bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract C016: Pancreatitis-induced resistance to KRAS targeted therapy: The role of cellular plasticity and underlying mechanisms
Authors: Deng Daiyong , Hou Pingping 
Published: September 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease characterized by cell plasticity, particularly the epithelial-to-mesenchymal transition (EMT) phenotype, which significantly contributes to both pancreatic tumorigenesis and therapy resistance. Chronic pancreatitis, a key risk factor for PDAC, induces fibrosis, recruits macrophages, and elevates TGFβ, an EMT master regulator, in the tumor microenvironment (TME). Despite the observed negative correlation between dependence on oncogenic KRAS signaling and the quasi- mesenchymal (QM) subtype, the role of cellular plasticity and the underlying mechanisms of resistance remain unclear. To address this, we employed genetically engineered mouse models that mimic human pancreatitis and PDAC, alongside an in vitro 3-D tumor spheroid culture system. Our study demonstrates that chronic pancreatitis promotes resistance to KRAS- targeted therapy through a canonical TGFβ signaling pathway-dependent mechanism. Nuclear Factor of Activated T Cells 5 (NFAT5) forms a hetero-pentamer with canonical TGFβ factors SMAD3 and SMAD4, inducing EMT and promoting therapy resistance. Analysis of human samples indicates a positive correlation between NFAT5 expression and pancreatic tumorigenesis, with elevated NFAT5 expression correlating with poorer overall survival in the TCGA PDAC dataset. Functional studies reveal that genetic depletion or chemical inhibition of NFAT5 thwarts resistance to KRAS inhibition induced by TGFβ or pancreatitis, impairs the growth of QM-like escaper tumors, and synergizes with KRAS inhibitors to further suppress tumor growth in pre-clinical models. Mechanistically, we identified the chaperone protein and extracellular matrix regulator S100A4 as a key effector transcriptionally activated by the NFAT5- SMAD complex, mediating therapy resistance partially through the activation of key KRAS downstream MAPK and AKT signaling pathways. Furthermore, our investigation reveals that TGFβ stimulates PDAC cells to secrete the chemokine CCL2, which recruits circulating macrophages. In turn, these macrophages support PDAC cells in bypassing KRAS inhibition through paracrine TGFβ and S100A4. Overall, this study establishes a molecular foundation for KRAS-targeted therapy resistance associated with cellular plasticity in PDAC, highlighting pancreatitis as a potential risk factor, and proposes a novel strategy to overcome this resistance through NFAT5 inhibition or S100A4 blockade.
Citation Format: Daiyong Deng, Pingping Hou. Pancreatitis-induced resistance to KRAS targeted therapy: The role of cellular plasticity and underlying mechanisms [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C016.
Abstract C017: Targeting KRAS selectively induce metabolic reprogramming in pancreatic cancer
Authors: Shiekh Laiba , Cheung Matthew , Zheng Linyuhui , Marlette Erica , Ezeh Chiamaka J. , Conde Don-Gerard , Nwosu Zeribe C. 
Published: September 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease largely due to the lack of effective treatments that overcome the tumor drug resistance. Oncogenic KRAS mutation contribute to most PDAC and drive multiple metabolic pathways to promote tumor growth. Despite this overarching role of KRAS, inhibition of KRAS/MAPK pathway often lead to resistance by yet unclear mechanism. Here we find that the pharmacological inhibition of KRAS/MAPK pathway induces distinct responses in various pancreatic cancer cells. Specifically, while KRAS/MAPK inhibition suppressed growth in some cells, the same treatment induced or did not change the growth of other cell lines and also selectively impacted cell migration. In addition, metabolic activities were suppressed in cells where growth was suppressed or not changed but was accelerated where KRAS/MAPK inhibition induced growth. Analysis of gene expression profile of human PDAC and KRAS-driven mouse tumors identified nutrient transporters that are upregulated KRAS induction but also upregulated upon KRAS inhibition. Our study reveals context-dependent response to KRAS inhibition in pancreatic cancer and suggest targeting nutrient transporters to overcome therapeutic resistance.
