bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3045: Investigating the influence of glycosylation using cellular models of neuroblastoma
Authors: Cook Meghan , Garcia Alma , Konieczny Katie , Ferguson Meghan , Campbell Robert 
Published: July 2021

Abstract
Background: Neuroblastoma is a common childhood malignancy with approximately 800 new cases diagnosed each year in the United States. Treatment of neuroblastoma directly depends on patient risk categories and includes combinations of surgery, radiation therapy, chemotherapy, stem cell therapy, immunotherapy, and retinoid therapy. Various characteristics of cancer in general and some specific to neuroblastoma cell lines contribute to a difficulty in delivering clinically relevant concentrations of therapeutic agents to neuroblastoma masses. Amplification of the MYCN gene in certain neuroblastoma cell lines correlates with increased cellular surface glycosylation levels as well as a worse prognosis for patients. Overexpression of the MUC1 gene is also associated with increased glycosylation, specifically type-O, in various cancers, but the role of MUC1 in neuroblastoma has not been thoroughly defined. The objective of this study was to evaluate the influence of type-O glycosylation on therapeutic uptake in different neuroblastoma cell lines.
Methods: The neuroblastoma cell line SK-N-DZ, a MYCN-amplified line, was compared to SK-N-SH, a non-MYCN-amplified line (negative control) and BT-20, a highly glycosylated breast cancer cell line (positive control). Benzyl-α-GalNAc, an O-glycosylation inhibitor, was introduced to each cell line. To determine glycosylation levels in the respective cell lines, fluorescence assays were performed using CD227 (anti-MUC1) antibody. In vitro cytotoxicity assays were performed to determine maximum non-toxic concentrations of the glycosylation inhibitor (benzyl-α-GalNAc) and antibody (CD227) and to subsequently evaluate the functional role of glycosylation using cellular models of neuroblastoma.
Results: The maximum non-toxic concentrations per 10,000 cells for each neuroblastoma cell line was 0.05 mg/ml of benzyl-α-GalNAc, and 6 µl of CD227 stock preparation. Preliminary results from fluorescence detection studies showed an increase in CD227-FITC antibody uptake by the MYCN-amplified neuroblastoma cells (SK-N-DZ) following exposure to the O-glycosylation inhibitor (benzyl-α-GalNAc). Cellular uptake of CD227-FITC by non-MYCN-amplified cell line (SK-N-SH) was less by comparison.
Conclusion: Preliminary findings suggest that O-glycosylation is a barrier capable of limiting cellular uptake of agents in MYCN-amplified neuroblastoma cell lines. Ongoing studies are focused on investigating the influence of glycosylation inhibition on cytotoxicity of FDA-approved therapeutic agents.
Citation Format: Meghan Cook, Alma Garcia, Katie Konieczny, Meghan Ferguson, Robert Campbell. Investigating the influence of glycosylation using cellular models of neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3045.
Abstract 3047: Spatial heterogeneity in diffuse intrinsic pontine gliomas treated with a PDGFR inhibitor
Authors: Arunachalam Sasi , Brady Samuel W. , Ma Xiaotu , Szlachta Karol , Mulder Heather , Easton John , Tinkle Christopher L. , Wetmore Cynthia , Baker Suzanne J. , Zhang Jinghui 
Published: July 2021

Abstract
Diffuse intrinsic pontine gliomas (DIPG) are lethal pediatric brain tumors that arise in the pons. To understand the spatial heterogeneity in DIPG, we performed ultra-deep sequencing and copy number profiling of 44 multi-region autopsy samples from 10 DIPG patients after phase I treatment with the PDGFR inhibitor crenolanib. Our study recapitulated the previously reported temporal order of driver mutation acquisition starting with histone H3 K27M followed by cell cycle (TP53 and PPM1D) or growth factor pathways (AVCR1, or PIK3R1), with mutations affecting PI3K and MAPK pathways being late, subclonal events. Further, we observed that aneuploidy was likely an early event as copy number heterogeneity was minimal in most patients. Compared to previous DIPG studies, we observed an enrichment in subclonal mutations and convergent evolution of PI3K alterations. This enrichment may have been due to selection for crenolanib resistance, or to the prior treatment history of the patients within the cohort. We also detailed intra-patient clonal composition among tumor samples and identified founder clones that were dominant in only a single location, which we considered to be non-migratory “occupier” clones, in four patients. By contrast, in six other cases, we observed clones that frequently invaded other sites. Interestingly, in one case with TP53 convergent evolution, aneuploidy clone carrying TP53 R273H mutation invades all other sequenced tumor sites whereas another clone with TP53 R248W does not. These results indicate the importance of understanding spatial heterogeneity within DIPG patients, which is crucial to the identification of effective treatments.
