bluuebunny/crossref_metadata_2025 huggingface dataset:
Zhidai Decoction Inhibits Cervical Cancer through Regulation of Vaginal Microbiota
Authors: Liu Suying , Yan Hua , Liu Yi , Tang Yongjun , Lu Yu , Shao Huizhi , Cui Yutong
Published: August 2020

Cervical cancer is one of the top lethal malignancies among women worldwide. The current treatment methods have so many drawbacks that new treatment methods need to be developed. Zhidai Decoction (ZDD) is an effective traditional Chinese herbal formulation for gynecological diseases. Its main effect is controlling abnormal leucorrhea which is a typical early clinical manifestation of cervical cancer. However, how ZDD directly affects cervical cancer has not been addressed. In this study, we established a mouse cervical cancer U14 cell subcutaneous transplantation tumor model and took an early intervention with ZDD to evaluate the antitumor effect of ZDD. In addition, we also investigated the regulatory effects of ZDD on the vaginal microbiota using 16S rRNA analysis in this study. Our results showed that ZDD can significantly improve systemic symptoms and reduce vaginal secretions of tumor‐bearing mice. Compared with the CCM group (the cervical cancer model group), in the ZDD‐treated group, the tumor inhibitory rate was 37.90%, the average daily food intake of mice was increased to 5.27 ± 0.74 g (P < 0.05), and the survival time was obviously prolonged to 21 days (P < 0.05). Analysis of the sequencing results of 16S rRNA showed that the main microbial genera of the CCM group were Pasteurella (27.20%) and Helicobacter (18.50%), while those in the ZDD group were Staphylococcus (13.22%) and Lactobacillus (4.68%). It revealed that ZDD has the effect of regulating the vaginal microbiota of cervical cancer, especially in increasing the relative abundance of Lactobacillus and Staphylococcus and decreasing the relative abundance of Pasteurella and Helicobacter. The analysis also showed that ZDD could adjust microbiota structure, species abundance, and community compositions of vaginal microbiota. In conclusion, ZDD displayed inhibitory effect on cervical cancer, and it might be based on restoring the balance of vaginal microbiota. Furthermore, our conclusion supports the promotion of ZDD in the early treatment of cervical cancer.
Optimisation Analysis of Structural Parameters of an Annular Slot Ejector Based on the Coanda Effect
Authors: Wu Fengliang , Li Zhisheng
Published: August 2020

To investigate the effect of structural parameters on the performance of an annular slot ejector, a series of numerical simulations were conducted with single-factor analysis. Moreover, a multifactor grey relational analysis was applied to examine the correlations between the structural parameters and entrainment ratio. Subsequently, the optimised model was verified by comparing the simulated results with experimental data. Results show that the performance of the optimised ejector model was improved. The RNG k-ε turbulent transport mode can simulate the internal field characteristics of an annular slot ejector, and the corresponding simulated results, as verified by experiment, satisfy engineering requirements. In addition, a quantitative correlation between structural parameters and entrainment ratio was obtained as follows: e (nozzle clearance) > θ (diffusing chamber angle) > HL (mixing chamber length) > d (throat diameter) > KL (diffusing chamber length). This work may provide a certain guiding significance for the design and application of annular slot ejectors.
Efficient Defense Decision-Making Approach for Multistep Attacks Based on the Attack Graph and Game Theory
Authors: Liu Jing , Zhang Yuchen , Hu Hao , Tan Jinglei , Leng Qiang , Chang Chaowen
Published: August 2020

In the multistep attack scenario, each rational attack-defense player tries to maximize his payoff, but the uncertainty about his adversary prevents him from taking the favorable actions. How to select the best strategy from the candidate strategies to maximize the defense payoff becomes the core issue. For this purpose, the paper innovatively designs a game theory model from the point of network survivability in combination with the attribute attack graph. The attack graph is created based on the network connectivity and known vulnerabilities using the MulVAL toolkit, which gives the full view of all the known vulnerabilities and their interdependence. Then, we use the attack graph to extract attack-defense actions, candidate attack-defense strategies, attack-defense payoffs, and network states, as well as other game modeling elements. Afterwards, the payoffs of attack-defense strategies are quantified by integrating attack-defense strength and network survivability. In addition, we input the above elements into the game model. Through repeated learning, deduction, and improvement, we can optimize the layout of defense strategies. Finally, the efficient strategy selection approach is designed on the tradeoff between defense cost and benefit. The simulation of attack-defense confrontation in small-scale LAN shows that the proposed approach is reliable and effective.
Metformin Inhibited Proliferation and Metastasis of Colorectal Cancer and presented a Synergistic Effect on 5‐FU
Authors: Sang Jing , Tang Ruixue , Yang Min , Sun Qing
Published: August 2020

