bluuebunny/crossref_metadata_2025 huggingface dataset:
Locomotor Challenges of Waterfall-Climbing Gobies during Transitions between Media
Authors: Maie Takashi
Published: June 2022

Synopsis

An amphidromous goby, Sicyopterus japonicus, migrates from the ocean to upstream regions of many streams and rivers in the Pacific coasts of Japan and Taiwan. Using its mouth and fused pelvic fins (pelvic sucker), this gobiid species exhibits a rock-climbing behavior and surmounts sizable waterfalls, which block the upstream movement of many of its competitors and predators. When gobies emerge from the water to commence their climbing behavior, the change in effective density (i.e., lack of buoyancy) that occurs in this transition substantially increases the force required for adhesion. Consequently, these fish must exert adhesive suction strong enough to support their body weight against gravity during climbing on the rock surface. Suction performance for adhesion and modulatory capacity of S. japonicus were evaluated with two different sets of experimental conditions: climbing on the vertical surface with no water flow versus climbing on a 60°-inclined surface with 2 L/min flow. Individuals of S. japonicus showed 50.7% greater mean safety factor (suction force for adhesion/gravitational force) and 56.6% shorter time to reach maximum pressure differential during climbing on the 60°-inclined surface with water rushing over their bodies than during climbing on the vertical surface with no water flow. These results indicate that when climbing with drag force from flowing water, greater functional demands are imposed and therefore, S. japonicus is required to increase neuromuscular stimulation of the pelvic muscles to elevate suction performance. In addition, S. japonicus individuals at different ontogenetic stages modulate their climbing behaviors and strategies to accommodate changing functional demands as they make transitions between different inclines, as well as media, while ascending waterfalls.
Model definition for genetic evaluation of purebred and crossbred lambs including heterosis
Authors: Vargas Jurado Napoleón , Notter David R , Taylor Joshua B , Brown Daniel J , Mousel Michelle R , Lewis Ronald M
Published: June 2022

Crossbreeding is a common practice among commercial sheep producers to improve animal performance. However, genetic evaluation of U.S. sheep is performed within breed type (terminal sire, semi-prolific, and western range). While incorporating crossbred records may improve assessment of purebreds, it requires accounting for heterotic and breed effects in the evaluation. The objectives of this study were to: 1) describe the development of a paternal composite (PC) line, 2) determine the effect of direct and maternal heterosis on growth traits of crossbred lambs, 3) estimate (co)variance components for direct and maternal additive, and uncorrelated maternal environmental, effects, and 4) provide an interpretation of the estimates of random effects of genetic groups, and to use those solutions to compare the genetic merit of founding breed subpopulations. Data included purebred and crossbred records on birth weight (BN; n = 14,536), pre-weaning weight measured at 39 or 84 d (WN; n = 9,362) depending on year, weaning weight measured at 123 d (WW; n = 9,297), and post-weaning weight measured at 252 d (PW; n = 1,614). Mean (SD) body weights were 5.3 (1.1), 16.8 (3.9) and 28.0 (7.6), 39.1 (7.2), and 54.2 (8.7) kg for BN, WN (at the two ages), WW, and PW, respectively. In designed experiments, the Siremax, Suffolk, Texel, Polypay, Columbia, Rambouillet, and Targhee breeds were compared within the same environment. Estimates of heterotic effects and covariance components were obtained using a multiple trait animal model. Genetic effects based on founders’ breeds were significant and included in the model. Percent estimates of direct heterosis were 2.89 ± 0.61, 2.60 ± 0.65, 4.24 ± 0.56, and 6.09 ± 0.86, and estimates of maternal heterosis were 1.92 ± 0.87, 4.64 ± 0.80, 3.95 ± 0.66, and 4.04 ± 0.91, for BN, WN, WW, and PW, respectively. Correspondingly, direct heritability estimates were 0.17 ± 0.02, 0.13 ± 0.02, 0.17 ± 0.02, and 0.46 ± 0.04 for BN, WN, WW, and PW. Additive maternal effects accounted for trivial variation in PW. For BN, WN, and WW, respectively, maternal heritability estimates were 0.16 ± 0.02, 0.10 ± 0.02, and 0.07 ± 0.01. Uncorrelated maternal environmental effects accounted for little variation in any trait. Direct and maternal heterosis had considerable impact on growth traits, emphasizing the value of crossbreeding and the need to account for heterosis, in addition to breed effects, if crossbred lamb information is included in genetic evaluation.
Shedding Light on T2 Bright Masses on Breast MRI: Benign and Malignant Causes
Authors: Gibson Averi L , Watkins Jade E , Agrawal Anushree , Tyminski Monique M , DeBenedectis Carolynn M
Published: June 2022

While T2 hyperintense masses on breast MRI are often benign, there are several malignant etiologies that can also be T2 hyperintense. Delineation between benign and malignant entities is important for the accurate interpretation of breast MRI. Common benign T2 hyperintense masses include cysts, fibroadenomas, and lymph nodes. Malignant processes that are T2 hyperintense include metastatic lymph nodes, mucinous breast carcinomas, papillary breast carcinomas, and breast cancers with central necrosis. Evaluation of the morphology and enhancement pattern of a T2 hyperintense mass can help to differentiate a benign process from a malignant one. This educational review will present both benign and malignant causes of T2 hyperintense masses on breast MRI and review common imaging findings and pertinent imaging characteristics that can be used to help accurately identify benign entities while also recognizing suspicious lesions that require additional evaluation.
Efficient least-squares reverse time migration using local cross-correlation imaging condition
Authors: Kim Sumin , Kim Young Seo , Chung Wookeen
Published: June 2022