Citation Format: Sasi Arunachalam, Samuel W. Brady, Xiaotu Ma, Karol Szlachta, Heather Mulder, John Easton, Christopher L. Tinkle, Cynthia Wetmore, Suzanne J. Baker, Jinghui Zhang. Spatial heterogeneity in diffuse intrinsic pontine gliomas treated with a PDGFR inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3047.
Abstract 3057: Development of radiation-triggered phosphor platform for localized activation in combinatory cancer treatment
Authors: Papineni Rao V. , Krishnan Sunil , Pulickel Ajayan , Sahin Onur 
Published: July 2021

Abstract
A defined spatial and temporal control of induction of toxicity in response to external ionizing radiation such as X-rays has unique clinical benefits over conventional systems such as passive drug delivery or its activation. Here, we have combined X-rays with well characterized nanoscintilators emitting light that activates paired photosensitizers in photodynamic therapy (PDT) that improves the prowess of PDT to deep seated tumor treatment. Yttrium oxide nanoparticle construct doped with Europium (YOE) and coated with a silica layer entrapping methylene blue (MB) as the photosensitizer was fabricated. The nanoconstruct (YSM, for YOE, silica, MB) was decorated with polyethylene glycol (PEG) to make it biocompatible and characterized extensively for physicochemically parameters. Transmission electron microscopy (TEM) revealed a resultant average nanoparticle diameter of 24.1 ± 5.7 nm, and dynamic light scattering (DLS) a hydrodynamic diameter of 135.3 ± 17.9 nm. This nanoconstruct was evaluated for its ability to generate singlet oxygen reactive oxygen species upon irradiation using singlet oxygen sensor green (SOSG) fluorescence assay. Further, demonstrated that this nanoconstruct was taken up by cancer cells in vitro and by tumors in vivo. The uptake of YSM particles by Panc02 murine pancreatic cancer cells was tested by inductively coupled plasma – mass spectrometry. This demonstrated robust uptake in cells after 24hr incubation. No noticeable cell death occurred with doses of 0 Gy and 4 Gy, cell viability decreased significantly after a dose of 8 Gy irradiation in cells cultured with YSM when compared to controls. Since 8 Gy is within the range of a clinically applicable dose used routinely in stereotactic radiotherapy regimens, these results verified the potential of YSM to be used as scintillator-photosensitizer complexes for x-ray activated photodynamic therapy. Finally the biodistribution of YSM nanoconstructs in vivo in C57BL6 mice harboring subcutaneous Panc02 tumors show YSM accumulation in tumors. A versatile, biocompatible Yttrium oxide scintillator-photosensitizer complex (YSM) that can generate x-ray induced cytotoxic reactive oxygen species is fabricated. This is capable of facilitating x-ray activated photodynamic therapy (XPDT (external beam) and/or iXPDT (internal x-ray source)). It shows promise in maximizing the efficacy of the combinatory treatment and enhanced improvement of the quality of life and overall survival of cancer patients.
Citation Format: Rao V. Papineni, Sunil Krishnan, Ajayan Pulickel, Onur Sahin. Development of radiation-triggered phosphor platform for localized activation in combinatory cancer treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3057.
Abstract 3059: Heavy ion radiation exposure perturbs intestinal stem cell homeostasis and induces accelerated tumorigenesis in apc mutant mouse intestine
Authors: Kumar Santosh , Suman Shubhankar , Datta Kamal , Fornace Albert J. 