The purpose of this study was to investigate the effect of metformin or the combination of metformin and 5‐FU on the growth and metastasis of colorectal cancer (CRC). For the in vitro experiments, HCT 116 and SW1463 cell lines were treated with metformin or the combination of metformin and 5‐FU. Cell proliferation and invasion were analyzed by CCK‐8, colony formation, and transwell assay, respectively. For the in vivo experiments, the CRC xenograft nude mice model was used to observe the effects of metformin or combined with 5‐FU on tumor growth and metastasis. Metformin significantly inhibited the proliferation and invasion of HCT116 and SW1463 cells in vitro, which showed synergetic effects to 5‐FU. In CRC xenograft nude mice, metformin alone and metformin combined with 5‐FU treatment significantly inhibited tumor cell proliferation and tumor metastasis. In summary, metformin played an inhibitory role in the proliferation and metastasis of CRC and had a synergistic effect with 5‐FU. Metformin may be a potentially effective anti‐metastatic drug or an anticancer adjuvant agent for treating CRC.
Synergistic Effect between Usnic Acid and Polymyxin B against Resistant Clinical Isolates of Pseudomonas aeruginosa
Authors: da Costa Júnior Sérgio Dias , da Silva Wagner Roberto Cirilo , da Silva Adriana Maria Costa Marques , Maciel Maria Amélia Vieira , Cavalcanti Isabella Macário Ferro
Published: August 2020

The present study aimed to characterize the susceptibility profile of Pseudomonas aeruginosa and Acinetobacter spp. clinical isolates to polymyxin B in a public hospital in Recife‐PE, Brazil, between the years of 2018 and 2019, as well as to search for the presence of the mcr‐1 gene and evaluate the interaction between polymyxin B and usnic acid against these isolates. The strains were identified using the BD Phoenix™ automated system and the agar‐spot test was used to determine the susceptibility profile to polymyxin B. The minimum inhibitory concentrations (MICs) of usnic acid and polymyxin B were determined through the broth microdilution method according to the Clinical and Laboratory Standards Institute (CLSI). Subsequently, Polymerase Chain Reaction (PCR) was performed to detect the mcr‐1 gene in the isolates. The interaction between usnic acid and polymyxin B was evaluated by the Checkerboard assay. Among 34 isolates of P. aeruginosa, 26.5% (9/34) were positive for the polymyxin B agar‐spot test, and 11.8% (4/34) presented an intermediate susceptibility (MIC = 4 μg/mL), while 14.7% (5/34) presented antimicrobial resistance with MIC values ranging from 8 to 32 μg/mL. Among 38 isolates of Acinetobacter spp., 13.2% (5/38) were positive for the polymyxin B agar‐spot test and all of them were resistant to polymyxin B with a MIC value > 32 μg/mL. The mcr‐1 gene was not detected in the clinical isolates. Regarding usnic acid, it presented a moderate antibacterial activity against two P. aeruginosa isolates (MIC = 250 μg/mL) and no activity was detected against the others. A synergistic effect between usnic acid and polymyxin B was observed against three clinical isolates of P. aeruginosa which were resistant to polymyxin B (FICI ≤ 0.5). Therefore, it was possible to observe that usnic acid is a promising candidate to be used in combination with polymyxin B against infections caused by resistant P. aeruginosa.
Abstract A18: Characterization of checkpoint inhibitors in the tumor microenvironment (TME) and peripheral blood in endemic Burkitt Lymphoma
Authors: Saikumar-Lakshmi Priya , Oduor Cliff , Forconi Catherine , Marsh Patrick , Ong’echa John Michael , Bailey Jeffrey , Moormann Ann
Published: August 2020

Introduction: The tumor microenvironment and the interaction between immune checkpoint inhibitors (ICIs) and tumor cells are essential to understand for designing future immunotherapy strategies. In this study, we aim to characterize the tumor microenvironment (TME) in children diagnosed with endemic Burkitt lymphoma (eBL), the most common pediatric cancer in Africa. A history of chronic malaria (Plasmodium falciparum) and Epstein-Barr virus (EBV) coinfections are both risk factors in the etiology of eBL.

Methods: Using multicolor flow cytometry and single-cell RNA sequencing, we analyzed the expression of immune checkpoint inhibitors in T cells from the tumor microenvironment and from peripheral blood mononuclear cells (PBMC) of eBL patients, along with age-matched controls with different malaria exposure. Additionally, CD8 T-cell infiltration was confirmed by immunohistochemistry.

Results: PD-1+ CD4 T cells from eBL PBMCs were increased in number compared to healthy controls from the malaria-endemic area (p=0.03). Both CD4 and CD8 T cells from eBL PBMCs reveal higher frequency of TIGIT expressers compared to healthy controls (non-malaria endemic) (p=0.002, p=0.007 respectively). PD1+ TIGIT+ IFNG- memory CD4 T cells phenotype from eBL PBMCs was increased upon short stimulation with PMA/ionomycin, as well as “naive-like” CD95+ PD1high TIGIT+ CTLA4+ IFNG+ CD8T cells. Tumor samples from 4 eBL patient were used on single-cell analysis; we observed activated T-cells profile that highly upregulated TIGIT within the tumor microenvironment. We also noticed relatively low expression of other ICIs such as PD1, TIM3, LAG3, and CTLA4. Base on all these data, we calculated an exhaustion score that was higher than the cytotoxicity score in our eBL-derived tumor-infiltrating lymphocytes (TILs). In addition, we use immunohistochemistry staining to confirm CD8 T-cell infiltration and ICI expression in eBL tumor fine needle aspirates. Our future directions will employ TIGIT blockade inhibitor studies of CD8 T cells, in order to increase expansion and function of CD8 TILs. Our results will help support future development of ICI therapies in endemic Burkitt lymphoma.