The data-domain least-squares reverse time migration (LSRTM), a promising imaging method for obtaining a high-resolution reflectivity image, can be implemented by matching the de-migrated data to the observed one. However, LSRTM requires expensive computational costs in its implementation due to tremendous memory usage (direct storage on disk/memory) for saving source wavefields and repeatable forward/backward wavefield simulations with iterations compared to conventional RTM. Although the source wavefield reconstruction technique can be used to reduce the memory usage, additional computational cost is inevitable because it is implemented during backward wavefield simulation. To alleviate the computational burden, we have developed an efficient LSRTM scheme with local cross-correlation imaging condition (LSRTM-LC), which can use pre-saved source wavefields according to the window size. Because the window size is much shorter than the total recording time for wavefield extrapolation, storing source wavefields into computer memory can be feasible. In addition, the procedure for storing source wavefields is implemented only at the first iteration because the background velocity is fixed during iterations of LSRTM. To validate the feasibility of the LSRTM-LC scheme, we have carried out several numerical tests with synthetic datasets. Numerical tests demonstrated that LSRTM-LC can provide us with equivalent de-migrated data from saved source wavefields and the gradient vector obtained from LSRTM-LC compared to those obtained from the conventional LSRTM. As a result, LSRTM-LC can generate the same quality of reflectivity models as conventional LSRTM, however, it requires less computational costs compared to conventional LSRTM.
Expression profiles of the genes associated with zinc homeostasis in normal and cancerous breast and prostate cells
Authors: Barman Shital K , Zaman Mohammad S , Veljanoski Filip , Malladi Chandra S , Mahns David A , Wu Ming J
Published: June 2022

Zn2+ dyshomeostasis is an intriguing phenomenon in breast and prostate cancers, with breast cancer cells exhibiting higher intracellular Zn2+ level compared to their corresponding normal epithelial cells, in contrast to the low Zn2+ level in prostate cancer cells. In order to gain molecular insights into the zinc homeostasis of breast and prostate cancer cells, this study profiled the expression of 28 genes, including 14 zinc importer genes (SLC39A1–14) that encode Zrt/Irt-like proteins 1–14 to transport Zn2+ into the cytoplasm, 10 zinc exporter genes (SLC30A1–10) which encode Zn2+ transporters 1–10 to transport Zn2+ out of the cytoplasm, and 4 metallothionein genes (MT1B, MT1F, MT1X, MT2A) in breast (MCF10A, MCF-7, MDA-MB-231) and prostate (RWPE-1, PC3, DU145) cell lines in response to extracellular zinc exposures at a mild cytotoxic dosage and a benign dosage. The RNA samples were prepared at 0 min (T0), 30 min (T30), and 120 min (T120) in a time course with or without zinc exposure, which were used for profiling the baseline and dynamic gene expression. The up-regulation of MT genes was observed across the breast and prostate cancer cell lines. The expression landscape of SLC39A and SLC30A was revealed by the quantitative reverse transcription polymerase chain reaction data of this study, which sheds light on the divergence of intracellular Zn2+ levels for breast and prostate cancer cells. Taken together, the findings are valuable in unraveling the molecular intricacy of zinc homeostasis in breast and prostate cancer cells.
The Xer activation factor of TLCΦ expands the possibilities for Xer recombination
Authors: Miele Solange , Provan James Iain , Vergne Justine , Possoz Christophe , Ochsenbein Françoise , Barre François-Xavier
Published: June 2022

The chromosome dimer resolution machinery of bacteria is generally composed of two tyrosine recombinases, XerC and XerD. They resolve chromosome dimers by adding a crossover between sister copies of a specific site, dif. The reaction depends on a cell division protein, FtsK, which activates XerD by protein-protein interactions. The toxin-linked cryptic satellite phage (TLCΦ) of Vibrio cholerae, which participates in the emergence of cholera epidemic strains, carries a dif-like attachment site (attP). TLCΦ exploits the Xer machinery to integrate into the dif site of its host chromosomes. The TLCΦ integration reaction escapes the control of FtsK because TLCΦ encodes for its own XerD-activation factor, XafT. Additionally, TLCΦ attP is a poor substrate for XerD binding, in apparent contradiction with the high integration efficiency of the phage. Here, we present a sequencing-based methodology to analyse the integration and excision efficiency of thousands of synthetic mini-TLCΦ plasmids with differing attP sites in vivo. This methodology is applicable to the fine-grained analyses of DNA transactions on a wider scale. In addition, we compared the efficiency with which XafT and the XerD-activation domain of FtsK drive recombination reactions in vitro. Our results suggest that XafT not only activates XerD-catalysis but also helps form and/or stabilize synaptic complexes between imperfect Xer recombination sites.
ATRT-22. Outcomes for children with recurrent atypical teratoid rhabdoid tumor: A single institution study with updated molecular and germline analysis
Authors: Carey Steven S , Huang Jie , Myers Jason R , Mostafavi Roya , Orr Brent , Michalik Layna H , Klimo Paul , Boop Frederick , Nichols Kim E , Merchant Thomas , Ellison David W , Robinson Giles W , Onar-Thomas Arzu , Gajjar Amar , Upadhyaya Santhosh
Published: June 2022

