bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 672: Prognostic significance of urokinase plasminogen activator system in a naturally occurring model of osteosarcoma
Authors: Matsuyama Arata , Mutsaers Anthony J. 
Published: July 2021

Abstract
Introduction Human pediatric and canine osteosarcoma (OSA) are both highly metastatic primary bone cancers that share molecular and clinical similarities. Urokinase plasminogen activator (uPA) and its receptor uPAR promote invasion, metastasis and angiogenesis in multiple cancer types and have been shown to play critical roles in malignant characteristics of OSA in vitro, yet their clinical significance has not been investigated in OSA patients.
Methods Serum samples of dogs with naturally-occurring appendicular OSA (n=26) and clinically healthy dogs (n=6) were analyzed using commercially available canine-specific ELISA and uPA activity kits. Dogs with OSA that presented without metastatic disease at diagnosis and received treatment with amputation plus adjuvant carboplatin chemotherapy were included. Survival data and patient characteristics were obtained from medical records. Differences in serum uPA/uPAR results between the groups was tested by t test or Wilcoxan rank sum test. Kaplan Meier survival curve and log rank test were used for survival analysis in the OSA cohort after subgrouping by X-Tyle software. Well-established prognostic factors and serum uPA/uPAR results were tested for prognostic significance by cox regression analysis in both univariate and multivariate analyses.
Results Dogs with OSA had significantly higher serum uPA (p=0.008; 1905.4 vs 1439.5 pg/mL) but not uPAR (p=0.866) levels compared to healthy dogs. OSA-bearing dogs with high serum uPA had significantly shorter progression-free (p=0.003; 94 vs 266 days) and overall survival (p=0.01; 123 vs 338 days) than dogs with low uPA level. Similarly, dogs with high serum uPA activity had significantly shorter progression-free survival (p=0.043; 227 vs 266 days). Serum uPAR was not prognostic in this cohort. Multivariate analysis revealed increased serum uPA level (p=0.024) as a poor prognostic indicator in addition to other established prognostic factors in dogs such as humeral location (p=0.022) and increased monocyte count (p=0.015).
Conclusions Circulating uPA quantity and activity are increased in canine OSA patients with more aggressive disease, indicating importance of the uPA system in OSA disease progression. While an OSA-associated increase in circulating uPAR was not evident, this receptor likely contributes to OSA malignancy subsequent to the increased uPA ligand production. Serum uPA may be an attractive prognostic biomarker in OSA and the up-regulated uPA/uPAR axis should be further investigated as a potential therapeutic target for this disease.
Citation Format: Arata Matsuyama, Anthony J. Mutsaers. Prognostic significance of urokinase plasminogen activator system in a naturally occurring model of osteosarcoma [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 672.
Abstract 677: Immune biomarkers of response to Ra223 dichloride and stereotactic body radiation therapy in patients with oligometastatic prostate cancers
Authors: Alcantara Marice , Dorff Tanya , Liu Jessica , Frankel Paul , Twardowski Przemyslaw , Dandapani Savita , Kortylewski Marcin 
Published: July 2021