Citation Format: Priya Saikumar-Lakshmi, Cliff Oduor, Catherine Forconi, Patrick Marsh, John Michael Ong’echa, Jeffrey Bailey, Ann Moormann. Characterization of checkpoint inhibitors in the tumor microenvironment (TME) and peripheral blood in endemic Burkitt Lymphoma [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A18.
Abstract A21: Time-to-event Bayesian optimal interval design to accelerate phase I pediatric oncology trials
Authors: Yuan Ying , Lin Ruitao , Li Daniel , Nie Lei , Warren Katherine
Published: August 2020

Late-onset toxicity is common for novel molecularly targeted agents and immunotherapy. It causes major logistic difficulty for existing adaptive phase I trial designs, which require the observance of toxicity early enough to apply dose escalation rules for new patients. The same logistic difficulty arises when the accrual is rapid. We propose the time-to-event Bayesian optimal interval (TITE-BOIN) design to accelerate phase I trials by allowing for real-time dose assignment decisions for new patients while some enrolled patients’ toxicity data are still pending. Similar to the rolling six design, the TITE-BOIN dose escalation/de-escalation rule can be tabulated before the trial begins, making it transparent and simple to implement, but is more flexible in choosing the target DLT rate and has higher accuracy to identify the MTD. Compared to the more complicated model-based time-to-event continuous reassessment method (TITE-CRM), the TITE-BOIN has comparable accuracy to identify the MTD but is simpler to implement with substantially better overdose control. A numerical study shows that the TITE-BOIN design supports continuous accrual, without sacrificing patient safety or the accuracy of identifying the MTD, and therefore has great potential to accelerate early-phase drug development.

Note: This abstract was not presented at the conference.

Citation Format: Ying Yuan, Ruitao Lin, Daniel Li, Lei Nie, Katherine Warren. Time-to-event Bayesian optimal interval design to accelerate phase I pediatric oncology trials [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A21.
Abstract A32: Selective inhibition of AuroraA by LY3295668 erbumine in neuroblastoma models induces apoptosis through a combination of S-phase DNA damage and mitotic arrest
Authors: Dowless Michele , Kremer Jill , Lowery Caitlin , Gong Xueqian , Klahn Joseph , Stephens Jennifer , Hui Yu-Hua , Blosser Wayne , Martinez Ricardo , Du Jian , Stancato Louis
Published: August 2020

Aurora kinase A (AuroraA) is a serine/threonine protein kinase critical for centrosome maturation, mitotic spindle formation, and spindle checkpoint activation. Aberrant expression of AuroraA promotes tumor initiation and disease progression, making it a promising therapeutic target in several cancer types. However, recent clinical trials of purported selective AuroraA inhibitors failed due to lack of efficacy and/or hematologic toxicity, likely due to concurrent inhibition of Aurora kinase B (AuroraB). Selective AuroraA inhibition leads to mitotic arrest and apoptosis, while AuroraB inhibition causes persistent DNA endoreduplication and polyploidy leading to genomic instability. LY3295668 erbumine (LY3295668) is a selective AuroraA inhibitor with preclinical activity in multiple models of cancer including neuroblastoma (NBL). High-risk NBL, a devastating pediatric cancer with few effective treatment options, is mainly stratified by MYCN amplification status. In NBL, AuroraA stabilizes N-MYC post-transcriptionally; moreover, AuroraA also controls N-MYC-dependent transcription during S-phase. Here, we evaluated LY3295668 in multiple NBL cell lines and in vivo mouse models where treatment resulted in apoptosis and tumor regressions, respectively. We compared LY3295668 to alisertib (a dual AuroraA/B inhibitor) in multiple cell-based assays that differentiate AuroraA activity from that of AuroraB and showed that LY3295668 has a distinct pharmacologic profile from alisertib. In addition, we determined the mechanism of action for LY3295668 includes DNA damage prior to mitotic block. Our results further support that AuroraA controls MYC-dependent transcription in S-phase and selective inhibition of AuroraA with LY3295668 promotes transcription-replication conflicts leading to DNA damage. In addition to AuroraA-mediated mitotic arrest, this DNA damage may contribute to the hypersensitivity of MYC-driven tumors such as NBL. In summary, LY3295668 is a selective AuroraA inhibitor with a dual mechanism of action in NBL involving DNA damage in S-phase and a cell cycle block in mitosis. These combined activities contribute to sensitivity of preclinical NBL models.

Citation Format: Michele Dowless, Jill Kremer, Caitlin Lowery, Xueqian Gong, Joseph Klahn, Jennifer Stephens, Yu-Hua Hui, Wayne Blosser, Ricardo Martinez, Jian Du, Louis Stancato. Selective inhibition of AuroraA by LY3295668 erbumine in neuroblastoma models induces apoptosis through a combination of S-phase DNA damage and mitotic arrest [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A32.
Abstract A51: Advances in the etiology and therapeutics of a lethal childhood cancer, fibrolamellar hepatocellular carcinoma
Authors: Lalazar Gadi , Jarmel Melissa , Wang Ruisi , Tomasini Michael , Requena David , Ng Denise , Simon Sanford M.
Published: August 2020

Introduction: Fibrolamellar hepatocellular carcinoma (FLC) is a liver cancer affecting adolescents and young adults without underlying liver disease. Patients with FLC are often diagnosed with advanced-stage disease and have a poor 5-year survival. Recently we have made advances in both understanding the etiology of FLC as well as developing therapeutics. We have found that the bulk of the genome lacks recurrent single-nucleotide or structural variants (inversions, amplifications) with the exception of a deletion in one copy of chromosome 19. This results in a fusion of the first exon of the heat shock protein, DNAJB1, with the 2nd through 10th exons of PRKACA, the catalytic subunit of protein kinase A. Expression of this fusion in the livers of mice, either by CRISPR or transposon, is sufficient to phenocopy the disease. The kinase activity of the fusion protein is essential for transformation, but equivalent expression of the native kinase is not sufficient.

