bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract PO-046: The effect of neoadjuvant therapy on immune profiling of pancreatic ductal adenocarcinoma: A prospective study of the PREOPANC-1 randomized controlled trial
Authors: Latifi Diba , de Koning Willem , Lau Sai ping , Grevers Frederiek , van Dam Coen , van Eijck Casper H. J. , Mustafa Dana A. M. 
Published: November 2021

Abstract
The randomized phase III trial (PREOPANC-1) that was performed in 16 centers in the Netherlands compared the effects of preoperative chemoradiotherapy (Gemcitabine and 2.4 Gy radiation) versus immediate surgery for resectable and borderline resectable pancreatic cancer. The outcomes of the secondary endpoints and predefined subgroup analyses suggest an advantage of the neoadjuvant approach. The aim of the present study was to investigate the changes in the immune microenvironment and infiltration caused by the neoadjuvant treatment. To that aim, we collected formalin-fixed, paraffin-embedded pancreatic cancer samples from all centers that participated in the PREOPANC -1 trial. We performed targeted gene expression using the PanCancer Immune Profiling panel of NanoString. Comparing 50 samples of the patient who were subjected to neoadjuvant treatment to 46 treatment-naïve samples showed a distinct genetic profile induced by the neoadjuvant therapy. More than 250 immune-related genes were significantly differentially expressed between the two groups of samples. The results indicate that neoadjuvant therapy resets the innate immune activation in the tissue samples. A significantly higher infiltration of CD14+, CD33+, CSF1R+, and CD163+, MRC1+ cells were found in samples of the neoadjuvant arm. In contrast, B cells and various subtypes of T cells like CD8+ and FOXP3+ showed a significant decrease in the same samples. Pathway analysis revealed that the neoadjuvant treatment stimulated the expression of genes related to the complement activation, chemotaxis, and wound repair, while genes related to lymphocyte activation and adaptive immune responses were dominant in the treatment-naïve arm. In conclusion, this is the first comprehensive study to describe the immune-molecular changes as a result of neoadjuvant therapy in a randomized clinical trial. The results reveal the enrichment of the myeloid compartment following neoadjuvant therapy which was significantly associated with a survival benefit for the patients. Studying the personalized effect of neoadjuvant therapy will guide choosing the appropriate combined therapy for pancreatic cancer.
Citation Format: Diba Latifi, Willem de Koning, Sai ping Lau, Frederiek Grevers, Coen van Dam, Casper H. J. van Eijck, Dana A. M. Mustafa. The effect of neoadjuvant therapy on immune profiling of pancreatic ductal adenocarcinoma: A prospective study of the PREOPANC-1 randomized controlled trial [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-046.
Abstract PO-082: Delineating the molecular basis of early dissemination of pancreatic cancer
Authors: Ekstrom Taelor J. , Grygoryev Dmytro , Morgan Terry , Zaret Kenneth S. , Kim Jungsun 
Published: November 2021

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at advanced stages rendering the already limited therapeutic options ineffective for many patients. Earlier diagnosis permits for “curative” surgery; however, 95% of these patients experience recurrence locally or distally and die within ten years of treatment. One hypothesis that can explain high recurrence is the early dissemination of PDAC progression. At the time of surgery, systemic subclinical dissemination of predominantly dormant cells found ubiquitously within patient livers has already occurred prior to the development of overt metastatic disease or bona fide recurrent PDAC. However, remarkably little is known about early PDAC cell dissemination despite these dismal outcomes, mainly due to the lack of human models to study disease progression. We previously demonstrated the cellular reprogramming “proof-of-principle” to model human PDAC progression (designated “10-22 cells”) and its use as a discovery tool for early biomarkers by unveiling a marker for stage 1 PDAC in human patients. We further analyzed transcriptomes of genetically tagged 10-22 cells progressing from pancreatic intraepithelial neoplasia (PanIN) to PDAC in mice and validated the results using the TCGA PDAC dataset, human clinical PanIN, PDAC tissues, and a well-established murine PDAC model. We found that extracellular vesicle transport and neuronal cell differentiation pathways were derepressed in the progression of PanINs to PDAC. HMG-Box Transcription Factor 1 (HBP1) emerged as a potential master factor regulating dynamically expressed genes in neuronal cell differentiation and dissemination during PDAC progression. HBP1 expression are aberrantly regulated in human and murine PanINs and PDAC tissue samples, and their mRNA expressions are inversely correlated with PDAC patients' prognosis. Ectopic overexpression of HBP1 increased proliferation and migration of normal and cancerous pancreatic cells. Conversely, knocking out HBP1 in PDAC cells decreased proliferation and migration. Altogether, our data indicate that HBP1 may confer the cell dissemination capacity in early PDAC progression. We are on the way to further dissect the mechanisms by which HBP1 regulates pancreatic cell migration and confers neuronal migratory phenotypes and how these signaling influence PDAC progression and prognosis.
