bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1384: Immunopeptidome analysis of mouse MHC Class I
Authors: Nyayapathy Seeta , Jones Richard , Ford Michael , Pisano Michael , Rumble Julie M. 
Published: June 2022

Abstract
MHC class I is required for antigen presentation to CD8 T cells. These cell-surface proteins are heterodimers consisting of a variable alpha chain associated with β2 microglobulin and are expressed on nucleated cells at varying levels. The antigen specificity of the interaction between MHC, peptide and T cell receptor can be exploited in development of personalized cancer vaccines and other immunotherapies against cancer. MHC sequences are species-specific and there are many different haplotypes of MHC class I. For this reason, the antibodies used for immunoprecipitation of MHC complexes are a critical component of the workflow for identification of antigens presented by MHC. Subclasses of mouse MHC class I are divided into classical (H-2D, H-2K and H-2L) and non-classical (H-2Q, H-2M and H-2T), and haplotypes of each are known for homozygous inbred laboratory strains of mice. One common strain is C57BL/6, which expresses H2-Db and H2-Kb classical MHC molecules. Antibody clone M1/42, which reacts with H-2 expressed on nucleated cells from mice of a, b, d, j, k, s and u haplotypes, is commonly referred to as a pan-MHC class I antibody. Antibody clones Y-3 and HB-27 recognize H2-Kb and H2-Db haplotypes, respectively. In this study we aimed to compare different antibodies to mouse MHC class I complexes for their efficiency of recovery of associated peptides. Input was murine EL-4 cells which are T lymphoblast cells derived from a C57BL/6 background. We performed immunoprecipitation with different antibodies either singly or sequentially to enrich MHC class I, followed by gentle elution of associated peptides and finally peptide analysis by mass spectrometry. Each immunoprecipitation workflow yielded a different (but overlapping) cohort of peptides, suggesting optimal methodologies for analyses of immunopeptidomes from common laboratory mouse strains.
Citation Format: Seeta Nyayapathy, Richard Jones, Michael Ford, Michael Pisano, Julie M. Rumble. Immunopeptidome analysis of mouse MHC Class I [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1384.
Abstract 1400: AS-1763: a highly potent, noncovalent and next generation BTK inhibitor for the treatment of patients with B-cell malignancies having C481S mutation in BTK
Authors: Kawahata Wataru , Asami Tokiko , Kiyoi Takao , Irie Takayuki , Kashimoto Shigeki , Furuichi Hatsuo , Sawa Masaaki 
Published: June 2022

Abstract
Introduction: Bruton's tyrosine kinase (BTK) has been recently recognized as a validated drug target for the treatment of B-cell malignances. The emergence of clinical resistance to the first-generation covalent BTK inhibitors is, however, becoming a serious concern. Patients are reported to develop resistance during the treatment due to substitution of cysteine residue at position 481 with serine (C481S mutation) in BTK, which prevents the covalent binding of the first-generation irreversible BTK inhibitors, resulting in the loss of inhibitory activities. Therefore, there is a high unmet medical need for new therapeutic approaches to overcome the BTK C481S-mediated resistance.
Material and methods: Compounds were tested in biochemical assays using recombinant human wildtype (WT) and C481S mutant BTKs. Cellular activity of AS-1763 was evaluated in human diffuse large B cell lymphoma (DLBCL) cell lines, OCI-Ly10 and its BTK[C481S] knock-in cells. The in vivo antitumor activity of AS-1763 was assessed in two tumor xenograft mouse models bearing WT or BTK [C481S] knock-in OCI-Ly10 cells.
Results: We have discovered AS-1763 as an orally available, highly potent, selective and reversible BTK inhibitor. AS-1763 showed potent inhibitory activities for WT BTK (an activated form, BTK[A]) and the C481S mutant with sub-nanomolar IC50s (IC50 = 0.85 and 0.99 nM for BTK[A] and BTK[C481S], respectively). In cellular assays, AS-1763 exhibited strong antiproliferative activities for WT and BTK [C481S] knock-in OCI-Ly10 cells. AS-1763 demonstrated significant tumor growth inhibition and tumor regression in WT as well as BTK[C481S] knock-in OCI-Ly10 xenograft model.
Conclusions: The preclinical data support the clinical development of AS-1763 in patients with B-cell malignancies both having WT and C481S mutation in BTK. The first-in-human Phase 1 clinical trial of AS-1763 in healthy volunteers (EudraCT 2020-005599-37) is currently ongoing, and the Phase 1b study in patients is expected to begin in 2022.
Citation Format: Wataru Kawahata, Tokiko Asami, Takao Kiyoi, Takayuki Irie, Shigeki Kashimoto, Hatsuo Furuichi, Masaaki Sawa. AS-1763: a highly potent, noncovalent and next generation BTK inhibitor for the treatment of patients with B-cell malignancies having C481S mutation in BTK [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1400.
Abstract 1422: A novel agonist of CD137 shows immunoprevention efficacy against various tumors by invoking an innate immune surveillance mechanism
Authors: Shirwan Haval , Batra Lalit , Li Qingsheng , Malik Mohammad T. , Shrestha Pradeep , Egilmez Nejat , Yolcu Esma S. 
Published: June 2022