Abstract
Prostate cancer is the second leading cause of death in men in the developed countries. Androgen deprivation therapy (ADT) is commonly used to treat prostate tumors at earlier stages due to hormone-dependence of cancer cells. However, the onset of androgen-resistance with tumor progression and the negative impact of ADT on the quality of life are significant challenges. To address these issues, we have initiated a novel clinical trial combining radium Ra223 dichloride with stereotactic body radiation treatment (SBRT) and short course of ADT in patients with oligometastatic, castration-sensitive prostate cancer (NCT03351735). Patients with one to four oligometastatic prostate cancer lesions have been receiving ADT for nine months, together with SBRT to all metastatic sites and six cycles of Ra223 to target micrometastatic bone lesions. Eight out of the planned 24 patients have already completed the full treatment course, with five patients currently on surveillance (not requiring any further treatment) and three patients receiving next cycle of therapy. As part of this investigator-initiated study, we have performed a comprehensive immune characterization of peripheral immune cells and serum immune biomarkers in all treated patients. Based on flow cytometric analysis, we found a significant decrease in the percentage of CD4+ T cells befoe and after SBRT (cycle 1) but no changes in the elevated levels of programmed cell death-1 (PD-1), a marker of T-cell exhaustion, on the circulating CD4+ and CD8+ T cells. In addition, we observed high levels of the activated STAT3 (pSTAT3) in myeloid-derived suppressor cells (MDSCs), together with its downstream target Arginase-I. Finally, IL-8 stood out as a cytokine strongly elevated in plasma of patients who received the complete Ra223 treatment but not directly after SBRT. Overall, these preliminary results suggest that this combinatorial radiotherapy patients with oligometastatic prostate cancers impacts immune cell activity but rather than leading to T cell activation it may promote tolerogenic activity of MDSCs.
Citation Format: Marice Alcantara, Tanya Dorff, Jessica Liu, Paul Frankel, Przemyslaw Twardowski, Savita Dandapani, Marcin Kortylewski. Immune biomarkers of response to Ra223 dichloride and stereotactic body radiation therapy in patients with oligometastatic prostate cancers [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 677.
Abstract 69: A biological circuit involving Mef2c, Mef2d and Hdac9 controls the immunosuppressive functions of CD4+Foxp3+ T-regulatory cells and anti-cancer immunity
Authors: Giorgio Eros Di , Wang Liqing , Xiong Yan , Han Rongxiang , Samanta Arabinda , Trevisanut Matteo , Hancock Wayne W. 
Published: July 2021

Abstract
The Mads/Mef2 (Mef2a/b/c/d) transcription factors (TFs) regulate differentiation of myocytes, neurons and hematopoietic cells. Mef2 TFs are subject to regulation by negative feedback in that they promote transcription of their strong repressor Hdac9, providing temporal control of Mef2-driven differentiative responses. Disruption of this feedback occurs within various sarcomas and leukemias. In addition, Mef2 TFs indirectly control tumor progression by regulating antitumor immunity. We recently reported that in CD4+CD25+Foxp3+ T-regulatory (Treg) cells, Mef2d is required for the acquisition of an effector Treg phenotype and the activation of an epigenetic program that in turn represses the anti-cancer responses of CD4, CD8 and B-cells. We now report that similarly to Mef2d, deletion of Mef2c in Tregs switches off expression of Il10 and Ctla4 and leads to enhanced antitumor immunity in syngeneic models of lung cancer. Mechanistically, Mef2c does not directly bind to the regulatory elements of Ctla4 and Il10, but rather, its loss-of-function in Tregs induces the expression of the transcriptional repressor Hdac9. As a consequence, Mef2d, the more abundant member of the Mef2 family, is displaced from p300 and is converted by Hdac9 into a transcriptional repressor at these loci. This leads to the impairment of Treg suppressive properties and to enhanced anti-cancer immunity. These data further highlight the central role played by Mef2/Hdac9 axis in the regulation of CD4+Foxp3+ Treg function and provide a rationale for the development of small molecules targeting Mef2 and/or Mef2-containing complexes.
Citation Format: Eros Di Giorgio, Liqing Wang, Yan Xiong, Rongxiang Han, Arabinda Samanta, Matteo Trevisanut, Wayne W. Hancock. A biological circuit involving Mef2c, Mef2d and Hdac9 controls the immunosuppressive functions of CD4+Foxp3+ T-regulatory cells and anti-cancer immunity [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 69.
Abstract 691: Antibody conjugated to a bispecific RNA molecule targeting RIG-I and PLK1
Authors: Rady Tony , Erb Stéphane , Deddouche-Grass Safia , Morales Renaud , Bouchard Hervé , Chaubet Guilhem , Cianférani Sarah , Wiederschain Dmitri , Basse Nicolas , Wagner Alain 
Published: July 2021