Results: Etiology: We have tested the ability of the native kinase and fusion oncokinase to phosphorylate potential substrates in human liver. We have found a discrete set of substrates that are phosphorylated in human liver for which we are now testing, which are critical for the pathogenesis of this cancer. Therapeutics: We have purified the fusion oncokinase without a tag and used a high-throughput screen to find inhibitors. We have found inhibitors in the nanomolar range for which we are using structural analysis to inform our medicinal chemistry. Additionally, we have developed several “never-in-plastic” patient-derived xenograft (PDX) models that retain expression of the driver, histology, transcriptome, and proteome of the original human tumor. We have also screened for compounds that induce tumor cell death and tumor regression in FLC PDXs.

Conclusion: Subtle changes in the kinase substrate profile of the fusion kinase provide new leads for therapeutics for FLC. The ability to find inhibitors of the kinase in the nanomolar range, as well as the ability to screen for inhibitors of the PDX, offers the first hope for treatment against this lethal tumor.

Citation Format: Gadi Lalazar, Melissa Jarmel, Ruisi Wang, Michael Tomasini, David Requena, Denise Ng, Sanford M. Simon. Advances in the etiology and therapeutics of a lethal childhood cancer, fibrolamellar hepatocellular carcinoma [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A51.
Abstract A63: Overcoming challenges in health care with machine learning: Innovation from retinoblastoma
Authors: Janusonis Isabella , Truong Tran , Liu Justin , Chen Mei , Gallie Brenda
Published: August 2020

Introduction: As retinoblastoma is a rare pediatric cancer (1/17,000 live births) with little evidence to justify treatment choices, we built a cloud-based retinoblastoma-specific electronic health record database for point-of-care data to support clinical and research collaboration and provide a quantitative analysis of prescribed treatments.

Methods: Disease-specific Electronic Patient Illustrated Clinical Timeline (DEPICT HEALTH) is online, cloud-based, interactive, with point-of-care timelines and corresponding retinal/tumor drawings, with standardized scoring of tumor number, size, and locations.

Results: DEPICT HEALTH records are contributed by the entire care team and used in quantitative treatment analyses. DEPICT HEALTH effectively communicates disease and treatment information to the patients’ circle of care and their parents, independent of language. The Retinoblastoma Activity Index (RAI) quantifies the active tumor (colored yellow) by counting the yellow pixels in the DEPICT HEALTH digital drawings. The drawings represent tumor at every encounter based on the collective opinion of the care team, and the RAI will quantitate tumor response to treatment. Two clinical trials were initiated using DEPICT HEALTH and RAI for eligibility and short- and long-term outcomes.

Conclusion: Using RAI to score tumor response provides RECIST (response evaluation criteria in solid tumors) for retinoblastoma research, a standard of measurement that has never before been available. Machine learning methods will ultimately analyze point-of-care data to predict patient outcomes and assist with clinical decision making. DEPICT HEALTH provides an unbiased view of the efficacy of treatments, with potential to allow global point-of-care data to be widely available for research, essentially an “n” of “ALL.”

Citation Format: Isabella Janusonis, Tran Truong, Justin Liu, Mei Chen, Brenda Gallie. Overcoming challenges in health care with machine learning: Innovation from retinoblastoma [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A63.
Abstract A75: Mithramycin evicts SWI/SNF from chromatin to induce epigenetic reprogramming in rhabdoid tumor
Authors: Chasse Maggie H. , Johnson Benjamin K. , Boguslawski Elissa A. , Sorensen Katie M. , Beddows Ian , Madaj Zachary , Foxa Gabrielle E. , Rybski Kristin J. , Kitchen-Goosen Susan M. , Williams Bart O. , Triche Timothy J. , Grohar Patrick J.
Published: August 2020

The text of this abstract has not been printed at the request of the authors due to intellectual property matters.

