bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1433: NeoTCR-P1, a novel neoepitope-specific adoptive cell therapy, consists of T cells with ‘younger’ phenotypes that rapidly proliferate and kill target cells upon recognition of cognate antigen
Authors: Sennino Barbara , Conroy Andrew , Purandare Bhamini , Litterman Adam , Jacoby Kyle , Moot Robert , Lu William , Nguyen Diana , Urbinati Fabrizia , Foy Susan , Hunter Theresa , Dalmas Olivier , Bethune Michael , Park Tim , Peng Songming , Franzusoff Alex , Mandl Stefanie
Published: August 2019

Clinical benefit observed with immuno-oncology trials often depends on the unleashing of a pre-existing intrinsic T cell immune response in each cancer patient. The targets of these intrinsic T cells are commonly ascribed to recognition of patient-specific neoantigens that arose from cancer mutations.

PACT Pharma has developed the ability to selectively capture neoantigen-specific CD8+ T cells from peripheral blood of the patient. Leveraging this technology, PACT Pharma is developing personalized, autologous neo-epitope specific TCR-engineered T cell therapies for the eradication of solid tumors.

Briefly, using PACT's proprietary TCR isolation technology neoepitope-specific TCRs are cloned and autologous CD8+ and CD4+ T cells from the same patient with cancer are precision genome engineered (using a DNA-mediated (non-viral) method) to express the neoTCR. NeoTCR expressing T cells are then expanded in a manner that preserves a “younger” T cell phenotypes, resulting in a NeoTCR-P1 product in which the majority of the T cells exhibit T memory stem cell and T central memory phenotypes.

Upon cognate antigen encounter, NeoTCR-P1 rapidly differentiate into potent effector T cells. Engineered NeoTCR-P1 cells rapidly expand, secrete effector molecules such as perforin and granzyme B, and cytokines such as interferon-gamma (IFN-γ), IL-2 and TNF-alpha (TNF-α). Single cell secretome analysis demonstrates that NeoTCR-P1 cells are highly polyfunctional (secretion of two or more cytokines or effector proteins). These results demonstrate that PACT’s autologous ex vivo engineered NeoTCR-P1 T cells represent a highly personalized adoptive T cell therapy with potential to provide significant clinical benefit to subjects with solid tumors.

Citation Format: Barbara Sennino, Andrew Conroy, Bhamini Purandare, Adam Litterman, Kyle Jacoby, Robert Moot, William Lu, Diana Nguyen, Fabrizia Urbinati, Susan Foy, Theresa Hunter, Olivier Dalmas, Michael Bethune, Tim Park, Songming Peng, Alex Franzusoff, Stefanie Mandl. NeoTCR-P1, a novel neoepitope-specific adoptive cell therapy, consists of T cells with ‘younger’ phenotypes that rapidly proliferate and kill target cells upon recognition of cognate antigen [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 1433.
Abstract 1439: Identification and characterization of neoantigen specific T cells
Authors: Naradikian Martin S. , Montero Leslie , Hall Samantha , Bahmanof Milad , Thota Rukman , Sternberg Luise , Lane Jerome , Kosaloglu-Yalcin Zeynep , Lanka Manasa , Miller Aaron , Peters Bjoern , Cohen Ezra , Schoenberger Stephen
Published: August 2019

Neoantigens (NeoAg) offer attractive therapeutic targets for directing a patient’s immune response to the immunogenic subset of mutations expressed exclusively by their cancer cells. Despite the specificity with which NeoAg enable tumor recognition, the majority of approaches for their identification rely on purely predictive methods such as calculating the ability of mutated peptides to bind to a patient’s set of HLA molecules, and have met with limited success in revealing natural targets present on tumor cells. We have developed a novel HLA-agnostic functional approach to NeoAg identification which combines genomic sequencing with bioinformatic analysis to nominate mutations for subsequent functional analysis using patient’s own T cells in an effort to identify natural responses generated under physiologic conditions. Using this, we identified a missense mutation (V205>I) in the ribosomal protein RPS2 that is recognized by CD8+ T cells from tumor-infiltrating lymphocytes (TIL) of a metastatic HPV-16+ Head and Neck Squamous Cell Carcinoma (HNSCC) lesion. We then performed adoptive cellular therapy (ACT) using either unseparated TIL or those enriched for RPS2 V205>I-specific CD8+ T cells and found the latter to be superior in controlling outgrowth of tumor of a PDX cell line generated from this lesion in NSG mice. Finally, we used single-cell transcriptomics to isolate the genes encoding the RPS2-specific TCR and show that it recognizes the mutated peptide bound to HLA-B*07.02 as well as the tumor cell line expressing the RPS2 protein. These results demonstrate that high-affinity NeoAg-specific T cell responses can be identified in cancer patients, that ACT of these cells can control tumor growth, and that the relevant TCR can be isolated for use in TCR engineering-based immunotherapy.

