasure-launch on Willey Water and several rowing boats, and guests could take tea either in the marquee that was set up in the grounds of the...
Sunday Evening
Authors: Lawrence D. H.
Published: June 2023

As the day wore on, the life-blood seemed to ebb away from Ursula, and within the emptiness a heavy despair gathered. Her passion seemed to bleed to death, and there was nothing. She sat suspended in a state of complete nullity, harder to bear...
The Industrial Magnate
Authors: Lawrence D. H.
Published: June 2023

In Beldover, there was both for Ursula and for Gudrun an interval. It seemed to Ursula as if Birkin had gone out of her for the time, he had lost his significance, he scarcely mattered in her world. She had her own friends, her...
Rabbit
Authors: Lawrence D. H.
Published: June 2023

Gudrun knew that it was a critical thing for her to go to Shortlands. She knew it was equivalent to accepting Gerald Crich as a lover. And though she hung back, disliking the condition, yet she knew she would go on. She equivocated. She...
Gladiatorial
Authors: Lawrence D. H.
Published: June 2023

After the fiasco of the proposal, Birkin had hurried blindly away from Beldover, in a whirl of fury. He felt he had been a complete fool, that the whole scene had been a farce of the first water. But that did not trouble him...
Excurse
Authors: Lawrence D. H.
Published: June 2023

Next day Birkin sought Ursula out. It happened to be the halfday at the Grammar School. He appeared towards the end of the morning, and asked her, would she drive with him in the afternoon. She consented. But her face was closed and unresponding,...
Death and Love
Authors: Lawrence D. H.
Published: June 2023

Thomas Crich died slowly, terribly slowly. It seemed impossible to everybody that the thread of life could be drawn out so thin, and yet not break. The sick man lay unutterably weak and spent, kept alive by morphia and by drinks, which he sipped...
Marriage or Not
Authors: Lawrence D. H.
Published: June 2023

The Brangwen family was going to move from Beldover. It was necessary now for the father to be in town.

Birkin had taken out a marriage licence, yet Ursula deferred from day to day. She would not fix any definite time—she still wavered. Her month’s...
Gudrun in the Pompadour
Authors: Lawrence D. H.
Published: June 2023

Christmas drew near, all four prepared for flight. Birkin and Ursula were busy packing their few personal things, making them ready to be sent off, to whatever country and whatever place they might choose at last. Gudrun was very much excited. She loved to...
Continental
Authors: Lawrence D. H.
Published: June 2023

Ursula went on in an unreal suspense, the last weeks before going away. She was not herself,—she was not anything. She was something that is going to be—soon—soon—very soon. But as yet, she was only immanent.

She went to see her parents. It was a...
Exeunt
Authors: Lawrence D. H.
Published: June 2023

When they brought the body home, the next morning, Gudrun was shut up in her room. From her window she saw men coming along with a burden, over the snow. She sat still and let the minutes goby.

There came a tap at her door....
Longitudinal Associations Between Sleep and Cognitive Function in a Cohort of Older Puerto Rican Adults: Sex and Age Interactions
Authors: Arévalo Sandra P , Nguyen-Rodriguez Selena T , Scott Tammy M , Gao Xiang , Falcón Luis M , Tucker Katherine L
Published: June 2023

Background

Evidence on sleep duration or quality and cognitive function in diverse older adults is limited. We examined prospective associations between subjective sleep measures and cognitive function, with modifying effects of sex and age (<65 vs ≥65 years).

Methods

Data are from the longitudinal Boston Puerto Rican Health Study, Waves 2 (n = 943) and 4 (n = 444), with mean follow-up of 10.5 years (range 7.2–12.8). Subjective measures of sleep duration (short <7, ref. 7, or long ≥8 hours) and insomnia symptoms (sum of difficulty falling asleep, waking up at night, and early morning awakening), were assessed at Wave 2. Linear regression models were used to assess changes in global cognition, executive function, memory, and Mini-Mental State Examination, and tested for modifying roles of sex and age.

Results

Significant 3-way interaction (sex × age × cognition) in fully adjusted models showed greater decline in global cognitive function in older men with short (β [95% confidence interval]: −0.67 [−1.24, −0.10]) or long sleep duration (−0.92 [−1.55, −0.30]), compared to women, younger men, and older men with 7 hours of sleep. Insomnia symptoms were associated with a greater decline in memory (−0.54, [−0.85, −0.22]) among older men, compared to women and younger men.

