bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2359: The MCPyV st-ag and IL33/ST2 axis: critical role in merkel cell carcinoma
Authors: Rasheed Kashif , Fismen Silje , Grimstad Øystein , Sveinbjørnsson Baldur , Moens Ugo Lionel 
Published: August 2019

Abstract
Merkel Cell polyomavirus (MCPyV) is a causal factor in Merkel Cell Carcinoma (MCC). The oncogenic potential is mediated through its viral oncoproteins large T-antigen (LT-ag) and small t-antigen (st-ag). Many cancers arise from sites of infection, chronic irritation and inflammation, and inflammatory signaling pathways are often activated by oncogenic mutations. Chemokines are a family of cytokines that regulate leukocyte trafficking in immunity and inflammation. The aberrant expression of chemokines and chemokine receptors in tumors may regulate the trafficking of leukocytes into the tumor microenvironment. IL33, a member of IL-1 family cytokines, is involved in the response to viral infection and plays important roles in type-2 innate immunity, tumorigenesis and tumor immune evasion.
We assessed IL33/ST2 expression in MCPyV-positive (MKL2) and –negative (MCC13) MCC cell lines in order to examine a possible role of IL33/ST2 pathway in MCC.
Using the human RT2 Profiler PCR Inflammatory Cytokines and Receptors Array, we did a PCR array analysis of 84 different human cytokines and receptor genes. Expression of IL-33 and ST2 was determined by qRT-PCR, immunohistochemistry and western-blot analysis. Luciferase analysis was done to monitor the effect of MCPyV early proteins on IL33 promoter activity and the effect of IL33 on MCPyV early and late promoter activity. Furthermore, mitogen-activated protein kinase (MAPK) and the NF-κB pathways were also assessed after stimulating MCC13 cells with recombinant human (rh) IL33 protein. Finally, proliferation activity after rhIL33 stimulation was assessed by MTT-assay.
PCR array analysis showed higher transcript levels of IL33 in MCC13 cells transfected with st-ag compared to control cells. Western blot analysis confirmed increased IL33 expression by st-ag. Luciferase analysis showed higher IL33 promoter activity in st-ag transfected MCC13 cells. Interestingly, IL33 also increased MCPyV early and late promoter activity. Furthermore, rhIL33 activated both MAPK and the NF-κB pathways and blocking ST2 receptor using polyclonal goat ST2 antibody abolished IL33 activity. Dose-dependent effect of rhIL33 showed higher proliferation activity of MCC13 cells. Immunohistochemical analysis of IL33 and ST2 showed a significant stronger expression in MCC tissues compared to normal skin.
Our study unveiled a novel st-ag dependent IL33 function in MCC. Therefore, neutralizing the IL-33/ST2 axis may thereby represent a therapeutic target in MCPyV-positive MCC patients.
Citation Format: Kashif Rasheed, Silje Fismen, Øystein Grimstad, Baldur Sveinbjørnsson, Ugo Lionel Moens. The MCPyV st-ag and IL33/ST2 axis: critical role in merkel cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2359.
Abstract 2374: Non-canonical TGF-beta signaling modulates pancreatic ductal adenocarcinoma progression
Authors: Hussain S. Mazher , Miranda-Carboni Gustavo , Alvarez Marcus A. , Elahi Abul , Hedrick Leah E. , Shibata David , Glazer Evan S. 
Published: August 2019