Citation Format: Taelor J. Ekstrom, Dmytro Grygoryev, Terry Morgan, Kenneth S. Zaret, Jungsun Kim. Delineating the molecular basis of early dissemination of pancreatic cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-082.
Abstract PO-103: Cellular origin influences immune microenvironment in a pancreatic cancer mouse model with loss of Pten and activation of Kras
Authors: Dou Yan , Hunt Wesley , Chhuor Justin , Taghizadeh Farnaz , Samani Atefeh , Sarai Karnjit , Dubois Claire , Schaeffer David F. , Sander Maike , Kopp Janel L. 
Published: November 2021

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with an overall 5-year survival rate of merely 9%. Although mouse studies in the past decade have made progress towards a better understanding of how PDAC cellular origin affects tumorigenesis, there hasn’t been study on the immune microenvironment differences between precursor lesions and PDAC derived from acinar and ductal cells. Following our previous study that showed loss of Pten with oncogenic KrasG12D mutations in the ductal cells (KPtenDuct/+) resulted the formation of intraductal papillary mucinous neoplasias (IPMN) as the precursor lesion in mice, we further found siminar mutations in the acinar cells (KPtenAcinar/+) formed pancreatic intraepithelial neoplasia (PanIN) instead. We subsequently used the KPtenDuct/+ and KPtenAcinar/+ models to elucidate the effect of cellular origin on the immune microenvironment by performing immunohistochemistry. We looked at immune cell infiltration densities between precursor lesions and PDAC derived from KPtenDuct/+ and KPtenAcinar/+ models and will present the data during the conference. Additionally, macrophages polarized by conditioned media derived from KPtenDuct/+ and KPtenAcinar/+ PDAC cells showed distinctive polarization status, indicating cellular origin could result in PDAC with different cytokine and chemokine profiles that affect the immune microenvironment. Our study is the first to directly compare immune cell population between acinar- and ductal-derived PDAC originating from different types of precursor lesions with the same genetic background. Our study suggests the potential role of cellular origin on influencing PDAC immune heterogeneity.
Citation Format: Yan Dou, Wesley Hunt, Justin Chhuor, Farnaz Taghizadeh, Atefeh Samani, Karnjit Sarai, Claire Dubois, David F. Schaeffer, Maike Sander, Janel L. Kopp. Cellular origin influences immune microenvironment in a pancreatic cancer mouse model with loss of Pten and activation of Kras [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-103.