Published: July 2021

Abstract
In a previous study, we demonstrated long-term decreased intestinal epithelial cell migration after low-dose heavy ion iron radiation, and this was associated with increased senescence-associated secretory phenotype (SASP) signaling. However, we know very little about the long-term effects of low dose space radiation on intestinal stem cell (ISC) senescence and SASP that have implications for intestinal homeostasis. Male Lgr5+ (Lgr5-EGFP-IRES-creERT) mice or Lgr5+/APC1638N/+ were exposed to 0.5 Gy of sham, γ-rays, or 28Si (69 keV/μm) radiation and were euthanized 60 or 150 days after irradiation. ISCs were FACS sorted for oxidative stress analysis and assessed for senescence and SASP signaling in tissue sections by immunostaining. Greater cellROX or mitoSOX staining was observed after 28Si indicating higher oxidative stress compared to γ-rays or control Lgr5 positive cells. β-gal co-staining with Lgr5, lysozyme, IL1R, or ILβ showed highest staining in 28Si irradiated compared to controls ISCs samples. γ-H2AX staining showed greater foci numbers in 28Si relative to γ-rays or control group. Higher expression of secretory cytokines IL8 and IL15 was observed in 28Si irradiated ISCs relative to γ-rays or control group at both time points. Elevated expression of DKK2 and activation of NF-κB and p38 MAPK were observed in senescent stem cells of 28Si irradiated relative to γ-rays or control group at these time points. A higher GI tumor count was observed in 28Si compared to γ-irradiated or control Lgr5+/APC1638N/+ mice. In summary, our results demonstrate low dose heavy ion exposure induces ongoing DNA damage, persistent oxidative stress, senescence and acquisition of the SASP in ISCs. Higher levels of oxidative stress, senescence and SASP were observed at 150 compared to the 60-day timepoint. Overall, space radiation-induced oxidative stress, senescence, SASP, and activated p38MAPK/NF-κB pathway may very well have implications in GI carcinogenesis, accelerated aging, and pathological conditions, such as intestinal dysfunction, in astronauts during deep space flights. Since similar effects have been seen in our studies with other particle beams including carbon ions, this has potential relevance to particle radiotherapy as well. This work was supported by NASA NNX15AI21G
Citation Format: Santosh Kumar, Shubhankar Suman, Kamal Datta, Albert J. Fornace. Heavy ion radiation exposure perturbs intestinal stem cell homeostasis and induces accelerated tumorigenesis in apc mutant mouse intestine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3059.
Abstract 3064: Investigation of ionizing radiation response in new resistance models of glioblastoma
Authors: Pinarbasi Nareg , Bagci-Onder Tugba , Erdem Ilknur Sur , Selek Ugur 
Published: July 2021

Abstract
Glioblastoma is one of the most aggressive central nervous system tumors, which constitutes 50% of all primary brain tumors. Glioblastomas have a very poor prognosis, approximately 12-15 months even with standard therapy. Current treatment protocols include surgery, chemotherapy, and radiotherapy. High rates of recurrence after treatment, genetic heterogeneity, and developing resistance to chemotherapy and radiotherapy are challenges to overcome in glioblastoma treatment. Therefore, developing models of chemo- or radio-resistance is of priority to understand the molecular mechanisms that operate during the transition of cells to therapy-refractory state, and to develop new therapeutic approaches. In this study, we generated ionizing radiation (IR)-exposed glioblastoma cell populations to investigate molecular alterations associated with acquired radiotherapy resistance. To generate a clinically relevant radioresistance model, we have exposed glioblastoma cells to a total dose of 60 Gy IR over a 6-week period and cultured age-matched parental cells. We successfully generated sustainable radioresistant cells, as demonstrated by cell viability and colony formation assays. RNA sequencing, performed on these matched cell lines revealed major alterations in the expression of genes of the cell cycle, DNA damage recognition, and repair machinery in the radioresistant cells. Specifically, elements of the DNA double strand break (DSB) recognition and repair, such as ATM, ATR, and CHK1 were markedly upregulated in the radioresistant cell populations. In line with these findings, DNA repair capacity of the radioresistant cell populations was increased, as revealed by the faster clearance of H2AX and 53BP1 in the radioresistant populations. Complementing this approach, pharmacological inhibition of major DNA damage response elements, such as ATM, ATR, as well as CHK1 markedly sensitized the radioresistant cells. Our results prepare a groundwork for studying the molecular mechanisms of radiotherapy resistance and developing novel combination therapy strategies for glioblastomas.