Citation Format: Martin S. Naradikian, Leslie Montero, Samantha Hall, Milad Bahmanof, Rukman Thota, Luise Sternberg, Jerome Lane, Zeynep Kosaloglu-Yalcin, Manasa Lanka, Aaron Miller, Bjoern Peters, Ezra Cohen, Stephen Schoenberger. Identification and characterization of neoantigen specific T cells [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 1439.
Abstract 1447: Predicting immunogenic neoepitopes with biology-aware machine learning
Authors: Mazzocco Giovanni , Niemiec Iga , Myronov Oleksandr , Kowalczyk Edyta , Kaczmarczyk Jan , Sanecka-Duin Anna , Stepniak Piotr
Published: August 2019

Introduction: The purpose of this study is to present a novel method for neoepitope prediction, along with extensive benchmarks to existing solutions and identification of the most predictive constituent biological features. The accurate prediction of neoepitope immunogenicity represents an invaluable tool for the design of personalized cancer vaccines with effective treatment outcomes. The effectiveness of the host’s adaptive immune response against cancer relies on the correct HLA-mediated neoepitope presentation and the recognition by specific CD8+ clones. Cancer immunotherapies act by boosting the activity of these effector T-cells.

Methods: The proposed AI-driven bioinformatics solution allows to perform an accurate prediction of HLA I-restricted neoepitope immunogenicity by including several analytical modules simulating biological processes leading to the activation of CD8+ T-cells. These modules can be flexibly composed on the basis of the data available and include: (i) selection of potential neoepitope based on cancer NGS data, (ii) expression of neoepitope-associated genes, (iii) similarity to self, (iv) prediction of neoepitope-HLA binding affinity and stability, (v) effect of post-translational modification on neoepitope presentation and TCR recognition, (vi) prediction of neoepitope:TCR recognition probability based on neoepitope-HLA:TCR structural-derived features and TCR CDR3 sequence similarities. The model was trained on a curated dataset joining records of multiple studies containing neoepitopes experimentally validated for their ability to elicit adaptive immune response.

Results: We present the results of a benchmarking study where we compare the performance of widely used methods for the assessment of neoepitope immunogenicity along with our solution. We investigate the predictive power of each analytical module to determine the individual information gain and determine the most informative ones. All the methods included in the benchmarking study were tested using the dataset provided by Chowell et al. 2015. As the metric for performance evaluation we use ROC AUC and the overall percentage of correctly detected immunogenic neoepitopes (precision).

Conclusion: The results present the utility of the compared methods for personalized cancer vaccine design and the importance of modules related to biological processes underlying the neoepitope presentation and immunogenicity.

Citation Format: Giovanni Mazzocco, Iga Niemiec, Oleksandr Myronov, Edyta Kowalczyk, Jan Kaczmarczyk, Anna Sanecka-Duin, Piotr Stepniak. Predicting immunogenic neoepitopes with biology-aware machine learning [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 1447.
Abstract 1461: mRNA therapeutics against cancers and infectious diseases
Authors: Arya Smriti , Lin Qiubin , Zhou Nan , Huang Jiandong
Published: August 2019

In vitro transcribed (IVT) mRNA is forming a new basis of drug delivery as it can be synthetically engineered to express the desired protein in lesser time and be more specific than the other 2 types of antigens. Using DNA (coding for proto-oncogenes) for immunization poses a risk for host cell transformation into a malignant one and hence proto-oncogenes would express for a longer time. Therefore, mRNA was considered for cancer immunotherapy as it does not integrate into the host cell's genome, so no question of insertional mutagenesis arises. Our main aim is to develop a stable mRNA system working both in vitro and in vivo and then use this system to develop mRNA vaccines. The stability of IVT mRNA can be increased by changing the 3' and 5' UTRs, adding a 5'cap and 3' poly-A tail which could even increase their half-life to a few days. For creating a stable mRNA working system in vitro, EGFP-2A gene was cloned along with the AdsA (Staphylococcus aureusgene important for infection) in a vector backbone with TMV 3’UTR and 5’UTR. The mRNA created in vitro was with modified uridine and cap 1 structure and transfected to the mammalian cell lines. This transfection was further enhanced by using liposome created in the lab (using some cationic and helper lipids in different ratios) by film rehydration method. The expression of luciferase mRNA was then detected in mice by live imaging indicating that the mRNA system is stable in vivo. Further, to direct the mRNA encoded antigens to MHC1 and MHC2 pathways they were tagged with a htPA secretion tag and MHC1 targeting signal along with a 3XFLAG tag. We tried various mode of injections with AdsA mRNA to have a profile of ELISPOT with differently exposed mRNA (in vivo in mice). Now we are focussing on some neo antigens for tumor to be used as. Avaccine in the form of mRNA.