Abstract
Introduction: While the genomic and proteomic characterization of pancreatic ductal adenocarcinoma (PDAC) is extraordinarily complex, the transforming growth factor-beta (TGF-β) pathway is critically important. TGF-β has a context dependent role- it is tumor suppressive in early PDAC and tumor promotive in metastatic PDAC. Our hypothesis is that non-canonical TGF-β signaling induces metastatic PDAC. Non-canonical signaling may help explain the paradoxical nature of TGF-β in PDAC.
Methods: Two cell lines were utilized- Panc-1, a cell line derived from primary PDAC, was compared to Capan-1, a cell line derived from metastatic PDAC- in order to model an early PDAC (Panc-1) and a more aggressive PDAC (Capan-1). We investigated the gene and protein expression of markers of epithelial to mesenchymal transition (Snail and Twist), Akt, β-catenin, and PD-L1 upon treatment with TGF-β and the Akt inhibitor MK-2206.
Results: While TGF-β increased Snail gene and protein expression in Panc-1 cells, it had nil effect on Capan-1 cells where TWIST1 protein expression increased with TGF-β. TGF-β increased pAkt expression in both cell lines. TGF-β increased active and total β-catenin expression in Capan-1 but not Panc-1 cell lines. We then found that PD-L1 expression was generally diminished by Akt inhibition in both cell lines but this was reversed with TGF-β receptor inhibition and gemcitabine treatment in the Capan-1 cells.
Conclusions: Our data suggests that modulation of the non-canonical TGF-β pathway may lead to increased epithelial to mesenchymal transition through multiple mechanisms. PD-L1 expression is a response to chemotherapy in metastatic PDAC when multiple proteins in that pathway are inhibited. Our data suggests that (1) personalized therapy based on the degree of non-canonical TGF-β pathway activation will be critical, (2) patients with uncontrolled non-canonical TGF-β pathway activation may have lower survival, and (3) there is an opportunity to utilize anti-PD-L1 based therapy in combination with other therapy in selected patients based on their response to chemotherapy.
Citation Format: S. Mazher Hussain, Gustavo Miranda-Carboni, Marcus A. Alvarez, Abul Elahi, Leah E. Hedrick, David Shibata, Evan S. Glazer. Non-canonical TGF-beta signaling modulates pancreatic ductal adenocarcinoma progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2374.
Abstract 2379: In vivo drug screening platform accelerated 4-1BB agonistic antibody development
Authors: Yang Benny(Yi) , Ni Jian , Li Yanan , Shen Yuelei , Lin Qingcong 
Published: August 2019

Abstract
4-1BB (TNFRSF9/CD137) belongs to the TNFR superfamily. 4-1BB is expressed by activated CD4 helper T cells, B cells, natural killer cells, natural killer T cells, dendritic cells, and activated endothelium. A majority of regulatory T cells (Tregs) also express 4-1BB, but it remains unclear whether agonistic antibody treatment exerts pro- or anti-suppressive effect on these cells. 4-1BB enhances tumor rejection because it is upregulated on T cells following activation and its engagement increases T cell proliferation and pro-inflammatory cytokine production. The clinical development of 4-1BB targeting therapy was slow due to the toxicity associated with overt immune activation. Fortunately, new therapeutic modalities using 4-1BB targeting aptamers as well as therapeutic combinations with other immuno-modulatory and traditional anti-cancer treatments have revived excitement for the use of 4-1BB agonists in the clinic.
We focused on discovering novel 4-1BB therapeutic antibodies for cancer patients. Candidate molecules obtained through the classical hybridoma technology were screened by high-throughput flow cytometry. Then, we took the advantages of Biocytogen’s humanized mice and screened the purified antibodies in B-h4-1BB mice bearing MC-38 tumor cells. We found some antibodies that worked as equivalent as BMS’s Urelumab. To determine which isotype should be adopted, we engrafted the antigen binding domain onto various human Fc backbones. Interestingly, we found that the human IgG1 isotype appeared to be more effective against tumors than other isotypes in B-4-1BB mice bearing MC-38 tumors. This study provides a reliable basis for our follow-up mechanism research and clinical evaluation for this target.
Citation Format: Benny(Yi) Yang, Jian Ni, Yanan Li, Yuelei Shen, Qingcong Lin. In vivo drug screening platform accelerated 4-1BB agonistic antibody development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2379.
Abstract 2383: The molecular binding mechanism of tislelizumab, an investigational anti-PD-1 antibody, is differentiated from pembrolizumab and nivolumab
Authors: Feng Yingcai , Hong Yuan , Sun Hanzi , Zhang Bo , Wu Hongfu , Li Kang , Liu Xuesong (Mike) , Liu Ye 
Published: August 2019