Citation Format: Nareg Pinarbasi, Tugba Bagci-Onder, Ilknur Sur Erdem, Ugur Selek. Investigation of ionizing radiation response in new resistance models of glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3064.
Abstract 3069: Radiation exposure of the base of the heart accelerates coronary atherosclerosis
Authors: Nepali Prerna R. , Mathieu Mickael , Kitz Sarah , Nakauchi Chiharuko , Russell James , Monette Sebastien , Rimner Andreas , Stewart Fiona A. , Jaimes Edgar A. , Haimovitz-Friedman Adriana 
Published: July 2021

Abstract
Purpose: To determine the mechanisms associated with the development of atherosclerotic lesions in different areas of the heart exposed to radiation therapy (RT). We hypothesize that accelerated development of cardiovascular disease (CVD) post-RT is dependent upon the differential sensitivity of regions of the heart to radiation.
Experimental procedures: Male Apolipoprotein E knockout (ApoE-/-) mice on a high fat diet received 16Gy cardiac irradiation targeted to the whole or partial (apical or basal) region of the heart at 9 weeks or 16 weeks of age. Atherosclerotic lesions and inflammatory changes in the hearts as compared to control unirradiated mice were assessed eight weeks following radiation.
Results: Our studies demonstrate that atherosclerotic lesion formation is accelerated by cardiac RT. Our results show that (1) Subendocardial atherosclerotic lesions at the base of heart of 9 weeks old mice after basal irradiation are comparable to those formed post whole heart irradiation. (2) A greater number of atherosclerotic lesions were present in the basal coronary arteries and basal subendocardial vasculature after irradiating the cardiac base as compared to unirradiated controls in older mice at 8 weeks post-RT. (3) Apical or whole heart irradiation had no impact on the development or acceleration of lesions in the basal region of the hearts of 16 week old mice, thus demonstrating the adverse impact of basal irradiation. (4) Infiltration of inflammatory cells (CD45 and CD3) and enhanced expression of endothelial adhesion molecules (CD31) were differentially and locally regulated based upon the site of irradiation. This also demonstrates a long-term inflammatory response to RT which may be crucial in the development of RT-related CVD.
Conclusion: Our results indicate that the base of the heart is more prone to development of RT-induced atherosclerotic lesions that could lead to CVD and thus omitting this area from RT direct exposure may improve the quality of life for cancer patients receiving thoracic RT.
Citation Format: Prerna R. Nepali, Mickael Mathieu, Sarah Kitz, Chiharuko Nakauchi, James Russell, Sebastien Monette, Andreas Rimner, Fiona A. Stewart, Edgar A. Jaimes, Adriana Haimovitz-Friedman. Radiation exposure of the base of the heart accelerates coronary atherosclerosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3069.
Abstract 3075: Effect of reducing AXIN2 levels in CRC cells with APC mutation and activated WNT signaling
Authors: Zhang Chi , Facey Caroline O. , Funk Katherine , Opdenaker Lynn M. , Boman Bruce M. 
Published: July 2021

Abstract
Regulation of the WNT/beta-catenin signaling pathway occurs by a negative feedback loop that keeps beta-catenin levels in check in normal cells. Dysregulation of this feedback mechanism due to APC mutation is well known. However, the role of AXIN2, another component of this negative feedback loop is less known, particularly in APC mutant tissues. Our goal is to study how AXIN2 functions as part of the negative WNT/beta-catenin signaling feedback loop and understand of how it contributes to CRC development. Our bioinformatics analysis suggests that CRC cells carrying APC-truncating mutations still retain residual function of the destruction complex, but there are significant changes between AXIN2 and APC expression levels. Therefore, we hypothesize that the interaction between truncated-APC and AXIN2 is responsible for the dysregulation of the feedback loop. We found, using a TCF/LEF reporter assay, that siRNA-mediated knockdown of AXIN2 leads to increased WNT/beta-catenin signaling. This result confirmed the functional integrity of the downstream part of the WNT pathway from destruction complex to transcription activation by TCF/beta-catenin complex. It also narrowed down the dysregulated component(s) to within the destruction complex. Protein analysis further demonstrated that AXIN2 siRNA-mediated knockdown changed expression of several WNT/beta-catenin target genes. Surprisingly, siRNA-mediated knockdown led to decreased cell proliferation of HT29 cells. We surmise that AXIN2 knockdown in the setting of mutant APC leads to a high level of WNT signaling that reduces the self-renewal capacity of colonic cancer stem cells and lowers the rate of cell proliferation. Overall, our results indicate that it is important to understand how WNT signaling levels play a role in SC self-renewal and stemness. We conjecture that if WNT signaling is not strictly controlled in CSCs, high WNT levels can be detrimental to CSC proliferation and/or survival, which could have important clinical implications.