Citation Format: Smriti Arya, Qiubin Lin, Nan Zhou, Jiandong Huang. mRNA therapeutics against cancers and infectious diseases [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 1461.
Abstract 1471: Short hairpin RNA-expressing oncolytic adenovirus-mediated inhibition of PDL1 significantly suppresses human cancer cell growth
Authors: Sheng Jipo , Wang Xue , Dong Xiaoming , Fu Jin , Kang Sanmao , Hu Fang
Published: August 2019

In cancer immunotherapy, it is known that aberrant expression of immune checkpoint proteins in tumor cells and their resulting immunosuppression in surrounding tumor microenviroment and even in whole immune system represent the crucial limiting factors toward successful cancer treatment. Multiple studies evidenced that oncolytic viruses carrying biological molecule including cytokines, shRNAs and miRNAs relieve or attenuate immunosuppression, and may be a promising way toward curing tumor. In this study we generated an oncolytic adenovirus with expression of shRNA targeting human PDL1. The adenovirus exhibited proliferation activity more than two orders of magnitude higher in human cancer cells than in human normal primary cells. Western blot showed significantly decreased expressing levels of PDL1 protein in human cancer cells upon infection of the PDL1 shRNA expressing-oncolytic virus. FACS assay also showed decreased expression levels of PDL1 on the cell membrane after the infection of same viruses. In vivo experiments in two different genetic backgrounds mouse model  demonstrated that the PDL1 shRNA expressing adenoviruses lysed the majority of the tumor cells derived from HCT116 colorectal cancer cells that were subcutaneously inoculated. Moreover, the adenoviruses downregulated PDL1 expression levels within the HCT116 colon cell-derived tumor cells, remarkably attenuated immunosuppression surrounding the HCT116 tumor. Consisted with these observations, TIL cell counts in the tumors derived from mice with shRNA expressing oncolytic adenovirus treatment were significantly higher than that from mice in other control groups. The growth of HCT116 colon cell-derived tumor in mice with oncolytic adenovirus treatment was greatly inhibited for a longer period compared with that in mice in other control groups. The oncolytic adenovirus described in this study features highly selective amplification in human tumor cells versus normal cells and inhibition of PDL1 expression in tumor cells, therefore it may be important toward developing novel method for cancer therapy.

Citation Format: Jipo Sheng, Xue Wang, Xiaoming Dong, Jin Fu, Sanmao Kang, Fang Hu. Short hairpin RNA-expressing oncolytic adenovirus-mediated inhibition of PDL1 significantly suppresses human cancer cell growth [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 1471.
Abstract 1491: Immune resistance emerges from tumor-initiating stem cells
Authors: Miao Yuxuan
Published: August 2019

The remarkable capacity of the long-lived stem cells-like population to self-renew, initiate and propagate a tumor placed these cancer stem cells (CSC) at the root of tumorigenesis. Many unique molecular features of stem cells endow these key population with specialized properties to drive tumor formation. However, in order to achieve these functions, the neoplastic stem cells must first overcome the immune barrier. Although it has long been postulated that, as the core of a tumor, CSCs must be superior at evading the immune detection, direct evidence is still lacking to demonstrate this stem cell trait. Another important feature of CSCs is that these cells are programed to resist traditional cancer treatments, including chemotherapy and radiation. Yet, it is still unexplored how CSCs react to the immunotherapy, which just start to revolutionize the cancer treatments. In order to address these fascinating questions, we have designed a spontaneous skin squamous cell carcinoma (SCC) mouse model that can be effectively targeted by adoptive cell transfer (ACT)-based immunotherapy, without losing the targeted tumor antigen. Employing this model, we have lineage traced the fate of tumor-initiating stem cells during and after ACT treatment. In this study, we will present data demonstrating that a subset of TGFβ-responding CSCs, residing at the tumor-stromal interface, are always able to survive from the injected CD8+ T cell treatment and give rise to the relapsed tumor. Furthermore, the extensive profiling of ACT surviving stem cells revealed that multiple immune resistant pathways are highly up-regulated in these stem cells. In addition, TGFβ appears to orchestrate these immune resistant processes in the tumor-initiating stem cells. This study highlights CSCs as the core to mediate immune evasion.

Citation Format: Yuxuan Miao. Immune resistance emerges from tumor-initiating stem cells [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 1491.
Abstract 1497: Identification of discrepancy between CTLA4 expression and CTLA4 activation in gastric cancer
Authors: Yu Yingyan
Published: August 2019

Objective: Recently, immune checkpoints blockers showed higher anti-tumor activity for advanced gastric cancer (GC). The purpose of the study is to find out biomarkers related to anti-CTLA4 therapy.

Materials and Methods: Datasets of GEO, TCGA and GESA were extracted. Differential expression of CTLA4 between cancer tissues and normal mucosa, enrichment of WT (wild type) vs CTLA4_KO (knockout) upregulated gene set and clinical significance were analyzed. The expression of CTLA4,CD3 and granzyme A (GZMA) were validated on 30 cases of Chinese GC. MSI marker MLH1 and EBV marker EBER were examined on 30 cases of Chinese GC by immunohistochemistry and in situ hybridization.

Results: CTLA4 was up-regulated in GC tissue relative to normal mucosa in datasets of GSE27342 (fold change=1.586, P<0.001) and GSE63089 (fold change=1.365, P<0.001). Increased CTLA4 expression was positively related to CTLA4 activation. EBV-associated GC (EBVaGC) and microsatellite instability GC (MSIGC) disclosed higher CTLA4 levels than other GCs. Genomic stability GC (GSGC) also showed higher enrichment score of CTLA4 activation. CTLA4 activation resulted in shorter overall survival in GC. The expression level of CTLA4 was well correlated to GZMA (R=0.701, P<0.001) and CD3 (R=0.750, P<0.001).

Conclusions: GSGC was firstly identified as the potential GC subtypes responsive to anti-CTLA4 treatment.

Note: This abstract was not presented at the meeting.