Conclusion

Sleep duration showed a U-shaped association with cognitive decline, and insomnia symptoms were associated with memory decline in fully adjusted models. Older men, versus women and younger men, were at relatively greater risk for cognitive decline associated with sleep factors. These findings are important for personalizing sleep interventions to support cognitive health.
Supplementing the Carbohydrate Structure Database with glycoepitopes
Authors: Toukach Philip V
Published: June 2023

Carbohydrate structures in the Carbohydrate Structure Database have been referenced to glycoepitopes from the Immune Epitope Database allowing users to explore the glycan structures and contained epitopes. Starting with an epitope, one can figure out the glycans from other organisms that share the same structural determinant, and retrieve the associated taxonomical, medical, and other data. This database mapping demonstrates the advantages of the integration of immunological and glycomic databases.
Diagnostic challenge: primary leptomeningeal melanoma with melanomatosis, illustrative case report
Authors: El Ouazzani Hafsa , Oudghiri Mohammed Yassaad , Abbas Salma , Regragui Asmaa , Elouahabi Abdessamad , Zouaidia Fouad , Cherradi Nadia
Published: June 2023

Primary leptomeningeal melanoma is an extremely rare type of intracranial melanoma. It cannot be reliably distinguished from metastatic melanoma on neuroimaging and histopathological characteristics alone; its diagnosis is established only after exclusion of secondary metastatic disease from a cutaneous, mucosal or retinal primary. Prognosis is poor, partly due to its high rate of misdiagnosis. Herein, we report a case of a primary meningeal melanoma of the skull base with melanomatosis, in a 31-year-old man, mimicking meningioma. Our aim is to highlight the diagnostic pitfalls and to discuss the histopathological differential diagnoses, especially with other pigmented lesions of central nervous system.
UHECR echoes from the Council of Giants
Authors: Taylor A M , Matthews J H , Bell A R
Published: June 2023

Recent anisotropy studies of UHECR data at energies ≳40 EeV have disclosed a correlation of their angular distribution with the extragalactic local structure, specifically with either local starburst galaxies or AGN. Using Monte Carlo simulations taking into account photodisintegration processes, we further explore a framework in which these UHECRs were accelerated by Centaurus A in a recent powerful outburst before being scattered by magnetic fields associated with local, Council of Giant, extragalactic structure. We find that the observed intermediate-scale anisotropies can be accounted for by the Council of Giant structure imposing a response function on the initial outburst of UHECRs from a single source located at Centaurus A’s position. The presence of these local structures create ‘echoes’ of UHECRs after the initial impulse and focusing effects. The strongest echo wave has a lag of ∼20 Myr, comparable to the age of synchrotron-emitting electrons in the giant Centaurus A lobes. Through consideration of the composition of both the direct and echo wave components, we find that the distribution of the light (1 < ln A < 1.5) component across the sky offers exciting prospects for testing the echo model using future facilities such as Auger prime. Our results demonstrate the potential that UHECR nuclei offer, as ‘composition clocks’, for probing propagation scenarios from local sources.
Exploring binary black hole mergers and host galaxies withsharkand COMPAS
Authors: Rauf Liana , Howlett Cullan , Davis Tamara M , Lagos Claudia D P
Published: June 2023

We explore the connection between the gravitational wave (GW) merger rates of stellar-mass binary black holes (BBHs) and galaxy properties. We do this by generating populations of stars using the binary population synthesis code COMPAS and evolving them in galaxies from the semi-analytic galaxy formation model Shark, to determine the number of mergers occurring in each simulation time-step. We find that metal-rich and massive galaxies with star formation rate (SFR) greater than $1\, {\rm M}_{\odot }\, \rm yr^{-1}$ are 10 times more likely to have GW events compared to younger, less massive, and metal-poor galaxies. Our simulation with the default input parameters predicts a higher local merger rate density compared to the third GW transient catalogue (GWTC-3) prediction from LIGO, VIRGO, and KAGRA, due to short coalescence times, low metallicities, and a high SFR at low redshift in the simulation, which produces more BBHs that merge within the age of the Universe compared to observations. We identify alternate remnant mass models that more accurately reproduce the volumetric rate and provide updated fits to the merger rate as a function of redshift. We then investigate the relative fraction of GW events in our simulation that are in observable host galaxies from upcoming galaxy surveys, determining which of those are ideal for tracing host galaxies with high merger rates. The implications of this work can be utilized for constraining stellar evolution models, better informing follow-up programs, and placing informative priors on host galaxies when measuring cosmological parameters such as the Hubble constant.
ATRT-12. HYPERACTIVATING THE INTEGRATED STRESS RESPONSE WITH PROTEASOME INHIBITION IN AT/RT
Authors: Novak Orlandi , Findlay Tyler , Rubens Jeffrey , Eberhart Charles , Raabe Eric
Published: June 2023

