bluuebunny/crossref_metadata_2025 huggingface dataset:
High frequency of ambophily in a Brazilian campos de altitude
Authors: Pacheco Amanda , Bergamo Pedro Joaquim , Freitas Leandro
Published: October 2024

Background and Aims

Ambophily, an intriguing pollination system in which plant species present adaptations to both biotic and abiotic pollination, has been scarcely reported. Most studies have been conducted with a single or few related species from wind-pollinated genera. We here assess for the first time the frequency of ambophily at the community level.

Methods

We evaluated pollen carried by wind in 63 animal-pollinated species from a Brazilian campos de altitude. For those with pollen carried by wind, we evaluated the contribution of wind and animals to seed production with controlled pollination experiments, as well as floral traits and floral visitor assemblages.

Key Results

Pollen of 23 species was carried by wind (~37 %). Animals and wind contributed to the reproduction of seven species (~11 %), including one pollinated by hummingbirds, large bees and wind. These seven ambophilous species presented unrestrictive floral morphologies and generalist pollination.

Conclusions

We found a high frequency of ambophily in a single community (11 %), which represented an increment of ~5 % of species relative to all ambophilous species reported in the literature so far. Investigating pollen transport by wind in zoophilous species combined with controlled experiments helped detect ambophily in species that are usually ignored in wind pollination studies. Our results showed that putative zoophilous species may actually be ambophilous, suggesting that the selective pressures towards ambophily also occur in zoophilous lineages.
DNA methylation analysis to differentiate reference, breed, and parent-of-origin effects in the bovine pangenome era
Authors: MacPhillamy Callum , Chen Tong , Hiendleder Stefan , Williams John L , Alinejad-Rokny Hamid , Low Wai Yee
Published: October 2024

Background

Most DNA methylation studies have used a single reference genome with little attention paid to the bias introduced due to the reference chosen. Reference genome artifacts and genetic variation, including single nucleotide polymorphisms (SNPs) and structural variants (SVs), can lead to differences in methylation sites (CpGs) between individuals of the same species. We analyzed whole-genome bisulfite sequencing data from the fetal liver of Angus (Bos taurus taurus), Brahman (Bos taurus indicus), and reciprocally crossed samples. Using reference genomes for each breed from the Bovine Pangenome Consortium, we investigated the influence of reference genome choice on the breed and parent-of-origin effects in methylome analyses.

Results

Our findings revealed that ∼75% of CpG sites were shared between Angus and Brahman, ∼5% were breed specific, and ∼20% were unresolved. We demonstrated up to ∼2% quantification bias in global methylation when an incorrect reference genome was used. Furthermore, we found that SNPs impacted CpGs 13 times more than other autosomal sites (P < $5 \times {10}^{ - 324}$) and SVs contained 1.18 times (P < $5 \times {10}^{ - 324}$) more CpGs than non-SVs. We found a poor overlap between differentially methylated regions (DMRs) and differentially expressed genes (DEGs) and suggest that DMRs may be impacting enhancers that target these DEGs. DMRs overlapped with imprinted genes, of which 1, DGAT1, which is important for fat metabolism and weight gain, was found in the breed-specific and sire-of-origin comparisons.

Conclusions

This work demonstrates the need to consider reference genome effects to explore genetic and epigenetic differences accurately and identify DMRs involved in controlling certain genes.
Justice “to Come”? Decolonial Deconstruction, from Postmodern Policymaking to the Black Horizon
Authors: Chipato Farai , Chandler David
Published: October 2024

This article explores the importance of what we call “decolonial deconstruction” for contemporary global politics and policy discourses and develops a critique of this approach. “Decolonial deconstruction” seeks to keep open policy processes, deconstructing liberal policy goals of peace, democracy, or justice as always “to come”. It emerged through a nexus of postmodern and decolonial framings, well represented in the critical Black studies tradition, where theorists have focused upon identity construction, rejecting static conceptions. These approaches have increasingly been taken up in international policymaking approaches and International relations theory, particularly in the field of peacebuilding and the broad policy approach of resilience. After highlighting the ways that processual understandings of deconstruction have transformed these policy areas, we suggest an alternative deconstructive approach. In doing so, we draw upon the critical Black studies tradition but emphasize the need to critique underlying ontological assumptions about the world. We heuristically set out this approach as the “Black Horizon.”
Keep Calm and Carry on? Fissure, Perception, and Narrative Contestation Following the Demise of the Crown
Authors: Gellwitzki C Nicolai L , Houde Anne-Marie , Rogers Lauren , Rosher Ben
Published: October 2024

On September 8, 2022, after more than 70 years on the throne, Queen Elizabeth II passed away. The responses among the public, media, and state institutions to the news were varied, with competing views on the role of the monarchy and the legacy of the queen. The questions this article seeks to answer are (1) how the monarch’s death introduced a fissure into the United Kingdom’s autobiographical narrative and (2) how exactly this moment led on the one hand to efforts to reaffirm the dominant UK autobiographical narrative and on the other to efforts to contest this narrative. In framing this analysis using Gestalt psychology, we theorize the role of perception in subjects’ experience of a fissure as well as their subsequent attempts to manage the ensuing anxieties. We show how perception enables and guides avenues for narrative contestation as well as conservative attempts to (re)establish the predominant autobiographical narrative by exploring how the government and the royal family sought to create a sense of continuity and transfer royal authority onto the next generation while activists attempted to subvert this established narrative to problematize the country’s (post)colonial history and societal inequalities.
A World of Many Walks? Zapatista World Ordering between Center and Margins
Authors: Unrau Christine
Published: October 2024