BACKGROUND: Children with recurrent atypical teratoid rhabdoid tumor (recATRT) who fail frontline therapies have dismal outcomes. The association of ATRT molecular groups (SHH, TYR and MYC) and presence of underlying cancer predisposition with survival post-recurrence (postRD) is unknown. METHODS: We previously reported outcomes from a single-institution retrospective study of children <21 years with recATRT treated at St. Jude Children’s Research Hospital from 2000 to 2020. Herein we report updated progression-free survival (PFS2: time from initial recurrence to subsequent first progression) and overall survival (OSpostRD: time from initial recurrence to death/last follow-up) outcomes by molecular groups determined by tumor DNA methylation and by germline SMARCB1/SMARCA4 alterations (GLA). RESULTS: Median age and time from initial diagnosis to recurrence for 64 eligible patients were 2.1 years (range: 0.5-17.9 years) and 5.4 months (range: 0.5–125.6 months), respectively. The 2- and 5-year PFS2 and OSpostRD were 3.1% (±1.8%)/1.6% (±1.1%) and 20.3% (±4.8%)/7.9% (±3.8%), respectively. PFS2 did not differ by molecular groups (p=0.210) for 42 participants with available data (MYC=11, SHH=21, TYR=10). Children with TYR group had a better 2-year OSpostRD [60.0% ±14.3% (TYR) vs. 18.2% ±9.5% (MYC) or 4.8% ±3.3% (SHH)] (p=0.018). In univariate analyses, OSpostRD was also better with older age at diagnosis (≥ 1 year vs <1 year; p=0.03), female gender (p=0.008), and metastatic site of recurrence compared to local or combined sites of disease (p<0.001). OSpostRD did not differ for those with positive GLA (n=12) compared to those without (n=21) (p=0.231). Only 6 children (9.4%) (TYR=4, SHH=1, NA=1) were alive at median follow-up of 7.7 years from recurrence. CONCLUSION: Children with recATRT have extremely poor outcomes. Older age at diagnosis, female gender, TYR group, and metastatic site of initial recurrence were associated with longer survival in our study. These results reinforce the dire need for better therapeutic options.
ATRT-26. The PI3k inhibitor Paxalisib combines with the novel HDAC1/3 inhibitor RG2833 to improve survival in mice bearing orthotopic xenografts of atypical teratoid/rhabdoid tumors
Authors: Findlay Tyler , Malebranche Kristen , Raabe Eric , Eberhart Charles , Rubens Jeffrey
Published: June 2022

We previously identified high activation of mTORC1 and mTORC2 in AT/RT by immunohistochemistry of 18 primary tumors expanding over each molecular subgroup of AT/RT. Paxalisib is a highly brain-penetrant PI3k inhibitor acting upstream of mTORC1/2 to fully inhibit the activation of both complexes. Ongoing pediatric clinical trials have reported Paxalisib as safe and well-tolerated. We find that Paxalisib leads to minimal toxicities in mice bearing AT/RT orthotopic xenografts, slows tumor growth (as determined by bioluminescent imaging), and significantly extends survival (CHLA-06: 40 to 54 days, p=0.0011; BT12: 21 to 35 days, p=0.02). However, due to limited durability of single agent therapy, we conducted pilot studies to identify rational combination therapies to further enhance these survival benefits. RG2833 is a novel, highly brain penetrant, histone deacetylase 1/3 (HDAC1/3) inhibitor. HDAC inhibitors have previously been identified as synergistic partners with PI3k/mTOR inhibitors through complementary activation of FOXO signaling pathways. We hypothesized that RG2833 would synergize with Paxalisib, minimize toxicities compared with pan-HDAC inhibitors, and maximize therapeutic benefits due to superior CNS penetration. We demonstrate that Paxalisib and RG2833 combine synergistically to decrease AT/RT cell growth (SynergyFinder ZIP score 11.1; CellTiter-Blue Cell Viability Assay, p<0.0001), and increase apoptosis (Western blot cPARP, MUSE Annexin V Assay, ANOVA p<0.001) compared to each agent alone and DMSO control. Our pilot combination study in orthotopic xenograft models of AT/RT demonstrate that combination therapy is well tolerated and slows tumor growth more significantly than each agent alone and vehicle control (IVIS bioluminescent imaging). This novel combination therapy could readily translate into a new clinical trial aimed at improving survival in this deadly pediatric brain tumor.
RARE-05. Legal degree of disability in childhood-craniopharyngioma survivors during long-term follow-up – results of the HIT-ENDO study
Authors: Boekhoff Svenja , Beckhaus Julia , Eveslage Maria , Friedrich Carsten , Müller Hermann L
Published: June 2022

BACKGROUND: Cranioparyngiomas are rare low-grade embryonic malformational tumors of the sellar/parasellar region. The prognosis after diagnosis during childhood and adolescence is influenced by endocrine and hypothalamic long-term sequelae. A legal status of the degree of disability (GdB), according to the German Social Code Book V that is worthy of support, provides financial means for psychosocial rehabilitation and participation of craniopharyngioma survivors. The aim of this study was to determine the association of clinical/psychosocial characteristics and quality of life (QoL) indicators with the resulting GdB. PATIENTS AND METHODS: HIT-Endo is a German registry study on craniopharyngioma patients aged ≤ 18 years at diagnosis and included before the year 2000. In a sample of 108 patients, the degree of disability and the association with endocrine, ophthalmological, neuropsychological and psychosocial parameters was analyzed after a mean follow-up period of 16 years (95% CI: 9.8-36.4). RESULTS: 44 patients (41%) did not receive a GdB, three patients (3%) received a GdB of 30-40, 43 patients (40%) a GdB of 50-90 and 18 patients (17%) the maximum GdB of 100. Higher GdB were associated with lower education, higher body mass index standard deviation and a higher degree of visual impairment and hypothalamic involvement of the craniopharyngeoma. Patients with a GdB of 100 reported loss in physical and cognitive function, as well as fatigue, dyspnea, and pain conditions, and limitations in social and occupational contexts. They further had a lower functional capacity (German daily life ability scale (FMH)) compared to those with a smaller GdB. CONCLUSION: The GdB is associated with psychosocial and physical impairments and reflects the long-term consequences of craniopharyngioma during childhood and adolescence. A low functional capacity (assessed by FMH) may indicate the eligibility for a high GdB in later life of craniopharyngioma survivors.
DIPG-12. Induced mitotic abnormalities associated with BMI-1 modulation sensitize diffuse intrinsic pontine glioma cells to ionizing radiation
Authors: Kumar Shiva Senthil , Mishra Deepak , Mchugh Todd , Drissi Rachid
Published: June 2022

