bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A069: Study of MUC16/ERBB axis in pancreatic cancer
Authors: Baniya Amina , Hollingsworth Michael A. (Tony)
Published: January 2024

Background: Pancreatic cancer is the third leading cause of cancer-related deaths due to its poor prognosis and highly malignant nature. The altered expression of glycans and glycoproteins is associated with malignancy. MUC16 (also known as CA125) is a member of mucin family of glycoproteins known to line epithelial cells for protection and lubrication and is overexpressed in several cancer types, including pancreatic cancer, often linked with enhanced disease progression, metastasis, and reduced patient survival. Significance: Circulating levels of MUC16/CA125 has been used as a biomarker to monitor adenocarcinoma for decades. However, the functional role of CA125/MUC16 is yet to be elucidated due to a lack of studies on its large, heavily glycosylated structure and unknown functional domains. We present evidence that in addition to serving as a biomarker, circulating MUC16 has pro-tumorigenic activities. Hypothesis: Based on recent findings, we hypothesize that isoforms of MUC16 have high avidity for ErbB receptor and integrin complexes, with concomitant activation of downstream signaling cascades that include Akt and FAK, respectively. These result in the increased tumorigenic potential of pancreatic cancer cells in an autocrine manner. Experimental Design: There are four members of ErbB receptors; where receptor dimerization is a function of ligand binding and results in distinct downstream oncogenic signaling cascades. We evaluated the binding of MUC16 to different ErbB receptors, and its capacity to activate downstream signaling pathways using pancreatic cell line models that have different combinations of knock out/down of each ErbB receptor. We evaluated the global changes in the phosphorylation of oncogenic signaling molecules due to MUC16 binding using Reverse Phase Protein Array (RPPA). Results: We found that MUC16 activates Erbb4 (Y1162) along with other members of ErbB receptor family, where glycosylation of MUC16 is crucial for its biological activity. MUC16 enhanced oncogenic signaling through the phosphorylation of various downstream molecules and activated PI3K, RTK, MAPK, and DNA repair pathways. Our future directions include elucidating the molecular mechanism by which MUC16 activates the oncogenic signaling cascades via binding to ErbB receptors using our pancreatic cell line-based models. Conclusions: Understanding the biological activity of MUC16 and its cleaved product will further help in investigating the role of MUC16 in tumor microenvironment and at distant organ sites to influence the metastatic niche.

Citation Format: Amina Baniya, Michael A. (Tony) Hollingsworth. Study of MUC16/ERBB axis in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A069.
Abstract A080: Target genes in pancreatic cancer cells of the pan-quadruplex clinical candidate compound QN-302 revealed by comparative transcriptome profiling
Authors: Ahmed Ahmed , Arshad Tariq , Roman-Escorza Maria , Neidle Dan M. , Neidle Stephen
Published: January 2024

QN-302 is a tetra-substituted naphthalene derivative designed to have high affinity to quadruplexes in cancer-related genes, which have multiple quadruplex occurrence in their promoter sequences. QN-302 has ca 1 nM in vitro activity against a panel of pancreatic ductal adenocarcinoma (PDAC) cell lines and shows high activity against four distinct PDAC in vivo models, including the KPC genetic model. QN-302 is currently being developed for clinical trials in solid tumors including PDAC. It has also recently been granted orphan drug drug (ODD) status by the FDA. We have previously reported on whole-genome transcriptome studies for QN-302, which show that it selectively targets quadruplex-rich genes in PDAC-related pathways, and thus acts as a pan-quadruplex agent. We have recently extended our analysis to include two closely related analogs of QN-302 as well as data from a gemcitabine-resistant line. QN-302 is consistently ca 10-fold more potent in PDAC cells and in vivo than the second-best analog. RNA-seq whole-cell and comparative bioinformatics analyses have been used to probe these differences. This has resulted in the identification of those target genes that the naphthalene diimide family have in common, many of which are involved in PDAC pathways such as hedgehog, axon guidance, WNT/β-catenin and hippo. It has also been possible to identify a small number of quadruplex target genes that are highly and selectively down-regulated by QN-302, and which are also highly up-regulated in human PDAC. We suggest that these contribute to the exceptional in vivo potency of this compound.

Citation Format: Ahmed Ahmed, Tariq Arshad, Maria Roman-Escorza, Dan M. Neidle, Stephen Neidle. Target genes in pancreatic cancer cells of the pan-quadruplex clinical candidate compound QN-302 revealed by comparative transcriptome profiling [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A080.
Abstract A092: Exploiting the neural-like properties of a new pancreatic cancer morpho-biotype for the development of a combinatorial treatment targeting tumor heterogeneity
Authors: Diaferia Giuseppe R. , Di Chiaro Pierluigi , Fiumani Francesca , Nacci Lucia , Zerbi Alessandro , Spaggiari Paola , Barozzi Iros , Natoli Gioacchino
Published: January 2024