At the current moment of multiple global crises, including of the International Liberal Order, a search for new practices of world ordering seems to coexist with a deep skepticism regarding the possibilities of global solidarity and common struggles between centers and margins. Against this background, this paper focuses on the world ordering practices of the Mexican Ejército Zapatista de Liberación Nacional, a group that occupies a position between center(s) and margin(s). While they clearly self-identify as being on the political and economic margins—geographically remote, economically weak and under constant threat of military repression—their ideas occupied center stage in the search for alternative visions of world order at least for a certain moment. The paper will explore the potential pathologies that a recourse to Zapatism may entail, namely romanticization, hollowing-out and epistemic extractivism/opportunism. It then asks if and how these pathologies can be overcome in a search for common ground for both social movements and International Political Theory when trying to think differently about world ordering from the margins. In this exploration, special emphasis will be given to the pathways toward a desirable order that the Zapatistas conceptualize and practice, namely creating, narrating and walking.
Traditional Authorities and Strategies in Demands for Self-Determination
Authors: Neupert-Wentz Clara , Kelle Friederike Luise
Published: October 2024

Ethnic groups employ different strategies to pursue demands for self-determination. While some act within conventional channels of political contestation, others choose non-conventional strategies, including violence and rebellion. We conceive of this as a result of bargaining between group and state and argue that both sides’ institutions affect the likelihood of escalation. Specifically, groups with traditional authorities have the capacity and incentives to escalate conflicts. Only when such institutions are matched with internal accountability mechanisms can groups credibly commit so that bargaining failure and violence less likely. Similarly, states with open elections can tie their hands more effectively, and constitutional regulations of traditional authorities formalize state-group interactions, which also mitigates the effect of traditional authorities on conflict. We use new global data on groups that demand self-determination, their traditional political institutions, and their strategy choice from 2005 to 2015. We find support for our argument using various identification and estimation approaches. Groups with traditional authorities are much more likely to use violence, a finding that is not sensitive to the omission of unobserved confounders. Furthermore, this relationship is moderated by group-level audience costs and the strategic environment provided by the state. Our findings advance new perspectives on the interactions of customary and national institutions in determining subnational conflict.
Aurora B/AIR-2 regulates sister centromere resolution and CENP-A/HCP-3 organization to prevent merotelic attachments
Authors: Wang Yue , Yu Wong Charmaine Yan , Yuen Karen Wing Yee
Published: October 2024

During cell division, the accurate capture of sister kinetochores that are built on the centromeres of chromosomes by microtubules emanating from opposite spindle poles governs faithful chromosome segregation. To ensure sister chromatids separate correctly, sister centromeres undergo resolution to achieve bi-polar orientation prior to microtubule attachments. Failure of centromere resolution increases the frequency of merotelic attachments, with microtubules from opposite poles attaching to the same sister kinetochore, causing lagging chromosome, aneuploidy, and even cancer progression. The Aurora B-mediated tension-sensing machinery to correct erroneous kinetochore–microtubule attachments has been well studied. However, preventative mechanisms to avoid merotelic attachments that occur in the earlier mitotic stage are poorly understood. In this study, we found that inactivation of mitotic kinase Aurora B/AIR-2 increases merotelic attachments in Caenorhabditis elegans. On one hand, Aurora B/AIR-2-deficient cells exhibited a delay in the occurrence of centromere resolution and a disruption in targeting condensin II components to chromatin. On the other hand, loss of Aurora B/AIR-2 results in an increased localization of centromeric proteins CENP-A/HCP-3 and M18BP1/KNL-2 as well as the kinetochore protein MIS-12 on chromatin, which may generate ectopic kinetochores causing erroneous attachments. To conclude, this study elucidated that Aurora B/AIR-2 regulates sister centromere resolution and CENP-A/HCP-3 deposition to actively prevent merotely and chromosome instability in cells.
Antimicrobial Resistance in Staphylococcus aureus and Enterococcus spp. Isolates From Bloodstream Infections in Australian Children, 2013–2021
Authors: Williams Anita , Coombs Geoffrey W , Bell Jan M , Daley Denise A , Mowlaboccus Shakeel , Bryant Penelope A , Campbell Anita J , Cooley Louise , Iredell Jon , Irwin Adam D , Kesson Alison , McMullan Brendan , Warner Morgyn S , Williams Phoebe C M , Blyth Christopher C
Published: October 2024

Background

Rising proportions of antimicrobial resistance (AMR) have been observed in both Staphylococcus aureus and Enterococcus spp. isolates.

Methods

The Australian Group on Antimicrobial Resistance surveillance program captures clinical and microbiological data of isolates detected in blood cultures across Australia. EUCAST 2022 was used for interpretation and the AMR package in R for data analysis.

Results

There were 2091 bloodstream infections (BSIs) with S. aureus and 534 enterococcal BSI episodes in children <18 years old over 9 years. Three quarters of S. aureus BSI episodes were community-onset (78.3%), while more than half of enterococcal BSIs were hospital-onset (56.9%). The median age for S. aureus BSIs was 6 years, while >50% of enterococcal BSIs were in children <12 months old. Fifteen percent of S. aureus isolates were methicillin-resistant. Overall, 85.3% of S. aureus were resistant to penicillin, 12.5% resistant to erythromycin, 10.3% to clindamycin, and 4.7% to ciprofloxacin. Resistance to penicillin decreased over time, while clindamycin resistance increased. Resistance in Enterococcus spp. was almost entirely observed in Enterococcus faecium; only 1 Enterococcus faecalis isolate was ampicillin-resistant, and no E. faecalis isolates were vancomycin or teicoplanin-resistant. Seventy-three percent of E. faecium were resistant to ampicillin, 25.5% to vancomycin (VREfm), and 8.8% to teicoplanin.