Diffuse intrinsic pontine glioma (DIPG) remains an incurable childhood brain cancer with a median overall survival of less than 12 months, affecting 200-300 children annually in the United States. Hence, there is an unmet need for the development of novel and effective targeted therapies. BMI-1 is a subunit of the multimeric protein complex Polycomb repressor complex 1 (PRC1) implicated in self-renewal of normal and cancer cells, and in DNA damage signaling. We have previously identified BMI-1 as a potential therapeutic target in DIPG and have shown that BMI-1 is highly expressed in DIPG tumors regardless of H3K27 mutational status. Treatment of DIPG cells with PTC596, a small molecule initially identified as a BMI-1 modulator, and ionizing radiation (IR) impairs the kinetics of DNA damage response. in vivo, treatment with PTC596 alone delayed tumor growth kinetics and induced in-tumor apoptosis. However, we observed tumor regrowth once PTC596 treatment is completed or discontinued. In the present study, we evaluated the use of PTC596 in combination with IR. Our in vivo results indicate that PTC596 sensitizes DIPG cells to IR inducing a prolonged cell growth arrest 14 days post-treatment compared to IR or PTC596 alone. The effectiveness of this combination is currently evaluated in murine orthotopic DIPG models and the results will be presented. PTC596 is being tested in newly diagnosed children with DIPG and high-grade gliomas (NCT03605550). Data collected from this study will support the development of a novel therapy including PTC596 in combination with radiotherapy to treat children with DIPG.
DIPG-13. Immune profiling by RNA-seq deconvolution and single-cell sequencing reveal myeloid cell enrichment in DIPG tumor microenvironment
Authors: Zhu Xiaoting , Mishra Deepak , Kumar Shiva Senthil , Mchugh Todd , Lazow Margot , Fouladi Maryam , Drissi Rachid
Published: June 2022

Diffuse intrinsic pontine glioma (DIPG) remains an incurable disease with median overall survival <12 months despite decades of clinical trials investigating multimodal therapies. Immunotherapy represents a promising treatment paradigm which has been successfully used in other cancers. An adequate understanding of the tumor microenvironment and immunologic profile is essential to identify potential immunotherapeutic targets to inform immunotherapy design. Previous studies have shown that most DIPG tumors harbor low mutational burden compared to adult cancers and are characterized by a non-inflammatory microenvironment, limiting the development of immunotherapies in this disease. Our team’s prior work similarly demonstrated that most DIPG tumors have an immunologically “cold” microenvironment, but a subset of tumors harbors a more inflammatory gene expression profile and/or higher mutational burden, with trends toward improved survival and favorable radiographic response to radiation. Here, we applied a deconvolution analysis using CIBERSORTx on bulk RNA-seq data from 28 DIPG patients’ tumors paired with matched normal tissue specimens, to profile the immune microenvironment of DIPG and evaluate immune-related gene expression to determine percentages of different types of immune cells. Our results indicate that DIPGs have very limited lymphocyte infiltration. However, the infiltration of macrophages “M2-like” type cells and CD4 memory resting T cells were significantly higher in tumors compared to normal tissue samples. Similar results were found using single-cell RNA sequencing performed on biopsy and autopsy tissue, with less than 5% of total cells identified as immune cells. MHC I components were widely expressed in DIPGs with no significant difference between tumor and normal tissue. Expression of CD11B and CD68 were higher in tumor compared to normal tissue, suggesting enrichment of myeloid cells. Overall, deconvolution analysis of bulk RNA-seq can be used to profile DIPG tumors’ immune microenvironment to aid in the thoughtful design of effective immunotherapeutic strategies for this disease.
DIPG-60. Avapritinib for targeting PDGFRA in H3K27M – mutated diffuse midline glioma
Authors: Mayr Lisa , Madlener Sibylle , Weiler-Wichtl Liesa , Rosenmayr Verena , Furtner-Srajer Julia , Guntner Armin , Stepien Natalia , Baumgartner Alicia-Christina , Dorfer Christian , Haberler Christine , Müllauer Leonhard , Palova Hana , Pokorna Petra , Sterba Jaroslav , Dieckmann Karin , Azizi Amedeo , Peyrl Andreas , Kim Sean , Hsieh Antony , Dimitrijevic Sasa , Gojo Johannes
Published: June 2022

