bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3146: EGFL6 induces immunosuppressive functions of tumor-associated myeloid cells and mediates resistance to anti-PDL1 therapy
Authors: Sinno Sarah , Bai Shoumei , Coronnello Claudia , Vlad Anda , Buckanovich Ronald J. , Cascio Sandra 
Published: June 2022

Abstract
Myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) are critical negative regulators of immunity in cancer. Understanding factors which regulate these cells could result in the identification of new approaches to enhance anti-tumor immunotherapy. One such factor is Epidermal growth factor-like 6 (EGFL6). EGFL6 is a secreted factor known to promote cancer stem like cell migration and regulate cancer cell differentiation. Similarly, EGFL6 promotes endothelial cell migration and proliferation. Indicating a potential role for EGFL6 as a myeloid cell regulatory factor, we found that mice which overexpress Egfl6 have an increased numbers of granulocytes and monocytes in both the bone marrow and spleen. In vitro and ex-vivo analysis indicated that EGFL6, via binding with beta integrins and activation of Syk/ERK signaling, (i) acts as a chemotactic factor for human myeloid cells migration and (ii) promotes their differentiation toward a suppressive state. Suggesting an important role in promoting an immunosuppressive tumor microenvironment (TME), using two syngeneic mouse models of ovarian cancer, we found that expression of Egfl6 in tumor cells resulted in increased accumulation of intra-tumoral MDSCs and TAMs and fewer cytotoxic CD8+ T cells. This was associated with increased tumor growth and shortened animal survival. Gene expression profiling and flow cytometry analysis of tumor infiltrating myeloid cells indicated that Egfl6 induced the expression of immunosuppressive factors, including CXCL2, IL-10 and PD-L1. Consistent with Egfl6 driving an immune suppressive TME, EGFL6 expression in an otherwise immune ‘hot’/anti-PD-L1 responsive tumor model completely inhibited response to anti-PD-L-1 therapy. We are currently evaluating the impact of Egfl6 neutralizing antibody on the efficacy of ICI therapy and anti-tumor immunity. Combined our data show that EGFL6 acts as a chemotactic factor to both recruit myeloid cells to the ovarian TME and subsequently promotes their differentiation to an immunosuppressive phenotype. This suggests EGFL6 is a potential novel therapeutic target to ovarian tumor mediated immunosuppression and enhance response to immune therapy in ovarian cancer patients.
Citation Format: Sarah Sinno, Shoumei Bai, Claudia Coronnello, Anda Vlad, Ronald J. Buckanovich, Sandra Cascio. EGFL6 induces immunosuppressive functions of tumor-associated myeloid cells and mediates resistance to anti-PDL1 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 3146.
Abstract 3158: Defining the mechanisms that lead to mutational heterogeneity in the normal respiratory epithelium
Authors: Gowers Kate H. , Clarke Sarah E. , Syaraf Ayu Hutami , Yoshida Kenichi , Przybilla Moritz J. , Selway Hugh , Pennycuick Adam , Campbell Peter J. , Janes Sam M. 
Published: June 2022

Abstract
It is well established that tobacco smoking causes lung cancer and this is thought to be the result of a progressive accumulation of genomic mutations induced by tobacco smoke exposure; however, until recently a detailed understanding of the effects of smoke exposure on the genomes of cells in the normal bronchial epithelium was lacking.
To address this, we defined the genomic architecture of normal airway basal cells in children and non-smoking, smoking and ex-smoking adults. We discovered two populations of basal cells in individuals with a smoking history: those with high mutational burden, driver gene mutations and tobacco-associated mutational signatures, and those with low mutational burden, similar to basal cells from never smokers and with an absence of mutational signatures associated with tobacco exposure. These cells expand preferentially in ex-smokers, accounting for 20-40% of basal cells compared with 2-5% in current smokers. We hypothesise that these cells are cancer-protective and their expansion reduces the risk of lung cancer development after smoking cessation.