Abstract
Programmed cell death protein 1 (PD-1) is an immune checkpoint receptor expressed by activated T, B, and NK cells, which interacts with its ligand PD-L1/L2 to inhibit T-cell proliferation and effector functions such as tumor cell killing and cytokine production. Two anti-PD-1 antibodies approved by the FDA, pembrolizumab and nivolumab, have shown efficacy in many cancer types, nevertheless there are some indications where limited efficacy is observed. Tislelizumab (BGB-A317), an investigational anti-PD-1 antibody, has demonstrated significant clinical activity (85.7% ORR, including 61.4% CR) in relapsed/refractory classical Hodgkin’s lymphoma (R/R cHL). Additionally, tislelizumab is being studied in global pivotal trials in a number of malignancies, including non-small cell lung cancer, hepatocellular carcinoma, and esophageal squamous cell carcinoma. However, how tislelizumab binds to PD-1 has yet to be shown, particularly in comparison to pembrolizumab and nivolumab. Here we report the co-crystal structure of PD-1 extracellular domain and the Fab of tislelizumab. Tislelizumab interacts with IgV-like domain of PD-1 with an interface area of 1112 Å2. Structure-guided mutagenesis of PD-1 and surface plasmon resonance were performed to compare the binding of tislelizumab, pembrolizumab and nivolumab to mutant and wild type PD-1. The dissociation rate (kd) of tislelizumab from wild type PD-1 is about 100-fold and 50-fold slower than that of pembrolizumab and nivolumab, respectively. Gln75, Thr76, Asp77 and Arg86 on PD-1 are critical epitopes for tislelizumab, but mutation of them showed little effect on binding of PD-1 to pembrolizumab and nivolumab. Both the co-crystal structure and mutagenesis study identified the unique epitopes of tislelizumab that correlate to the extremely slow-off property of tislelizumab after binding to PD-1. In conclusion, we observed that tislelizumab is differentiated from pembrolizumab and nivolumab by its unique binding epitopes as well as binding kinetics.
Citation Format: Yingcai Feng, Yuan Hong, Hanzi Sun, Bo Zhang, Hongfu Wu, Kang Li, Xuesong (Mike) Liu, Ye Liu. The molecular binding mechanism of tislelizumab, an investigational anti-PD-1 antibody, is differentiated from pembrolizumab and nivolumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2383.
Abstract 2385: Discovery of highly specific claudin 6 monoclonal antibodies
Authors: Stafford L Joe 
Published: August 2019

Abstract
Claudin 6 (CLDN6) is an oncofetal tight junction protein involved in the cell-to-cell adhesion of epithelial and endothelial cell sheets. Although silenced in healthy adult human tissues, CLDN6 expression has been found in ovarian, gastric, pediatric, and other cancer tissues and can lead to a poor prognosis. Monoclonal antibody (MAb) discovery against CLDN6 has been encumbered by the high homology of endogenously expressed claudin 9 (CLDN9), which varies from CLDN6 by only 3 amino acids in the extracellular domain. Our MPS Antibody Discovery platform utilizes proprietary technologies to overcome key barriers to MAb discovery, enabling the isolation of MAbs against multipass membrane proteins such as CLDN6. Using the MPS platform, we have successfully isolated and characterized panels of highly specific MAbs to CLDN6. Nine chickens were immunized with the target antigen, and titer was achieved in all but one animal. Following 2 rounds of phage panning, we screened 2,000 clones for CLDN6 specificity, identifying 788 hits and 68 unique VH CDR3 families. From these clones, 72 antibodies were selected for binding to CLDN6 and CLDN6/9. Two lead antibodies, IM-171 and IM-136, showed high specificity and high affinity to CLDN6 but not to claudins 3, 4, or 9. Using high-resolution Shotgun Mutagenesis Epitope Mapping, we confirmed that our lead candidate MAbs bind distinct residues on CLDN6 compared to previously described MAbs. Specificity analysis with our Membrane Proteome Array revealed no significant binding of either of our lead MAbs to any other membrane protein in the human proteome, including any of the other 20+ claudin proteins. Both of our lead MAbs bound endogenously expressed CLDN6 on ovarian carcinoma (PA-1) cells. Our preclinical CLDN6 antibodies are now being developed for use in various formats, including bispecifics, antibody-drug conjugates, and CAR-T applications.
Citation Format: L Joe Stafford. Discovery of highly specific claudin 6 monoclonal antibodies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2385.
Abstract 2387: NKG2A-antagonizing monoclonal antibodies identified through phage display
Authors: Gao Jing , Hu Lili , Sui Ruirui , Guo Cuicui , Wang Lina , Yang Teddy , Han Jack , Duan Qing , Liu Louis 
Published: August 2019