H3K27M-mutated diffuse midline glioma (H3K27M DMG) are an almost universally fatal disease with a median survival of less than 6 months post progression and no effective therapy. PDGFRA-signaling has shown to promote and sustain a subset of oligodendrocyte precursor-like tumor cells that are responsible for tumor propagating potential and high proliferation rates. However, first attempts to target PDGFRA in adult glioblastoma with dasatinib/imatinib or pediatric refractory brain tumors with sunitinib were not successful. We report on the first experience in two patients receiving avapritinib, a highly potent, selective, brain penetrant PDGFRA/KIT inhibitor under a compassionate use program. Our first patient with spinal H3K27M DMG developed supratentorial metastases ten months after initial diagnosis. Molecular profiling revealed de novo PDGFRA and KIT amplifications and treatment with dasatinib was initiated. Due to disease progression and novel metastases, therapy was switched to avapritinib showing near complete resolution of the previously unirradiated frontal lesion with additional disease stabilization of other metastatic sites. Following re-resection and irradiation of progressing cerebellar lesions, the patient remains clinically stable on avapritinib therapy over 12 months. The second patient with diffuse intrinsic pontine glioma showed disease progression nine months after diagnosis and was treated with focal re-irradiation (30Gy). As the tumor harbored a PDGFRA R841del alteration, avapritinib was initiated seven weeks after radiation upon further tumor progression resulting in partial response. Pharmacokinetic sampling of cerebrospinal fluid (CSF) detected an increasing CSF/plasma ratio over time and up to 4 µM avapritinib in tumor tissue. Avapritinib CSF levels in both patients were distinctly higher than dasatinib levels. Avapritinib was generally well tolerated besides lower limb edema, elevated LDH and liver enzymes. Hence, effective CNS penetration of avapritinib at pharmacologically relevant brain tumor concentrations resulted in clinical response in two patients with rapidly progressive H3K27M DMG.
EPID-09. Characterizing the epidemiology of radiation-induced gliomas following cranial radiotherapy for pediatric cancers: a population-based study
Authors: Leary Jacob , Anderson-Mellies Amy , Green Adam
Published: June 2022

BACKGROUND: Cranial radiotherapy (RT) is used to treat pediatric central nervous system (CNS) cancers and leukemias. RT carries a risk of secondary CNS malignancies, including radiation-induced gliomas, the epidemiology of which is poorly understood. METHODS: This retrospective study using SEER registry data (1975-2016) included two cohorts. Cohort 1 included patients diagnosed with Grade III/IV or ungraded glioma as a second malignancy >/=2 years after receiving beam radiation and/or chemotherapy for a first malignancy diagnosed at ages 0-19 years, either a primary CNS tumor treated with RT (1a, n=77) or leukemia with unknown RT treatment (1b, n=20). Cohort 2 included patients with possible missed RIG who received RT for a primary CNS tumor diagnosed at 0-19 and then died of presumed progressive disease more than 5 years after diagnosis, since previous studies have documented many missed RIGs in this group (n=296). Controls (n=10,687) included all other patients ages 0-19 who received RT for a first CNS tumor or leukemia who did not fit inclusion criteria above. RESULTS: For Cohort 1 (likely/definite RIGs), 0.97% of patients receiving cranial RT went on to develop RIG. 3.39% of patients receiving cranial RT for primary CNS tumors fell in Cohort 2 (possible RIGs). Median latency to RIG diagnosis was 11.1 years; latency was significantly shorter for Cohort 1b (median 10.0, range 5.0-16.1) vs. 1a (12.0, 3.6-34.4, p=0.018). Median OS for Cohort 1 was 9.0 months. Receiving surgery, radiation, or chemotherapy were all associated with a non-statistically significant improvement in OS (p 0.1-0.2). CONCLUSION: Within the limitations of a population-based study, 1-4% of patients undergoing cranial RT for pediatric cancers later develop RIG, which is incurable and can occur anywhere from 3-35 years later. Effective treatment of RIG remains unclear and is thus deserving of increased attention in preclinical and clinical studies.
GCT-07. Central nervous system germ cell tumors of children in Slovakia from 2000 to 2020
Authors: Hederova Stanislava , Mocna Andrea , Bublakova Estera , Ballova Anna , Husakova Kristina , Stancokova Terezia , Deak Ladislav , Kolenova Alexandra
Published: June 2022

INTRODUCTION: Central nervous system germ cell tumors (CNS GCTs) are very heterogenous group of tumors, which are divided into two main subgroups - germinomas and non- germinomatous germ cell tumors (NGGCTs). NGGCTs consist of embryonal carcinomas, yolk sac tumors, choriocarcinomas, and teratomas - mature, immature, or with malignant transformation, as well as mixed types. CNS GCTs are rare tumors, accounting approximately for 4-5% of all brain tumors in children, with a peak of incidence between the ages of 10 and 15 years, affecting predominantly boys. METHODS: Retrospective study of a cohort of 34 patients, age 0-18 years old, with CNS germ cell tumors diagnosed and treated in one of three Slovak pediatric oncology centers over a 21-year period from 01/2000 to 12/2020. Treatment was done according to the SIOP strategy. RESULTS: Out of 34 patients 15 patients were treated in the largest center, in Bratislava and 19 patients in the remaining 2 centers. Germinomas occurred in 16 (47.1%) and non-germinomatous germ cell tumors in 18 (52.9%) patients, 7 of whom had teratomas. In our cohort, 24 patients (70.6%) survived with an average follow-up age of 8.5 years. Twenty two patients remain in the 1st remission of the disease, 2 patients got through after disease recurrence. Ten patients (29.4%) died, 9 patients due to disease progression and 1 patient due to treatment complications. CONCLUSION: The overall survival of children with CNS GCT is most dependent on the histologic subtype of the tumor. Overall survival in children with germinomas reaches 90% and with NGGCTs around 60-70%, depending on the extent of the disease. In our cohort, we have achieved 70.6% 5 year overall survival of patients.
HGG-06. Phase 2 Study of Veliparib and Local Irradiation, Followed by Maintenance Veliparib and Temozolomide, in Patients with Newly Diagnosed High-Grade Glioma without H3 K27M or BRAF Mutations: A Report from the Children's Oncology Group ACNS1721 Study
Authors: Karajannis Matthias , Onar-Thomas Arzu , Baxter Patricia , Butingan Nina , Fuller Christine , Gajjar Amar , Haque Sofia , Jabado Nada , Lin Tong , Lucas John , MacDonald Shannon , Matsushima Celeste , Patel Namrata , Pierson Christopher , Springer Linda , Stark Eileen , Souweidane Mark , Walsh Michael , Zaky Wafik , Fouladi Maryam , Cohen Kenneth
Published: June 2022