Citation Format: Maggie H. Chasse, Benjamin K. Johnson, Elissa A. Boguslawski, Katie M. Sorensen, Ian Beddows, Zachary Madaj, Gabrielle E. Foxa, Kristin J. Rybski, Susan M. Kitchen-Goosen, Bart O. Williams, Timothy J. Triche Jr., Patrick J. Grohar. Mithramycin evicts SWI/SNF from chromatin to induce epigenetic reprogramming in rhabdoid tumor [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A75.
Abstract B01: Alternative splicing as a therapeutic vulnerability in pediatric rhabdomyosarcoma
Authors: Khurshid Safiya , Montes Matias , Roberts Ryan , Rigo Frank , Chandler Dawn S.
Published: August 2020

Rhabdomyosarcoma (RMS) is the most common pediatric soft-tissue sarcoma, and children who present with metastatic disease at the time of diagnosis have a poor prognosis and survival rate. The molecular events distinguishing these tumors are poorly understood. Comprehensive genetic analysis of pediatric RMS samples has revealed that these tumors are “quiet” at the genomic level and have a relatively low mutation rate. Thus, we have turned our attention to the RMS spliceome, the alternatively or aberrantly spliced transcripts, to identify new therapeutic targets. Indeed, recent advances in high-throughput sequencing technologies have uncovered a surprising number of alternatively spliced variants associated with tumorigenesis, implicating regulated splicing in the tumor phenotype. We hypothesize that differentially spliced isoforms provide a novel opportunity to modulate splicing as a therapeutic intervention in these cancers. We have identified two major splicing networks that are altered in response to tumor specific physiologic changes in RMS. We have identified RNA binding protein and their specific cis-regulatory sequence binding sites that control the splicing changes. In collaboration with Ionis Pharmaceuticals, we have designed splice-switching oligonucleotides that target the specific sequences in the pre-mRNA transcript to occlude protein binding and engineer splicing away from the tumorigenic isoforms. The splice switching oligonucleotides (SSOs) have been successful in targeting the desired transcripts to change the splice isoform, repressing RMS cell growth, and preventing migration, invasion, and angiogenesis. We are currently testing the SSOs in RMS xenograft models as well as in genetically engineered mice to assess their efficacy in vivo. Our long-term goal is to understand the role of alternative splicing in cancer and to target pre-mRNA splicing pathway as a therapeutic intervention point. From these studies, we expect to better understand the cellular events that activate alternative splicing in the pathway to tumorigenesis and how to target transcripts for therapeutic benefit in the future. Furthermore, our findings implement a new splice-modulating paradigm for cancer treatment and pioneer a strategy that may be applied throughout the spliceome to treat cancer and provide a new avenue of rational therapy design.

Citation Format: Safiya Khurshid, Matias Montes, Ryan Roberts, Frank Rigo, Dawn S. Chandler. Alternative splicing as a therapeutic vulnerability in pediatric rhabdomyosarcoma [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B01.
Abstract B16: MECOM dysregulation is associated with poor outcome in pediatric therapy-related myeloid neoplasms
Authors: Lamprecht Tamara , Schwartz Jason R. , Ma Jing , Walsh Michael P. , Klco Jeffery M.
Published: August 2020

Therapy-related myeloid neoplasms (tMN) occur in children as a consequence of cytotoxic therapies used to treat childhood malignancies, are typically resistant to conventional chemotherapies, require hematopoietic cell transplantation as the only curative option, and typically have a dismal prognosis. While the genomic alterations that drive tMN in children have yet to be comprehensively described, alterations involving the MECOM locus have been described in some myeloid neoplasms like tMN. Overexpression of MECOM is associated with poor prognosis in myeloid malignancies, is present in ~10% of adult cases, and occurs at an increased frequency in pediatric AML with KMT2A rearrangements (KMT2Ar). RNA sequencing from a cohort of 56 pediatric tMN cases collected at St. Jude shows that 24 (43%) cases within our cohort express high levels of MECOM (FPKM value >5). In these 24 cases, we identified one with a canonical fusion (RUNX1-MECOM), one with a NUP98 fusion (NUP98-HHEX), and 18 with KMT2Ar. Whole-genome sequencing demonstrated that two of the remaining MECOMHigh cases have a t(2;3)(p21;q26.2) involving MECOM on chromosome 3 and noncoding regions of chromosome 2 adjacent to ZFP36L2, a gene highly expressed in hematopoietic cells. Further, ENCODE data support that this region of the genome is an active enhancer, suggesting a proximity effect in which this enhancer has been hijacked to drive high levels of MECOM expression. The two remaining cases with aberrant and unexplained MECOM expression are currently under evaluation. In our cohort, MECOM expression levels are predictive of a worse outcome (overall survival at 2 years: MECOMHigh=12.5% vs. MECOMLow=40.6%; log rank p<0.01). Although KMT2Ar was frequently present in our cohort 28/56 (50%) and enriched in the MECOMHigh group (MECOMHigh=75% (18/24) vs. MECOMLow=31% (10/32; p<0.01), high MECOM expression did not confer a significant survival difference within the KMT2Ar group (overall survival at 2 years: MECOMHigh=16.7% vs. MECOMLow=40%; log rank p=0.33). In conclusion, we report a large cohort of pediatric tMN and show that high levels of MECOM expression predicts a worse outcome. Additionally, we identify enhancer hijacking as the mechanism through which at least a portion of high MECOM expression may be explained.