Conclusions

Significant shifts in the epidemiology and resistance profiles of S. aureus and Enterococcus spp. BSIs in Australian children were observed, making clear the importance of age-stratified reporting in AMR data.
Use of tricortical iliac crest allograft for augmentation of depressed lateral tibial plateau fracture: a surgical technique
Authors: Schwab Pierre-Emmanuel , Bravin Daniel , Milby Joshua
Published: October 2024

Lateral tibial plateau fractures with significant articular depression and metaphyseal comminution in the setting of osteoporosis are challenging to manage. The subchondral bone defect and capacious cancellous void after surgical elevation of the articular surface is usually filled with nonstructural graft such as autologous cancellous bone graft, allogenic cancellous bone graft, or bone graft substitutes. Reports have shown a high rate of subsidence with these grafts when patients start to bear weight and ultimately failure of the construct. Structural grafts demonstrated stronger mechanical properties and lower subsidence rates. The purpose of this note is to describe a novel surgical technique using structural tricortical iliac crest allograft for the treatment of osteoporotic depressed lateral tibia plateau fracture.
Sex Chromosome Evolution: Hallmarks and Question Marks
Authors: Saunders Paul A , Muyle Aline
Published: October 2024

Sex chromosomes are widespread in species with separate sexes. They have evolved many times independently and display a truly remarkable diversity. New sequencing technologies and methodological developments have allowed the field of molecular evolution to explore this diversity in a large number of model and nonmodel organisms, broadening our vision on the mechanisms involved in their evolution. Diverse studies have allowed us to better capture the common evolutionary routes that shape sex chromosomes; however, we still mostly fail to explain why sex chromosomes are so diverse. We review over half a century of theoretical and empirical work on sex chromosome evolution and highlight pending questions on their origins, turnovers, rearrangements, degeneration, dosage compensation, gene content, and rates of evolution. We also report recent theoretical progress on our understanding of the ultimate reasons for sex chromosomes’ existence.
Mortality and associated factors in patients with systemic sclerosis-associated pulmonary hypertension with and without interstitial lung disease: A long-term follow-up study
Authors: Amikishiyev Shirkhan , Yalçınkaya Yasemin , Mammadova Konul , Aliyeva Numune , Durak Gorkem , Artim-Esen Bahar , Gül Ahmet , Bilge Ahmet Kaya , Okumuş Gulfer , Inanc Murat
Published: October 2024

Objectives

We aimed to investigate mortality and prognostic factors in systemic sclerosis (SSc) patients with pulmonary hypertension (PH) with or without interstitial lung disease (ILD).

Methods

The associations between mortality and demographics, transthoracic echocardiography, right heart catheterization (RHC), pulmonary functional parameters at baseline, and treatment modalities were evaluated.

Results

Survival rates for PH-SSc patients (42 female, mean age 56.6 ± 13.5, median follow-up 45 months) were 91% at the first year, 75% at 2 years, and 43.1% at 5 years. The majority of the deceased patients had PH + ILD (P = .007). The PH + ILD group had more diffuse skin involvement, anti-Scl-70, high C-reactive protein, low FVC, and lower DLCO. The deceased patients had higher estimated pulmonary arterial systolic pressure (PASP), low cardiac output, and FVC values. Median survival time was significantly better in patients on combined therapy. Mortality-related factors in the PH + ILD group were decreased initial FVC, high estimated PASP, low cardiac output, deteriorated functional class, and monotherapy.

Conclusion

This is the first reported SSc-PH cohort from Turkey by a multidisciplinary team. PH is a severe complication of SSc with high mortality especially in patients with accompanying severe ILD.
NICU Music Therapy: Lessons Learned from a Randomized Trial
Authors: Germano Elizabeth , Grossoehme Daniel H , Richner Gwendolyn , Jenkins Rachel , Teal Connie M , Brown Miraides , Delahanty Douglas L , Friebert Sarah
Published: October 2024

Mothers of infants hospitalized in the neonatal intensive care unit (NICU) are at risk for developing acute and posttraumatic stress disorder, but mothers’ positive coping may improve with progress in the infant’s well-being. There is a need to investigate complementary therapies that increase infant well-being and decrease maternal stress. A pacifier-activated lullaby (PAL) device is one evidence-based intervention to assist premature infants by playing a few bars of a lullaby after an effective suck, improving feeding behavior and shortening the length of NICU stay. The PAL may be personalized with lullabies sung and recorded by the neonate’s mother or other family. This study’s purpose was to quantify the effect of a PAL intervention on maternal stress symptoms. The experimental PAL intervention included a singing and recording session with a board-certified music therapist with NICU certification. This was a single-site randomized trial comparing the effect of maternal voice recording versus standard conditions. A total of 245 infant–mother dyads were screened; 18 mothers consented to participate and 12 were randomized to one of three conditions: mother’s recorded lullaby for PAL administration, a generic female voice used for the PAL, and no intervention. Barriers arising during the study included lengthy enrollment processes, maternal visitation patterns, and an overly ambitious study design. Despite attempts to mitigate perceived barriers, we did not achieve the enrollment necessary to perform the intended analysis. We, therefore, present lessons learned and possible solutions for future music therapy research in the interest of transparency, reducing publication bias, and replication of problematic design issues in future trials.
JS03.6.A TUMOR ASSOCIATED MACROPHAGE DERIVED EXOSOMES MODULATE IMMUNOTHERAPEUTIC SENSITIVITY OF SHH MEDULLOBLASTOMA BY TARGETING M6A MODIFIED FOXD1
Authors: Chang Q , Liu Y
Published: October 2024

BACKGROUND

Medulloblastoma (MB) is the most common malignant brain tumor in children. The infiltration of tumor-associated macrophages (TAMs) in tumor microenvironment (TME) is correlated with the poor prognosis in SHH subtype of MB patients. Epigenetic alterations on RNA m6A modification were identified in this tumor. However, it remains unclear whether the TAMs infiltration in TME was correlated with the m6A modification status during tumor progression.