Citation Format: Laiba Shiekh, Matthew Cheung, Linyuhui Zheng, Erica Marlette, Chiamaka J. Ezeh, Don-Gerard Conde, Zeribe C. Nwosu. Targeting KRAS selectively induce metabolic reprogramming in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C017.
Abstract C020: Identification of KRAS-specific TCRs from human peripheral blood
Authors: Shen Jiao , Smith Blake E. , Alberto Winiffer Conce , Kim Ellen J. , Dougan Michael L. , Singh Harshabad , Birnbaum Michael E. , Dougan Stephanie K. 
Published: September 2024

Abstract
Mutant KRAS is the predominant driver oncogene in pancreatic cancer accounting for approximately 90% of KRAS mutations. However, these mutant KRAS peptides exhibit weak binding affinity to most human leukocyte antigens (HLAs), impeding their recognition by the immune system and the subsequent generation of a corresponding T cell response. Identification of KRAS-mutant specific T cells would be useful to track tumor-specific T cell responses in patients and could also be used for adoptive transfer of TCR-transduced cells. Current efforts to identify KRAS-specific T cells have been limited by their restriction to specific HLA haplotypes or the provision of only a few T cell receptor (TCR) sequences. In this study, we developed a facile means of detecting KRAS-specific T cells from peripheral blood at frequencies as low as 1 in 1,000,000. We employ an α41BB agonist-selective lentivirus system combined with a KRAS peptide pool to facilitate the high-throughput discovery of KRAS-specific TCRs in peripheral blood mononuclear cells (PBMCs) derived from both patients with pancreatic cancer and healthy donors. Through in vitro stimulation and single-cell TCR analysis, we identified a series of T cell expansions sharing the same clonotype, indicating a response to KRAS-mutant peptide stimulation. We have quantified CD4 and CD8 KRAS-specific TCRs from patients with a diverse range of HLA haplotypes.
Citation Format: Jiao Shen, Blake E. Smith, Winiffer Conce Alberto, Ellen J. Kim, Michael L. Dougan, Harshabad Singh, Michael E. Birnbaum, Stephanie K. Dougan. Identification of KRAS-specific TCRs from human peripheral blood [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C020.
Abstract C024: Quantitative mass spectrometry-based multi-omic profiling to overcome drug resistance in pancreatic cancer post KRAS G12D inhibition
Authors: Yu Qijia , Sindoni Nicole , Zhang Huan , Li Ziyue , Paulo Joao A. , Aguirre Andrew J. , Mancias Joseph D. 
Published: September 2024

Abstract
Recently developed inhibitors targeting the KRASG12D oncoprotein are undergoing clinical trial evaluation including in patients with pancreatic adenocarcinoma (PDAC). However, resistance to such targeted therapies is a frequent occurrence, potentially undermining the long-term success of KRAS inhibitors (KRASi). To uncover the adaptive pathways and cell surface biomarkers to KRASi and to identify effective drug combinations that can overcome resistance, we employ a mass spectrometry-based quantitative temporal proteomics workflow. This approach allows us to map the proteomic changes in response to KRASi in both in vitro and in vivo PDAC models. We identify and quantify 10,898 proteins, creating the most extensive proteomic dataset related to KRASi to date. We identify shared mechanisms of both acute and long-term adaptation to KRASi across PDAC models. Utilizing this proteomic information, we are pinpointing drug combinations that pair KRASi with inhibitors of CDK4/6, AURKA, and mTOR to increase cytotoxicity and thereby reduce development of long-term resistance. Surfaceome analyses identifies cell surface proteins upregulated upon acute and long-term KRASi, including TACSTD2 (Trop-2). Antibody-drug conjugates targeting upregulated surface proteins may be a useful orthogonal approach towards preventing or circumventing KRASi resistance with testing of Trop-2 and other candidates ongoing. In summary, through mass spectrometry-based quantitative temporal proteomics, we identify proteomic adaptations to KRASi in PDAC and propose combination treatments with promising therapeutic potential.
Citation Format: Qijia Yu, Nicole Sindoni, Huan Zhang, Ziyue Li, Joao A. Paulo, Andrew J. Aguirre, Joseph D. Mancias. Quantitative mass spectrometry-based multi-omic profiling to overcome drug resistance in pancreatic cancer post KRAS G12D inhibition [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C024.