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers in which high intra-tumor heterogeneity and plasticity makes PDAC poorly responsive to available treatments. Coupling transcriptional profiling with laser capture microdissection of groups of cancer cells defined by distinct histological patterns, we were able to describe three PDAC “morpho-biotypes”. Such morpho-biotypes represent the combined morphological, molecular and functional properties of PDAC cells that coexist, in various proportions, in nearly all patients analyzed. Compared to single cells, our approach, that integrates morphological and spatial features, was able to clearly identify a novel morpho-biotype, primed toward a neural-like lineage differentiation. Only combining the expression of those genes able to discriminate all three morpho-biotypes, we achieved high prognostic power, underscoring the relevance of the co-existence of different cancer populations for clinical assessment. We therefore hypothesize that only combinatorial therapies, that target all the different biotypes simultaneously, can result in an effective cancer treatment. We identified an antiepileptic drug to be the best candidate to interfere with the neuronal-like program we unexpectedly found enriched in one of the PDAC morpho-biotypes. Using this drug with other oncogenic inhibitors specific for the other morpho-biotypes we obtained a complete stop of the tumor progression in a mouse model of xenografted human tumor fragments that maintained tumor heterogeneity. A similar neural progenitor-like signature was recently found enriched in single cell data form neo-adjuvant treated patients. This founding indirectly suggests that the new morpho-biotype we described in treatment-naïve patients could be responsible for the failure of the available treatments. This study not only contributes to our understanding of the effects of the combinatorial treatment, but also provides valuable molecular data for development of improved treatment schemes and histological maps that can guide pathologists’ diagnosis.

Citation Format: Giuseppe R. Diaferia, Pierluigi Di Chiaro, Francesca Fiumani, Lucia Nacci, Alessandro Zerbi, Paola Spaggiari, Iros Barozzi, Gioacchino Natoli. Exploiting the neural-like properties of a new pancreatic cancer morpho-biotype for the development of a combinatorial treatment targeting tumor heterogeneity [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A092.
Abstract A107: MAPK signaling is a conserved mechanism explaining phenotypic heterogeneity across diverse drivers of epithelial-mesenchymal transition in pancreas cancer
Authors: Barbeau Michelle C. , Lazzara Matthew J.
Published: January 2024

Epithelial-mesenchymal transition (EMT) is a developmental process that is aberrantly activated in cancers such as pancreatic ductal adenocarcinoma (PDAC) to promote disease progression and chemoresistance. EMT occurs heterogeneously among PDAC ductal cells, which frustrates efforts to identify the underlying signaling regulatory mechanisms. We hypothesize that cell-to-cell variation in the activities of specific signaling pathways explains EMT heterogeneity. To test this, we developed a workflow integrating: 1) iterative indirect immunofluorescence imaging (4i) to quantify the activities of up to seven purported EMT-regulating pathways with single-cell resolution and 2) a multivariate mutual information computational model to predict the pathways that are most informative of the EMT phenotype. In cultured PDAC cells, EMT was induced by treating cells with growth factors present in the tumor microenvironment (hepatocyte growth factor, epidermal growth factor, transforming growth factor β1, or two combinations) or with chemotherapeutics (gemcitabine or 5-fluorouracil). EMT phenotypic markers and signaling pathway proxies were assessed daily for up to 96 hr. A mutual information analysis of the aggregated data identified ERK as the most important signaling node explaining EMT heterogeneity across the diverse set of agonists investigated. Kinase inhibition and siRNA studies confirmed the implied role of ERK but also revealed a compensatory, EMT-driving JNK activation in the context of MEK inhibition that explains a cooperative effect of simultaneous MEK and JNK inhibition on EMT antagonism. Importantly, a model based on cell population-level measurements nominated JNK as more informative than ERK for determining EMT state in response to growth factors. We are implementing this approach in vivo using pancreas cancer tissue sections to determine generalizability of these findings in different microenvironmental contexts. Overall, our results demonstrate the pervasive importance of ERK for diverse drivers of EMT and the need to account for the effects of heterogeneous signaling pathway activation in the determination of EMT.

Citation Format: Michelle C. Barbeau, Matthew J. Lazzara. MAPK signaling is a conserved mechanism explaining phenotypic heterogeneity across diverse drivers of epithelial-mesenchymal transition in pancreas cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A107.
Abstract A115: Collective invasion facilitates liver metastasis in pancreatic ductal adenocarcinoma
Authors: Eng Jennifer R. , Pelz Carl , Chin Koei , Sivagnanam Sam , Jason Link M. , Keith Dove , Coussens Lisa , Sears Rosalie C.
Published: January 2024