Understanding the functional differences between high- and low-mutant airway basal cells and the mechanisms by which some cells resist the accumulation of smoking-induced mutations will be crucial to understanding the earliest stages of lung carcinogenesis.
To address this, we performed RNAseq on a subset of whole-genome sequenced airway basal cells. Preliminary data show that expression of markers of stemness is significantly different between high- and low-mutant basal cells. In addition, initial analysis shows that pathways such as carcinogen metabolism and MHC class I antigen presentation are higher in high-mutant basal cells. Further analysis in more patients is ongoing. To complement these data, we expanded whole-genome sequenced basal cell clones in culture and performed a range of assays to assess their progenitor and differentiation capacity. We assessed proliferation, colony-forming efficiency, longevity and differentiation and found no apparent differences between low- and high-mutant basal cells.
Initial analysis suggests that carcinogen metabolism and MHC class I antigen presentation may be key pathways in establishing heterogeneity in mutational burden and clonal dynamics in the normal airway epithelium. Additional assays and analysis are ongoing and will be the focus of future research.
Citation Format: Kate H. Gowers, Sarah E. Clarke, Ayu Hutami Syaraf, Kenichi Yoshida, Moritz J. Przybilla, Hugh Selway, Adam Pennycuick, Peter J. Campbell, Sam M. Janes. Defining the mechanisms that lead to mutational heterogeneity in the normal respiratory epithelium [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 3158.
Abstract 3162: Macrophage-derived C/EBPb regulates adult mammary gland homeostasis
Authors: Rojo Michelle D. , Burke Caitlin M. , Dow Alexa M. , Schwertfeger Kathryn L. , Machado Heather L. 
Published: June 2022

Abstract
Throughout mammary gland development, there are distinct stages that are “hot spots” of breast cancer risk. During these critical windows, tissue resident macrophages function to maintain the homeostatic balance within the stromal microenvironment and the ductal epithelium, and alterations in these interactions disrupt tissue homeostasis and impact breast cancer risk. However, the signaling and mechanisms by which macrophages regulate mammary gland homeostasis are poorly understood. Our recent studies (and others) have identified transcriptional profiles of distinct tissue resident macrophage subpopulations in the mammary gland. We found that Cebpb, a transcription factor important for myeloid cell differentiation and mammary gland development, is highly expressed in Cx3cr1+ ductal macrophages and localizes to macrophages in close contact with the epithelial ducts. Genetic ablation of C/EBPβ in CSF1R-expressing macrophages results in deficient alveolar budding during diestrus, while branching morphogenesis was normal. Interestingly, this phenotype is also seen in macrophage null models and suggests that C/EBPβ in macrophages plays a crucial role in signaling to the mammary epithelium. Analysis of serum hormone levels show that circulating estrogen and progesterone levels are not changed in CebpbΔMφ mice, however, the number of progesterone receptor (PR)-expressing cells are significantly increased in the ductal epithelium, suggesting altered local progesterone signaling. Further examination of the mammary epithelium shows alterations in a number of Wnt family members, including Wnt1, Wnt2b, Wnt3a and Axin2, indicative of decreased canonical Wnt signaling. Importantly, canonical Wnt signaling has been shown to be critical for regulating mammary stem cell expansion during diestrous budding. Analysis of the C/EBPβ-null macrophages show decreased expression of TGFβ, which is known to signal to basal epithelial stem cells to induce Wnt expression. Finally, other signals, such as Notch 2, which have important roles in the mammary gland development are altered. Ongoing studies are aimed at delineating how macrophage-derived C/EBPβ facilitates mammary stem cell function during the estrous cycle in a progesterone-independent manner. The results of these studies will have critical implications for understanding how the signaling between macrophages and the ductal epithelium regulate tissue homeostasis and the inherent dysregulations that lead to tumorigenesis.
Citation Format: Michelle D. Rojo, Caitlin M. Burke, Alexa M. Dow, Kathryn L. Schwertfeger, Heather L. Machado. Macrophage-derived C/EBPb regulates adult mammary gland homeostasis [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 3162.