Atypical teratoid/rhabdoid tumor (AT/RT) is an aggressive pediatric brain tumor with a poor prognosis. AT/RT has increased baseline activation of the integrated stress response (ISR), an evolutionarily conserved system that enables cells to tolerate various forms of stress. Elevated expression of ATF4 indicates activation of the ISR. Transient or low-level expression of this transcription factor protects cells from stress, while sustained, high-level activation results in cell death. Ixazomib is an orally bioavailable proteasome inhibitor that causes endoplasmic reticulum stress, which is a major upstream activator of the ISR. Because AT/RT has a high baseline level of ATF4, we hypothesized that this tumor would be susceptible to ISR activators such as ixazomib. After determining the IC50 of ixazomib, AT/RT cell lines were treated with increasing concentrations of the drug. Cleaved caspase-3 immunofluorescence showed a significant increase of apoptosis (CHLA06 p<0.0001 by ANOVA). We are currently testing ixazomib in combination with idarubicin, a brain-penetrant anthracycline, and gemcitabine, a brain-penetrant nucleoside analog. Synergy testing in CHLA06 showed an overall zero-interaction-potency (ZIP) synergy score of 23.464 with inhibitory concentrations of ixazomib and idarubicin in the low nanomolar range (scores of 10 or above indicate synergy). Similarly, ixazomib and gemcitabine synergized to suppress CHLA06 growth and induce apoptosis (67% Annexin V+ cells in combination compared to 14 and 24% Annexin V+ with single agent treatment). In the future, we will determine if ixazomib selectively kills AT/RT while sparing normal cells in iPSC brain organoids. We will also test ixazomib in orthotopic xenografts of AT/RT. These results suggest that ixazomib, especially in combination with idarubicin, gemcitabine or other ISR activators, has the potential to serve as an effective therapy for AT/RT.
ATRT-16. THE PI3K INHIBITOR PAXALISIB COMBINES SYNERGISTICALLY WITH THE MEK INHIBITOR MIRDAMETINIB TO TARGET ATYPICAL TERATOID/RHABDOID TUMORS
Authors: Malebranche Kristen , Findlay Tyler , Geethadevi Anupa , Eberhart Charles , Raabe Eric , Rubens Jeffrey
Published: June 2023

Atypical teratoid/rhabdoid tumors (AT/RT) are aggressive pediatric brain tumors and the most common malignant brain tumors of infancy. The four-year event-free survival rate is only 37%. There are limited treatment options for patients with relapsed AT/RT, but precision therapies may help improve survival for patients with this deadly disease. We have previously identified strong activation of the PI3K-AKT-mTOR (mTOR) signaling pathways in AT/RT. Paxalisib is a highly brain-penetrant PI3K inhibitor acting upstream of mTOR. We find that Paxalisib slows tumor growth in orthotopic xenograft models of AT/RT and extends median survival from 40 to 54 days (p=0.001, log-rank test). RNASeq after mTOR pathway inhibition identifies reflexive activation of the RAS-RAF-MEK-ERK (MAPK) pathway as a possible mechanism of therapy resistance (KEGG pathway analysis). The RAS-RAF-MEK-ERK (MAPK) pathway plays a pivotal role in regulating cell growth and survival and activation of the pathway which contributes to the aggressive growth of numerous cancers. Mirdametinib is a small, allosteric MEK inhibitor currently used in clinical trials for both pediatric low- and high-grade gliomas (PD0325901). We find that dual inhibition of both the mTOR and MAPK pathways by Paxalisib and Mirdametinib synergize to reduce AT/RT growth and viability (Bliss synergy score 16.77). Paxalisib also combines with Mirdametinib to induce high levels of apoptosis and cell senescence (as determined by western blot: cPARP, pRB, P21, P16). Naïve treatments and a current survival study in mice bearing AT/RT orthotopic tumors suggest that combination therapy decreases mTOR and MAPK pathway activation (as determined by western blot). These data support using Paxalisib and Mirdametinib combination therapy as a promising novel therapy to treat relapsed AT/RT.
BIOL-06. UNDERSTANDING OLIGODENDROCYTE PROGENITOR CELL CONTRIBUTION TO GLIOMAGENESIS USING A NOVEL PHARMACOGENETIC ABLATION TOOL
Authors: Xing Lulu , Merson Tobias , Petritsch Claudia
Published: June 2023

In the central nervous system (CNS), gliomas represent almost 50% of all pediatric tumors and due to their complex histological and biological heterogeneity, aggressive standard treatment consisting of surgery and chemoradiotherapy remains ineffective. As a result, more biologically based therapies are urgently needed, and this requires a deeper knowledge of the etiology and biology of gliomas and the tumor microenvironment. Oligodendrocyte progenitor cells (OPCs) are a potential origin of human gliomas (as suggested by studies in genetically engineered mouse models) and human OPC-like tumor cells contribute to tumor heterogeneity and malignancy. Resident (non-neoplastic) OPCs have been found to intermix with glioma cells and proliferate within the tumor microenvironment. The significance of the interactions of resident OPCs and glioma cells remains unknown. We hypothesize that resident OPCs functionally integrate into the tumor cell network and affect tumor properties. We have generated a novel mouse model of conditional OPC ablation to overcome methodological challenges of most current approaches that often result in partial and transient OPC ablation, which limits our understanding of long-term function of OPCs. Here in our study, we have successfully developed a novel pharmacogenetic model of conditional OPC ablation, eliminating 98.6% of all OPCs throughout the mouse brain for up to 12 days post ablation. In the future, we plan to combine the mouse model of complete OPC ablation with orthotopic glioma models to reveal the longitudinal and spatial functional roles and the necessity for resident OPCs in the tumor context. Understanding the OPC-tumor cell crosstalk by using our state-of-the-art approach at both cellular and molecular levels will have significant clinical implications for improving treatment for patients with pediatric gliomas.
BIOL-08. RADIATION DRIVES METASTASIS IN MEDULLOBLASTOMA THROUGH AN INFLAMMATORY PROCESS
Authors: Nor Carolina , Kharas Kaitlin , Rasnitsyn Alexandra , Vladoiu Maria , Ramaswamy Vijay , Raleigh David , Taylor Michael
Published: June 2023