Abstract
Introduction: Immune checkpoints have been the focus of intense research due to their critical roles in regulating immune responses. The CD137 is an immune checkpoint stimulator has pleiotropic immune functions along with its canonical role in driving CD8+ T cell responses. Using a novel form of its natural ligand (SA-4-1BBL) as a single agent, we recently showed its robust cancer immunoprevention efficacy against various transplantable tumor types in mice. In this study, we report its efficacy in a spontaneous tumor model and elucidate the mechanistic basis of prevention.
Study design: Mice were treated subcutaneously with SA-4-1BBL protein twice, two weeks apart, and challenged with various tumor types 1-14 weeks later. Animals were monitored for tumor growth. The LSL-KrasG12D mice, as a model of spontaneous lung cancer, were intranasally infected with 2.5 × 107 PFUs of adenoviral-cre to induce cancer. Animals were treated with SA-4-1BBL twice, two weeks apart, pre or post-infection with adeno and euthanized at various times to collect the lung and lymphoid tissues for histopathology and flow cytometry.
Results: Pretreatment with SA-4-1BBL was effective in preventing the growth of various transplantable tumors, B16-F10 melanoma, 3LL lung cancer, A20 lymphoma, 4T1 breast cancer, in different mouse strains. Treatment with SA-4-1BBL induced a window of protection against tumors that lasted over 14 weeks. SA-4-1BBL treatment significantly reduced the lung tumor burden in LSL-KrasG12D mice that was associated with increased absolute numbers of CD137+CD4+CD44hi T cells and CD137+NKG2D+NK cells expressing IFN-γ and TNF-α. A blocking antibody to NKG2D reversed the immunopreventive efficacy of SA-4-1BBL in the 3LL and B16-F10 tumor models, providing direct evidence for the role of this receptor in cancer immunoprevention. Gamma/delta T cells did not play a role in the cancer prevention efficacy of SA-4-1BBL as mice lacking these cells showed protection.
Conclusions: These results demonstrate that SA-4-1BBL invokes an innate immune surveillance mechanism orchestrated by cross-communication between memory-like CD4+ T cells and NK cells with long-term protection against various tumor types. Funded in parts by NIH R41CA199956, T32HL134644, NCI R25CA134283, and Kentucky KSTC-184-512-16-237 awards.
Citation Format: Haval Shirwan, Lalit Batra, Qingsheng Li, Mohammad T. Malik, Pradeep Shrestha, Nejat Egilmez, Esma S. Yolcu. A novel agonist of CD137 shows immunoprevention efficacy against various tumors by invoking an innate immune surveillance mechanism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1422.
Abstract 1423: NKX3.1 expression predicts response to metformin intervention in prostate cancer
Authors: Papachristodoulou Alexandros , Dutta Aditya , Abate-Shen Cory 
Published: June 2022