Fifty percent of PDAC patients present with distant metastasis and face a dismal prognosis of 8 to 11 months. However, patients with lung metastases have better prognosis than patients with metastatic spread to other sites. In our PDAC metastasis cohort, patients with lung-only metastasis survived longer than patients with liver metastasis, despite sharing the same tumor subtype. To understand features of the primary tumor linked to metastatic site, we generated a novel gene signature for primary organotropism (pORG) that distinguishes primary tumors that developed liver metastasis from those that developed lung metastasis, independent of known tumor subtypes. Our pORG signature predicts survival independently of transcriptional subtype, genetic alterations and clinicopathological variables and in a validation cohort consisting of TCGA pancreatic cancer. Primary tumors with high pORG scores, i.e., liver-tropic primaries, have increased transcriptomic signatures of proliferation and replication stress whereas low pORG tumors have increased lymphocyte gene expression. To validate our findings, we generated cyclic immunofluorescence multiplex imaging data from 34 primary tumors. As anticipated, single cell image analysis revealed high B and T cell infiltration in low-pORG tumors, and increased proliferation and replication stress foci in high-pORG tumors. Intriguingly, malignant cells from high pORG tumors had an increased fraction KRT19-high tumor cells relative to low pORG tumors and were distinctly epithelial in appearance. To reconcile the metastatic behavior of high pORG tumors with their apparent enrichment for epithelial-state cells, we hypothesized that liver-tropism was associated with a partial epithelial-to-mesenchymal transition (EMT) state and metastasis via collective invasion. Bulk transcriptional analysis of 200 PDAC primary tumors revealed a distinct subset of high pORG tumors have increased expression of markers linked to partial EMT and collective invasion, including RAB11a, Rho-like GTPases, and proteases MMP7 and KLK7. Our results support a model of E-cadherin internalization facilitating partial EMT and collective invasion. Current efforts include in-vitro characterization of migration modes in patient-derived cell lines and organoids. Our work suggests unique and targetable tumor intrinsic features linked to organotropism in PDAC.

Citation Format: Jennifer R. Eng, Carl Pelz, Koei Chin, Sam Sivagnanam, Link M. Jason, Dove Keith, Lisa Coussens, Rosalie C. Sears. Collective invasion facilitates liver metastasis in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A115.
Abstract B009: Identifying of a novel diagnostic markers for pancreatic neuroendocrine tumors by proteomics with patient blood
Authors: Koh Eun-Young , Jeong Ji Hye , Ahn Hee-Sung , Kim Kyunggon , Jun Eunsung
Published: January 2024

Neuroendocrine tumors are tumors originating from endocrine cells in various organs, and present very heterogeneous characteristics, and the incidence rate is gradually increasing. Among them, neuroendocrine tumors originating from pancreas are divided into functional tumors and non-functional tumors according to the presence hormone secretion function. Since non-functional tumors are often asymptomatic, early diagnosis is not easy, and differential diagnosis from pancreas ductal adenocarcinoma (PDAC) is difficult, making it difficult to determine the direction of treatment. Therefore, we aimed to find protein biomarkers for the diagnosis and differential diagnosis of pancreatic neuroendocrine tumors (PNET) through proteomic analysis of human blood. First, a total of 60 human plasma samples were obtained from 17 PNETs, 23 PDACs, and 20 Healthy donors (HD), and liquid chromatography-mass spectrometry (LC-MS) proteomics analysis was performed. For 60 cases of raw data obtained through LC-MS analysis, identification and label-free quantification were performed through the Human swissprot protein sequence database. Through pre-processing and normalization, an average of 549 protein lists for each sample were obtained. And through quantitative evaluation, the proteomes that were increased or decreased for each disease were analyzed and classified, and ACTR3, CD163, and LECT2, which were increased in PNET, were selected as diagnostic biomarker candidates. The diagnostic AUC for distinguishing PNET from HD was 0.706 for ACTR3, 0.971 for CD163, and 0.541 for LECT2. The diagnostic AUC to distinguish PNET from PDAC was 0.821 for ACTR3, 0.870 for CD163, and 0.783 for LECT2. We selected three candidates, ACTR3, CD163, and LECT2, as blood biomarkers for the accurate diagnosis of PNET. And through the combination of markers, it is expected that the sensitivity and accuracy of the diagnosis can be further increased. In the future, we will study the function as a marker that can simultaneously predict diagnosis and treatment response by identifying the molecular biological mechanism for the generation and progression of PNET through these three markers.

Citation Format: Eun-Young Koh, Ji Hye Jeong, Hee-Sung Ahn, Kyunggon Kim, Eunsung Jun. Identifying of a novel diagnostic markers for pancreatic neuroendocrine tumors by proteomics with patient blood [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B009.
Abstract B025: IL-1 blockade prevents cardiac toxicity and improves immunotherapy efficacy in mouse models of pancreatic cancer
Authors: Talele Nilesh P. , Kumra Heena , Gomes-Santos Igor L. , Roberge Sylvie , Ho William W. , Andersson Patrick , Chatterjee Sampurna , Siwicki Marie , Duda Dan G. , Pittet Mikael J. , Fukumura Dai , Jain Rakesh K.
Published: January 2024