METHODS

The expression of m6A modification-related proteins and TAMs specific marker were assessed by immunohistochemistry in 40 SHH MB primary tumors. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptomic RNA sequencing (RNA-seq) were used to screen target genes affected by TAM-derived exosomes in SHH MB cells. Mechanisms of m6A-modification on target gene (FOXD1) were demonstrated by WB, qPCR, RNA half-life time and RNA immunoprecipitation assays. Combination treatment with AAV2/9-shFOXD1 and PD-1 inhibitors were performed in the NeuroD2: SmoA1 mouse model.

RESULTS

We reported for the first time that significant infiltration of TAMs was associated with decreased expression of METTL14 in primary SHH MBs. Exosomal microRNAs (miR-320e, miR-196b-5p, and miR-628-5p) released by TAMs targeted to the 3’-UTR (3’ Untranslated Region) of METTL14 in MB cells, promoting the gene’s degradation and consequently downregulating the overall m6A level in SHH MB. MeRIP-seq and RNA-seq analyses screened out Forkhead box D1 (FOXD1) as the target gene upregulated by TAMs-derived exosomes through m6A modification in MB cells, which was correlated with poor prognosis in SHH MB patients. Further experiments in vitro verified YTHDF2 can recognize m6A-modified FOXD1 and promote its mRNA degradation. Knockdown of FOXD1 in SHH MB cells significantly promoted the release of the CD8+T cell recruiting chemokines CXCL10/11. Treatment with AAV2/9-shFOXD1 significantly enhanced the anti-tumor effect of PD-1 inhibitor in NeuroD2: SmoA1 SHH MB mice.

CONCLUSION

Our study revealed the m6A modification status of SHH MBs influenced by TAMs derived exosomal miRNAs. FOXD1 promoted the malignant progression of SHH MB through m6A modification. Increased immunotherapeutic sensitivity of the combination treatment with FOXD1 knockdown and anti-PD-1 blockade in vivo shed lights on a novel therapeutic strategy of SHH MB.
JS06.5.A MERTK ON TUMOUR CELLS AND MACROPHAGES: A THERAPEUTIC OPTION FOR NF2-RELATED AND SPORADIC MENINGIOMA
Authors: Hanemann C , Dave F , Herrera K , van de Weijer L L , Henderson S , Dunn J , Singh L , Adams C L , Ercolano E , Hilton D A , Kurian K M , Maze E A , Ammoun S , Laraba L , Parkinson D B
Published: October 2024

BACKGROUND

Meningioma are common tumours of the nervous system. They occur sporadically or as part of the hereditary NF2-related schwannomatosis syndrome. There is an unmet need for new effective drug treatment.

MATERIAL AND METHODS

We analysed tumour tissue and used cell culture including 3D cultures and also PDX models applying different functional read outs after pharmacological inhibition and knock down. This was complemented by Western blots, co-IP, RNA seq and proteomic analysis.

RESULTS

We demonstrate overexpression/activation of TAM (TYRO3/AXL/MERTK) receptors and overexpression/release of ligand GAS6 in patient-derived meningioma tumour cells and tissue. For the first time, we reveal formation of MERTK/TYRO3 heterocomplexes in meningioma. We demonstrate interdependency of TAM receptor expression. We show that MERTK and AXL contribute to increased proliferation and survival of meningioma cells, which we inhibited in vitro using the MERTK/FLT3 inhibitors and the AXL inhibitors. MERTK inhibition was more effective and we show an effect also in 3D tumour models as well as PDX models. Further we found that TAM receptors are expressed by tumour-associated macrophages in meningioma and that MERTK inhibition strongly depleted macrophages in meningioma.

CONCLUSION

Inhibiting MERTK is a new therapeutic option for meningioma
JS08.7.A SURGERY TRANSIENTLY DISRUPTS THE BLOOD BRAIN BARRIER OF THE GLIOBLASTOMA RESECTION MARGIN: OPPORTUNITIES FOR EARLY AND SELECTIVE POSTOPERATIVE TREATMENT
Authors: Fernandes L F , Lozano N , Peeyatu C , Ho Y , Thompson L , Kostarelos K , Kisby T
Published: October 2024

BACKGROUND

Resection surgery is the first line therapy for glioblastoma (GBM) that is performed in >70% of patients typically within days of suspected, MRI-based diagnosis. Current standard protocols for follow-on chemo/radiotherapy have shown only modest efficacy in eliminating residual disease, with inevitable tumour recurrence. There remains a need to develop new approaches to swiftly and effectively treat post-operative residual disease to prevent the rapid progression of recurrent GBM.