Abstract C032: De novo pyrimidine biosynthesis inhibition synergizes with BCL-XL targeting in pancreatic cancer
Authors: huan zhang  , Qijia yu  , Santana-Codina Naiara , Poupault Clara , Campos Claudia , Qin Xingping , Padhye Aparna , Sindoni Nicole , Kuljanin Miljan , Wang Junning , Dorman Matthew J. , Aguirre Andrew J. , Dougan Stephanie K. , Sarosiek Kristopher A. , Mancias Joseph D. 
Published: September 2024

Abstract
Oncogenic KRAS, the genetic driver of 90% of PDAC, induces a metabolic rewiring characterized, in part, by dependency on de novo pyrimidine biosynthesis. Dihydroorotate dehydrogenase (DHODH) is the enzymatic ‘chokepoint’ of the de novo pyrimidine biosynthesis pathway and an in vivo metabolic liability in pancreatic ductal adenocarcinoma (PDAC). Targeting enzymes in the de novo pyrimidine synthesis pathway such as dihydroorotate dehydrogenase (DHODH) with clinically available inhibitor brequinar (BQ) starved the tumor of nucleotide synthesis and restrained growth of PDAC cells in vitro. However, therapeutic resistance limited BQ long-term effects in PDAC xenografts, which suggests compensatory pathways and that combinatorial strategies are required for enhanced efficacy. Here, we integrated a mass spectrometry (MS)-based quantitative temporal proteomics workflow, LC/MS- based metabolomics and in vitro and in vivo drug-anchored CRISPR/Cas9 genetic screens to identify compensatory pathways to DHODH inhibition (DHODHi) and targets for combination strategies. We demonstrate that DHODHi alters the apoptotic regulatory proteome thereby enhancing sensitivity to inhibitors of the anti-apoptotic BCL2L1 (BCL-XL) protein. Combinatorial regimens with DHODH and BCL-XL inhibition synergistically induce apoptosis in PDAC cell lines and patient-derived PDAC organoids. In vivo DHODH inhibition with Brequinar and BCL-XL degradation with DT2216, a proteolysis targeting chimera (PROTAC), significantly inhibits the growth of PDAC tumors. Our data defines mechanisms of adaptation to DHODH inhibition and identifies a combination therapy strategy in PDAC.
Citation Format: huan zhang, Qijia yu, Naiara Santana-Codina, Clara Poupault, Claudia Campos, Xingping Qin, Aparna Padhye, Nicole Sindoni, Miljan Kuljanin, Junning Wang, Matthew J. Dorman, Andrew J. Aguirre, Stephanie K. Dougan, Kristopher A. Sarosiek, Joseph D. Mancias. De novo pyrimidine biosynthesis inhibition synergizes with BCL-XL targeting in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C032.
Abstract C034: MUC1 positive extracellular vesicles play an important role on gemcitabine resistance in PDAC
Authors: Huang Ying , Wang Dezhen , He Chunbo , Tu Bo , Mehla Kamiya , Singh Pankaj K. , Hollingsworth Michael A. 