Abstract
The goal of precision prevention is to tailor interventions based on individualized patient cancer risk and likelihood of progression. This approach is particularly relevant for prostate cancer since it is characteristically indolent, and thus delaying disease progression can be highly advantageous for patients. Therefore, identifying molecular features predictive of cancer progression and response to specific interventions is vital to improve precision prevention in prostate cancer. In this regard, expression levels and localization of the tissue-specific homeobox protein, NKX3.1, helps distinguish men with high risk for developing more aggressive prostate cancer. Our recent study revealed a novel function for NKX3.1 in mitochondria, where it regulates aberrant mitochondrial oxidative stress to suppress prostate cancer initiation. Lower NKX3.1 expression levels at gene and protein levels are associated with poor outcome and higher risk for aggressive prostate cancer. We are now investigating the role of NKX3.1 as a prognostic marker and potential target for prostate cancer precision prevention interventions. Our new preliminary data indicate a role for metformin as a preventative intervention in contexts of reduced NKX3.1. Specifically, we have shown that metformin reduces oxidative stress and suppresses cancer initiation in the prostates of Nkx3.1 mutant mice. Moreover, studies in human prostate cancer cells as well as human prostate cancer organotypic assays revealed that metformin can indeed, restore mitochondrial function and inhibit tumorigenicity in the absence of NKX3.1. Although men on active surveillance for prostate cancer may benefit from metformin intervention, it has been unclear whether metformin is effective in delaying disease progression and, if so, whether specific patients are more likely to benefit. Our new data implicate NKX3.1 status as a predictor of response to metformin, suggesting that it can stratify high-risk prostate cancer patients most likely to benefit from such intervention during active surveillance.
Citation Format: Alexandros Papachristodoulou, Aditya Dutta, Cory Abate-Shen. NKX3.1 expression predicts response to metformin intervention in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1423.
Abstract 1431: ADO contributes to tumour initiating phenotypes
Authors: Lee Sandy Che-Eun Serena , Pyo Andrea Hye An , Koritzinsky Marianne 
Published: June 2022

Abstract
2-aminoethanethiol dioxygenase (ADO) is a thiol dioxygenase that plays a role in both metabolism and protein stability. ADO directly metabolizes cysteamine to produce hypotaurine and taurine in mammals. ADO has also been recently identified to promote oxygen dependent stability of a subset of substrates involved in the N-degron pathway in mammals (IL32, RGS4 and RGS5). The ability of ADO to target protein stability of signaling molecules suggests that it may have the potential to transduce rapid responses to hypoxia and affect tumour initiation and progression phenotypes. Here, we have successfully knocked down and knocked out ADO using two independent siRNAs and clustered regularly interspaced short palindromic repeats associated protein 9 (CRISPR-Cas9) system, respectively. We have assessed proliferation and migration through the Incucyte® ZOOM system by imaging cell confluency over time. Survival was assessed through a clonogenic assay. siRNA mediated knockdown of ADO in cervical (HeLa and SiHa), pancreatic (Panc1 and Capan2) and liver (SNU499 and Huh6) cancer cell lines drastically reduced proliferation, survival, and migration in normoxia. These results were also replicated in hypoxia (0.2% O2) across all 6 cell lines. Out of the 6 cell lines, the liver cancer cell lines were most drastically affected by the knockdown of ADO. This phenotype was replicated in the ADO KO cell lines. Taken together, these data suggest that expression of ADO may contribute to phenotypes that induce aggressive tumour phenotypes by targeting the stability of specific proteins and altering cellular metabolism in mammals.
Citation Format: Sandy Che-Eun Serena Lee, Andrea Hye An Pyo, Marianne Koritzinsky. ADO contributes to tumour initiating phenotypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1431.
Abstract 1464: Zaniya Mark
Authors: Mark Zaniya A. , Li Guoliang , Matusik Robert , Chen Zhenbang 
Published: June 2022