MATERIAL AND METHODS

Using two syngeneic preclinical models of glioblastoma resection/recurrence (GL261 and IDH-WT glioma neurospheres), we identified a spatially and temporally restricted window of resection margin-localized blood brain barrier (BBB) disruption during the immediate and early postoperative periods. This was mapped overtime by intravenous administration of fluorescently labelled lipid nanoparticles (LNPs) and using a combination of in vivo and ex vivo imaging modalities.

RESULTS

LNPs showed a selective accumulation at the postoperative resection margin site while largely being excluded from areas of the brain with an intact BBB. From longitudinal assessment of this phenomenon, we identified a biphasic increase in LNP accumulation whereby initial BBB disruption appeared to be mediated by the surgical procedure itself (minutes post-surgery), whereas a second temporary period of disruption (2-3 days after surgery) presumably driven by a post-operative inflammatory tissue response and remodelling. Confocal analysis confirmed the presence of extravasated LNPs in the parenchyma which largely interacted with glial populations that closely associated with residual tumour tissue. Exploiting this, we performed early intravenous administration of doxorubicin chemotherapy loaded LNPs coinciding with the peak of postoperative BBB disruption and demonstrated complete inhibition of tumour recurrence from a single administration. In contrast, late administration of doxorubicin LNPs (in line with the typical clinical post-operative treatment schedule) did not achieve such profound efficacy. Notably, administration of doxorubicin alone (not encapsulated in LNP) also did not show significant efficacy highlighting the importance of this selective nanocarrier in combination with BBB disruption.

CONCLUSION

Overall, this work underscores the importance of this early post-operative timeframe for margin/residual disease selective treatments that may have been overlooked in most trials of experimental GBM medicines. Furthermore, this demonstrates that clinically approved nanomedicines could be readily repurposed for early post-operative therapy in aggressive brain tumours. Further work is warranted to develop novel nanoparticle enabled approaches for the early treatment of residual GBM toward overcoming this longstanding clinical need.
P01.11.B PATIENT-DERIVED GLIOBLASTOMA CELLS ARE CAPABLE OF FORMING TUBE-LIKE STRUCTURES IN VITRO SUGGESTIVE OF VASCULOGENIC MIMICRY
Authors: Maddison K , Bowden N A , Graves M C , Fay M , Tooney P A
Published: October 2024

BACKGROUND

The tube formation assay (TFA), widely used to assess the angiogenic ability of endothelial cells in vitro, involves plating endothelial cells on a basement membrane matrix layer that promotes the differentiation of the cells, observed as the formation of tubule-like structures. The extent and characteristics of the tubule network are influenced by cell seeding density, addition of growth factors, and the composition of the basement membrane matrix. Tube formation by tumour cells in vitro is considered to be an indicator of the ability of these cells to undergo vasculogenic mimicry (VM), the process by which tumour cells form functional vessel-like structures. The TFA has therefore been used to assess VM in various tumours, including glioblastoma. However, aspects of the TFA, including seeding density, basement membrane matrix, media composition, and imaging timepoint, vary greatly between previous studies of VM in glioblastoma, resulting in difficulty comparing results between studies and uncertainty relating to the conditions under which glioblastoma cells may undergo tube formation. We therefore aimed to assess the tube formation ability of multiple glioblastoma cell lines assayed under the same conditions.

MATERIAL AND METHODS

Twelve patient-derived glioblastoma cell lines were plated for TFAs at multiple seeding densities in serum-free media on a 150µL/cm2 layer of growth factor-reduced (GFR) Matrigel. Cells were imaged 2-hourly for 24 hours using an Incucyte SX5 Live-Cell Analysis Instrument in order to determine the tube formation ability and optimal seeding density of each cell line. Human umbilical vein endothelial cells (HUVECs) were used as a positive control. The Angiogenesis Analyzer plugin for ImageJ was used to quantify number of tubules, average tubule length, tubule area, and number of branch points for HUVECs and tube forming glioblastoma cells.

RESULTS

Three of the 12 glioblastoma cell lines tested were considered capable of in vitro tube formation, consistently forming tubule-like networks that morphologically resembled those formed by HUVECs within 24 hours of plating for a TFA. Network characteristics differed between HUVECs and glioblastoma cells, with the glioblastoma cells generally forming a higher number of shorter tubules, and therefore having a higher number of branch points. This did not correspond to a larger total tubule area, which was comparable between the HUVECs and glioblastoma cells.

CONCLUSION

A subset of patient-derived glioblastoma cell lines are able to form tube-like structures in vitro when grown in serum-free media on GFR Matrigel. Further experiments assessing additional TFA conditions and subsequent analyses of gene and protein expression in tube-forming glioblastoma cell lines may provide further insight into the mechanisms by which VM may be occurring.
P04.03.A TARGETING SCD TRIGGERS LIPOTOXICITY OF CANCER CELLS AND ENHANCES ANTI-TUMOR IMMUNITY IN BREAST CANCER BRAIN METASTASIS MOUSE MODELS
Authors: Sammarco A , Guerra G , Eyme K M , Kennewick K , Qiao Y , El Hokayem J , Williams K J , Su B , Zappulli V , Bensinger S J , Badr C E
Published: October 2024

BACKGROUND

Breast cancer brain metastases (BCBM) are a significant cause of mortality and are incurable. Thus, identifying BCBM targets that reduce morbidity and mortality is critical. BCBM upregulate Stearoyl-CoA Desaturase (SCD), an enzyme that catalyzes the synthesis of monounsaturated fatty acids. This finding highlights a potential metabolic vulnerability of BCBM, but the lack of brain-penetrant inhibitors of SCD has precluded their pre-clinical effectiveness. Additionally, increasing evidence suggests that fatty acid homeostasis in immune cells represents a key regulatory node to control inflammation, and manipulation of fatty acid metabolism has significant effects on immune cell functions. In this study, we tested the effect of a brain-penetrant clinical-stage inhibitor of SCD (SCDi), on breast cancer cells and mouse models of BCBM.