Abstract
Simultaneous access to several targets has become the subject of intense studies in immuno-oncology. In order to benefit from the synergies provided by the activation of different signaling pathways in immunology and the knockdown of proteins involved in cancer cell survival, we established a bispecific approach. The activation of the innate immune response by delivering agonists of pattern-recognition receptors (PRR) such as RIG-I (retinoic acid-inducible I) represents a promising strategy. RIG-I detects short double-stranded RNA molecules ended by a 5'-di/triphosphate moiety (5'ppp-dsRNA). RIG-I activation promotes type I IFN secretion and cancer-cell selective apoptosis. To obtain a bifunctional molecule, the 5'ppp-dsRNA sequence was designed to silence PLK1 (polo-like kinase 1). Suppressing PLK1 expression with small interfering RNAs (siRNA) leads to cell cycle arrest and retards cancer cell growth. This concept of bifunctional RNAs has been validated by using non-targeted systems.1
To enhance this synergy, we conjugated this 5'ppp-siPLK1 to an antibody for a specific delivery to cancerous cells that overexpress erythropoietin-producing hepatocellular receptor A2 (EphA2) at their surface. Upon binding to EphA2 receptor, the antibody is well internalized, thus making it a good vehicle to deliver the bispecific 5'ppp-siPLK1. After EphA2-positive cells treatment, we observed RIG-I specific activation as well as PLK1 depletion. Both effects were correlated with cellular apoptosis and the mode of action was further confirmed with mechanistic and kinetic studies. Finally, while non-modified unconjugated siRNA has a very short half-life in plasma, we observed an increase in stability for the antibody-5'ppp-siPLK1 conjugates. These data suggest that anti-EphA2 receptor antibody could be used to deliver a bispecific RNA molecule.
References:1H. Poeck, R. Besch, C. Maihoefer, M. Renn, D. Tormo, S. S. Morskaya, S. Kirschnek, E. Gaffal, J. Landsberg, J. Hellmuth, A. Schmidt, D. Anz, M. Bscheider, T. Schwerd, C. Berking, C. Bourquin, U. Kalinke, E. Kremmer, H. Kato, S. Akira, R. Meyers, G. Häcker, M. Neuenhahn, D. Busch, J. Ruland, S. Rothenfusser, M. Prinz, V. Hornung, S. Endres, T. Tüting and G. Hartmann, 5′-triphosphate-siRNA: turning gene silencing and Rig-I activation against melanoma, Nat. Med., 2008, 14, 1256-1263.
Citation Format: Tony Rady, Stéphane Erb, Safia Deddouche-Grass, Renaud Morales, Hervé Bouchard, Guilhem Chaubet, Sarah Cianférani, Dmitri Wiederschain, Nicolas Basse, Alain Wagner. Antibody conjugated to a bispecific RNA molecule targeting RIG-I and PLK1 [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 691.
Abstract 694: Novel conditionally active bispecific EpCAM x CD3 T cell engagers targeting solid tumors
Authors: Cugnetti Ana Paula G. , Liu Haizhen , Wang Jing , Xing Charles , Wheeler Christina , Lucas Matthew , Chang Cathy , Frey Gerhard , Boyle William , Short Jay 
Published: July 2021

Abstract
Epithelial cell adhesion molecule (EpCAM) is a transmembrane glycoprotein that plays many roles in cancer biology. EpCAM is an attractive therapeutic target due to its expression on most solid tumors. However, targeting of EpCAM protein has been limited since it is also expressed on normal epithelial tissues. In fact, initial attempts to develop EpCAM-specific T cell engagers were not successful due to severe cytokine release effects as well as serious on-target off-tumor drug related toxicities. Conditionally Active Biologic (CAB) technology is a proprietary platform that generates bispecific antibodies which have no or very little binding to CD3 or to the target antigen in healthy tissue (normal physiological conditions), but have strong binding in the context of diseased tissues (tumor microenvironment) based on the glycolytic tumor metabolism (Warburg effect). Using our CAB technology, we have developed CD3 mono-CAB (WT EpCAM x CAB CD3) and CD3/EpCAM dual-CAB (CAB EpCAM x CAB CD3) bispecific antibodies. In vitro and in vivo efficacy data as well as toxicology studies in non-human primates for mono- and dual-CAB EpCAM x CD3 bispecific antibodies targeting EpCAM will be presented. Our data demonstrate that both mono- and dual-CAB EpCAM x CD3 bispecific antibodies have potent anti-tumor activities in vivo and have much lower toxicity compared to non-CAB bispecific antibodies. The mono- and dual-CAB EpCAM x CD3 bispecific antibodies generated by the CAB technology represent a new class of potent, effective T-cell engagers with potential for increased safety margin and therapeutic index in the clinic.
Citation Format: Ana Paula G. Cugnetti, Haizhen Liu, Jing Wang, Charles Xing, Christina Wheeler, Matthew Lucas, Cathy Chang, Gerhard Frey, William Boyle, Jay Short. Novel conditionally active bispecific EpCAM x CD3 T cell engagers targeting solid tumors [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 694.
Abstract 715: Flow cytometry analysis of immune response to COVID-19 vaccine candidates using an in vitro stimulation model
Authors: Shi Xiaoshan , Bornheimer Scott J. , Saksena Suraj , Widmann Stephanie , Tyznik Aaron 
Published: July 2021