Citation Format: Yingyan Yu. Identification of discrepancy between CTLA4 expression and CTLA4 activation in gastric cancer [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 1497.
Abstract 150: Stromal cell plasticity and immune surveillance revealed by single-cell transcriptomics
Authors: Regan Claire , Hao Yuan , Preall Jonathan
Published: August 2019

Pancreatic ductal adenocarcinomas are typically characterized by a highly desmoplastic stroma, which is dense in collagen and other extracellular matrix components that limit access to the growing tumor by immune cells and targeted therapies. ECM components are mainly deposited by cancer-associated fibroblasts (CAFs), which are thought to arise primarily from pancreatic stellate cells and have been shown to polarize into at least two distinct subtypes within the tumor microenvironment in response to extracellular ligands. Recent studies have suggested potentially antagonistic roles for the different CAF subtypes in either promoting or restraining tumor growth. While depletion of the restrictive desmoplasia is likely to be a desirable therapeutic avenue, a complete understanding of phenotypic variation and interconversion between CAF populations will be essential for designing targeted therapies.

Using single-cell RNAseq, we have profiled the non-immune stromal cells of pancreatic ductal adenocarcinomas in the KPC mouse model, as well as from orthotopically transplanted organoid-derived pancreatic tumors. In addition to the canonically reported myofibroblastic and inflammatory CAF subtypes, we observe at least one additional distinct type-I collagen expressing fibroblastic cell type in the tumor microenvironment. The high degree of transcriptional divergence suggests that these CAFs may arise from distinct progenitors, whereas myo- and inflammatory-CAFs lie along a continuous pseudotemporal gradient marked by signatures of transcriptional programs driven by extracellular ligand signaling, including Wnt-family genes. Our single-cell transcriptomic results point toward pathway utilization that could be exploited for modulating PDAC desmoplasia and enabling targeted combination therapies.

Citation Format: Claire Regan, Yuan Hao, Jonathan Preall. Stromal cell plasticity and immune surveillance revealed by single-cell transcriptomics [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 150.
Abstract 1503: Effect of immune cell depletion on the responses to PD1 treatment in syngeneic models
Authors: Jin Ying , Shan Yongli , An Annie Xiaoyu , Li Henry Qixiang , Ouyang Davy Xuesong
Published: August 2019

Immunological checkpoint inhibitors, i.e., PD1 or PD-L1 antibodies, reverse cancer immunosuppression and promote antitumor immune responses in several cancer types. However, targeting PD-1/PD-L1 axis is only effective in ~20% of cancer patients, while some of the initial responders also develop resistance to the treatment. It is critical to fully understand which lineages of immune cells play major roles mediating PD1 responses in a given tumor microenvironment. While it’s well-known that PD1 antibody works through activating cytotoxic T cells, the contributions of other immune cell populations in PD1 treatment are not well defined. To understand how different lineages of immune cells impact PD1 efficacy, we removed various immune cell subpopulations in MC38 and Hepa 1-6 murine models when treated with PD1 antibody. In this study, mice inoculated with MC38 or Hepa1-6 tumors were treated with PD1 antibody or a combination of PD1 with depletion antibodies. The effectiveness of immune cell depletion was assessed by flow cytometry. CD4-, CD8- T cells, NK cells, MDSC and macrophages were depleted with anti-CD4 (GK1.5), anti-CD8 (2.43), anti-NK1.1 (PK136), anti-GR1 (RB6-8C5) antibodies and clodronate liposomes, respectively. As expected, depletion of CD8 T cells completely abrogated the antitumor effect of PD1 treatment, confirmed the crucial roles for CD8 T cells in tumor killing. Surprisingly, depletion of CD4 T cells and macrophages showed quite opposite effects in MC38 and Hepa1-6 lines - while significantly sensitizing MC38 tumors to PD1 treatment, PD1 efficacy is deteriorated in Hepa1-6. Depletion of NK cells enhanced the tumor inhibition effect in Hepa1-6 with 4 tumors showed complete or partial regression, without significant impact on MC38 tumors. Taken together, our studies have shown an unequivocal role of CD8 T cells in PD1 induced tumor growth inhibition. However, other lineages of immune cells may act differently upon PD1 blockade release, presumably depending on specific tumor microenvironment. Additional study is needed to differentiate the effects of Treg depletion vs. non-Treg CD4 T cell depletion.

Citation Format: Ying Jin, Yongli Shan, Annie Xiaoyu An, Henry Qixiang Li, Davy Xuesong Ouyang. Effect of immune cell depletion on the responses to PD1 treatment in syngeneic models [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 1503.
Abstract 1508: Primary tumors induce neutrophil extracellular traps with targetable metastasis promoting effects
Authors: Rayes Roni F. , Mouhanna Jack G. , Nicolau Ioana , Vourtzoumis Phil , Wong Carson , Eustache Jules , Bourdeau France , Giannias Betty , Siblini Aya , Lee Emma , Sangwan Veena , Rousseau Simon , Quail Daniela , Walsh Logan , Bertos Nicholas , Cools-Lartigue Jonathan , Ferri Lorenzo E. , Spicer Jonathan D.
Published: August 2019