Current treatment for medulloblastoma is comprised of surgery, radiotherapy (RT) and/or chemotherapy. Although the primary tumor is controlled with this approach, recurrent metastatic disease is ubiquitously fatal. However, little is known about the biology of metastatic recurrences in medulloblastoma. In the present study, we observe across 3 non-overlapping cohorts of infant medulloblastoma that patients recur locally without focal RT and metastatically after focal RT. Using 3 independent murine flank xenograft medulloblastoma models, we found that the incidence of leptomeningeal metastasis was significantly increased in mice that received RT compared to sham controls. We have also found a significant increase in viable circulating tumor cells after RT. Our multi-omics (bulk RNA-seq, scRNA-seq and proteo/phosphoproteomics) approach using immunocompetent sporadic medulloblastoma models treated with RT showed activation of the innate inflammatory response through the overexpression of chemokines, cytokines and activation of immune cell types. In situ analysis of protein expression after RT showed a gradual increase in the abundance of macrophages, neutrophils and dendritic cells after RT, suggesting increased permeability and cell trafficking across the blood brain barrier. Applying live intravital microscopy using a low molecular weight vascular dye (150kDa), we observed a striking increase in blood vessel permeability in RT vs sham-treated brain tumors. Our observations support a model where RT drives metastasis through inflammation. To test this, we applied lipopolysaccharide (LPS), an inflammation inducing treatment, to a sporadic murine medulloblastoma model which significantly increased the metastatic burden. We then treated a xenograft model with dexamethasone in combination with RT, which resulted in total abrogation of metastatic dissemination compared to RT alone. Collectively, our findings suggest that while external beam irradiation is an effective and essential treatment for medulloblastoma, it may facilitate metastatic dissemination through an inflammation-induced process. These findings can help inform potential approaches to prevent disseminated relapsed disease.
BIOL-09. PROTEOMIC ANALYSES REVEAL THAT CO-CULTURE OF DIFFUSE INTRINSIC PONTINE GLIOME (DIPG) WITH CORTICAL ORGANOIDS ALTERS CELL ADHESION, DNA SYNTHESIS AND REPLICATION, AND DENDRITIC GROWTH SIGNALLING
Authors: Prior Victoria , Maksour Simon , Miellet Sara , Hulme Amy , Mirzaei Mehdi , Wu Yunqi , Dottori Mirella , O’Neill Geraldine
Published: June 2023

Diffuse Intrinsic Pontine Gliomas (DIPGs) are deadly brain cancers in children for which there is currently no effective treatment. In part, this can be attributed to preclinical models that lack essential elements of the in vivo tissue environment, resulting in treatments that appear promising preclinically, but fail to result in effective cures. Recently developed co-culture models combining stem cell-derived brain organoids with brain cancer cells provide tissue dimensionality and a human-relevant tissue-like microenvironment. As these models are technically challenging and time consuming it is imperative to establish whether interaction with the organoid influences DIPG biology and thus warrants their use. To address this question, we cultured DIPG cells with GFP-expressing cortical organoids. We created “mosaic” co-cultures enriched for tumour cell-neuronal cell interactions, where disaggregated spheroids and organoids were mixed and allowed to reform, versus “assembloid” co-cultures enriched for tumour cell-tumour cell interactions, where preformed tumour spheroids and organoids were combined. Sequential window acquisition of all theoretical mass spectra (SWATH-MS) was used to analyse the proteomes of DIPG fractions isolated by flow-assisted cell sorting. Control proteomes from DIPG spheroids were compared with DIPG cells isolated from mosaic and assembloid co-cultures. This revealed that tumour cell adhesion was reduced, and DNA synthesis and replication were increased, in DIPG cells under either co-culture condition. By contrast, the mosaic co-culture was alone associated with pathways implicated in dendrite growth. We propose that co-culture with brain organoids is a valuable tool to parse the contribution of the brain microenvironment to DIPG tumour biology.
BIOL-11. PRECLINICAL MODELLING OF PEDIATRIC BRAIN TUMORS USING ORGANOID TECHNOLOGY
Authors: Roosen Mieke , Meulenbroeks Chris , Stathi Phylicia , Maas Joris , Morscio Julie , Bunt Jens , Kool Marcel
Published: June 2023

Molecular characterization has resulted in improved classification of pediatric brain tumors, leading to many novel (sub)types with distinct oncodriving events. To study tumor biology and to perform translational research on each of these tumors, preclinical models are essential. However, we are currently lacking sufficient models, especially in vitro, to represent each (sub)type and their heterogeneity.

To generate large series of preclinical in vitro models for pediatric brain tumors, we are using organoid technology. Cells from patient samples and patient-derived xenograft samples have been taken into culture to establish 3D organoids using tumor type specific culture conditions. These organoid lines retain the molecular characteristics of the original tumor tissue. They can be used to perform high-throughput drug screens, genetic manipulations, and co-cultures with, for instance, immune cells.