Abstract
T cell immunity is vital for the control of viral infections. Cytotoxic CD8 T cells play a crucial role in eliminating virus-infected cells while CD4 helper T cells mediate host immune responses and promote B cells to secrete antibodies. For both, T cell recognition of viral antigens in the form of short peptides presented by HLA complexes is a prerequisite for T cell activation. Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has become a global pandemic that has disrupted economies and resulted in an enormous burden on health care systems. Despite the worldwide intensive efforts on development of COVID-19 therapeutics, a safe and effective COVID-19 treatment or vaccine is not yet available. In this study, we established an in vitro stimulation system in which peripheral blood mononuclear cells were treated with putative SARS-CoV-2 immunogenic peptides. T cell immune responses were measured using different quantitative flow cytometry panels that were designed for evaluating cytokine production or identifying T cell subsets. Evaluation of host immune responses with a suite of flow cytometric panels may prove to be useful in the study of COVID-19.
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Citation Format: Xiaoshan Shi, Scott J. Bornheimer, Suraj Saksena, Stephanie Widmann, Aaron Tyznik. Flow cytometry analysis of immune response to COVID-19 vaccine candidates using an in vitro stimulation model [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 715.
Abstract 722: The hallmark of COVID-19 cancer disparities: Cellular sequelae
Authors: McGhee Eva , LI Mengtao , Lin Yi-Ling , Carr Nefertari , Njubigbo Chinelo , Sadeghi Rohun , Su-Velez Brooke , Handler Julian , Handler Adin , Okoro Judith , Afework Sebhat , Vadgama Jay 
Published: July 2021

Abstract
Coronavirus disease-19 (COVID-19). Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel coronavirus resulting in a severe threat to safety and public health. Genetic analyses suggest that SARS-COV-2 belongs to the Betacoronavirus group and Middle East respiratory syndrome coronavirus (MERS-CoV). Like most viruses, some are oncogenic, and genetic instability is involved in the initiating factor for tumor progression that is known to lead to malignancy, resulting in disease sequelae. Genomic instability is characterized by the increased rate of acquisition of alterations in the mammalian genome. These changes encompass a diverse set of biological end points including gene mutation and amplification, cellular transformation, clonal heterogeneity and delayed reproductive cell death. The loss of stability of the genome is becoming accepted as one of the most important aspects of viral induced carcinogenesis, and the numerous genetic changes associated with cancer cell implicate genomic stability as contributing to the neoplastic phenotype. The aim of this study is to analyze the influence of COVID-19 cancer related diseases and determine the epigenetic-genomic profiles in these diseases. In our experimental procedures, we will use oral epithelium cells as a model for this cancer study. We proposed a novel approach to study COVID-19-induced genetic changes with oral epithelium cells. We used these cells with COVID-19 co treatment to determine mechanisms that lead cells into crisis. Preliminary data using oral viral infected cells show that the viral infection can trigger certain gatekeeper proteins like p53 and pRB to be degraded and forcing cells to go into crises, and telomerase is turned on. In this study we will determine if COVID-19 transfected cells can follow the process using the Hayflick model, which show cells that are in crises, and some may progress to cancer. In summary, preliminary data show that viral infected cells that are none cancerous and are telomerase positive, may use a similar mechanism to send cells into crisis that turn telomerase on resulting in cellular malignancy.
Citation Format: Eva McGhee, Mengtao LI, Yi-Ling Lin, Nefertari Carr, Chinelo Njubigbo, Rohun Sadeghi, Brooke Su-Velez, Julian Handler, Adin Handler, Judith Okoro, Sebhat Afework, Jay Vadgama. The hallmark of COVID-19 cancer disparities: Cellular sequelae [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 722.
Abstract 738: Targeting metabolic vulnerabilities of endocrine resistant breast cancers using XPO1 and NAMPT inhibition
Authors: Zuo Qianying , Mogol Ayca , Imir Ozan , Landesman Yosef , Erdogan Zeynep Madak 
Published: July 2021