Targeting the dynamic tumor immune microenvironment can provide effective therapeutic strategies for cancer. Neutrophils (polymorphonuclear neutrophils, PMNs) are the predominant circulating leukocyte population in humans and are vital to fight infection. Despite mounting evidence that PMNs can promote tumor progression, depleting PMNs is not a viable therapeutic option. Neutrophil extracellular traps (NETs) are networks of extracellular neutrophil DNA fibers that are capable of trapping tumor cells and promoting their growth and their metastasis. Targeting NETs can therefore be a potentially successful therapeutic option to block the tumor promoting functions of PMNs. Here we demonstrate that circulating NET levels are elevated in esophageal, gastric and lung cancer patients compared to healthy controls. This increase correlates with disease stage and NET levels are independent predictors of advanced stage. Using pre-clinical murine models of lung and colon cancer, we observe elevated NET levels in tumor bearing mice compared to non-tumor bearing mice; these levels correlated with tumor size. NET levels significantly decrease following tumor resection or treatment with DNase1, a NET degrader, or neutrophil elastase inhibitor (NEi), a NET inhibitor. NET levels do not rise following tumor inoculation in peptidyl arginine deiminase-IV knock out (PAD4-/-) mice; PAD4 being an enzyme essential for citrullination of histones, a crucial step in NET release. Moreover, PMNs from tumor bearing mice are more primed for NETosis than PMNs from non-tumor bearing mice or NEi-treated or PAD4-/- tumor bearing mice. Finally, elevated in vivo hepatic adhesion and spontaneous liver and lung metastases are observed in tumor bearing mice compared to DNase1- or NEi-treated or PAD4-/- tumor bearing mice. Therefore, inhibiting NETs represents a promising strategy to impede metastatic dissemination in several types of cancer patients.

Citation Format: Roni F. Rayes, Jack G. Mouhanna, Ioana Nicolau, Phil Vourtzoumis, Carson Wong, Jules Eustache, France Bourdeau, Betty Giannias, Aya Siblini, Emma Lee, Veena Sangwan, Simon Rousseau, Daniela Quail, Logan Walsh, Nicholas Bertos, Jonathan Cools-Lartigue, Lorenzo E. Ferri, Jonathan D. Spicer. Primary tumors induce neutrophil extracellular traps with targetable metastasis promoting effects [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 1508.
Abstract 1510: Androgen regulated IL-8 expression in prostate cancer: Insights into tumor cell mediated immunosuppression
Authors: Bujanda Zoila A. Lopez , Haffner Michael C. , Chaimowitz Matthew G. , Chowdhury Nivedita , Hurley Paula J. , Christiano Angela M. , Drake Charles G.
Published: August 2019

Androgen deprivation therapy (ADT) results in castration-resistant prostate cancer (CRPC) in a significant fraction of patients. We have previously reported that the protein levels of interleukin-8 (IL-8) were inversely correlated with disease progression in men with biochemical recurrent prostate cancer treated with Lenalidomide. Recently, polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) were implicated as potential drivers of CRPC. Here we show that IL-8 expression is upregulated as a consequence of ADT and mediates the recruitment of PMN-MDSCs to the tumor microenvironment. We found that IL-8 expression is regulated by both an inflammatory stimulus (NF-kβ mediated) and loss of androgen receptor (AR) signaling following ADT. We confirmed direct binding of both the p65 subunit of NF-kβ and AR to the IL-8 promoter, and their respective effects on promoter activity. The suppressive activity of AR was further supported by a reduction in active transcription markers at the chromatin level surrounding the IL-8 promoter. Accordingly, intratumoral infiltration of PMN-MDSCs correlated with IL-8 expression, and was reduced in IL-8 knockouts. Taken together, these results suggest an innate inflammatory response, loss of AR suppressive activity, and subsequent chemokine upregulation as a potential mechanism that regulates the infiltration of PMN-MDSCs to the tumor microenvironment of CRPC after ADT. These findings open a window of opportunity for therapeutic interventions aiming to improve responses to checkpoint blockade in prostate cancer.

Citation Format: Zoila A. Lopez Bujanda, Michael C. Haffner, Matthew G. Chaimowitz, Nivedita Chowdhury, Paula J. Hurley, Angela M. Christiano, Charles G. Drake. Androgen regulated IL-8 expression in prostate cancer: Insights into tumor cell mediated immunosuppression [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 1510.
Abstract 1525: Kaiso influences immune signaling of breast cancer exosomes
Authors: Ahmed Md Shakir U. , Jenkins Brittany , Adu-Addai Benjamin , Karanam Balasubramanyam , Davis Melissa B. , Grizzle William E. , Wang Honghe , Yates Clayton C.
Published: August 2019

Introduction: Exosomes are communication vesicles between tumor cells and immune cells. However, the mechanism underlining this cell-cell communication is not well understanding, particularly in African American (AA) breast cancer patients. Kaiso, a bi-modal transcription factor is highly expressed in AA patients and high Kaiso expression correlates with aggressiveness and the disparity in survival outcomes compared to European American (EA) patients. However, the biological consequences of Kaiso in immune signaling of breast cancer exosomes has not been studied. Herein we demonstrate the biological role of Kaiso in immune signaling in breast cancer exosomes.