Viable tissue is not always available for all tumor (sub)types and specific oncodrivers. To circumvent this lack of tissue, we can also induce tumors in vitro. Therefore, we generate cerebral and cerebellar brain organoids from human pluripotent stem cells. These organoids mimic human developing brain cells and can be genetically manipulated to model different brain tumor types. These genetically engineered brain tumor models allow us to study the cellular origins of pediatric brain tumors and the different tumor driving mechanisms. Tumors induced in the brain organoids histologically and molecularly resemble human patient samples based on (single cell) transcriptomic analyses. Moreover, the tumor cells are able to establish xenografts in mouse brains.

In summary, organoid technology provides a novel avenue to establish in vitro models for pediatric brain tumors. At the meeting we will present data for various new ependymoma, medulloblastoma and embryonal brain tumor organoid models.
BIOL-23. LOSS OF MICRORNAS COOPERATES WITH TUMOR SUPPRESSORS TO INITIATE MYC-DEPENDENT METASTATIC MEDULLOBLASTOMA
Authors: Llaguno Sheila Alcantara , Nazarenko Inga , Chen Yuntao , Sun Daochun , Gudenas Brian , Saulnier Olivier , Rocca Gaspare La , Pedraza Alicia , Burns Dennis , Bale Tejus , Ventura Andrea , Northcott Paul , Taylor Michael , Parada Luis
Published: June 2023

To determine the role of microRNA regulation in brain tumor development, we incorporated a conditional allele of the microRNA processing enzyme Dicer to a glioma mouse model based on inactivation of the tumor suppressors Nf1, Trp53, and Pten using the Nestin-creERT2 transgene. Loss of Dicer and tumor suppressors at adult ages led to glioma development; however, mutant mice tamoxifen induced at early postnatal ages developed medulloblastoma (MB) instead of glioma. The switch in tumor spectrum occurred with 100% penetrance and the cerebellar tumors were histologically indistinguishable from human MB. The minimum genetic mutations required for MB formation were Dicer1 and Trp53, while additional loss of Pten produced more invasive tumors with leptomeningeal metastasis. Analysis of tumor transcriptome and MB subtype-specific markers show that Dicer tumors most resemble human Sonic Hedgehog (SHH) MB. The presence of leptomeningeal metastasis, Trp53 loss and upregulation of Mycn and Gli2 in the setting of activated Shh signaling suggests that this model phenocopies extremely high risk p53-mutated SHH MB, which carries poor prognosis and is associated with the majority of treatment failures in SHH MB. Analysis of pre-symptomatic mutant mice showed proliferative defects and retained cells in the external granule cell layer (EGL), suggesting that tumors may arise from cerebellar granule neuron precursors (CGNPs). However, targeting CGNPs using Math1-creERT2 did not lead to MB development, suggesting that an earlier EGL precursor may be required for tumorigenesis. Dicer tumors exhibit reduced microRNAs and RNA-induced silencing complexes consistent with loss of Dicer. One of these downregulated microRNAs, miR-101, is a regulator of Mycn and its overexpression leads to Mycn downregulation and inhibition of MB growth. Likewise, genetic and pharmacologic inhibition of Myc leads to inhibition of MB growth. These studies demonstrate a role for microRNAs in Myc-dependent MB development and show an alternative pathway for SHH MB tumorigenesis.
DIPG-06. PRECLINICAL EVALUATION OF A NOVEL ACVR1 INHIBITOR IN DIFFUSE INTRINSIC PONTINE GLIOMAS
Authors: Kumar Shiva Senthil , Shoffner Rebecca , Devine Brendan , Drissi Rachid
Published: June 2023

Diffuse intrinsic pontine glioma (DIPG) is an incurable brain disease in children. DIPG is refractory to current available therapies. Hence, new therapeutic approaches are urgently needed. About 80% of DIPGs harbor histone 3 lysine to methionine (H3K27M) mutation, in H3-3A (encoding H3.3 histone) and H3C2 (encoding H3.1 histone) genes. One quarter of DIPG tumors harbor somatic mutations in ACVR1 gene, encoding the serine/threonine kinase receptor ALK2. ACVR1 mutations co-segregate with H3.1K27M mutation, representing a specific tumour subtype with distinct clinicopathological and molecular features. These mutations are associated with an aberrant activation of SMAD pathway believed to promote cell proliferation in DIPGs. In the present studies, we evaluated the effectiveness of an orally bioavailable ALK inhibitor, TP-0184 (Tolero Pharmaceuticals) in ACVR1 mutated (ACVR1-mut) and wildtype (ACVR1- WT) DIPG models. Our results indicate that TP-0184 effectively inhibited cell proliferation in primary-patient derived DIPG cell lines. However, we did not observe any selectivity toward ACVR1 mutations. TP-0184 does not induce cell death, but rather cell cycle inhibition, arresting cells in G2/M phase. Interestingly, when treated with ionizing radiation (IR), ACVR1-mut cells preferentially activated SMAD signaling compared to ACVR1-WT. We are currently evaluating the combination efficacy of TP-0184 with IR in our in vitro and in vivo DIPG models. Data on tumor growth kinetics, survival and the effect on SMAD signaling pathway will be presented and discussed.
DIPG-09. ATOVAQUONE RADIOSENSITISES DIFFUSE MIDLINE GLIOMAS BY INHIBITING MITOCHONDRIAL METABOLISM AND HYPOXIA
Authors: Mudassar Faiqa , Chang Cecilia , Ing Prunella , Nguyen Sandy , Cook Kristina M , Warnken Zachary N , O’Neill Geraldine , Shen Han , Hau Eric
Published: June 2023