Citation Format: Tamara Lamprecht, Jason R. Schwartz, Jing Ma, Michael P. Walsh, Jeffery M. Klco. MECOM dysregulation is associated with poor outcome in pediatric therapy-related myeloid neoplasms [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B16.
Abstract B28: A cross-species enhancer activity analysis approach to identify the Ewing sarcoma cell of origin
Authors: Grissenberger Sarah , Poetsch Anna , Heinzl Monika , Morelli Luisa , Sheffield Nathan , Popitsch Niko , Kovar Heinrich , Distel Martin
Published: August 2020

Ewing sarcoma is a malignant bone and soft tissue tumor in children and adolescents. In 85% of all cases the formation of Ewing sarcoma is caused by a chromosomal translocation, leading to the expression of the oncogene EWS-FLI1. This aberrant transcription factor is the main driver of the disease and leads to massive transcriptional dysregulation. Although the genetic mechanism driving Ewing sarcoma is well understood, an animal model adequately mimicking the disease is still lacking. One reason why modeling attempts have remained difficult is the elusive cell of origin in Ewing sarcoma. Several cell types including neural crest progenitor cells and mesenchymal stem cells have been proposed, but none of them has yet been confirmed as cell of origin of Ewing sarcoma. Towards identifying this cell of origin, we are currently following a novel cross-species approach by exploring the use of enhancers, which are specifically active in Ewing sarcoma cells, but were not created de novo by EWS-FLI1. Injection of reporter constructs into zebrafish embryos allows for visualization of cell types with activity of the selected enhancers and provides us with cell-of-origin candidate cell types. To investigate which of these candidate cells are permissive for development of Ewing-like tumors, we will also express EWS-FLI1 in these cells. If successful, this approach will not only reveal the Ewing sarcoma cell of origin but also result in a zebrafish Ewing sarcoma model, which will help to understand tumor initiation and progression and, furthermore, will be a valuable tool to develop novel therapeutic strategies.

Citation Format: Sarah Grissenberger, Anna Poetsch, Monika Heinzl, Luisa Morelli, Nathan Sheffield, Niko Popitsch, Heinrich Kovar, Martin Distel. A cross-species enhancer activity analysis approach to identify the Ewing sarcoma cell of origin [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B28.
Abstract B37: Menin and EWS/FLI1 activate serine biosynthesis via ATF4 in Ewing sarcoma
Authors: Jiménez Jennifer A. , Ruiz Ramon Ocadiz , Apfelbaum April , Kumar Abhijay , Kerk Samuel , Grembecka Jolanta , Lyssiotis Costas A. , Lawlor Elizabeth R.
Published: August 2020

Ewing sarcoma (ES) is an aggressive bone and soft-tissue tumor, most commonly driven by the EWS/FLI1 fusion oncogene. Previous work has revealed that the scaffolding protein menin functions to promote ES tumorgenicity. Additionally, our recent studies revealed a previously undescribed role for menin in the activation of the serine biosynthetic pathway (SSP), a critical metabolic pathway that is aberrantly activated in many human cancers. The transcription factor ATF4 has been identified in other tumor types as a master transcriptional regulator of the SSP. Furthermore, regulation of the SSP by EWS/FLI1 has been described, although the mechanism of this regulation remains unknown. The biologic functions of menin are largely determined by its protein-binding partners, the best characterized of which is MLL in epigenetic trithorax complexes. In the current study, we are investigating the mechanistic link between menin, EWS/FLI1, and SSP hyperactivation to test the hypothesis that, in the context of ES, these transcriptional regulators cooperate to promote metabolic reprogramming via ATF4. Through gain- and loss-of-function studies, our results show that ATF4 regulates the SSP in ES cells, and that loss of ATF4 impairs ES cell proliferation. Additionally, both pharmacologic inhibition with the menin:MLL interaction inhibitor, MI-503, and doxycycline-inducible shRNA knockdown of menin lead to loss of ATF4, coincident with loss of SSP expression. Knockdown of EWS/FLI1 similarly results in loss of both ATF4 and SSP expression. Interrogation of publicly available ChIP-seq data further shows enrichment for EWS/FLI1 binding at the ATF4 gene promoter that is lost with EWS/FLI1 knockdown, and ChIP-qPCR shows menin binding at the ATF4 gene promoter in association with H3K4me3 enrichment. ChIP-qPCR also shows enrichment of ATF4 binding at SSP gene promoters, which is diminished upon menin inhibition with MI-503. Preliminary studies suggest that ATF4 overexpression may rescue the effects of menin loss of function on the SSP. Together these findings support the hypothesis that menin hijacks the SSP via aberrant activation of ATF4, and that this depends on cooperation with EWS/FLI1. Ongoing studies are assessing whether this is mediated by trithorax-dependent or -independent functions of menin.

Citation Format: Jennifer A. Jiménez, Ramon Ocadiz Ruiz, April Apfelbaum, Abhijay Kumar, Samuel Kerk, Jolanta Grembecka, Costas A. Lyssiotis, Elizabeth R. Lawlor. Menin and EWS/FLI1 activate serine biosynthesis via ATF4 in Ewing sarcoma [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B37.
Abstract B40: EWS-FLI1 orchestrates Ewing sarcoma plasticity through a post-translational modification cascade regulating FOXM1 stability
Authors: Ban Jozef , Aryee Dave , Bierbaumer Lisa , Kovar Heinrich
Published: August 2020