Methods: We utilized Nanostring immune profiling technology along with multiple in vitro and in vivo assays to study the role of Kaiso in breast cancer immune escape.

Results: Nanostring pan cancer immune profiling showed that EA breast cancer exosomes exhibited higher expression of TILs markers, T cell activation markers and CD8+T Cells markers compared to AA, while we observed an increase in the expression of anti-phagocytic molecule CD47 in breast cancer patient exosomes of AA compared to EA. In addition to that CD47 and SIRP-α (Signal Regulatory Protein) are highly expressed in Kaiso-scrambled MDA-MB-231 cells (sh-SCR) and exosomes, whereas THBS1, which is a regulator of CD47 expression and is regarded as angiogenesis inhibitor is significantly increased in sh-Kaiso MDA-231 cells and exosomes. Additionally, we observed that Kaiso directly binds methylated sequences in the promoter region of CD47 and THBS1 by ChIP assay. Furthermore, in vivo sh-Kaiso cells injected into athymic mice exhibited delayed tumor formation after four weeks with smaller tumor size as compared to sh-SCR cells, and we observed higher expression of THBS1 with lower expression of CD47 and SIRP-α molecules by IHC and exosomes isolated from invivo tumors, indicating that Kaiso is associated with macrophage mediated immune escape.

Conclusion: Our findings demonstrate the role of kaiso in immune signaling through exosomes which may be related with more aggressive cancer phenotype in breast cancer specially in African Americans.

Citation Format: Md Shakir U. Ahmed, Brittany Jenkins, Benjamin Adu-Addai, Balasubramanyam Karanam, Melissa B. Davis, William E. Grizzle, Honghe Wang, Clayton C. Yates. Kaiso influences immune signaling of breast cancer exosomes [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 1525.
Abstract 1527: Intraperitoneal myeloid-derived suppressor cells in peritoneal dissemination mouse model
Authors: Sugita Yutaka , Yamashita Kimihiro , Takimoto Rishu , Tanaka Tomoko , Arimoto Akira , Fukuoka Eiji , Nakamura Tetsu , Suzuki Satoshi , Kakeji Yoshihiro
Published: August 2019

Background: Myeroid-derived suppressor cells (MDSCs) are heterogeneous cell populations derived from bone marrow, and two subsets of M-MDSC and PMN-MDSC are known in mice. They accumulate in the tumor-bearing host, and suppresse cell-mediated immunity mainly on T cells, and inhibit anti-tumor immune responses. We have previously reported that (1) the increase of MDSCs in lung, peripheral blood, and spleen reflects the cancer progression, (2) MDSCs in peripheral blood would be useful as a marker of recurrence as it increases in recurrent cases after surgical resection. On the other hand, no detailed report on the dynamics of intraperitoneal MDSCs has been made. In this study, we made peritoneal dissemination mouse models and monitored intraperitoneal MDSCs, and investigated whether MDSCs are involved in the progression of peritoneal dissemination.

Methods: MC38 colon cancer cell line was intraperitoneally injected to C57BL / 6J mice and the change in the number and ratio of immune cells (MDSC, Macrophage, T-cell, B-cell) in the spleen, peripheral blood and peritoneal cavity was monitored over time. We examined the correlation between transition of immune cells and cancer progression.

Results: MDSCs increased with cancer progression in all spleen, peripheral blood, and intraperitoneal cavity. The proportion of PMN-MDSCs in MDSCs increased in peripheral blood. In contrast, the proportion of M-MDSCs increased initially, then the PMN-MDSCs increased in the abdominal cavity.

Conclusion: Intraperitoneal MDSCs were thought to reflect the progression of peritoneal dissemination as well as spleen and peripheral blood. The proportion of M-MDSCs reflects the disease state in the microperitoneal dissemination with serous ascitic fluid, and ascites became bloody and the proportion of PMN-MDSCs increased with the progression of seeding. We are examining treatment for peritoneal dissemination with this feature in mind.

Citation Format: Yutaka Sugita, Kimihiro Yamashita, Rishu Takimoto, Tomoko Tanaka, Akira Arimoto, Eiji Fukuoka, Tetsu Nakamura, Satoshi Suzuki, Yoshihiro Kakeji. Intraperitoneal myeloid-derived suppressor cells in peritoneal dissemination mouse model [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 1527.
Abstract 1542: Bispecific T cell engager-induced toxicity in an immunocompetent solid tumor model
Authors: Godbersen-Palmer Claire , Coupet Tiffany , Grada Zakaria , Sentman Charles
Published: August 2019