Diffuse Midline Glioma (DMG) is a uniformly fatal paediatric brainstem tumour with median survival of less than 1 year. Radiotherapy has been the only effective treatment for decades, but most DMGs recur within several months due to radioresistance. The hypoxic tumour microenvironment, a main feature of solid tumours including gliomas, is a major contributor to radioresistance and impedes the efficacy of radiotherapy. Therefore, alleviating tumour hypoxia to enhance the effectiveness of radiotherapy is a therapeutic strategy to improve survival outcomes of DMG patients. Here, our strategy is to decrease the oxygen consumption rate (OCR) of DMG cells by targeting their mitochondria, which in turn will alleviate hypoxia by sparing more oxygen and subsequently improve the radiosensitivity of DMG cells. Specifically, we performed a high-throughput screening to identify potent OCR inhibitors using a library of 1963 FDA-approved drugs. The most promising OCR inhibitor identified was atovaquone, a drug used for treatment of pneumocystis pneumonia and malaria. We found that atovaquone inhibited mitochondrial metabolism of DMG cells by specifically targeting the mitochondrial complex III. It induced the formation of mitochondrial reactive oxygen species suggesting that it increases oxidative stress. It alleviated hypoxia and decreased the expression of hypoxia-inducible factor-1a in several 3-dimensional DMG neurospheres and improved the radiosensitivity of a range of DMG cultures. To overcome the issues of poor bioavailability of commercially available atovaquone resulting in low therapeutically effective brain concentrations, we tested its efficacy against the amorphous solid dispersion (ASD) atovaquone formulation which appears to enhance the atovaquone levels in the brain. We found that both the formulations inhibited OCR and hypoxia at similar doses and improved the radiosensitivity of DMG. With these promising findings, our further work is assessing the in vivo efficacies of commercially available atovaquone and ASD atovaquone formulation using orthotopic DMG models.
DIPG-12. OUTCOMES IN PEDIATRIC MALIGNANT CENTRAL NERVOUS SYSTEM TUMORS UTILIZING TEMOZOLOMIDE, BEVACIZUMAB, AND IRINOTECAN
Authors: Reel Sarah , Smiley Natasha Pillay , Hummel Trent , Lane Adam
Published: June 2023

High-grade glioma (HGG) and diffuse intrinsic pontine glioma (DIPG) are the most common high-grade glial tumors in pediatrics. Hummel et al. assessed the feasibility of bevacizumab (BVZ) ± temozolomide (TEM) with radiation, followed by BVZ, irinotecan (IRO) ± TEM. The regimen conferred no survival benefit to patients with DIPG. The study was limited by sample size. Further defining efficacy of this therapy is important. We aimed to examine the outcomes of patients with HGG and DIPG treated with BVZ, IRO, and TEM. This is a retrospective review of patients treated at Cincinnati Children’s Hospital from 03/2005 to 10/2022. We examined progression-free survival (PFS) and overall survival (OS). Descriptive analyses were used to examine age, sex, diagnosis, and tumor location. 47 patients were treated with BVZ, IRO ± TEM. Patients were 55% female and 45% male. Average age at diagnosis was 12 years. The diagnoses included patients with HGG (45%), DIPG (51%), and other tumor types (4%). 79% of patients were treated at initial diagnosis with the regimen of BVZ in addition to IRO ± TEM. 21% of patients were treated at progression. Median OS for patients with DIPG and HGG was 12.4 months and 35.9 months, respectively. 3-year OS for DIPG was 10.8% (SE 7.2%) and for HGG it was 48.6% (SE 11.0%). Median PFS for DIPG and HGG was 7.7 and 19.0 months, respectively. 1-year PFS for DIPG was 31.9% (SE 10.7%). For HGG it was 65.6% (SE 10.6%). 3-year PFS for HGG was 20.2% (SE 9.0%). The limitations of this study are that newly diagnosed and recurrent patients are included and the study does not examine radiologic and biologic data. Results from this study show promising data for OS and PFS. Additional studies are needed to further examine larger cohorts of patients to demonstrate survival benefit from this regimen.
DIPG-15. CONCURRENT GB-13 (IL13.E13K-PE4E) IMPROVES THE EFFICACY OF RADIATION THERAPY IN DIFFUSE INTRINSIC PONTINE GLIOMA
Authors: Rechberger Julian S , Schrecengost Randy S , Zhang Liang , Ge Jizhi , Nonnenbroich Leo F , Sarkaria Jann N , Daniels David J
Published: June 2023