Oscillations between proliferative and migratory/invasive cell states are at the core of the metastatic process. Transition between these states involves reversible shifts in transcriptional programs that orchestrate cytoskeletal remodeling. Ewing sarcoma pathogenesis depends on EWS-FLI1, an aberrant ETS transcription factor that drives cellular transformation and proliferation of presumably mesenchymal progenitor cells. Recently, it has been reported that transient modulation of EWS-FLI1 expression results in an epithelial-to-mesenchymal transition-like phenotype of Ewing sarcoma cells and in increased metastasis (Chaturvedi et al., 2014; Franzetti et al., 2016). It has been proposed that EWS-FLI1 low cells exist in small amounts in primary Ewing sarcoma tumors and thus provide a potential source for tumor dissemination, leading to adverse prognosis. In our studies, we investigate the mechanistic basis of EWS-FLI1 dose-dependent Ewing sarcoma plasticity and recently reported on the activation of an MRTFB/TEAD transcriptional module promoting cytoskeletal reprograming in response to low EWS-FLI1 levels (Katschnig et al., 2016). Here, we show that the proliferative state depends on the activity of nuclear beta-catenin complexed to FOXM1. We find that EWS-FLI1 not only drives FOXM1 expression on the RNA level, but also sustains nuclear FOXM1 stability by a mechanism involving FOXM1 protein demethylation by lysine-specific demethylase 1 (LSD1/KDM1A). Experimental evidence suggests that EWS-FLI1 regulates LSD1 protein stability in Ewing sarcoma cells by directly activating a ubiquitin-specific protease. Modulation of EWS-FLI1 led to loss of expression of the deubiquitinting enzyme (DUB), and consequently to rapid depletion of LSD1 and FOXM1 proteins and subcellular redistribution of beta-catenin to the cytoplasm. Genetic (siRNA) and pharmacologic inhibition of the DUB or LSD1 recapitulated the destabilizing effect on FOXM1 in EWS-FLI1-high Ewing sarcoma cells, blocking tumor cell proliferation. In addition, they led to complete loss of beta-catenin expression by a mechanism that is currently under investigation. Therefore, our study identifies targetable enzymatic activities downstream of EWS-FLI1 that are required to sustain Ewing sarcoma proliferation.

Citation Format: Jozef Ban, Dave Aryee, Lisa Bierbaumer, Heinrich Kovar. EWS-FLI1 orchestrates Ewing sarcoma plasticity through a post-translational modification cascade regulating FOXM1 stability [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B40.
Abstract B47: Overexpression of TLX3 or HOXA9 in association mutant IL7Rα are sufficient to generate T-ALL in vivo
Authors: Rodrigues Gisele O.L. , Hixon Julie , Winer Hila , Li Wenqing , Durum Scott
Published: August 2020

Background: Mutations of the IL7Rα chain occur in approximately 10% of pediatric T-cell acute lymphoblastic leukemia cases. While we have shown that mutant IL7Rα is sufficient to transform an immortalized thymocyte cell line, mutation of IL7Rα alone was insufficient to cause transformation of primary T cells, suggesting that additional genetic lesions may be present, contributing to initiate leukemia. Studies addressing the combinations of mutant IL7Rα plus TLX3 or HOXA9 overexpression indicate in vitro grow advantage, suggesting these two genes as potential collaborative candidates. Furthermore, patients with mutated IL7Rα were more likely to have TLX3 or HOXA subgroup leukemia.

Objective: We sought to determine whether combination of mutant hIL7Rα plus TLX3 or HOXA9 overexpression is sufficient to generate T-cell leukemia in vivo.

Methods: Double-negative thymocytes were isolated from C57BL/6J mice and transduced with retroviral vectors containing mutant hIL7Rα plus TLX3 or HOXA9. The same combinations were tested for the hIL7Rα wild-type. Transduced thymocytes were cultured on the OP9-DL4 bone marrow stromal cell line for 7-13 days and accessed for driver oncogenes expression and then injected into sublethally irradiated Rag-/- mice. Mice were euthanized at onset of clinical signs, and cells were immunophenotyped by flow cytometry.

Results: Thymocytes transduced with muthIL7Rα-TLX3 showed overexpression of c-Myc and Pim-1. Nonetheless, there was no difference in the protein level expression for these two proteins in either thymocytes transduced with muthIL-7Rα-HOXA9 or in the control wthIL7Rα-TLX3. Mice injected with either muthIL7Ra-TLX3 or muthIL7Rα-HOXA9 cells, but not the controls (wthIL7Rα-TLX3 or wthIL7Rα-HOXA9), developed leukemia approximately 14 days post injection, characterized by GFP-expressing T-cells in blood, spleen, liver, lymph nodes, and bone marrow.

Conclusion: Thymocytes transduced with muthIL7Rα-TLX3 showed c-Myc and Pim-1 upregulation. Cells expressing the combination muthIL7Rα-TLX3 or muthIL7Rα-HOXA9 were sufficient to trigger T-cell leukemia in vivo.

Citation Format: Gisele O.L. Rodrigues, Julie Hixon, Hila Winer, Wenqing Li, Scott Durum. Overexpression of TLX3 or HOXA9 in association mutant IL7Rα are sufficient to generate T-ALL in vivo [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B47.
Abstract B66: Nutritional intakes are associated with HDL-cholesterol levels in survivors of childhood acute lymphoblastic leukemia
Authors: Morel Sophia , Amre Devendra , Teasdale Emma , Laverdière Caroline , Sinnett Daniel , Levy Emile , Marcil Valérie
Published: August 2020

Background: Survivors of childhood acute lymphoblastic leukemia (cALL) are at high risk of developing dyslipidemia (high LDL-cholesterol, high triglycerides, or low HDL-cholesterol). Studies showed that, similarly to the general population, cALL survivors do not respect dietary guidelines. However, whether nutritional intakes affect the lipid profile of this high-risk population remains unknown. This study aims to examine the associations between macro- and micronutrients and the presence of dyslipidemia in children and young adult survivors of cALL.