Chimeric antigen receptor (CAR) T cells and bispecific T cell engagers have demonstrated clinical efficacy, however are often accompanied by severe toxicity including cytokine release syndrome (CRS), neurotoxicity or macrophage activation syndrome (MAS). Mechanistic understanding of the development of these toxicities and testing of therapeutic interventions is limited by a lack of suitable immunocompetent pre-clinical models. We have developed both human and murine versions of a bispecific molecule with specific activity against target expressing tumor cells in vitro and in vivo. These bispecific proteins are constructed from the extracellular portion of either mouse or human NKG2D receptor and target cells expressing the cognate ligands by redirecting T cells through their CD3 binding arm. Using the murine bispecific protein, mNKG2DxCD3, we have developed an immunocompetent mouse tumor model which exhibits treatment induced toxicity and recapitulates key features similar to those observed in human CRS. Toxicity was observed between the 2nd and 4th bispecific protein injections but was not observed following subsequent injections. Monitoring of toxicity kinetics showed transient symptoms peaking 3-4 hours following bispecific protein injection with complete resolution after 8 hours. Weight loss and elevated plasma cytokines including IFNγ, IL6, TNFα, IL2 and IL10 were also associated with toxicity. Pathology analysis showed a reduction in white pulp in the mouse spleens, however, other organs evaluated (brain, kidney, lung and heart) were normal. Using mouse genetic knockout models, we were able to show that T cells, IFNγ and Perforin were required for development of this toxicity. Additionally, In vivo depletion of either CD4+ or CD8+ T cells was sufficient to prevent the onset of toxicity. These findings highlight the importance of T cell activation and function and shed light on the mechanistic underpinnings of bispecific T cell engager protein induced toxicity.

Citation Format: Claire Godbersen-Palmer, Tiffany Coupet, Zakaria Grada, Charles Sentman. Bispecific T cell engager-induced toxicity in an immunocompetent solid tumor model [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 1542.
Abstract 1547: DNA-encoded bispecific T-cell engagers and antibodies present long-term antitumor activity
Authors: Perales-Puchalt Alfredo , Duperret Elizabeth K. , Muthumani Kar , Weiner David B. , Yang Xue , Zhu Xizhou , Wojtak Krzysztof , Tello-Ruiz Edgar , Wise Megan C.
Published: August 2019

Specific antibody therapy, including monoclonal antibodies and bispecific T cell engagers (BiTEs), are important new tools for cancer immunotherapy. However, these approaches are slow to develop and may be limited in their production thus restricting the patients who can access these treatments. BiTEs exhibit a particularly short half-life and difficult production. The development of an approach allowing simplified development, delivery and in vivo production would be an important advance. Here we describe development of a designed synthetic DNA plasmid, which we optimized to permit high expression of an anti-HER2 antibody (HER2DMAb) and delivered it into animals through adaptive electroporation. HER2DMAb was efficiently expressed in vitro and in vivo, reaching levels of 50ug/ml in mouse sera. Mechanistically, HER2DMAb blocked HER2 signaling and induced antibody-dependent cytotoxicity. HER2DMAb delayed tumor progression for HER2-expressing ovarian and breast cancer models. We next used the HER2DMAb scFv portion to engineer a DNA-encoded BiTE. This HER2DBiTE was expressed in vivo for approximately 4 months after a single administration. The HER2DBiTE was highly cytolytic and delayed cancer progression in mice. These studies illustrate a novel approach to generate DBiTEs in vivo which represent promising immunotherapies for HER2+ tumors including ovarian and potentially other cancers.

Citation Format: Alfredo Perales-Puchalt, Elizabeth K. Duperret, Kar Muthumani, David B. Weiner, Xue Yang, Xizhou Zhu, Krzysztof Wojtak, Edgar Tello-Ruiz, Megan C. Wise. DNA-encoded bispecific T-cell engagers and antibodies present long-term antitumor 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 1547.
Abstract 156: Visfatin induces LOX expression and promotes tumor metastasis through the Src/Akt signaling pathway in human chondrosarcoma cells
Authors: Yu Cheng-Chieh , Lin Chih-Yang , Tang Chih-Hsin
Published: August 2019

Chondrosarcoma, a common primary bone malignancy that affects the joints and bones, is associated with metastases in the lung, especially in cases of high-grade chondrosarcoma. The protein lysyl oxidase (LOX) can contribute to tumor growth and metastasis, while the adipokine visfatin is pro-angiogenic and facilitates tumorigenesis as well as metastasis. However, it is unclear as to whether any association exists between visfatin and LOX expression in human chondrosarcoma metastasis. We have discovered that visfatin induces the migration, invasion and increased expression of LOX mRNA and protein in human chondrosarcoma cell lines (JJ012 and SW1353). Pretreatment of these cell lines with Src and Akt inhibitors, or transfecting them with small interfering RNAs (siRNAs), inhibited visfatin-induced chondrosarcoma metastasis and LOX expression. Thus, visfatin promotes chondrosarcoma metastasis by inducing LOX expression via the Src/Akt signaling pathway in the JJ012 cell line. microRNA analysis revealed that visfatin-induced Src/Akt signaling is responsible for downregulating mature miR-26b-5p, which targets the 3' untranslated region (3`UTR) of LOX but does not affect primary and precursor miR-26b-5p expression. This downregulation of miR-26b-5p expression by visfatin was dose-dependent. Pretreatment with Src and Akt inhibitors or transfection with siRNA reversed miR-26b-5p expression. The migration and invasion ability of JJ012 cells was reduced when they were transfected with the miR-26b-5p mimic. In summary, our data demonstrate that visfatin induces LOX expression and promotes chondrosarcoma cell migration and invasion through the Src/Akt signaling pathway, by inhibiting miR-26b-5p.