Diffuse midline glioma with H3 K27 alterations (DMG) is the most aggressive primary malignant brain tumor in the pediatric population. Radiation therapy (RT) is the standard-of-care; however, it has not demonstrated a significant improvement in overall survival or stalled disease progression, and children usually succumb to disease within 12-15 months of diagnosis. Consequently, finding efficient treatments for DMG remains one of the most critical unmet needs in modern neuro-oncology. Interleukin 13 receptor subunit alpha 2 (IL-13Rα2) is a cell-surface receptor upregulated in ~80% of DMG versus normal brain, posing a potentially promising therapeutic target. Immunotherapies harnessing IL-13Rα2 to selectively delivery cytotoxic payloads, such as pseudomonas exotoxin A (PE), to tumor cells have been previously demonstrated to be safe in DMG patients and efficacious in preclinical models of DMG with high IL-13Rα2 expression using convection-enhanced delivery (CED). Furthermore, there is evidence that PE-based therapies can sensitize cells to RT. In this study, we utilized in vitro and in vivo models of DMG to evaluate clinically-relevant combination treatments of RT and the IL-13/PE immunotoxin GB-13 (IL13.E13K-PE4E). GB-13 improved the effectiveness of low-dose RT in multiple DMG cell lines by promoting caspase activation, which boosted apoptotic cell death. Intratumoral administration of GB-13 via chronic CED decreased tumor burden and prolonged survival in both DMG patient-derived orthotopic xenograft and genetically engineered mouse models. When GB-13 and RT were administered concurrently, this impact became even more prominent, informing future preclinical and clinical investigation of a potentially efficacious therapeutic approach in a subset of DMG.
DIPG-16. ACUTE VERSUS PROLONGED CONVECTION-ENHANCED DELIVERY OF ALISERTIB INTO H3 K27M-MUTANT MODELS OF DIFFUSE MIDLINE GLIOMA
Authors: Rechberger Julian S , Zhang Liang , Ge Jizhi , Daniels David J
Published: June 2023

Convection-enhanced delivery (CED) is a potentially promising strategy to administer therapeutics directly into the brainstem of children harboring H3 K27-altered diffuse midline glioma (DMG). While early-phase clinical trials have demonstrated the safety of this technique, efficacy has yet to be achieved. Here, we describe how different variations of CED may be exploited to extend survival in a DMG murine patient-derived orthotopic xenograft model. Either 1-day (8 µL/hr) or 7-day (1 µL/hr) continuous CED infusions were performed to deliver an equivalent volume of the aurora kinase inhibitor alisertib to the mouse brainstem. Bioluminescence and magnetic resonance images were acquired to monitor tumor progression, validate CED catheter positioning, and analyze infusion-related imaging changes. Both infusion regimens significantly prolonged survival versus control (median survival benefit of 6.5 and 8 days, p=0.03 and p=0.01, for 1-day and 7-day CED, respectively). Postmortem examination of brains revealed no signs of tissue necrosis, cavitary lesions, or cellular (inflammatory) infiltrate at the site of infusion. However, the tumor parenchyma surrounding the cannula tract was markedly hypocellular in treated animals. Alisertib induced a robust increase in H3 K27 trimethylation along with decreased H3 K27M and Ki-67. Our findings indicate that CED of alisertib is well tolerated and effective, in both the acute and prolonged setting, underscoring the potential of this approach in the management of DMG.
DIPG-20. DELINEATING MEDIATORS OF ONCOGENESIS IN FOXR2-EXPRESSING DIFFUSE MIDLINE GLIOMAS
Authors: Tsai Jessica , Cejas Paloma , Coppola Marissa , Wang Dayle , Patel Smruti , Wu David , Arounleut Phonepasong , Wei Xin , Zhou Ningxuan , Syamala Sudeepa , Dubois Frank , Pelton Kristine , Vogelzang Jayne , Sousa Cecilia , Baguette Audrey , Chen Xiaolong , Condurat Alexandra , Dixon-Clarke Sarah , Zhou Kevin , Lu Sophie , Gonzalez Elizabeth , Chacon Madison , Digiacomo Jeromy , Kumbhani Rushil , Novikov Dana , Tsoli Maria , Ziegler David , Dirksen Uta , Jager Natalie , Balsubramanian Gnana Prakash , Kramm Christof , Nathrath Michaela , Bielack Stefan , Baker Suzanne , Zhang Jinghui , McFarland James , Getz Gad , Aguet Francois , Jabado Nada , Witt Olaf , Pfister Stefan , Ligon Keith , Hovestadt Volker , Kleinman Claudia , Long Henry , Jones David , Bandopadhayay Pratiti , Phoenix Timothy
Published: June 2023

BACKGROUND

Diffuse midline gliomas (DMGs) are a universally fatal brain tumor of childhood. While histone mutations are a critical tumor initiating event, they are insufficient to drive gliomagenesis. Histone mutations co-occur with somatic alterations in other pathways including TP53, MAPK, and MYC signaling. However, the mechanisms through which these pathways are activated have not been fully elucidated.

METHODS

We applied an integrative approach using transcriptomics, epigenetics, proteomics, in vitro cancer models, and in vivo mouse models to systematically evaluate how FOXR2 mediates gliomagenesis.