Abstract
The inhibitory receptor NKG2A-CD94 is mainly expressed on NK cells and some T cell and mediates an inhibitory signal through association with a non-classical MHC class I molecule HLA-E, which is commonly over-expressed in human cancers. Targeting NKG2A with monoclonal antibody holds potentials in immunotherapy of cancer. However, proteins with homologous sequences such as NKG2C/CD94 or NKG2E/CD94 complexes generally deliver an activating signal upon ligand binding. NKG2A-specific antagonizing antibodies would be needed to further explore therapeutic potentials of targeting NKG2A for immunotherapy of cancer.
We have developed and characterized panels of monoclonal antibodies (mAbs) that specifically recognize NKG2A. Balb/c or SJL mice had been immunized with recombinant NKG2A/CD94 protein, recombinant plasmids encoding hNKG2A or stable cell line with ectopic expression of hNKG2A. Splenocytes from such immunized animals were collected for construction of phage-displayed antibody library in a single chain variable fragment (scFv) format. The NKG2A-specific antibodies, that had no binding to NKG2C, NKG2E or CD94, were isolated through multiple rounds of phage panning and ELISA-based screening. Such antibodies also block HLA-E ligand binding and enhanced cytotoxicity of NK cell lines and primary NK cells on cancer cells.
In summary, isolation and characterization of a panel of NKG2A-specific antagonizing antibodies enable us to further determine the feasibility of NKG2A-targeted immunotherapy of cancer.
Citation Format: Jing Gao, Lili Hu, Ruirui Sui, Cuicui Guo, Lina Wang, Teddy Yang, Jack Han, Qing Duan, Louis Liu. NKG2A-antagonizing monoclonal antibodies identified through phage display [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2387.
Abstract 2388: In vitro assessment of tumor associated I.O. markers in cancer cell lines following Vicinium treatment
Authors: Chooniedass Shilpa , Dillon Rachelle L. , Premsukh Arjune , MacDonald Glen C. , Cizeau Jeannick , Adams Gregory P. 
Published: August 2019

Abstract
Vicinium is a fusion protein that comprises a scFv fragment specific for the Epithelial Cell Adhesion Molecule (EpCAM) genetically fused to a truncated form of Pseudomonas exotoxin A, ETA, via a flexible linker. Vicinium is used for the treatment of loco-regionally accessible tumors and is currently in a phase III clinical trial (VISTA) for the treatment of high-grade non-muscle invasive bladder cancer and a phase I study in combination with durvalumab for the same indication. In a different phase I study in late stage squamous cell carcinoma of the head and neck, direct injection of Vicinium led to shrinkage of the principal injected tumor as well as non-targeted tumors in some patients suggesting the activation of a T cell-mediated anti-tumor response through cross-priming. Supporting this hypothesis, in vitro studies have demonstrated that Vicinium mediated tumor cell killing elicits biological features of an immunogenic cell death (ICD). Tumor cells’ ability to evade the innate and adaptive immune response plays a major role in cancer development and progression. Altered expression of immune modulators is a key mechanism responsible for tumor escape. Recent studies have shown that exposure to chemotherapeutic drugs results in the selection of tumor cells expressing immunosuppressive markers such as PD-L1, CD47 and CD39. Following in vitro treatment with Vicinium, the enrichment of tumor cell population expressing I.O. markers was examined and compared to chemotherapeutic agents. Unlike small molecule chemotherapies, Vicinium treatment did not lead to an enrichment of CD47 or CD39 positive tumor cell populations. Taken together, the data suggests that Vicinium does not induce an immunosuppressive environment.
Citation Format: Shilpa Chooniedass, Rachelle L. Dillon, Arjune Premsukh, Glen C. MacDonald, Jeannick Cizeau, Gregory P. Adams. In vitro assessment of tumor associated I.O. markers in cancer cell lines following Vicinium treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2388.
Abstract 2389: Role of Midkine in molecular targeted therapy to TIP1 for lung cancer treatment
Authors: Kapoor Vaishali , Singh Abhay K. , Thotala Dinesh , Hallahan Dennis 
Published: August 2019