Citation Format: Cheng-Chieh Yu, Chih-Yang Lin, Chih-Hsin Tang. Visfatin induces LOX expression and promotes tumor metastasis through the Src/Akt signaling pathway in human chondrosarcoma cells [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 156.
Abstract 1583: Genetic interaction analysis among oncogenesis-related genes revealed novel genes and networks in lung cancer development
Authors: Li Yafang , Xiao Xiangjun , Gorlov Ivan , Han Younghun , Hung Rayjean , Amos Christopher
Published: August 2019

The development of cancer is driven by the accumulation of many oncogenesis-related genetic alterations and tumorigenesis is triggered by complex networks of involved genes rather than independent actions. To explore the epistasis existing among oncogenesis-related genes in lung cancer development, we conducted pairwise genetic interaction analyses among 35,031 SNPs from 2027 oncogenesis-related genes. The genotypes from three independent genome-wide association studies including a total of 24,037 lung cancer patients and 20,401 healthy controls with Caucasian ancestry were analyzed in the study. Using a two-stage study design including discovery and replication studies, and stringent Bonferroni correction for multiple statistical analysis, we identified significant genetic interactions between SNPs in RGL1:RAD51B (OR=0.44, p value=3.27x10-11 in overall lung cancer and OR=0.41, p value=9.71x10-11 in non-small cell lung cancer), SYNE1:RNF43(OR=0.73, p value=1.01x10-12 in adenocarcinoma) and FHIT:TSPAN8 (OR=1.82, p value=7.62x10-11 in squamous cell carcinoma) in our analysis. None of these genes have been identified from previous main effect association studies in lung cancer. We further explored the impact of identified genetic interactions on the expression of involved cancer-related genes using the lung eQTL dataset including a total of 409 subjects with both genotyping and gene expression data. In the study between TSPAN8 gene and rs1882898:rs1705235 SNP pair, we identified decreased gene expression in individuals with reduced lung cancer risk which supports the oncogene function of TSPAN8. In the gene expression analysis between SYNE1 and rs10515157:rs1554783 SNP pair, we also identified consistent evidence between gene expression and lung cancer risk. Finally, we conducted gene set enrichment analysis to reveal potential pathways and gene networks underlying molecular mechanisms in overall lung cancer as well as histology subtypes development. Our results provide evidence that genetic interactions between oncogenesis-related genes play important roles in lung tumorigenesis. Epistasis analysis, combined with functional annotation, provides a valuable tool for uncovering functional novel susceptibility genes that contribute to lung cancer development by interacting with other modifier genes.

Citation Format: Yafang Li, Xiangjun Xiao, Ivan Gorlov, Younghun Han, Rayjean Hung, Christopher Amos. Genetic interaction analysis among oncogenesis-related genes revealed novel genes and networks in lung cancer 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 1583.
Abstract 1586: ADAM32 is amplified in a wide range of malignancy
Authors: Rajan Aditya , Tonk Vijay , Bhende Kishore , Singh Sharda , Tonk Sahil , Awasthi Sanjay
Published: August 2019

Cytogenetic analysis using karyotyping and fluorescence in-situ hybridization (FISH) has been the method of choice for identifying chromosomal abnormalities in cancer and other diseases. FISH is a powerful tool enabling detection the amplification or deletion of specific genes of interest using specific fluorescent labelled DNA probes. It has high sensitivity and specificity and enables detection of chromosomal abnormalities present in many genetic disorders. Unfortunately, FISH is labor intensive, gives information only regarding chromosomal changes specifically designated by the nucleotide sequence of the probes. Recently, DNA microarray techniques have allowed the simultaneous detection of vast number of chromosomal abnormalities including deletions, amplifications and translocations. These assays are suitable for large scale screening to discovery previously unknown associations of chromosomal lesions with many types of cancer. In present studies, we performed a retrospective analyses on anonymized data from the Constitutional v3 Array from the Texas Tech University Cytogenetics Lab (Children’s Oncology Group reference lab) on 198 sequential patients to determine the frequency of chromosomal aberrations and their disease associations. The patient population included children and adults. The majority of patients had malignancy, but some had pancytopenia or immune deficiency. We found chromosomal rearrangements, amplifications or deletions at 794 loci. The most commonly affected loci were 8p11.21-8p11.22, 15q11.1-15q11.2, 14q11.2, 14q32.33, 9p24 and 9p13. The 8p11.2 locus was amplified in 81 cases and deleted in 17 cases, an amplification/deletion ratio greater than any other locus. At this locus, the KAT6A, ADAM32 and TACC1 genes are known to associate with cancer, while no associations of GPAT4 and TM2D2 have been reported. The ADAM32 gene amplification, previously identified only in breast cancer, was also found in hepatocellular carcinoma, T-cell Lymphoma, acute lymphoblastic leukemia, acute myelogenous leukemia, Wilm’s Tumor, neuroblastoma, rhabdomyosarcoma, fibromatosis, chondroblastoma, enchondroma, and giant cell tumor of the bone. An oncogenic role of ADAM32 should be investigated in a broad spectrum of pediatric and adult malignancy.

Citation Format: Aditya Rajan, Vijay Tonk, Kishore Bhende, Sharda Singh, Sahil Tonk, Sanjay Awasthi. ADAM32 is amplified in a wide range of malignancy [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 1586.