Abstract
Prostate cancer (PCa) is one of the most common types of cancers diagnosed in American men. Moreover, PCa malignancy disproportionally strikes more on African American (AA) men than any other ethnic groups including Caucasian American (CA) men. Forkhead Box A1 (FOXA1) is frequently mutated in hormone receptor-driven cancers including PCa. FOXA1 mutation rates in AA PCa specimens are 3-fold higher than that in CA PCa. By annotating the FOXA1 mutation landscape two hotspots were defined in AA PCa patients located in the forkhead domain: D226N and R219C. FOXA1 expression and functions are regulated by lysine [K]-specific demethylase 5B (KDM5B). KDM5B contributes to the activation of signaling pathways that promote cancer progression. Here in this project, we will focus on the mechanistic role of FOXA1 dysregulation and its interaction with KDM5B and AR on PCa progression in AA vs CA PCa cells. Therefore, we hypothesize that the dysregulation of FOXA1 plays an essential role in the progression of PCa by altering chromatin remodeling and AR interaction, and FOXA1 mutation promotes more aggressive malignancies in AA PCa cells. In order to investigate the biological function and regulation of FOXA1 in PCa cells we first need to knockout (KO) the endogenous expression using CRISPR technology and then knockin (KI) the unique mutants R219C and D226N. These in vitro studies of FOXA1 mutations found in AA PCa will be critical to determine the biological functions of these mutants for PCa progression. The findings from this study will provide valuable insights into the contributions of the FOXA1 regulation and will add to our knowledge base for the potential development of a novel therapeutic strategy to reduce PCa disparities between AA and CA populations. This project was supported, in part, by MVTCP Cancer Partnership Grant U54 CA163069.
Citation Format: Zaniya A. Mark, Guoliang Li, Robert Matusik, Zhenbang Chen. Zaniya Mark [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1464.
Abstract 1470: Characterization of ER receptor transcription complex using super resolution STORM microscopy
Authors: Akhshi Tara , Brown Myles 
Published: June 2022

Abstract
Steroid/thyroid hormone receptors are ligand-dependent transcription factors (TFs) that play fundamental roles in cell development and homeostasis. They bind to their DNA response elements and modulate the transcription of target genes via interaction with co-regulators termed co-activators or co-repressors. Estrogen Receptor α (ERα) is an important member of this family which is expressed in in hormone receptor positive (ER+) breast cancer, one of the leading causes of death among women. Current therapeutic options involve endocrine therapies, however despite its effectiveness, a significant number of patients eventually experience resistance to these treatments, leading to disease recurrence and relapse. One of the major hurdles to combat resistant cells, is lack of comprehensive information about ERα transcriptional complex activity. While biochemical assays have provided significant information on interaction with its coregulators, it is not clear how the dynamic between these transpire. This is while ERα is a highly dynamic protein with a fast rate of interaction with coregulators and cycling between chromatin, nucleus, and cytosol. Consequently, it is critical to imply techniques that allow direct visualization of ERα activity and gain spatiotemporal information on its regulation. One of the major limitations to conduct such studies was due to the resolution limits inherited with light microscopes. However, the emerge of super resolution microscopes, offers a promising tool to overcome this challenge. Here, we imply super resolution microscopy to examine the mechanism of ERα transcriptional activity in the presence of estrogen as well as compounds that are currently used for endocrine therapy, Tamoxifen and Fulvestrant. We determine how each of these compounds influence ERα interaction with its co-activators (P300, SRC-3), and its co-inhibitor (NCoRI), and how these interactions modulate chromatin activity. Obtaining such information of ERα dynamics is critical to map the mechanism of its activity under different treatments, and thus is key to overcome some of the hurdles faced in endocrine therapy.
Citation Format: Tara Akhshi, Myles Brown. Characterization of ER receptor transcription complex using super resolution STORM microscopy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1470.
Abstract 1494: 5-methyltetrahydrofolate (5-MTHF) as a superior ligand for delivery of small RNAs for cancer therapy
Authors: Kasireddy Sudarsan R. , Abdelaal Ahmed M. , Low Philip S. , Kasinski Andrea L. 
Published: June 2022