Abstract PO-107: Fibroblast differentiation trajectories elicit regional tissue states in pancreatic cancer
Authors: Grünwald Barbara T. , McCloskey Curtis , Devisme Antoine , Vyas Foram , Andrieux Geoffroy , Aliar Kazeera , Notta Faiyaz , O’Kane Grainne , Wilson Julie , Knox Jennifer , Fischer Sandra , Kislinger Thomas , Boerries Melanie , Gallinger Steven , Khokha Rama 
Published: November 2021

Abstract
Intratumoral heterogeneity is a critical frontier in understanding how the tumor microenvironment (TME) propels malignant progression. We recently deconvoluted regional heterogeneity in the human PDAC stroma to assess its role in disease progression and discovered two types of ‘sub-tumor microenvironments’ (subTMEs), called ‘reactive’ and ‘deserted’. These histologically definable tissue states exhibit strong regional relationships with tumor immunity, subtypes, differentiation, and treatment response. Here, we set out to define their cell biological underpinnings through a combination of subTME-specific cancer-associated fibroblast (CAF) models, integrative histopathology, quantitative image analysis, multiOMICs, scRNAseq, and controlled functional assays. Remarkably, the growth patterns of CAF cultures closely recapitulated the characteristic histomorphology of their originating subTMEs, and these distinct phenotypes were accompanied by behavioral differences. Unsupervised graph-based clustering of scRNAseq profiles showed that CAFs largely grouped by their originating subTME yet comprised up to 10 individual clusters. The subTME-specific multi-subpopulation CAF communities self-organized into distinct ‘coordinated states’, represented by cluster-overarching functional profiles and distinct morpho-histological and behavioral phenotypes. These differences originated in cellular differentiation trajectories, with an ‘intermediate’ transitory state evident both in single cell transcriptomics and in situ. Noticeably, this CAF differentiation potential was associated with distinct tumor-related functions and, similar to stem cells, was marked by RNA diversity and pluripotency markers. Therefore, regional TME programs in PDAC appear to result largely from transitions between subpopulation-overarching fibroblast differentiation states that guide multifaceted CAF and immune cell communities into recurrent tissue self-organizational units.
Citation Format: Barbara T. Grünwald, Curtis McCloskey, Antoine Devisme, Foram Vyas, Geoffroy Andrieux, Kazeera Aliar, Faiyaz Notta, Grainne O’Kane, Julie Wilson, Jennifer Knox, Sandra Fischer, Thomas Kislinger, Melanie Boerries, Steven Gallinger, Rama Khokha. Fibroblast differentiation trajectories elicit regional tissue states in pancreatic cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-107.
Abstract PO-114: STAT3 in cancer-associated fibroblasts promotes an immunosuppressive tumor microenvironment
Authors: Lefler Julia E. , Ostrowski Michael , MarElia-Bennett Catherine 
Published: November 2021

Abstract
One of the defining characteristics of pancreatic ductal adenocarcinoma (PDAC) is the formation of a dense stroma comprised of cancer associated fibroblasts (CAFs) and immune cell populations. This stroma is immunosuppressive and can act as a physical barrier against common therapeutic treatments. Attempts to therapeutically target the PDAC stroma have yielded contradictory results, suggesting both tumor promoting and tumor limiting roles for CAFs. These studies emphasize the need to understand important transsignaling pathways between CAFs, tumor cells, and the immune microenvironment. IL-6 is a pleiotropic cytokine involved in several physiological functions and its increased expression is strongly associated with poor survival rates in PDAC patients. STAT3 is a major downstream target of IL-6, and its aberrant activation has been implicated in PDAC tumor progression and immune evasion. IL-6 expression and the IL-6/STAT3 signaling axis in PDAC has been characterized in epithelial tumor cells, however its stromal-specific function on PDAC has yet to be elucidated. We hypothesized that the STAT3 signaling axis in pancreatic CAFs contributes to the immunosuppressive and fibrotic phenotype seen with disease progression. Employing CreLoxP technology, the fibroblast specific protein-1 (Fsp-Cre) transgene was used to conditionally delete STAT3 in fibroblasts in the PdxFlp; KrasG12D; p53frt/frt (KPF) PDAC mouse model developed by our lab. Deletion of STAT3 in fibroblasts significantly increased the survival in a cohort of KPF mice compared to those with intact STAT3. In preliminary investigations, we found an increase in CD8+ T cell infiltration but a decrease in regulatory T cells in the STAT3-deleted cohort. We also observed a decrease in immunosuppressive M2 macrophage populations and an increase in M1 macrophages in the STAT3-deleted cohort. These preliminary results demonstrate a previously unexplored role of IL-6/STAT3 signaling in fibroblasts during PDAC progression.