Abstract 317: Isolation of highly selective antibodies against claudin 18.2 for the treatment of solid tumors
Authors: Screnci Brad , Barnes Trevor , Shema Kristen , Rimkunas Rebecca , Kannan Shruthi , Phillips Tim , Navia Carmen , Azuelos Charles , Charpentier Tom , Houtmann Jennifer , Miller Lisa , Stafford Lewis J. , Doranz Benjamin J. , Rucker Joseph B. , Chambers Ross 
Published: June 2022

Abstract
Monoclonal antibodies (MAbs) are a well-established treatment approach in oncology and other diseases. Nevertheless, many multipass membrane proteins are largely inaccessible as antibody targets due to their poor expression, membrane-dependent structure, small extracellular regions, and high sequence conservation between humans and rodents. Integral Molecular’s MPS Antibody Discovery platform specifically addresses each of these challenges. A key enabling feature of MPS is the use of chickens as an evolutionarily divergent host species for immunization, allowing a more robust immune response for targets that are highly conserved in mammals. We will present on antibodies isolated against challenging membrane protein targets in oncology including Claudin 18.2 (CLDN18.2).CLDN18.2 is a transmembrane adhesion protein undetectable in most adult healthy tissues but highly expressed in gastric, pancreatic, esophageal, and lung cancers. Antibody discovery efforts against this validated target are challenging due to the abundant expression of the splice isoform CLDN18.1 differing by only 8 amino acids in the extracellular domain. As part of the MPS platform, we used virus-like particles (Lipoparticles) to immunize chickens with a high concentration of native CLDN18.2 protein and obtain high-titer immune responses. This enabled us to generate and isolate a large and diverse collection of MAbs (48 unique clones) and select candidates for optimization. We present a panel of three highly specific, humanized CLDN18.2 MAbs with picomolar affinities that are superior to the clinical-stage benchmark. We will show in-depth profiling data for the MAb panel that were used for lead selection and de-risking clinical development. These data include biosensor binding kinetics, amino-acid resolution epitope mapping, and specificity testing against the Membrane Proteome Array (MPA) consisting of 6,000 membrane proteins. This panel of preclinical antibodies are being developed for therapeutic use in various formats, including bispecifics, antibody-drug conjugates, and CAR-T applications.
Citation Format: Brad Screnci, Trevor Barnes, Kristen Shema, Rebecca Rimkunas, Shruthi Kannan, Tim Phillips, Carmen Navia, Charles Azuelos, Tom Charpentier, Jennifer Houtmann, Lisa Miller, Lewis J. Stafford, Benjamin J. Doranz, Joseph B. Rucker, Ross Chambers. Isolation of highly selective antibodies against claudin 18.2 for the treatment of solid tumors [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 317.
Abstract 3188: Modulating UGDH expression in ovarian cancer tumor-initiating cells alters the tumor microenvironment
Authors: Harrington Brittney S. , Kamdar Rahul , Wong Nathan , House Carrie D. , Annunziata Christina M. 