Background: Immune checkpoint blockers (ICBs) have revolutionized cancer treatment, but they are often associated with severe immune related adverse events (irAEs). These severe irAEs are more often seen in patients with obesity or concomitantly treated with cytotoxic therapies. Methods: We aimed to understand the mechanisms of ICB-induced irAEs, in the context of obesity and ICB/chemotherapy combinations. We developed a mouse model of cardiac irAEs, which is the most fatal type of irAE in ICB-treated cancer patients, with clinically relevant features: (i) an ICB-resistant cancer (pancreatic ductal adenocarcinoma or PDAC), (ii) obesity induced with high-fat diets, and (iii) a combination treatment of ICB (α-PD1 + α-CTLA4) and chemotherapy (FOLFIRINOX). Results: Our FDA and single institution retrospective analyses indicate that patients treated with ICB had greater relative risk of developing myocarditis as compared to other anti-cancer therapies. Mice with orthotopic PDAC and obesity developed irAEs after treatment with ICB and chemotherapy as compared to chow diet. These irAEs recapitulated those observed in patients with cancer and obesity, including cardiac dysfunction consistent with myocarditis, cardiac fibrosis, and increased circulating levels of interleukin-1 beta (IL-1b). IL-1β blockade prevented myocarditis and reduced cardiac fibrosis after immunotherapy. Importantly, IL-1β blockade also enhanced the anti-tumor effects of ICB + FOLFIRINOX combination therapy, and increased mouse survival. Conclusions: We developed a translationally relevant 'triple hit' mouse model and discovered that IL-1β mediates ICB-induced cardiotoxicity. In addition, we found that IL-1β blockers, which are already used in the clinic for cardiology indications, both reduce adverse events and simultaneously enhance the antitumor effects triggered by immunotherapy.

Citation Format: Nilesh P. Talele, Heena Kumra, Igor L. Gomes-Santos, Sylvie Roberge, William W. Ho, Patrick Andersson, Sampurna Chatterjee, Marie Siwicki, Dan G. Duda, Mikael J. Pittet, Dai Fukumura, Rakesh K. Jain. IL-1 blockade prevents cardiac toxicity and improves immunotherapy efficacy in mouse models of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B025.
Abstract B033: Tumor cell-intrinsic mPGES-1-PGE2-EP4 signaling is a major immunosuppressive pathway in pancreatic cancer
Authors: Markosyan Nune , Kim Il-Kyu , Arora Charu , Quinones Liz , Cheng Noah , Stanger Ben Z. , Vonderheide Robert H.
Published: January 2024

Pancreatic adenocarcinoma (PDA) is the 4th leading cause of cancer-related deaths in the US partly because of its resistance to conventional chemotherapies. Immunotherapies that improve survival in many cancers, almost universally fail in PDA. The resistance to immune checkpoint blockade is at least partially explained by the lack of T cells in the tumor microenvironment (TME) in PDA. As demonstrated previously, tumor cell-derived prostaglandin E2 (PGE2) is one of the tumor intrinsic factors that creates/supports immunosuppressive TME in PDA. The current study investigates how depleting tumor cell-derived PGE2 or disrupting its autocrine signaling through the cognate EP4 receptors on tumor cells reverses the T cell low, myeloid cell rich PDA TME and suppresses the tumor growth. Pharmacological blockade of EP4 receptors combined with anti-PD-1 and agonistic CD40 antibodies induced complete tumor regressions with a lasting vaccine effect. Knockout (KO) of Ptges, the gene encoding PGE2 synthesis enzyme mPGES-1, or EP4 receptor gene, Ptger4, in KrasG12D/P53R172H/Yfp/PdxCre (KPCY) pancreatic tumor cells was sufficient to abolish the growth of implanted tumors (p<0.0001 both). The rejection of the primary KO and rechallenge control tumors was T cell-dependent as it did not happen in hosts depleted of CD4+ and CD8+ T cells. Both KO tumor cells were more susceptible to TNF-a killing while their TMEs were enriched with central memory T cells and phagocytic macrophages and depleted of granulocytic myeloid-derived suppressor cells (gMDSC). Further analysis of Ptger4 tumors revealed changes in CCL2, CXCL9, and GM-CSF production probably causing the changes in TME. In addition, in both Ptges and Ptger4 KO tumors, the adenosine synthesis pathway was significantly downregulated probably due to decreased TGF-b signaling in tumor cells. When cultured ex vivo in hypoxic conditions, Ptger4 KO tumors made significantly less immunosuppressive adenosine (p<0.001). Consequently, 57% of Ptger4 KO tumors in adenosine deaminase inhibitor treated hosts accumulated enough adenosine to suppress the anti-tumor immune response and grow out. The study demonstrates a primary role for the tumor cell-intrinsic mPGES1-PGE2-EP4 signaling in creating immune-suppressive TME in PDA, suggesting EP4 blockade as a novel approach in the treatment of pancreatic cancer.