MATERIAL AND METHODS

Lipidomic analyses, qPCR, and western blot were used to study the in vitro effect of SCDi on breast cancer cells. Single-cell RNA sequencing (scRNAseq) was used to explore the effects of SCDi on cancer and immune cells in the tumor microenvironment (TME) in a BCBM mouse model.

RESULTS

Pharmacological inhibition of SCD markedly reshaped the lipidome of breast cancer cells and resulted in endoplasmic reticulum stress, DNA damage, loss of DNA damage repair, and cytotoxicity. Importantly, SCDi alone or combined with a PARP inhibitor prolonged the survival of BCBM-bearing mice. When tested in a syngeneic mouse model of BCBM, scRNAseq revealed that pharmacological inhibition of SCD enhanced antigen presentation by dendritic cells, was associated with a higher interferon signaling, increased the infiltration of cytotoxic T cells, and decreased the proportion of exhausted T cells and regulatory T cells in the TME. Additionally, interaction analysis between immune cells in the TME revealed that pharmacological inhibition of SCD decreased engagement of immunosuppressive pathways, including the PD-1:PD-L1/PD-L2 and PVR/TIGIT axes.

CONCLUSION

These findings suggest that SCD inhibition could be an effective strategy to intrinsically reduce tumor growth and reprogram anti-tumor immunity in the brain microenvironment to treat BCBM.
P05.02.B MOLECULAR MECHANISMS OF ANEUPLOIDY AND GLIOBLASTOMA AGGRESSIVENESS INDUCED BY DIAPH3 LOSS
Authors: Jabbour C , Tajeddine N
Published: October 2024

BACKGROUND

Diaphanous-related formin 3 (Diaph3) belongs to the formin family of dimeric multidomain proteins that are master regulators of actin and microtubule dynamics. It plays a role in the cytoskeleton remodeling, more specifically in cytokinesis and karyokinesis. In the mouse brain, loss of Diaph3 induced aneuploidy followed by massive apoptosis in neural stem cell, leading to microcephaly. Given the potential role of aneuploidy in cancer development, we are interested to unravel whether Diaph3 depletion during gliomagenesis could aggravate glioblastoma (GBM) aggressiveness

MATERIAL AND METHODS

To analyze whether Diaph3 is a potential therapeutic target in human GBM, we will use siRNA-mediated depletion of Diaph3 in a panel of GBM cell lines (U251 and U87). We conducted karyotyping followed by analysis of the DNA Damage response (DDR) induction, DNA repair and cell cycle progression.

RESULTS

Our results showed that siRNA-mediated depletion of Diaph3 in p53 mutated GBM cells (U251 cells) disrupted microtubules and caused mitotic defects such as multipolar mitosis. Karyotyping showed an increase in aneuploidy in Diaph3-depleted U251 cells. Since it has been shown that numerical abnormalities in chromosomes segregation could trigger DDR, we hypothesize that the loss of Diaph3 induces increased activity of the DDR pathway and we aim to decipher their underlying molecular mechanism.

CONCLUSION

We believe that this study may provide insights into the mechanisms by which Diaph3 prevents aneuploidy in glioblastoma cells but also, more generally, into the role of aneuploidy in gliomagenesis.
P09.16.B THE ROLE OF PERFUSION-MRI IN THE DETECTION OF PROGRESSIVE DISEASE OR THERAPY RELATED CHANGE AFTER PROTON-BOOST IRRADIATED IN PRIMARY GLIOBLASTOMA
Authors: Goett H , Singer L , Struffert T , Uhl E , Stein M
Published: October 2024

OBJECTIVE

Therapy related change (TRC) in glioma patients after radiotherapy are common. In daily practice TRC is difficult to differentiate from true progressive disease (PD). Perfusion-MRI could be a helpful tool to differ between PD and TRC after radiotherapy. However, data for the evaluation of perfusion-MRI after proton therapy in glioblastoma is still missing Our study aims to evaluate perfusion MRI for the differentiation between PD and TRC in primary glioblastoma patients after proton-boost radiotherapy.

METHODS

We evaluate MRI scans from 37 patients with newly diagnosed glioblastoma, who received either photon irradiation (60Gy) or photon irradiation with proton boost (50 + 10Gy). A retrospective analysis regarding T1 contrast enhancement, FLAIR hyperintensity and correlating leakage-corrected relative DSC-CBVmax (relCBVmax) values of the contrast enhancing or FLAIR hyperintense areas in a ratio to a corresponding ROI in the contralateral white matter were performed. Whether scans showed PD or TRC was defined afterwards depending on histology or proceeding growth in the follow up scans. Groups were compared via Mann-Whithney U-Test. For the CBVmax values AUC analysis was performed.

RESULTS

MRI scans in patients after proton therapy showed more often increase of contrast enhancement (59.34%) compared to patients after photon therapy (46.15%). However, the difference was not statistically significant (p=0.1001). RelCBVmax of the FLAIR hyperintense area was not significantly correlated with PD after photon therapy. To predict PD after proton-boost irradiation the cut-off value for the relCBVmax of the FLAIR hyperintense area was >86.3% (sens.: 81.82%/spec.: 58.7%;p=0.0009). For prediction of PD the relCBVmax of contrast enhancing areas the cut-off value after photon irradiation was >145.8% (sens.: 66.67%/spec.:84.21%; p=0.0037). PD after proton-boost therapy could be predicted with a cutoff value of the relCBVmax of 180.7% (sens.:60.61%/spec.:86.21%; p=0.0003).