Published: September 2024

Abstract
Introduction Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest epithelial malignancies. The high death rate caused by PDAC results from complex factors, including difficulties in diagnosing early-stage disease, increased metastatic potential, and resistance to traditional therapies. Mucin1 (MUC1) is one of the transmembrane mucins typically expressed on the apical surface of epithelial cells but is not apically restricted and upregulated dramatically in pancreatic cancer cells. Our study showed that MUC1CT positive EVs promote tumor cell proliferation and migration in vitro, in vivo tumor growth, and metastasis. Moreover, MUC1 increases glucose metabolism in pancreatic cancer cell to resistance gemcitabine though stabilizing HIF-1α. However, the role of MUC1 in gemcitabine resistance has not been well studied and understood. Methods We used CRISPR-Cas9 to knockout MUC1 in pancreatic cancer cells to investigate MUC1 effects on chemotherapy resistance. EVs were isolated from MUC1 positive cells and MUC1 knockout cells by a sequence of centrifugation and ultracentrifugation steps. Proteomics and liquid chromatography-mass spectrometry-based metabolomics were performed to identify specific proteins and metabolites in MUC1-associated EVs. To evaluate the cargo of MUC1+ EVs and MUC1- EVs on chemotherapy resistance, 13C- labeled glucose with metabolomics was applied to trace glucose-related metabolites when the cells were treated with or without gemcitabine and EVs. Results We identified that MUC1 increased gemcitabine resistance in pancreatic cancer cells. MUC1 positive EVs could increase gemcitabine resistance in MUC1 knockout cells. Unique protein cargo in MUC1-positive EVs was enriched in DNA replication and DNA repair pathways. Phosphogluconate dehydrogenase (PGD) was packaged in MUC1-positive EVs, which helped glucose-derived ribose to increase MUC1 knockout cell gemcitabine resistance. Metabolomics in EVs showed that pyrimidine and purine nucleotides biosynthetic pathway-related metabolites are enriched in MUC1-positive EVs. Uridine is one of the important metabolites in MUC1-positive EVs. Our data showed that the pentose phosphate pathway (PPP) and pyrimidine metabolism were involved in MUC1- positive EV-induced gemcitabine resistance.
Citation Format: Ying Huang, Dezhen Wang, Chunbo He, Bo Tu, Kamiya Mehla, Pankaj K. Singh, Michael A. Hollingsworth. MUC1 positive extracellular vesicles play an important role on gemcitabine resistance in PDAC [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C034.
Abstract C037: Characterization of cysteine dependency implicates glutathione metabolism as a critical adaptation axis in pancreatic cancer
Authors: Ezeh Chiamaka J , Ward Matthew H , Jain Chesta , Charlestin Verodia , Kim Daeho D , Yang Andrew , Nassif Maya , Mbah Nneka , Sajjakulnukit Peter , Andren Anthony , Zhang Li , Pasca di Magliano Marina , Lyssiotis Costas A , Nwosu Zeribe C 
Published: September 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a deadly cancer that is highly malignant and lethal. The treatment options are limited, contributing to its high mortality rate. PDAC is known to have profound metabolic alterations that enable its growth and survival. Here, we screened for amino acid dependency in PDAC cell lines and found that the cells cluster into cysteine highly dependent, moderately dependent, and independent cells. In the highly dependent cells, cysteine deprivation reduces viability by ∼90%, which could be rescued by glutathione (GSH) supplementation. Metabolomics revealed that cysteine deprivation led to GSH depletion, suggesting an impairment in the GSH pathway machinery in these cells. Consistently, most metabolite intermediates in the GSH pathway are downregulated in the cysteine-reliant PDAC cell lines compared to cell lines that resist cysteine deprivation, and those cells showed higher sensitivity to oxidative stress induction. Bioinformatics analysis of multiple PDAC tumor gene expression datasets indicated that the GSH pathway is strongly upregulated in PDAC and correlates with proliferation, metastasis, and oncogenic KRAS upregulation. Using CRISPR/Cas9, we found that the knockout of GSH genes enhanced sensitivity to oxidative stress. Our data implicate the GSH pathway as a critical nexus to be targeted to overcome metabolic adaptation in PDAC.
Citation Format: Chiamaka J Ezeh, Matthew H Ward, Chesta Jain, Verodia Charlestin, Daeho D Kim, Andrew Yang, Maya Nassif, Nneka Mbah, Peter Sajjakulnukit, Anthony Andren, Li Zhang, Marina Pasca di Magliano, Costas A Lyssiotis, Zeribe C Nwosu. Characterization of cysteine dependency implicates glutathione metabolism as a critical adaptation axis in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C037.