Citation Format: Nune Markosyan, Il-Kyu Kim, Charu Arora, Liz Quinones, Noah Cheng, Ben Z. Stanger, Robert H. Vonderheide. Tumor cell-intrinsic mPGES-1-PGE2-EP4 signaling is a major immunosuppressive pathway in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B033.
Abstract B053: Physical activity regulates targetable transcriptomic changes in the adipose tissue of obese PDAC mice
Authors: Hsueh Hsiang-Yin , Pita-Grisanti Valentina , Vélez-Bonet Ericka , Cao Lei , Huang Wei , Cruz-Monserrate Zobeida
Published: January 2024

Background: Obesity is a risk factor for pancreatic ductal adenocarcinoma (PDAC), a highly aggressive cancer with a low 5-year survival rate. The association between obesity and PDAC could be attributed to the inflammatory effects of obesity and its impact on the adipose microenvironment. Physical activity (PA) is a potential approach to counteract obesity and its associated inflammation. Moreover, a recent study revealed that exercise-induced interleukin (IL)-15 in tumors has an anti-tumor response. However, there is still limited understanding of the mechanisms underlying how PA impacts the adipose-tumor microenvironments in PDAC. In this study, we hypothesized that PA could upregulate anti-inflammatory signaling in the adipose tissue and that targeting some of these signaling pathways could be a novel therapy for obesity-associated PDAC. Methods: Transcriptomic analysis was performed on adipose tissue obtained from a genetically engineering mouse model of obesity-associated PDAC. The mice were fed an obesogenic high-fat diet and divided into groups with and without PA intervention for one month. An adipose-specific recombinant adeno-associated vector (rAAV) was generated and mouse IL-15 cDNA was subcloned into the vector. C57BL/6J mice were administered intraperitoneal injections of either the rAAV/empty or rAAV/IL-15 vectors. Three weeks after rAAV intraperitoneal injection, mice were orthotopically injected with mouse KRasG12D/Trp53−/−/PDX-1-CRE cells expressing firefly luciferase to monitor growth in vivo and expression of IL-15 in the adipose tissue was confirmed via qPCR. Results: PA intervention increased the expression of genes related to metabolic and inflammation-related pathways. The administration of a novel adipose-targeted rAAV resulted in the upregulation of IL-15 within the adipose tissue and not the tumor. Increasing IL-15 expression in the adipose tissue led to a notable delay in tumor growth in an orthotopic mouse model. Conclusions: Here, we show that PA modulates gene expression in the adipose tissue and the beneficial impact of adipose tissue molecular remodeling on anti-tumor effects. However, more studies are needed to characterize the full extent of the adipose-tumor interactions and how they can be effectively targeted for therapeutic interventions.

Citation Format: Hsiang-Yin Hsueh, Valentina Pita-Grisanti, Ericka Vélez-Bonet, Lei Cao, Wei Huang, Zobeida Cruz-Monserrate. Physical activity regulates targetable transcriptomic changes in the adipose tissue of obese PDAC mice [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B053.
Abstract B061: Development of a pancreatic ductal adenocarcinoma 3D tumor model for high-throughput drug screening
Authors: Song Xiaoyu , Nihashi Yuma , Kida Yasuyuki S.
Published: January 2024

Pancreatic ductal adenocarcinoma (PDAC) is a persistent malignancy that is difficult to diagnose in its early stage and is one of the leading cancer-related deaths worldwide. Currently, limited therapeutic options are available for PDAC, resulting in an extremely low 5-year survival rate. To speed up the discovery of novel therapeutics, a reliable 3D model that highly simulates the PDAC tumor microenvironment is needed for large-scale drug screening. In this study, we propose a novel 3D model for restoring the PDAC tumor microenvironment by targeting cancer-associated fibroblasts (CAFs), which serve as the key component of the PDAC, providing its heterogeneity and contributing to reciprocal signaling and drug resistance. Our previous studies have demonstrated that Adipose-derived mesenchymal stem cells can differentiate into varying subtypes CAFs when co-cultured with PDAC cells both in vitro and in vivo. Following this strategy, we utilize the fibroblast-populated collagen lattice (FPCL) modeling approach, which relies on the contractility of fibroblasts in a collagen gel matrix, to provide the mechanical stress and hypoxic conditions for the 3D tumor models. Human Adipose-derived mesenchymal stem cells as CAF precursors and PDAC cell lines were mixed with collagen solution to make the collagen discs, resulting in the formation of 3D PDAC tumor models within a week. The morphological analyses, along with global transcriptome and metabolomic analyses, were performed to confirm the clinical-like mature ductal glands of PDAC cells and CAFs-like spindle-shaped of mesenchymal stem cells in the interior of PDAC-FPCL (PDAC-F). Moreover, the PDAC-F has shown a high tumorigenic potential in vivo animal model. Additionally, PDAC-F was shown to allow combination therapies screening of anticancer and antifibrotic drugs in the drug screening test, demonstrating that the combination therapeutics have better efficacy. In conclusion, our PDAC-F is built with distinct features of PDAC, reproducing the heterogeneous and high stiffness with a clinical-like PDAC morphology. In addition, the short modeling time and the high reproducibility of this PDAC-F open the possibilities for large-scale drug screening, which is expected to accelerate new drug development and provide effective treatment for pancreatic cancer patients.