CONCLUSION

The observed sensitivity was low. However, hyperperfusion in relCBVmax can help for the differentiation between PD and TRC. Perfusion-MRI is a very cost-effective technique and could be a useful tool to determine which patients should receive PET-scans for further diagnostics.
P10.06.A AGENT-BASED MODELING FOR PATIENT-CENTERED CLINICAL DECISION SUPPORT IN NEURO-ONCOLOGY
Authors: Rodriguez Almaraz E , Miao B , Yadav Y , de Groot J , Young J , Vo A , Butte A , Mitchel B S , Raleigh D , Butowski N , Alaa A
Published: October 2024

BACKGROUND

Complex clinical decision-making in neuro-oncology is a multifaceted process involving numerous specialties influenced by various objective factors and patient preferences. Modeling these multidisciplinary neuro-oncology discussions presents significant challenges, particularly given the multimodal nature of the data. Recent advancements in large language models (LLMs) have enabled the development of LLM “agents”. These agents pave the way for multi-agent systems capable of simulating interacting components, thus capturing the nuances of interdisciplinary clinical discussions.

MATERIAL AND METHODS

Utilizing GPT-4, we developed conversational agents with an agent-based modeling (ABM) approach; each agent was assigned a specific specialty. We simulated their interactions in various clinical decision-making scenarios. Lastly, we simulated 30 patient-agents and included them in the ABM system. We applied this ABM approach to a dataset of 16 clinical vignettes extracted from the UCSF Clinical Data Warehouse of primary adult glioma patients who underwent tumor board (TB) reviews. The TB decision was used as ground truth for quantitative evaluation. Seven independent clinicians evaluated the final decisions.

RESULTS

Our quantitative assessment showed that, when blinded to whether ABM or TB generated responses, evaluators preferred ABM recommendations 47.8% of the time, followed by TB recommendations (38%). The highest recommendation concordance was between TB and ABM (50.6%). The ABM was deemed clinically accurate in 76.8% of cases and provided clinically appropriate reasoning in 73.2%. Our qualitative assessment showed that including the patient agent significantly influenced the course of discussions, notably when the patient agents participated in the system by stating their healthcare goals. The most recommended individual treatment was standard-of-care chemotherapy, followed by targeted therapies, clinical trials, immunotherapy, and palliative care. The least frequently recommended management options were radiation, surgery, consultation with other specialties, and devices.

CONCLUSION

This study underscores the potential of ABM in neuro-oncology, particularly in simulating complex, real-world scenarios. ABM not only empowers patients but also offers clinicians a novel tool for understanding and navigating the multifaceted landscape of patient preferences and treatment options. It provides a platform for clinicians to visualize the potential impacts of various decisions, enhancing their ability to provide personalized, effective care. We envision future work where ABM systems are patient-centric, enabling patients to explore the potential impacts of their individual characteristics on clinical management options.
P10.10.B CLASSIFYING LOWER-GRADE GLIOMA SUBTYPES WITH 3D WHOLE-BRAIN MRI SCANS AND DEEP LEARNING: A NON-INVASIVE AND INTERPRETABLE APPROACH
Authors: Iadarola B , Sforazzini F , Luchetti L , Leoncini M , Battaglini M , D’Aurizio R
Published: October 2024

BACKGROUND

Patient management with lower-grade glioma (LGG) requires tumour sampling to identify IDH mutation and 1p19q codeletion status, which are pivotal for subtype classification and subsequent therapy. The use of MRI has been investigated so far by radiomics which focuses on features extracted from 2D images of the tumour region only. Deep Learning (DL) algorithms, and in particular Neural Networks (NN), proved to be effective in improving the detection of cancers from diverse imaging data, often through tumour segmentation masking. We aimed to develop a DL-based framework to streamline the LGG molecular-based subtypes classification from the whole-brain 3D MRI scans and, subsequently, to extract a fine map of the brain regions which resulted relevant for the classification.

MATERIAL AND METHODS

Pre-operative MRI scans (T2-FLAIR, T1gad) and molecular information (IDH mutation, 1p19q codeletion status) of 82 LGG patients were collected from the TCIA and TCGA datasets. 56 “IDH-mutant astrocytomas” and 26 “IDH-mutant 1p19q codeleted oligodendrogliomas” were split into class-balanced training (65) and test (17) sets. A computational framework was developed to preprocess the MRIs, train and optimize different DL models through hyperparameters fine-tuning and to automatically detect the best-performing one. We explored a total of 162 configurations, using single and multiple MRI modalities within two residual NN and calculated the attention maps using guided back-propagation.

RESULTS

In the test set we obtained a balanced accuracy of 92% and a F1-weighted score of 89% in differentiating IDH-mutant astrocytomas (sensitivity=0.83) from IDH-mutant 1p19q codeleted oligodendrogliomas (sensitivity=1). The generated attention maps confirmed that features extracted from the perilesional regions positively influenced the classification of the tumour subtypes, especially of astrocytomas (100% of cases); on the contrary, the widely used tumoral region was scarcely considered in the classification of this subtype (10%), having an impact only in oligodendrogliomas (60%). Interestingly, contralateral and other distant-from-the-tumour areas were relevant in the classification of both subtypes (40%), with a focus on distant-from-the-tumour areas in oligodendrogliomas (60%).