Abstract
Introduction: Approximately 70% of human breast cancers express estrogen receptor alpha (ERα), providing the potential for targeted endocrine therapy for patients. Unfortunately, 30-40% of ER+ patients still experience recurrence and metastasis with a 5-year relative overall survival rate of just 24%. Previously, we described metabolic changes in metastatic breast cancer cells that are driven by single therapies and the metastatic organ microenvironment. Combining selinexor (SEL), a small molecule inhibitor of exportin 1 (XPO1) approved by the FDA for treatment of some hematologic malignancies, with the current therapies used for advanced breast cancers (e.g. tamoxifen) decreased metabolic adaptations in response to individual drug treatments and prevented colony formation in hydrogels and tumor growth in xenograft models. Since we observed a reliance on NAD+ metabolism in cancer cells that are treated with single therapies, in the current study we investigated co-targeting metabolic alterations using SEL and the NAMPT inhibitor KPT-9274.
Methods: We established 3D cell culture systems in novel hydrogels derived from decellularized bone, lung, and liver tissues - the major sites of metastasis of ER+ breast cancers, and compared with standard Matrigel culture. Endocrine responsive (MCF7 and T47D) and resistant (MCF7 and T47D cells with ESR1 Y537S or D538G mutations) breast cancer cell lines were treated with SEL or KPT-9274. Tumorigenicity was assessed using in vitro cell viability and colony formation assays and in vivo breast cancer cell line xenografts in athymic mice. Metabolic changes were assessed using whole metabolite profiling by GC-MS and a Seahorse XF analyzer.
Results: Combining an FDA-approved XPO1 small molecule inhibitor, Selinexor (SEL) with the NAMPT inhibitors decreased metabolic adaptations in response to individual drug treatments, and prevented colony formation in hydrogels and tumor growth in xenograft models.
Conclusions: Targeting drug and metastatic-site induced adaptations to regenerate new vulnerabilities in endocrine-resistant breast tumors are novel. Given the need for better strategies for improving therapy response of metastatic ER+ tumors, our findings show uncovering the role XPO1-NAMPT crosstalk plays in metastatic breast cancer could lead to new combined therapies that reduce mortality.
Citation Format: Qianying Zuo, Ayca Mogol, Ozan Imir, Yosef Landesman, Zeynep Madak Erdogan. Targeting metabolic vulnerabilities of endocrine resistant breast cancers using XPO1 and NAMPT inhibition [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 738.
Abstract 743: Altered ER and PR transcription factor activity associated with endocrine therapy resistance in breast cancer
Authors: Huggins Rosemary J. 
Published: July 2021

Abstract
Half of estrogen receptor (ERα)-positive breast cancer patients treated with endocrine therapies display intrinsic or acquired therapy resistance. One-third of patients with acquired resistance present with metastatic tumors containing ERα-Y537S mutations. This mutation results in constitutive activity of ERα and altered ERα-associated gene expression. Previous research suggests that ERα and the progesterone receptor (PR) engage in complex interactions involving reciprocal regulation of ERα and PR transcription factor activity known as ERα/PR crosstalk. My central hypothesis is that ERα-Y537S alters the transcription factor activity of ERα and PR, causing dysregulation of gene expression in SERM-resistant breast cancer. While previous research has assessed the impact of the ERα-Y537S mutation on ERα-associated chromatin binding and gene expression, here I assess the effect of the resistance-associated ERα-Y537S mutation on ERα and PR activity and crosstalk. Simultaneous analysis of transcription factor binding activity (ChIP-seq), gene expression (RNA-seq), and proximity-based interaction (NanoBRET) indicates that active PR binding across the genome is increased in the context of ERα-Y537S, suggesting that ERα/PR crosstalk is significantly altered. Importantly, PR chromatin binding in the context of ERα-Y537S appears to be elevated regardless of the stimulation of PR activity with the agonist R5020. These findings, along with identification of candidate genes of potential therapeutic value, will be applied using patient-derived tumor organoids to determine the efficacy of simultaneously targeting ERα and PR to overcome endocrine therapy resistance in breast cancer.
Citation Format: Rosemary J. Huggins. Altered ER and PR transcription factor activity associated with endocrine therapy resistance in breast cancer [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 743.