Citation Format: Xiaoyu Song, Yuma Nihashi, Yasuyuki S. Kida. Development of a pancreatic ductal adenocarcinoma 3D tumor model for high-throughput drug screening [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B061.
Abstract B072: SMAD4 loss allows progression from benign to malignant disease in intraductal papillary mucinous neoplasms
Authors: Means Anna L. , Yoo Hannah , Trinh Quoc-Huy , Thiagarajan Roshini , Zi Jinghuan , Revetta Frank L. , Tan Marcus C. , DelGiorno Kathleen E. , Washington Mary K.
Published: January 2024

As increasing numbers of MRIs and other scans are ordered for unrelated diseases, more and more people are being diagnosed with cystic neoplasms of the pancreas. While many or most of these will likely remain benign, intraductal papillary mucinous neoplasms (IPMNs) have a risk of progression to cancer and IPMN is now recognized as another precursor to pancreatic ductal adenocarcinoma. We are investigating the mechanisms by which IPMNs progress from benign to malignant disease in order to identify markers of progression and targets to block that progression. We found that loss of SMAD4 in conjunction with Krasmutation leads to IPMN that quickly becomes invasive in a mouse model. Examining human IPMN tissues, we found that only one in 46 benign IPMN tumors lacked detectable SMAD4 protein. Among 19 cases of invasive IPMNs, the sites of active invasion were SMAD4 negative in 7 cases, nuclear negative/cytoplasm positive in 3 cases (suggesting no active canonical signaling), and a mix of positive and negative cells in 3 cases, implicating complete or partial loss of SMAD-mediated signaling in 68% of actively invading cells. In order to understand how SMAD signaling blocks progression to invasion, we are examining cell lines from a benign mouse model of IPMN. While these lines do not have endogenous TGF beta signaling, they are capable of responding to exogenous TGF beta, suggesting that TGF beta-related ligands may be supplied by the tumor microenvironment rather than the tumor cells themselves. We are currently determining how different TGF beta family members contribute to regulation of growth and invasion in these cells. In summary, loss of the tumor suppressor SMAD4 allows an otherwise benign disease to progress to invasive cancer.

Citation Format: Anna L. Means, Hannah Yoo, Quoc-Huy Trinh, Roshini Thiagarajan, Jinghuan Zi, Frank L. Revetta, Marcus C. Tan, Kathleen E. DelGiorno, Mary K. Washington. SMAD4 loss allows progression from benign to malignant disease in intraductal papillary mucinous neoplasms [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B072.
Abstract B082: Extinction of oncogenic Kras in genetic mouse models eradicates pancreatic cancer by inducing Fas-dependent apoptosis by CD8+ T cells
Authors: LeBleu Valerie S. , Mahadevan Krishnan K. , Ramirez Elena V. , Chen Yang , Li Bingrui , Sockwell Amari M. , Gagea Mihai , Sugimoto Hikaru , Tampe Desiree , Zeisberg Michael , Ying Haoqiang , Jain Abhinav K. , DePinho Ronald A. , Maitra Aniban , McAndrews Kathleen M. , Kalluri Raghu
Published: January 2024

Oncogenic KrasG12D (Kras*) is critical for the initiation and maintenance of pancreatic ductal adenocarcinoma (PDAC), and a known repressor of tumor immunity. Conditional extinction of Kras* in genetic mouse models of PDAC leads to reactivation of Fas, CD8+ T cell mediated apoptosis, and complete eradication of tumors. Kras* extinction recruits CD4+ and CD8+ T cells, promotes the activation of putative antigen presenting CD11b−CD11c+ dendritic cells, and suppresses CD11b+ myeloid cell infiltration. Our findings shows that Kras* drives T cell suppression in PDAC. Mechanistically, Kras* mediated immune evasion involves epigenetic regulation of the death receptor Fas in cancer cells, via repression of its promoter region mediated by functional recruitment of DNA methyltransferase 1 (DNMT1), trimethylation of histone 3 at lysine 27 (H3K27me3), the histone methyltransferase EZH2, and suppression of acetylation of histone 3 at lysine 27 (H3K27ac). Further, analysis of human RNA sequencing reveals that Kras* expression levels inversely correlate with FAS expression and PDAC tumors with high KRAS demonstrate low CD8+ T cell infiltration, which is associated with shorter overall survival in PDAC patients. Given that specific and effective targeting of Kras* results in the CD8+ T cell mediated, Fas dependent apoptosis of cancer cells and eradication of PDAC in mice, this study highlights the direct role of Kras* in suppression of tumor immunity and supports a role for immunotherapy in combination with Kras* targeting strategies to control PDAC.