BACKGROUND: The outcome for pediatric patients with high-grade glioma (HGG) remains poor. Veliparib, a potent oral PARP1/2 inhibitor, enhances the activity of radiotherapy and DNA-damaging chemotherapy. Preclinical data indicates that veliparib crosses the blood-brain-barrier and enhances the efficacy of radiotherapy and temozolomide in IDH mutant and wild-type HGG models. ACNS1721 was a single-arm, non-randomized phase 2 clinical trial designed to determine whether treatment with veliparib and radiotherapy, followed by the poly (ADP-ribose) polymerase (PARP) inhibitor veliparib and temozolomide, improves progression-free survival (PFS) in pediatric patients with newly diagnosed HGG without H3 K27M or BRAF mutations compared to patient level data from historical cohorts with closely matching clinical and molecular features. METHODS: Following surgical resection, newly diagnosed children with non-metastatic HGG were screened by rapid central pathology review and molecular testing. Eligible patients without somatic H3 K27M or BRAF mutations were enrolled on Stratum 1 (IDH wild-type) or Stratum 2 (IDH mutant). Protocol radiochemotherapy consisted of involved field radiotherapy with concurrent veliparib at 65 mg/m2 twice daily. Adjuvant chemotherapy consisted of up to 10 cycles of veliparib 25 mg/m2 twice daily and temozolomide 135 mg/m2 once daily for 5 days every 4 weeks. RESULTS: Both strata were closed to accrual for futility after planned interim analyses. Among the 23 eligible patients who enrolled on Stratum 1 and received protocol therapy, the 1-year progression-free survival (PFS) was 0.29 (SE = 0.09) and 1-year overall survival (OS) was 0.67 (SE = 0.10). Among the 14 eligible patients who enrolled on Stratum 2 and received protocol therapy, the 1-year PFS was 0.57 (SE = 0.15) and 1-year OS was 0.90 (SE = 0.09). CONCLUSION: Rapid central pathology review and molecular testing was feasible. The protocol therapy was well tolerated but failed to improve outcome compared to clinically and molecularly matched historical control cohorts.
HGG-14. Molecular characterization of unique biological subgroups among H3 wild type high-grade gliomas
Authors: Vanova Katerina , Krskova Lenka , Vicha Ales , Sumerauer David , Zamecnik Josef , Koblizek Miroslav , Libý Petr , Benes Vladimir , Malinova Bela , Zapotocky Michal
Published: June 2022

INTRODUCTION: Paediatric high-grade gliomas (HGG) are characterised by the aggressive biological behaviour with dismal prognosis of long-term survival 10-15%. Current molecular-biological diagnostic approaches allow for more precise characterization and determination of new unique subgroups of HGG. Our aim was to identify novel and rare HGG subgroups within our institution cohort. PATIENTS AND METHODS: Our reference centre patients′ cohort consisted of 97 clinically annotated patients with HGG diagnosed between 2000 and 2021. Sanger sequencing was used for screening of the most common HGG-related oncogenic drivers; furthermore we employed whole genome methylation array (Illumina Infinium MethylationEPIC BeadChip) and for selected samples RNA sequencing and expression profiling. RESULTS: Based on H3 status and previous radiotherapy we separated our HGG cases into the RIG, H3mut and H3wt groups. In contrast to H3mut(n=35) and RIG(n=11) that were uniformly fatal, H3wt group contained a proportion of long-term survivors. In the H3wt group we found patients carrying driver mutations in IDH1/2 (n=2) and BRAFV600E (7). Five young patients (under 3) consisted of 3 infant hemispheric gliomas (with NTRK and ROS1 fusions), one gliomatosis cerebri and one brainstem anaplastic astrocytoma with MYB/QKI fusion. We also identified a rare EWSR1-PATZ1 gene fusion in one patient. Importantly, long-term survivors recruited from these subgroups. On the contrary, four cases of MYCN GBM with poor prognosis presented in various locations: one disseminated, one gliomatosis cerebri and two with hemispheric tumour. We identified one patient with “hypermutated” glioblastoma and used targeted therapy with Nivolumab. In three samples of our patients with thalamic glioblastomas, we detected “loss of H3K27-trimethylation” caused by EZHIP overexpression. These tumours proved to be very aggressive with early metastatic recurrence and dismal prognosis. SUMMARY: Detailed characterization of H3 wild-type HGG is very important for further understanding of their biological behaviour, diagnostics, prognostication and identification of therapeutic targets.
HGG-15. Generation of a novel mouse model for brain tumors of the DNA methylation class “GBM MYCN”
Authors: Schoof Melanie , Godbole Shweta , Walter Carolin , Dottermusch Matthias , Albert Thomas , Ballast Annika , Göbel Carolin , Neyazi Sina , Holdhof Dörthe , Kresbach Catena , Blattner-Johnson Mirjam , Modemann Franziska , Afflerbach Ann-Kristin , Eckhardt Alicia , Struve Nina , Jones David , Kerl Kornelius , Neumann Julia E , Schüller Ulrich
Published: June 2022