Abstract
MicroRNAs (miRNAs) are small noncoding RNAs that regulate a wide array of genes. Because miRNA downregulate translation proteins associated with cancer progression, miRNA-based therapeutics have great potential as anticancer drugs. Nonetheless, the therapeutic potential of miRNA replacement is limited due to lack of safe and efficient delivery vehicles, and inability to target miRNAs to the intended cells/tissues. Thus, identifying molecules that are able to deliver therapeutic miRNA is of critical need. This could be achieved by targeting receptors that are overexpressed on target tumor cells. For example, the folate receptor (FR) is overexpressed on various tumor types including breast, lung, ovarian and brain tumors. Our laboratory has previously developed a unique strategy that directly links a miRNA mimic to the high affinity FR ligand, folate (FolamiRs). In the present work, to further improve the potency of FolamiRs, we introduce the reduced folate metabolite, 5-methyltetrahydrofolate (5-MTHF) that maintains nanomolar affinity for the FR at pH 7, but disengages from the FR at a significantly higher pH than that of folate, which is important when including an endosomal escape agent that typically disrupts endosomal acidification. We synthesize and conjugate 5-MTHF ligand to the potent tumor suppressor miRNA-34a (5-MTHF-miR-34a). We show that 5-MTHF-miR-34a uptake is specific to the cells overexpressing FR and represses target gene expression. Our data supports the use of 5-MTHF in combination with the endosomal escape agent, nigericin, to achieve robust cytosolic localization of therapeutically relevant miRNAs such as miR-34a. This work provides the foundation for future studies using 5-MTHF- conjugated therapeutic agents for targeting additional FR expressing cells, including myeloid derived suppressor cells (MDSCs) and macrophages. Collectively these studies will pave the way for developing 5-MTHF-based small RNA conjugates for treating FR-expressing cancers. The details of these intriguing results will be discussed in the poster.
Citation Format: Sudarsan R. Kasireddy, Ahmed M. Abdelaal, Philip S. Low, Andrea L. Kasinski. 5-methyltetrahydrofolate (5-MTHF) as a superior ligand for delivery of small RNAs for cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1494.
Abstract 1509: Genome-wide CRISPR/Cas9 library screening identified THRAP3 as a critical driver for resistance to ATR inhibitor in sarcomas revealing synthetic lethality with ATM inhibition
Authors: Spalato Mariella , Laroche-Clary Audrey , Chaire Vanessa , Italiano Antoine 
Published: June 2022

Abstract
Background: ATR plays a crucial role in maintaining genomic integrity by responding to a large spectrum of DNA damage, including double strand breaks (DSBs) that interfere with replication. We have previously demo started that ATR inhibition is associated with anti-tumor activity in pre-clinical models of soft-tissue sarcomas (STS) (Laroche et al., 2020). We decided to investigate the mechanisms of resistance to ATR inhibition in sarcomas.
Methods: We used a CRISPRa was to identify genes that mediate resistance to AZD6738 in STS cells. The anti-tumor activity of AZD6738 (ATR inhibitor) and AZD0156 (ATM inhibitor) was investigated in a panel for 10 STS cell lines and two patient-derived xenografts (PDX) established at Institut Bergonié (Bordeaux, France).
Results: We used a CRISPR approach in a STS cell line resistant to AZD6738 and we made a negative-selection screen, to identify genes whose silencing conferred sensitivity to low doses of ATR inhibition. Among these genes, we identified THRAP3 which encodes a protein phosphorylated in response to DNA damage and primarily by ATR. THRAP3 is involved in the maturation and further export of transcripts encoding the ATM and its depletion results in deficient processing of transcripts encoding the ATM kinase. We validate the result of our CRISPR analysis by demonstrating that selective THRAP3 inhibition reduce significantly ATRi IC50. Given the role of role of THRAP3 on the regulation of ATM activity, we decided to investigate the potential synergy between ATR and ATM inhibition in vivo and in vitro. AZD6738 and AZD0156 displayed a synergistic or additive effect in above all the STS cell lines tested. We noted that ATRi treatment reduced phosphorylation of the ATR kinase target CHK1 but increased ATM phosphorylation, suggesting that ATM pathway takes over for DNA Damage Response and cells survival. In contrast, both ATR and ATM pathway were inhibited when AZD6738 and AZD0156 were used in combination, as shown by reduction of CHK1 and ATM phosphorylation. We validated our in vitro results in an in vivo model of liposarcoma xenograft in which AZD6738 and AZD0156 had synergistic anti-tumor activity.
Conclusion: Our study demonstrates synthetically lethal interactions between ATM and ATR in vitro and in vivo. This combination deserves further investigaitons in sarcomas.
Citation Format: Mariella Spalato, Audrey Laroche-Clary, Vanessa Chaire, Antoine Italiano. Genome-wide CRISPR/Cas9 library screening identified THRAP3 as a critical driver for resistance to ATR inhibitor in sarcomas revealing synthetic lethality with ATM inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1509.