Abstract C038: Cancer-associated fibroblasts maintain critical pancreatic cancer cell lipid homeostasis in the tumor microenvironment
Authors: Han Xu , Burrows Michelle , Kim Laura C , Xu Jimmy , Vostrejs Will , Van Le Tran Ngoc , Jiang Yanqing , Cukierman Edna , Kim Reiss Binder , Stanger Ben Z , Mesaros Clementina , Keith Brian , Simon Celeste 
Published: September 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy whose abundant cancer-associated fibroblasts (CAFs) create a hallmark “desmoplasia” that severely limits oxygen and nutrient delivery. Hypoxia inhibits oxygen-dependent metabolic processes. For example, unsaturated lipid biosynthesis relies on oxygen to maintain desaturase enzymatic activities. Here, we investigated the mechanisms by which PDAC cells maintain lipid homeostasis under these conditions. Exogenous unsaturated lipids, rather than de novo synthesis, sustain PDAC cell viability by relieving endoplasmic reticulum (ER) stress under nutrient scarcity. Furthermore, CAFs are less hypoxic than adjacent malignant cells in vivo due to proximal blood vessel accessibility, nominating them as a potential source of these obligatory species. CAF-conditioned medium promoted PDAC cell survival upon nutrient and oxygen deprivation, an effect reversed by delipidation. We determined that lysophosphatidylcholines (LPCs) are particularly enriched in CAF-conditioned medium and preferentially taken up by PDAC cells, where they are converted to phosphatidylcholines (PCs) to sustain membrane integrity. Inhibiting LPC to PC conversion reversed the ability of exogenous unsaturated LPCs to sustain cancer cell survival and restrain ER stress in vitro and in vivo. Collectively, these results reveal a critical lipid cross-feeding mechanism enabling PDAC cell survival and identify an innovative approach to targeting this metabolic dependency. Efforts to target lipid crosstalk between CAFs and PDAC cells will be discussed.
Citation Format: Xu Han, Michelle Burrows, Laura C Kim, Jimmy Xu, Will Vostrejs, Tran Ngoc Van Le, Yanqing Jiang, Edna Cukierman, Reiss Binder Kim, Ben Z Stanger, Clementina Mesaros, Brian Keith, Celeste Simon. Cancer-associated fibroblasts maintain critical pancreatic cancer cell lipid homeostasis in the tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C038.
Abstract C041: Emerging role of P2X receptors as Golgi pH regulators in pancreatic cancer
Authors: Galapate Cheska Marie , Galenkamp Koen , Fisher Charles , Heynen-Genel Susanne , Commisso Cosimo 
Published: September 2024

Abstract
Cancer cells reprogram their metabolism to meet their elevated energy demands, favoring energy production via glycolysis even with functional mitochondria. Upregulated glycolysis results in rapid production of lactate and protons in the cytoplasm. This would normally reduce the intracellular pH (pHi); however, cancer cells employ mechanisms such as ion transporters that remove excess protons from the cytoplasm to maintain an alkaline pHi, allowing for cell growth, evasion of cell death and cell proliferation. Our previous studies have shown that in pancreatic ductal adenocarcinoma (PDAC), the Golgi apparatus is among the intracellular compartments that can uptake excess protons, giving PDAC cells a cell fitness advantage. The underlying mechanisms that drive Golgi acidification in PDAC are incompletely understood. Here, we set out to comprehensively identify novel modulators that can affect this process. By using a fluorescent-protein-based ratiometric pH biosensor targeted to the Golgi membrane, we screened thousands of chemical compounds for an impairment in Golgi acidification, which would lead to pHi dysregulation and cell death. One of our hits from the screen was an inhibitor of the P2X family of receptors (P2XRs). P2XRs consist of seven subtypes (P2X1-7) and are ATP-gated ion channels that mediate the passage of non-selective cations through the plasma membrane and intracellular compartments. P2XRs have also been shown to regulate the pHi. We are elucidating the mechanism by which P2XRs may regulate pHi via the Golgi in PDAC. Our preliminary results show that concomitant with the alkalinization of the Golgi, P2XR inhibition leads to a pronounced decrease of pHi and results in cell death in PDAC while normal untransformed pancreas cells are unaffected. These data suggest that P2XRs play a role in pHi regulation and cell fitness maintenance through a function in the Golgi. Targeting this metabolic reprograming dependency may serve as a novel therapeutic tool for PDAC.
Citation Format: Cheska Marie Galapate, Koen Galenkamp, Charles Fisher, Susanne Heynen-Genel, Cosimo Commisso. Emerging role of P2X receptors as Golgi pH regulators in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C041.