CONCLUSION

3D whole-brain scans coupled with optimized DL-based approach showed to be a non-invasive and promising alternative in classifying LGG molecular-based subtypes, providing a more exploratory insight in the subject-level discrimination of brain regions differently associated with IDH mutation and 1p19q codeletion status. Further validations are needed to prove the efficacy of the proposed method in supporting the clinical decision-making.
P10.22.B PREDICTING INTRAOPERATIVE 5-ALA-INDUCED TUMOR FLUORESCENCE VIA MRI AND DEEP LEARNING IN GLIOMAS WITH RADIOGRAPHIC LOWER-GRADE CHARACTERISTICS
Authors: Suero Molina E , Azemi G , Özdemir Z , Russo C , Valls Chavarria A , Liu S , Thomas C , Stummer W , Di Ieva A
Published: October 2024

BACKGROUND

Lower-grade gliomas typically exhibit 5-aminolevulinic acid (5-ALA)-induced fluorescence in only 20-30% of cases, a rate that can be increased by doubling the administered dose of 5-ALA. Fluorescence can depict anaplastic foci, which can be precisely resected to avoid undergrading. We aimed to analyze whether a deep learning model can predict intraoperative fluorescence based on preoperative magnetic resonance imaging (MRI). Material and Methods: The MRI images of gliomas lacking high-grade characteristics (necrosis, extended contrast-enhancement, a.o.) consisted of T1, T1-post gadolinium, and FLAIR sequences. The preprocessed MRIs were fed into an encoder-decoder convolutional neural network (U-Net), pre-trained for tumor segmentation using those three MRI sequences. We used the outputs of the bottleneck layer of the U-Net in the Variational Autoencoder (VAE) as features for classification. We identified and utilized the most effective features in a Random Forest classifier using the principal component analysis (PCA) and the partial least square discriminant analysis (PLS-DA) algorithms. We evaluated the performance of the classifier using a 10-fold cross-validation procedure.

RESULTS

We evaluated a cohort of 163 glioma patients categorized as fluorescent (n=83) or non-fluorescent (n=80). Our proposed approach’s performance was evaluated using metrics such as mean balanced accuracy, mean sensitivity, and mean specificity. The optimal results were obtained by employing top-performing features selected by PCA, resulting in a mean balanced accuracy of 80% and mean sensitivity and specificity of 84% and 76%, respectively.

CONCLUSION

Our findings highlight the potential of a U-Net model, coupled with a random forest classifier, for intraoperative fluorescence prediction. We achieved good accuracy using advanced techniques such as deep learning-based tumor segmentation and Variational Autoencoder for radiomics feature extraction. While the model can still be improved, it has the potential for evaluating when to administer 5-ALA to gliomas lacking typical high-grade radiographic features.
P16.01.B DOXORUBICIN GLYCOSYLATION AS A NOVEL APPROACH TO SPECIFICALLY TARGET GLIOBLASTOMA
Authors: Iorio A , Marzano C , Tirinnanzi B , Lenci E , Bucaletti E , Castelli B , Fonte C , Tellini M , Guidi M , Di Nicola M , Giunti L , La Torre C , Trabocchi A , Sardi I
Published: October 2024

BACKGROUND

Despite recent advances in the treatment of cancer, malignant brain tumors such as Glioblastoma (GBM) are still a major challenge in oncology with a poor prognosis. This evidence can be partly explained by the inability of most drugs, such as Doxorubicin (DOX), to be delivered within the brain due to the presence of drug resistance mechanisms including the active efflux mediated by ATP-binding cassette transporters, which are overexpressed on the blood brain barrier (BBB).Malignant tumors like GBM also show a significant glycolytic rate and a high glucose request through glucose transporters (Warburg Effect). In this context, GLUT1 is reported to be implicated in glucose uptake through the BBB.In our study we have developed an innovative approach able to increase drug efficiency and selectivity, by conjugating the anticancer agent DOX to glucose.

MATERIAL AND METHODS

DOX glycoconjugates were obtained using oxime-based linkers with hydroxylamine-containing spacers between position number 6 of glucose and carbonyl group of DOX. Two different glycoconjugates (EB73 and EB74) were synthesized and characterized for their absorbance, fluorescence and binding affinity to ctDNA. MTT assay was performed to evaluate the cytotoxic effect of EB73 and EB74, compared to DOX, in two GBM cell lines (A172 and DOX resistant T98G). These cells were also used to evaluate the effect of glucose deprivation on the expression levels of GLUT1 and breast cancer resistance protein (BCRP) by Western Blot. Molecules uptake by cells was evaluated using an in vitro BBB model and immunofluorescence (IF) in glioblastoma and neuroglia cell lines.

RESULTS

Our results showed that EB73 and EB74 have kept Ka binding constants comparable to DOX itself, confirming that functionalization with glucose did not alter DOX intercalation capability and fluorescence.The in vitro cytotoxicity results demonstrated that EB74 has the major effect in A172 compared to DOX and revealed a high efficacy in T98G DOX-resistant cells starting from 24 hours of treatment. Moreover, glucose deprivation showed a GLUT1 overexpression and BCRP downregulation in both cell lines improving EB74 efficacy. According to MTT results, BBB in vitro model and IF experiments revealed that only EB74 was able to accumulate in cells nuclei as conventional DOX.

CONCLUSION

In conclusion, these results indicated that glycoconjugation of DOX and glucose deprivation may be helpful instruments to increase drugs uptake and effectiveness in aggressive and chemoresistant tumor cells.