Methods: Participants (n=247) survivors of cALL were recruited as part of the PETALE study at Sainte-Justine University Health Center (49.4% boys; median age: 21.7 yrs, range: 8.5-41.0 yrs; median time since diagnosis: 15.2 yrs, range: 5.4-28.2 yrs). Nutritional data were collected using a validated food frequency questionnaire (FFQ) comprising 190 items. Fasting blood was used to determine participants’ lipid profile by enzymatic reactions. Multivariable logistic regression models were fitted to evaluate the associations between intakes of macro- and micronutrients and dyslipidemia. The model included the following covariables: body mass index, age at diagnosis, age at diagnosis2, sex, and total energy intake.

Results: Despite their young age, 41.3% of cALL survivors had dyslipidemia defined by having at least one abnormal lipid value. Specifically, 12.2% had high triglycerides and 17.4% high LDL-cholesterol and 23.1% low HDL-cholesterol. Our analysis revealed that having low HDL-cholesterol was associated with higher intakes in several nutrients (3rd vs. 1st tertile). They were proteins [odd ratio (OR): 0.27, 95%CI: 0.08-0.92, P<0.05], zinc (OR: 0.26, 95%CI: 0.08-0.84, P<0.05), copper (OR: 0.34, 95%CI: 0.12-0.99, P<0.05), selenium (OR: 0.17, 95%CI: 0.05-0.59, P<0.01), niacin (OR: 0.25, 95%CI: 0.08-0.84, P<0.05), riboflavin (OR: 0.24, 95%CI: 0.07-0.84, P<0.05), and vitamin B12 (OR: 0.35, 95%CI: 0.13-0.90, P<0.05).

Conclusion: Our study shows the potential protective role of specific macro- and micronutrients on HDL-cholesterol levels in cALL survivors. These results stress the importance of deepening our understanding of the impact of nutrition in the development of dyslipidemia after cancer treatment. Nutritional strategies could be a valuable approach to prevent long-term cardiometabolic complications in cALL survivors.

Citation Format: Sophia Morel, Devendra Amre, Emma Teasdale, Caroline Laverdière, Daniel Sinnett, Emile Levy, Valérie Marcil. Nutritional intakes are associated with HDL-cholesterol levels in survivors of childhood acute lymphoblastic leukemia [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B66.
Abstract B67: EGFR as a target in pediatric solid tumors
Authors: Albert Catherine M. , Pinto Navin R. , Rudzinski Erin R. , Park Julie R.
Published: August 2020

The epidermal growth factor receptor (EGFR or HER1) is a cell surface tyrosine kinase receptor that is expressed in a diverse group of epithelial and nonepithelial tissues and broadly associated with cell proliferation and differentiation. Expression of wild-type EGFR and activating mutations are described in many malignancies, including a variety of pediatric solid tumors. In the setting of malignancy, EGFR has been associated with aggressive disease, chemotherapy resistance, and increased metastatic potential. Employment of anti-EGFR agents has yielded some promising results, but they are not always effective against all cancer-associated aberrant EGFR expression and are frequently associated with notable off-tumor toxicities due to the expression of EGFR in normal tissue. The unique EGFR monoclonal antibody (mAb) 806 selectively binds to an epitope on the extracellular portion of human EGFR expressed on the surface of tumor cells. This antibody recognizes the deletion mutant EGFRvIII commonly present in glioblastomas and some other solid tumors as well as wild-type EGFR. We designed a phase I trial for pediatric and young adult patients with recurrent or refractory solid tumors expressing epidermal growth factor (EGFR) to examine the safety and feasibility of administering autologous, peripheral blood-derived T cells that have been genetically modified to express a second-generation (2G) EGFR806-specific chimeric antigen receptor (CAR). Literature review and evaluation of EGFR immunohistochemistry (IHC) performed on several tissue microarrays were used to estimate the percentage of EGFR positivity among common subtypes of pediatric cancer. Using these tools, we hypothesized that 15-40% of otherwise eligible patients would meet the eligibility criteria of EGFR positivity. The trial opened in August of 2018. To date, a total of 33 patient tumors have undergone EGFR IHC to determine eligibility for the trial. 9/33 (27.3%) have been EGFR+. EGFR+ histologies include BCOR fusion sarcoma (3), germ cell tumor (2), osteosarcoma, Ewing sarcoma, desmoplastic small round cell tumor, and synovial sarcoma. Our eligibility testing thus far demonstrates EGFR expression by IHC in a variety of histologies. Two rare diseases, recurrent BCOR fusion sarcoma and refractory germ cell tumors, have demonstrated a significantly higher rate of EGFR IHC positivity, (3/3)100% and (2/3) 66.7%, respectively. These early results indicate that this trial and other anti-EGFR therapies may be most effectively targeted to certain subgroups of pediatric cancer patients.

Citation Format: Catherine M. Albert, Navin R. Pinto, Erin R. Rudzinski, Julie R. Park. EGFR as a target in pediatric solid tumors [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B67.