Citation Format: Valerie S. LeBleu, Krishnan K. Mahadevan, Elena V. Ramirez, Yang Chen, Bingrui Li, Amari M. Sockwell, Mihai Gagea, Hikaru Sugimoto, Desiree Tampe, Michael Zeisberg, Haoqiang Ying, Abhinav K. Jain, Ronald A. DePinho, Aniban Maitra, Kathleen M. McAndrews, Raghu Kalluri. Extinction of oncogenic Kras in genetic mouse models eradicates pancreatic cancer by inducing Fas-dependent apoptosis by CD8+ T cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B082.
Abstract B102: Development of covalent inhibitors targeting Ras Q61 hotspot mutants
Authors: Pampel Julius , Morstein Johannes , Zheng Qinheng , Peacock David M. , Shokat Kevan M.
Published: January 2024

Mutations in the proto-oncogenes RAS are a key driver of various cancers, including pancreatic, colorectal, non–small cell lung cancer (NSCLC), melanoma, and thyroid cancer. Despite being considered undruggable for many years, recent efforts have led to the FDA approval of two drugs, Sotorasib and Adagrasib. They covalently target the K-Ras mutant isoform K-Ras(G12C), thereby inhibiting its oncogenic effect. However, the use of these drugs is inherently limited to cancers driven by the K-Ras(G12C) mutant, which is very common only in NSCLC. Although other covalent inhibitors targeting the K-Ras mutants K-Ras(G12S) and K-Ras(G12R) have been developed, it has so far not been possible to target the other frequently mutated amino acid Q61. Here we present our approach for the development of novel covalent inhibitors specifically targeting Q61 mutations in Ras proteins, which are prevalent in melanoma, multiple myeloma, and thyroid cancer. We demonstrate how covalent inhibitors specifically react with the mutant Q61C in both K and H-Ras proteins as proof-of-concept and show our efforts to extend this to the other Q61 mutant isoforms. We base our strategy on the modification of well-established switch-II pocket K-Ras inhibitors and explore multiple novel scaffolds specifically designed to target mutations of Q61. In addition to its occurrence in various cancers, Ras(Q61X) is also a common resistance mutation in patients treated with MAPK inhibitors. This work could further increase the number of patients potentially benefiting from Ras(Q61X) targeting drugs.

Citation Format: Julius Pampel, Johannes Morstein, Qinheng Zheng, David M. Peacock, Kevan M. Shokat. Development of covalent inhibitors targeting Ras Q61 hotspot mutants [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B102.
Abstract C052: Ketogenic diet enhanced nutrient metabolic pathways but did not inhibit tumor growth in an obesity-associated PDAC mouse model
Authors: Velez-Bonet Ericka , Gumpper-Fedus Kristyn , Choueiry Fouad , Jiangjiang Zhu , Cruz-Monserrate Zobeida
Published: January 2024

Background: Pancreatic ductal adenocarcinoma (PDAC) has a dismal 5-year survival rate due to ineffective treatments. Obesity is a recognized risk factor for PDAC. Thus, developing effective weight management strategies is essential to decrease obesity, and potentially mitigate PDAC risk. The high-fat, low-carbohydrate ketogenic diet (KD) promotes weight loss and is a promising therapeutic strategy in some cancer preclinical models by altering tumor metabolism. Purpose: The KD will disrupt cancer metabolism, promote weight loss, and delay tumor growth in obesity-associated PDAC. Methods: C57BL/6 mice were fed an obesogenic high-fat diet (HFD) for 15 weeks to induce obesity, after which were randomized to a control diet (CD), a KD, or continued in the HFD for 7 weeks. After, mice were orthotopically injected with mouse KRas G12D/Trp53−/−/PDX-1-CRE (mKPC) cells containing the firefly luciferase gene. Tumor growth was monitored using luminescence through an In Vivo Imaging System. Body weight, glucose tolerance tests, and ketone measurements were performed before, during, and at the study end. Tumors metabolomics were analyzed by Liquid Chromatography Mass Spectrometry. Results: Mice gained weight after 15 weeks of an obesogenic diet. Mice that were switched to a KD or CD lost weight compared to mice that remained on the HFD following diet intervention. Mice fed a KD maintained increased ketone concentrations and increased glucose tolerance after tumors. However, none of the dietary interventions decreased tumor growth. Tumors in mice fed a KD showed significant enrichment in metabolic processes, such as, vitamin B6 and vitamin B5 metabolism, the citrate cycle, and arginine biosynthesis compared to mice that remained on a HFD. Conclusions: Although the KD induced weight loss and altered tumor metabolism, it was insufficient to decrease tumor growth in an obesogenic PDAC mouse model. Our data identified vitamin B6 and vitamin B5 metabolism, the citrate cycle, and arginine biosynthesis as important compensatory metabolic processes induced by the KD. Understanding the availability and functions of these metabolic processes could identify mechanisms of diet interventions for obesity-associated PDAC to decrease obesity, and potentially mitigate PDAC growth.

Citation Format: Ericka Velez-Bonet, Kristyn Gumpper-Fedus, Fouad Choueiry, Zhu Jiangjiang, Zobeida Cruz-Monserrate. Ketogenic diet enhanced nutrient metabolic pathways but did not inhibit tumor growth in an obesity-associated PDAC mouse model [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C052.
Abstract C053: Autophagy regulates MAT2A in response to hypoxia in pancreatic cancer cells
Authors: Yang Yang , Wang Wenping , Rademaker Gilles , Ravichandran Mirunalini , Hu Jingjie , Li Alexander , Mancias Joseph D. , Guo Jessie Yanxiang , Perera Rushika M.
Published: January 2024