Citation Format: Julia E. Lefler, Michael Ostrowski, Catherine MarElia-Bennett. STAT3 in cancer-associated fibroblasts promotes an immunosuppressive tumor microenvironment [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-114.
Abstract PO-118: The tumor immune microenvironment is decisive in the survival of pancreatic ductal adenocarcinoma
Authors: Aziz Hosein M. , Saida Lawlaw , de Koning Willem , Stubbs Andrew , Li Yunlei , van Eijck Casper H. J. , Mustafa Dana A. M. 
Published: November 2021

Abstract
Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy associated with a poor prognosis. Only 10% of the patients survive longer than five years. So far, factors underlining long-term survivorship in PDAC are not well understood. Therefore, we aimed to identify the key players in the tumor immune microenvironment (TIME) associated with long-term survivorship in PDAC patients. Methods: The immune-related gene expression profiles of surgically resected PDAC tumors of patients who survived and remained recurrence-free of disease for &gt; 3 years (long-term survivors, n=10) were compared to PDAC tumors of patients who had survived ≤ 6 months (short-term survivors, n=10) due to tumor recurrence. Samples were profiled using the nCounter® PanCancer Immune Profiling Panel of NanoString Technology. Validation was performed by spatial analysis of immune cells using the GeoMx™ Digital Spatial Profiler. Results: Tumor-infiltrating B cells were found to be significantly increased in the TIME of long-term survivors by gene expression profiling (p=0.018). The high tumor infiltration of B cells was confirmed by spatial protein profiling (p=0.049). This increase was accompanied by more T cells and antigen-presenting cell infiltration. Moreover, the activated immune cells were found to infiltrate in between tumor cells as well as in stromal areas in long-term survivors. In contrast, the TIME of short-term survivors was characterized by a high density of immunosuppressive cells like CD25 and regulatory T cells infiltrating in a highly fibrotic vicinity. Conclusion: This is the first comprehensive study that connects the immune landscape of gene expression profiles and protein spatial infiltration with the survivorship of PDAC patients. We found higher infiltration of B cells in TIME of long-term survivors which highlights the importance of targeting B cells and B cell-based therapy for future personalized immunotherapy in PDAC patients.
Citation Format: Hosein M. Aziz, Lawlaw Saida, Willem de Koning, Andrew Stubbs, Yunlei Li, Casper H. J. van Eijck, Dana A. M. Mustafa. The tumor immune microenvironment is decisive in the survival of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-118.
Abstract PO-119: DFMO mediated improvement in survival of an orthotopic model of pancreatic cancer is associated with modulating immune suppression in the tumor microenvironment
Authors: Nakkina Sai Preethi , Gitto Sarah B. , Pandey Veethika , Beardsley Jordan M. , Rohr Michael W. , Parikh Jignesh G. , Phanstiel Otto , Altomare Deborah A. 