Abstract
Non-small cell lung cancer (NSCLC) ranks among the highest cancer-related mortalities world-wide. Targeted therapy has been a growing topic of investigation to improve therapeutic efficacy for NSCLC. A few targeted therapies that exploit aberrant protein expression profiles have been approved for NSCLC. However, marginal improvement in efficacy observed with these therapeutic approaches highlights the need for discovery of additional therapeutic targets. We identified Tax interacting protein 1 (TIP1) which is overexpressed in various cancers as a molecular targets. We focused on antibody-based targeting of the chaperone protein TIP1. The functional domain of TIP1 (PDZ domain) caps the C-terminus of many cellular proteins that regulate important cellular functions. Knocking down TIP1 revealed that it plays an important role in cell signaling, cancer development, and progression. Comparing antibodies targeting different epitopes of TIP1, we found that antibodies against the PDZ domain of TIP1 were most effective in inducing cytotoxicity of lung cancer cells but not normal cells. Anti-PDZ/TIP1 antibodies injected into mice bearing lung cancer bind specifically to cancer and substantially enhance tumor control. A mass spectrometry-based approach identified Midkine (MDK) as a putative protein that modulates this cytotoxicity by anti-TIP1 antibodies. Additional studies suggested that the β-catenin/Wnt signaling may be involved in induction of MDK after blocking of TIP1. These studies led to the hypothesis that MDK is upregulated by the anti-PDZ/TIP1 antibody via the β-catenin/Wnt signaling pathway, which subsequently modulates downstream signaling mechanisms. This project will systematically characterize the mechanisms of cytotoxicity by the anti-PDZ/TIP1 antibodies. To achieve this, a number of novel methodologies including genome-wide CRISPR knockout, proteomics and mass cytometry to characterize the link between TIP1 and MDK will be applied. The project will guide development of combination therapies to optimize efficacy of NSCLC treatment. One strategy proposed, is dual-targeting of TIP1 and MDK for enhanced efficacy. This project will lead to identification of novel molecular targets for NSCLC treatment that have never been considered before.
Citation Format: Vaishali Kapoor, Abhay K. Singh, Dinesh Thotala, Dennis Hallahan. Role of Midkine in molecular targeted therapy to TIP1 for lung cancer treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2389.
Abstract 2404: Mechanistic insight into anti-tumor activity of DKN-01, a therapeutic antibody with immune modulatory activity
Authors: Haas Michael , Heath Heidi , Schurpf-Huber Franziska , Wu Yinyuan , Zhang Xinjun , He Xi , Yang Min , Newman Walter , Kagey Michael 
Published: August 2019

Abstract
Wnt signaling is a fundamental pathway that is dysregulated in oncology. The Wnt signaling modulator DKK1 is expressed in a variety of tumor types and elevated levels frequently correlate with poor survival. DKK1 promotes tumor growth by stimulating proliferation, metastasis, and angiogenesis, and has been implicated in contributing to an immune suppressive tumor microenvironment. DKN-01 is a humanized monoclonal therapeutic antibody that binds DKK1 with high affinity and selectivity. It is currently being evaluated clinically as a monotherapy and in combination with chemotherapies and other immunotherapies in a variety of solid tumors. Here we demonstrate that efficacy from a murine version of DKN-01 (mDKN-01) in a syngeneic tumor model requires NK cells. mDKN-01 also reduces lung metastasis, further supporting a model where DKK1 neutralization stimulates a NK mediated anti-cancer response. In addition, DKN-01 has efficacy in a human prostate xenograft model that expresses high levels of DKK1 and retains functioning NK cells. Taken together, these data support an innate immunotherapeutic mechanism of action of DKN-01 and suggest that tumor expression of DKK1 may predict response. As such, evaluation of peripheral blood and tumor biopsies from patients undergoing treatment with DKN-01 in combination with chemotherapy or other immunotherapies are underway to demonstrate innate immune mediated anti-tumor activity and validate DKK1 expression as a biomarker.
Citation Format: Michael Haas, Heidi Heath, Franziska Schurpf-Huber, Yinyuan Wu, Xinjun Zhang, Xi He, Min Yang, Walter Newman, Michael Kagey. Mechanistic insight into anti-tumor activity of DKN-01, a therapeutic antibody with immune modulatory activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2404.