RESULTS

We have recently found that a subset of DMGs aberrantly express FOXR2, a forkhead transcription factor. FOXR2 is both sufficient to enhance tumor formation, and necessary for FOXR2-expressing DMGs. While FOXR2 indeed enhances MYC protein stability, FOXR2 exerts oncogenesis through MYC-independent functions and specifically hijacks E26-transformation specific (ETS) transcriptional circuits and FOXR2 DNA-binding is highly enriched at ETS motifs. We have performed proteomic and phospho-proteomic analysis of FOXR2-expressing human neural stem cells to identify proteins and phospho-sites that are highly enriched in FOXR2-expressing cells.

CONCLUSION

Taken together, this study elucidates how FOXR2 interacts with ETS transcription factors to mediate oncogenesis in FOXR2-expressing diffuse midline gliomas.
DIPG-27. DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG) CHALLENGE: FROM GENE EXPRESSION PROFILE TO DRUG
Authors: Scilimati Antonio , Armenise Domenico , Baldelli Olga , Centonze Antonella , Derri Davide , Ferorelli Savina , Miciaccia Morena , Solidoro Roberta , Perrone Maria Grazia
Published: June 2023

Diffuse intrinsic pontine glioma (DIPG) accounts for 80% of pediatric brainstem tumors and about 10-20% of all central nervous system tumors in childhood. Despite the adoption of aggressive therapeutic approaches, DIPG remains the leading cause of cancer-related mortality in childhood: prognosis is still poor with more than 90% of affected children dying within 18-24 months from the diagnosis.1 Decades of clinical attempts involving more than 200 trials evaluating different conventional cytotoxic drugs, targeted drugs and studies with radiation dose escalating and new radio sensitizing agents, have failed to improve the overall survival of children with DIPG. Since available drugs have proven no benefits hereto for DIPG, it is fundamental to gain insights into the gene expression profile of DIPG patients and speed up the discovery of novel therapeutics for this dismal malignancy. Only the compound ONC201 was discovered to reduce DIPG tumors size in DIPG H3K27M mutated and now is in phase III clinical trials.

Given the complex molecular mechanisms underlying DIPG, it would be necessary to fully utilize gene expression profiles to build a fully knowledge of DIPG-related genes and pathways. Preliminarily, the gene expression profile of eight pediatric DIPG samples and two primary pontine tissue samples was downloaded and analyzed starting from the Gene Expression Omnibus (GEO) database2. The GEO data were used to evaluate the differentially expressed genes (DEGs) in the pediatric DIPG samples. Subsequently, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome pathways of DEGs were enriched, integrated, and analyzed to find out genes and signaling pathways involved in the biological and clinic-pathological features of DIPG. More data are being to be added to our meta-analysis.
DIPG-33. P16 IMMUNOHISTOCHEMICAL EXPRESSION AS A SURROGATE ASSESSMENT OF CDKN2A ALTERATION IN GLIOMAS LEADING TO PROGNOSTIC SIGNIFICANCES
Authors: Geyer Lucas , Wolf Thibaut , Chenard Marie Pierre , Cebula Helene , Schott Roland , Noel Georges , Guerin Eric , Pencreach Erwan , Reita Damien , ENTZ-WERLE Natacha , Lhermitte Benoit
Published: June 2023

CDKN2A is a tumor suppressor gene encoding for p16 protein. Its homozygous deletion is a central prognostic factor for numerous brain cancers. This deletion can be detected by several techniques. Up to now, immunohistochemistry (IHC) using p16 antibody is not recommended as a surrogate test. This study aimed to evaluate to what extent IHC levels of p16 expression may provide information about CDKN2A homozygous deletion. A retrospective study was conducted in 173 gliomas comprising 50 circumscribed low-grade MAPK-altered gliomas, 18 pediatric diffuse high-grade gliomas (HGG), and 105 adult-type diffuse gliomas of all grade, using p16 IHC and CDKN2A fluorescent in situ hybridization. Survival analyses were performed to assess their prognostic impact. Three patterns of p16 expression were observed: absence of expression, focal expression and overexpression. The prognostic impact of p16 overexpression was dependent on the tumor drivers. Indeed, it was associated to a better prognosis in MAPK-induced tumors, but to a worse survival in IDH-wild-type glioblastomas. CDKN2A homozygous deletion present in all type of high grade pediatric or adult gliomas was significantly linked to a worse outcome in the entire population. Regarding specifically to H3K27-altered gliomas, no significant prognostic impact was observed, probably related to the small size of our population. Nevertheless, this p16 lost expression was rarely reported in this pediatric population. The lost expression was observed in 7/9 H3K27M-mutants and in 6/8 wild-type cases. Its implication should be considered more largely and is probably opening the path for therapies targeting the p16 pathway in this population. Regarding the IHC technique itself, beyond the association between absence of p16 protein expression and the CDKN2A loss (p<0.001), this technique seems to have a strong sensitivity and a high negative predictive value. These data suggest that p16 IHC might be a pertinent test to detect cases harboring CDKN2A homozygous deletion.