Multiple recent publications have described a highly aggressive subgroup of pediatric glioblastoma, which is clearly separable from other pediatric and adult glioblastoma based on its DNA methylation profile (GBM MYCN). These tumors almost exclusively occur in children and have a median overall survival of only 14 months. Many tumors in this group are driven by MYCN amplifications and harbor TP53 mutations. Otherwise, information about these tumors are still sparse and treatment is ineffective and causes severe side effects in many cases. In order to further investigate the biology and treatment options of these tumors, preclinical models are urgently needed. Here, we describe the generation of hGFAP-cre::TP53Fl/Fl::lsl-MYCN mice, which carry a loss of TP53 and show aberrant MYCN expression in neural precursors of the central nervous system. These animals develop large forebrain tumors within the first 80 days of life with 100 % penetrance. These tumors resemble human GBM MYCN tumors by histology, global gene expression, and DNA methylation. In order to understand the developmental biology and intratumoral heterogeneity, we employed single cell RNA sequencing (scRNAseq) to the murine tumors with first results indicating a resemblance of tumor cells to committed oligodendrocyte precursors. We further show that both murine and human tumor cells are sensitive to AURKA inhibition in vitro, suggesting a potential new therapeutic option for improved patient care. We believe that further characterization and utilization of the model will pave the way to improved treatment strategies for patients with these highly aggressive tumors.
HGG-18. Long-term efficacy and safety of larotrectinib in paediatric patients with tropomyosin receptor kinase (TRK) fusion-positive primary central nervous system (CNS) tumours
Authors: Nysom Karsten , Doz François , Geoerger Birgit , Øra Ingrid , Perreault Sebastien , Norenberg Ricarda , Fellous Marc , De La Cuesta Esther , Laetsch Theodore W , van Tilburg Cornelis M
Published: June 2022

INTRODUCTION: Neurotrophic tyrosine receptor kinase (NTRK) gene fusions are oncogenic drivers in various tumours. Larotrectinib, a highly selective TRK inhibitor, demonstrated an objective response rate (ORR) of 75% across 206 evaluable patients with various non-primary CNS cancers (Hong et al, ASCO 2021). We report long-term data on larotrectinib-treated paediatric patients with TRK fusion-positive primary CNS tumours. METHODS: Patients aged <18 years with TRK fusion-positive primary CNS tumours enrolled in two clinical trials (NCT02637687, NCT02576431) were included. Larotrectinib was administered at 100 mg/m2 (maximum: 100 mg) twice-daily. Response was investigator-assessed per RECIST v1.1 and RANO. RESULTS: As of July 2021, 28 patients with TRK fusion-positive primary CNS tumours were enrolled, including 14 high-grade and eight low-grade gliomas. Median age at enrolment was 7.0 years (range 1.0–17.0). Twenty-three patients (82%) received prior systemic therapy and 12 (43%) received prior radiotherapy. The ORR was 39% (95% confidence interval [CI] 22–59): three complete responses, eight partial responses, 15 stable disease and two progressive disease. The 24-week disease control rate was 82% (95% CI 63–94). Median duration of response (DoR) was not reached; median follow-up was 25.6 months. Median progression-free survival was 21.9 months (95% CI 9.2–not estimable). Median overall survival (OS) was not reached; median follow-up was 27.6 months. DoR and OS 24-month rates were 53% and 71%, respectively. Treatment duration ranged from 1.0 to 39.0+ months. Treatment-related adverse events (TRAEs) were mostly Grade 1–2. Grade 3–4 events occurred in three patients (increased gamma-glutamyltransferase, hyperglycaemia, hypernatraemia, hyponatraemia and neutropaenia). No patients discontinued treatment due to TRAEs. Fourteen patients progressed on treatment; four continued treatment post-progression for ≥4 weeks. CONCLUSION: Larotrectinib demonstrated high disease control rate, durable responses and a manageable safety profile. These results support testing for NTRK gene fusions in paediatric patients with primary CNS tumours.
HGG-19. Co-occurrences of a high-grade glioma with cavernous malformations and pathogenic variants inPDCD10 andSMARCA4
Authors: Glanz Hannah , Damodharan Sudarshawn , Smith-Simmer Kelcy , Bradley Kristin , Rebsamen Susan , Casey Kristin , Iskandar Bermans , Helgager Jeffrey , Puccetti Diane
Published: June 2022

INTRODUCTION: The co-occurrence of multiple disease processes can make for more challenging diagnoses. Here we report an unusual case of a patient found to have an IDH1-mutant high-grade glioma along with multiple cerebral cavernous malformations and pathogenic germline variants in PDCD10 and SMARCA4. CASE DESCRIPTION: A 17-year-old female presented with left arm paresthesia and weakness along with persistent headaches within the frontal and occipital regions that progressed in intensity to include nausea and emesis. A fast sequence magnetic resonance imaging (MRI) of her head was obtained that revealed the presence of multiple bilateral cystic lesions suspicious for cavernomas, with the most notable lesion in the right parietal lobe. Ophthalmology consultation revealed grade III papilledema bilaterally. A full brain MRI with and without contrast was obtained and demonstrated a right anterior parietal lobe lesion with associated mass effect, as well as multiple bilateral supratentorial and left cerebellar cavernous malformations. The patient underwent tumor debulking of her dominant lesion. Pathology revealed an IDH1-mutant diffuse astrocytoma, WHO grade III. Tumor genetic testing was done and identified a SMARCA4 and two TP53 variants. Germline genetic testing was then pursued which revealed a PDCD10 pathogenic variant consistent with familial cerebral cavernous malformation syndrome and a likely pathogenic variant in SMARCA4. Treatment of her high-grade-glioma included radiation therapy followed by maintenance oral temozolomide. DISCUSSION: This case illustrates the unusual co-occurrences of a high-grade glioma with familial cavernous malformation syndrome and germline pathogenic variants in PDCD10 and SMARCA4. Our patient continues to do well clinically, but because of her risk of developing small cell carcinoma of the ovary she has elected to undergo a prophylactic bilateral salpingo-oophorectomy. Recognition of abnormal genetic results is critical in the setting of multiple disease processes and can play a crucial role in the on-going care for a patient.
HGG-20. PRMT5 promotes the formation and growth of pediatric high-grade glioma by maintaining tumor stem cell populations
Authors: DeSisto John , Knox Aaron , Balakrishnan Ilango , Chatwin Hannah , Coleman Philip , Venkataraman Sujatha , Vibhakar Rajeev , Green Adam
Published: June 2022