Published: November 2021

Abstract
There remains an urgent need to target pancreatic tumor cells using innovative strategies. KRAS and MYC, are important oncogenes in pancreatic ductal adenocarcinoma (PDAC) which pose a challenge to successful treatment of PDAC. Our previous studies have shown that inhibition of ornithine decarboxylase 1 (ODC1) using difluoromethylornithine (DFMO) decreases MYC expression and tumorigenesis. GW5074 can modulate RAF1, a downstream effector of KRAS. Here we test the responsiveness of pancreatic tumor cells treated with DFMO alone and in combination with GW5074. We used an orthotopic animal model of pancreatic tumor using KRas-driven murine pancreatic cancer cells (PanO2) to test the effects of these compounds on tumor microenvironment and overall survival. Cellular and molecular changes in the tumor microenvironment were assessed using immunohistochemistry. The results showed an inhibition of pancreatic cancer cell viability in DFMO and DFMO+GW5074 treatment groups in vitro, with a significant decrease in tumor weight compared to control treatment group in vivo. However, in terms of overall survival, DFMO alone resulted in a dramatic increase in survival compared to control treatment group. Interestingly, GW5074 alone or DFMO in combination with GW5074 did not result in a detectable effect on survival. Further investigation of immune cells in the tumor microenvironment revealed that standalone DFMO treatment was associated with an increase in infiltration of macrophages, T cell costimulatory marker CD86 and T cell markers (CD3, CD4 and CD8) compared to control and GW5074 treated groups. Additionally, DFMO is associated with decreased MYC expression compared to control and GW5074 treated groups. In conclusion, DFMO decreased MYC expression and associated immune suppression in the PDAC microenvironment. In contrast standalone GW5074 treatment resulted in maintenance of MYC expression and worse survival. In conclusion, the present study highlights the success of DFMO in PDAC treatment in part through downregulation of MYC and a decrease in associated immune suppression.
Citation Format: Sai Preethi Nakkina, Sarah B. Gitto, Veethika Pandey, Jordan M. Beardsley, Michael W. Rohr, Jignesh G. Parikh, Otto Phanstiel, Deborah A. Altomare. DFMO mediated improvement in survival of an orthotopic model of pancreatic cancer is associated with modulating immune suppression in the tumor microenvironment [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-119.
Abstract PO-129: Targeting CCR1 reprograms tumor associated macrophages in pancreatic cancer
Authors: Zhang Yaqing , Brown Kristee L. , Yan Wei , Nwosu Zeribe C. , Carpenter Eileen K. , Donahue Katelyn L. , Velez-Delgado Ashley , Yang Sion , Pasca di Magliano Marina 
Published: November 2021

Abstract
The tumor microenvironment of pancreatic ductal adenocarcinoma (PDA) includes abundant fibroblasts and infiltrating immune cells, the latter largely immunosuppressive. We previously showed that targeting regulatory T cell (Treg), a prevalent T cell population in pancreatic cancer, failed to relieve immunosuppression and led to accelerated tumor progression. We discovered that Treg depletion reprogrammed tumor associated fibroblasts and increased immunosuppressive myeloid cell recruitment, an effect that was partially mediated by CCLs/CCR1signaling. Thus, we sought to investigate the potential therapeutic effect of targeting CCR1 in pancreatic cancer. By single cell RNA sequencing, we found CCR1 to be mainly expressed by tumor associated macrophages (TAMs) and neutrophils (or granulocytes) in both human and mouse PDA. We then orthotopically transplanted syngeneic mouse pancreatic cancer cells in CCR1 knockout hosts, and observed reduced tumor growth which was rescued by CD8 T cell depletion. Histological analysis showed elevated Granzyme B expression in infiltrating T cells, as well as an increase in cleaved caspase 3 positive cancer cells in tumors implanted in Ccr1−/− mice. Through cytometry by time of flight (CyTOF) and co-immunofluorescence we also discovered that TAMs in tumors implanted in Ccr1−/− mice expressed less Arginase 1 and CD206 -both markers of immunosuppressive macrophages- compared to TAMs in wild type tumors. Thus, our data is consistent with the notion that tumor associated macrophages lacking CCR1 expression are less immunosuppressive, consequently allowing increased CD8 T cell-mediated anti-tumor immunity. We are currently exploring combination approaches targeting CCR1 in pancreatic cancer.
Citation Format: Yaqing Zhang, Kristee L. Brown, Wei Yan, Zeribe C. Nwosu, Eileen K. Carpenter, Katelyn L. Donahue, Ashley Velez-Delgado, Sion Yang, Marina Pasca di Magliano. Targeting CCR1 reprograms tumor associated macrophages in pancreatic cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-129.