Published: June 2022

Abstract
Epithelial ovarian cancer (EOC) is a global health burden, with the poorest five-year survival rate of the gynecological malignancies due to diagnosis at advanced stage and high recurrence rate. Recurrence in EOC is driven by the survival of chemoresistant, stem-like tumor-initiating cells (TICs) that are supported by a complex extracellular matrix (ECM) and immunosuppressive microenvironment. To target TICs to prevent recurrence, we identified genes critical for TIC viability from a whole genome siRNA screen. A top hit was the cancer-associated, ECM synthesis enzyme UDP-glucose dehydrogenase (UGDH). Immunohistochemistry was used to delineate UGDH expression in histological and molecular subtypes of EOC. Clustering analysis was performed to characterize EOC cell lines to aligned to the molecular subtypes observed in tumors. UGDH expression was modulated in the cell lines using inducible shRNA, and the effects on TICs and on the cells in the supporting microenvironment were examined. High UGDH expression was observed in the majority of high-grade serous ovarian cancers and variable expression was observed in clear cell, mucinous and endometrioid histotypes. A distinctive survival prognostic for UGDH expression was revealed when serous cancers were stratified by molecular subtype, where high UGDH was associated with a poor prognosis in the mesenchymal subtype. Using OV90 as a representative cell line for the mesenchymal subtype, we examined the effect of UGDH knockdown on the tumor cells alone, and on mesothelial support cells in co-culture with the tumor cells. Knock down of UGDH in the OV90 cells reduced the viability, sphere-formation and colony formation capacity of TICs and reduced extracellular hyaluronan production. Knocking down UGDH in the tumors affected the mesothelial cells in co-culture by significantly reducing the expression of ECM signaling and remodeling proteins Versican, Vitronectin, Laminin and matrix metalloprotease 1. These data show that modulation of UGDH expression in tumors influences cells in the microenvironment and reveal a distinct role for UGDH in the mesenchymal molecular subtype of EOC. UGDH is a strong prospective therapeutic target in TICs, for the treatment of metastatic and recurrent EOC, particularly in patients with the mesenchymal molecular subtype.
Citation Format: Brittney S. Harrington, Rahul Kamdar, Nathan Wong, Carrie D. House, Christina M. Annunziata. Modulating UGDH expression in ovarian cancer tumor-initiating cells alters the tumor microenvironment [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 3188.
Abstract 3194: Cancer-associated fibroblast heterogeneity in neuroblastoma
Authors: Peterson Nicolas B. , Thomas Paul G. 
Published: June 2022

Abstract
Extracellular matrix (ECM) remodeling is a critical process within the solid tumor microenvironment. Cancer associated fibroblasts (CAFs) are the primary producers of matrix proteins and remodeling enzymes that cross-link and degrade matrix proteins. CAFs are enigmatic in that they can promote or impede tumor growth, suggesting heterogeneity that is not completely understood. How CAF heterogeneity evolves over tumor progression and how this evolution impacts ECM remodeling within solid tumors remain an outstanding question across cancer models. Recent studies have focused on CAF function in models of adult cancer, but little attention has been directed toward understanding CAF heterogeneity and ECM remodeling in childhood cancers, which are etiologically different diseases. Neuroblastoma (NB) is a childhood cancer of neuroendocrine cells that accounts for 15% of pediatric cancer deaths. Like other solid tumors, the NB tumor microenvironment includes malignant cells, CAFs, and immune cells. Our laboratory studies NB using a penetrant, spontaneous model of NB (TH-MYCN, AlkF1178L/+) in immunocompetent mice, allowing in vivo investigation of the tumor immune microenvironment from tumorigenesis to progressive disease. Using this model, we previously demonstrated the pro-tumorigenic role of macrophages and CD4+ T cells by showing that their depletion significantly reduced the formation of tumors and extended survival. In this study, 10X Chromium gene expression analysis of stromal cells from nascent and mature tumors identified two distinct subsets of CAFs characterized by alpha smooth muscle actin (Acta2) and Wilms tumor 1 (Wt1) expression. Interestingly, only Wt1 CAFs expressed chemokines and cytokines involved in recruitment of myeloid and T cells. Wt1 CAFs were enriched in the early tumor microenvironment and expressed genes encoding ADAMTS enzymes involved in degradation of the proteoglycan versican. Our preliminary findings indicate that Wt1 CAFs may be a crucial early recruiter of pro-tumorigenic immune cells in our model of neuroblastoma.
Citation Format: Nicolas B. Peterson, Paul G. Thomas. Cancer-associated fibroblast heterogeneity in neuroblastoma [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 3194.