Citation Format: Chi Zhang, Caroline O. Facey, Katherine Funk, Lynn M. Opdenaker, Bruce M. Boman. Effect of reducing AXIN2 levels in CRC cells with APC mutation and activated WNT signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3075.
Abstract 3077: ATRXLoss and IDH1R132H impair self-renewal of glioma stem cells after proton radiotherapy
Authors: Garcés Ángel Adrian , Bronk Lawrence , Bhat Krishna P. , Grosshans David R. 
Published: July 2021

Abstract
Background: Glioblastoma Multiforme (GBM-Grade IV) is the most aggressive form of glioma in the USA carrying only a 15 month median survival time. IDH1R132H is an early onset mutation present in 70-80% of low grade gliomas (LGG-Grade I and II) and secondary GBM patients that causes intracellular oxidative stress and impairment of post-radiation DNA damage repair (DDR) via Homologous Recombination (HR). Although IDH1R132H is associated with improved patient survival and clinical response to chemotherapy, astrocytoma (LGG) patients specifically also harbor ATRXLoss, a genetic alteration that inactivates the ATRX chromatin remodeling protein and impairs DDR via non-homologous end joining (NHEJ). Importantly, the recent discovery of glioma stem cells (GSCs), a subpopulation of chemoradioresistant, self-renewable, tumor initiating cells known to promote tumor recurrence, presents a new target for therapeutic intervention. However, the mechanisms by which IDH1R132H and ATRXLoss contribute to GSC sensitivity to proton radiotherapy (PRT), a more tumor specific and cytotoxic form of radiation therapy than conventional X-rays (XRT), is not well understood. We hypothesize that both IDH1R132H and ATRXLoss contribute to the impairment of GSC self-renewal after PRT, but not after XRT.
Methods: Isogenic MGG18-IDH1WT, MGG18-IDH1R132H, TS543-ATRXWT, and TS543-ATRXLoss patient derived glioma cells were cultured as neurospheres and treated with 3-6 Gy of XRT or PRT. GSC self-renewal, based on neurosphere formation frequency, was quantified using extreme limiting dilution analysis (ELDA).
Results: TS543-ATRXLoss significantly inhibited GSC self-renewal over TS543-ATRXWT when subject to PRT (Pairwise Testing Pr(&gt;χ2)&lt;0.01). However, TS543-ATRXWT displayed lower GSC self-renewal compared to TS543-ATRXLoss when subject to XRT (Pr(&gt;χ2)&lt;0.0001). Interestingly, similar results were found in the isogenic MGG18 cell lines. MGG18-IDH1R132H displayed higher radiosensitivity to PRT (Pr(&gt;χ2)&lt;0.05) while MGG18-IDH1WT displayed higher radiosensitivity to XRT (Pr(&gt;χ2)&lt;0.01), as defined by GSC self-renewal.
Conclusions: We conclude that ATRXLoss and IDH1R132H both substantially contribute to PRT sensitivity in GSCs, thereby supporting the benefits of PRT for astrocytoma patients. Our future experiments will further elucidate the biological mechanisms by which ATRXLoss and IDH1R132H confer PRT sensitivity, especially via dsDNA damage and apoptosis.
Citation Format: Ángel Adrian Garcés, Lawrence Bronk, Krishna P. Bhat, David R. Grosshans. ATRXLoss and IDH1R132H impair self-renewal of glioma stem cells after proton radiotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3077.