BACKGROUND: Pediatric high-grade gliomas (PHGG) are aggressive, undifferentiated CNS tumors comprising two broad subtypes: diffuse midline glioma with H3K27M mutations (DMG) and cortical high-grade glioma (H3K27-wild-type (wt) PHGG). During normal development, PRMT5 promotes stem cell self-renewal through methylation of arginine residues in histone tails. We hypothesized that PRMT5 controls self-renewal essential to the proliferation of PHGG tumor initiating cells (TICs). METHODS: We identified PRMT5 as potentially oncogenic in PHGG through a screen of 4,139 shRNAs targeting 406 genes with epigenetic activity. To elucidate PRMT5’s activity, we used lentiviral shRNA delivery to knock down (KD) PRMT5 expression in four DMG and one H3K27-wt PHGG cell lines. We performed in vitro growth, cell cycle, apoptosis, limiting dilution and bulk RNA-Seq assays to determine the phenotypic effects of PRMT5 KD. To identify PRMT5’s gene targets, we performed cleavage under targets & release using nuclease (CUT&RUN) followed by qPCR and are currently performing CUT&RUN-Seq. We orthotopically implanted PRMT5 KD PHGG cells into mice and tracked survival, tumor growth and tumor histological characteristics. RESULTS: In vitro, PRMT5 KD reduced cell growth (p<0.001), slowed cell cycle progression and increased apoptosis. PRMT KD also slowed neurosphere formation, demonstrating reduced self-renewal (p<7E-9). Geneset expression analysis showed PRMT5 KD reduced expression of self-renewal genes and increased expression of differentiation genes (FDR<0.0001). In vivo, PRMT5 KD reduced tumor growth, as monitored by bioluminescence and MRI, and aggressiveness, based on Ki-67 staining (p<0.05), leading to increased survival (p<0.001). CUT&RUN-qPCR results showed PRMT5 KD led to decreased expression and H3K4me3 promoter occupancy at PAX3, and decreased expression and increased H3K27me3 occupancy at S100A6. PAX3 and S100A6 are oncogenes that preserve TIC self-renewal. CONCLUSION. In vitro experiments show that PRMT5 KD epigenetically reduces TIC self-renewal. In vitro and in vivo, PRMT5 KD reduced PHGG tumor cell growth and aggressiveness.
HGG-43. Abrogation of exosome biogenesis significantly affects cell motility in heterogenous sub-populations of paediatric-type diffuse high-grade glioma
Authors: Pericoli Giulia , Galardi Angela , Petrilli Lucia Lisa , Paolini Alessandro , Mortera Stefano Levi , Pepe Gerardo , Palma Alessandro , de Billy Emmanuel , Ferretti Roberta , Colletti Marta , Giorda Ezio , Burford Anna , Mackay Alan , Pascucci Luisa , Peinado Hector , Jones Chris , Citterich Manuela Helmer , Putignani Lorenza , Carai Andrea , Mastronuzzi Angela , Masotti Andrea , Locatelli Franco , Giannatale Angela Di , Vinci Maria
Published: June 2022

Paediatric-type diffuse High-Grade Gliomas (PDHGG) are highly heterogenous tumours comprised of distinct cell sub-populations co-existing within the same tumour mass. We have shown that primary patient-derived sub-clones, as well as optical-barcoded sub-clones, function as an interconnected network conferring an aggressive phenotype. Here, we explored the role of exosomes in mediating PDHGG inter-clonal communication. A comprehensive characterization of 7 optical-barcoded single cell-derived clones obtained from two patient-derived cell lines (one DMGH3K27-altered and one diffuse high-grade paediatric-type glioma H3WT), confirmed extensive genomic and phenotypic heterogeneity. Live single-cell tracking in 3D migration and invasion assays demonstrated the key role of the inter-clonal crosstalk in driving a more aggressive phenotype. To determine the exosome role in this crosstalk, we first characterised them in terms of size, marker expression and cargo. Moreover, we demonstrated that exosomes were actively internalized by the sub-clones. Exosomal proteomic analysis showed differential protein contents implicated in the regulation of biological processes such as focal adhesion and extracellular matrix organization. The analysis of exosomal miRNome did not show differentially expressed miRNAs between sub-clones, however, specific and distinct exosomal miRNAs were found uniquely expressed by each sub-clone. The abrogation of the exosome biogenesis by GW4869 phospholipase inhibitor did not affect sub-clones viability, but significantly inhibited their motility, when cultured individually and more prominently in co-culture condition. Analysis of the exo-miRNAs uniquely expressed by the sub-clones highlighted a set of target genes regulating cell motility/invasion/migration. These target genes were differentially expressed when sub-clones were co-cultured compared to mono-culture. Moreover, the expression levels of these genes (e.g. CD44, PTRZ, GLI3, NTRK2) were significantly modulated upon GW4869 treatments. In conclusion, our study highlights the importance of the exosomes in the inter-clonal communication and suggests that interfering with the exosome biogenesis may be a valuable strategy to inhibit cell motility in PDHGG.