Abstract 3200: Examining the role of obesity and leptin signaling in triple negative breast cancer
Authors: Brock Courtney , Wright Maryl , Nguyen Khoa , Hebert Katherine , Alzoubi Madlin , Cheng Thomas , Collins-Burow Bridgette , Burow Matthew 
Published: June 2022

Abstract
Individuals with a high body mass index (BMI) have an increased risk of developing many adult cancers, including breast cancer. In triple negative breast cancer (TNBC), a clinically aggressive subtype of breast cancer, increased BMI is associated with more aggressive tumor types and a higher risk of recurrence. The differences in outcomes between obese and non-obese breast cancer patients is a consequence of the complex interplay between social, environmental, and physiological factors that contribute to the etiology of breast cancer. Therefore, understanding the complex signaling events in the obese tumor microenvironment is essential. Adipose stem cells (ASCs) are a component of the breast microenvironment, and are a subset of mesenchymal stem cells. ASCs from obese patients (obASCs) secrete higher levels various cytokines and adipokines that induce a more invasive phenotype in triple negative breast cancer cells compared to ASCs from lean individuals. Leptin, an adipokine that is expressed proportionally to fat mass, has been implicated in many cancers. Increased leptin and leptin receptor expression is associated with worse prognosis. This study seeks to examine the role of leptin signaling in triple negative breast cancer.
Previous work in conjunction with a collaborating lab has shown that leptin signaling promotes metastasis and increased expression of epithelial-mesenchymal transition (EMT) markers in triple negative breast cancer. This project expands upon this work through using both patient-derived cell lines and and patient-derived xenografts (PDX), and examines the role of leptin signaling both in vitro and in vivo. To determine the effects of obesity upon a PDX model, a high fat diet was used to induce obesity in vivo. Exposure to conditioned media harvested from obASCs increased the percentage of TNBC cells that expressed cancer stem cell markers, whereas exposure to a small peptide antagonist of the leptin receptor decreased the percentage of cells with CSC markers. PDX tumors implanted into diet-induced obesity mice had an increased volume compared to tumors implanted into lean controls. Conclusions: These molecular differences may contribute to the differences in cancer outcomes between obese and lean individuals with breast cancer, and further study of the crosstalk between obASCs and TNBC is critical.
Citation Format: Courtney Brock, Maryl Wright, Khoa Nguyen, Katherine Hebert, Madlin Alzoubi, Thomas Cheng, Bridgette Collins-Burow, Matthew Burow. Examining the role of obesity and leptin signaling in triple negative breast 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 3200.
Abstract 3206: Three-dimensional tumor angiogenesis mapping in metastatic gastric cancer patients
Authors: Ko Jihoon , Hyung Sujin , An Minae , Jeon Noo Li , Lee Jeeyun 
Published: June 2022

Abstract
Background: Patients with gastric cancer (GC) develop malignant ascites as the disease progresses due to peritoneal metastasis. The presence of malignant ascites is a critical prognostic sign of tumor progression. With an understanding of these patient subsets, better optimized treatment strategies are needed.
Method: We analyzed whole exome and transcriptome sequences of ascites or primary tumor samples obtained from 46 patients with advanced gastric cancer. In addition, we engineered a microfluidic-based gastric cancer patient-on-a-chip (GRASP) to develop a tumor-induced patient-specific angiogenesis model and evaluate the ramucirumab responses.
Results: Through single-cell sequencing, 46 patients were classified into two groups according to the level of KDR gene (VEGFR2) expression. (high KDR, N=25; low KDR, N=21) In the group with high VEGFR2 expression, 68% (17 of 25) samples were from ascites, and all samples with low KDR were from primary tumors. In the GRASP system, the quantitative results of random co-culture of PDCs from 46 patients with blood vessels demonstrated high concordances to the sequence results. In addition, the angiogenesis inhibitory effect of Ramucirumab was also high in the KDR high group.
Conclusion: Understanding angiogenesis inhibition as part of a therapeutic strategy considering tumor microenvironment has important clinical implications. It would be a significant outcome for our analysis system to bring therapeutic benefits to GC patients.
Citation Format: Jihoon Ko, Sujin Hyung, Minae An, Noo Li Jeon, Jeeyun Lee. Three-dimensional tumor angiogenesis mapping in metastatic gastric cancer patients [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 3206.