Methionine adenosyltransferase 2A (MAT2A) is an essential enzyme responsible for biosynthesis of S-adenosylmethionine, a methyl-group donor of various methyltransferases. Pancreatic ductal adenocarcinoma PDAC is characterized by severe hypoxia and upregulates autophagy and lysosomal biogenesis to enhance nutrient recycling and stress resistance. Here we show that a subset of MAT2A is targeted via the autophagy pathway for degradation by the lysosome under normoxia in PDAC cells, but is subsequently protected against degradation under hypoxia. Mechanistically, we show that the autophagy cargo receptor SQSTM1 (p62) binds to MAT2A in a ubiquitin-dependent manner under normoxia to regulate its autophagic capture. Under hypoxic conditions, stabilized MAT2A potentially facilities increased flux of methionine towards increased SAM, suggesting that protection of MAT2A against lysosomal degradation might enable alterations in methionine metabolism that drive epigenetic and metabolic adaptation to stress.

Citation Format: Yang Yang, Wenping Wang, Gilles Rademaker, Mirunalini Ravichandran, Jingjie Hu, Alexander Li, Joseph D. Mancias, Jessie Yanxiang Guo, Rushika M. Perera. Autophagy regulates MAT2A in response to hypoxia in pancreatic cancer cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C053.
Abstract C087: Window-of-opportunity trial of metastatic pancreatic cancer reveals mechanisms of response to targeting RAS signaling
Authors: Tsuda Motoyuki , Daniel Colin J. , Pelz Carl , Sivagnanam Sam , Keith Dove , Corless Christopher L. , Chin Koei , Coussens Lisa M. , Brody Jonathan R. , Lopez Charles D. , Mills Gordon B. , Sears Rosalie C.
Published: January 2024

KRAS is mutated in ~85% of pancreatic ductal adenocarcinoma (PDAC) patients' tumors, suggesting that it is a key node of PDAC targeted therapy. RAF/MEK/ERK signaling is downstream of KRAS signaling. Preclinical studies targeting MEK showed promises but clinical trials failed to show the benefit compared to Standard-of-Care treatment chemotherapy. To elucidate the mechanism of action and resistance to several targeted therapies including MEK inhibition in human PDAC, we conducted a Window-Of-Opportunity trial for Metastatic pancreatic cancer (WOOM trial). In this trial, metastatic PDAC patients received 10 days of Cobimetinib, a FDA approved MEK inhibitor, therapy and specimens of pre- and post- treatment were obtained by biopsy to evaluate the response to targeted treatment using deep multi-omic analytics including DNA-seq, RNA-seq, multiplex IHC, cyclic IF and Digital Spatial Profiling (DSP). The clinical grade KI67 staining positivity was used as a readout of tumor response. We found three of 15 patients’ tumors had significantly decreased KI67 staining after MEKi treatment. Genomic sequence showed that two of three KI67-decreased patient’s tumors had KrasG12R mutations, which is significantly higher penetration compared to none of twelve KI67-non-responsive patient’s tumors. RNA-seq analysis showed that these KI67-decreased tumors are more classical-like compared to Ki67-non-responsive tumors. DSP analysis confirmed the downregulation of ERK phosphorylation after treatment in all examined cases. Moreover, MYC protein expression change is significantly correlated with KI67 protein expression change, which suggests MYC downregulation is the mechanism of action of MEK-inhibitor. Interestingly, MEK phosphorylation was upregulated after treatment in all examined cases. This suggests paradoxical RAF activation as a potential resistance mechanism. Furthermore, we found that Cobimetinib treatment changed the tumor microenvironment. Here, we summarize the multi-omics data and discuss the mechanism of response and resistance to target RAS signaling and related microenvironmental changes.

Citation Format: Motoyuki Tsuda, Colin J. Daniel, Carl Pelz, Sam Sivagnanam, Dove Keith, Christopher L. Corless, Koei Chin, Lisa M. Coussens, Jonathan R. Brody, Charles D. Lopez, Gordon B. Mills, Rosalie C. Sears. Window-of-opportunity trial of metastatic pancreatic cancer reveals mechanisms of response to targeting RAS signaling [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C087.
Abstract C089: A novel role of p53 in pancreatic acinar cell identity
Authors: Twardowski Jennifer J. , Mello Stephano S. , Heist Thomas I.
Published: January 2024

Pancreatitis is an inflammatory disease that affects acinar cells in the exocrine pancreas, and can be triggered by several factors, such as alcohol abuse, smoking and familial genetic alterations. Pancreatic injury associated with pancreatitis is characterized by inflammation, acinar cell death, and acinar-to-ductal metaplasia (ADM), a regenerative process in which metaplastic cells proliferate and re-differentiate into acinar cells. Recurrent pancreatitis can cause persistent ADM, impairing exocrine function and causing precancerous lesions known as pancreatic intraepithelial neoplasia (PanIN) that can initiate pancreatic ductal adenocarcinoma (PDAC), a nearly always fatal disease. Importantly, the lack of treatment options for pancreatitis patients reinforces the need for strategies that could resolve pancreatic damage and stop disease progression. We have recently shown that pancreatic cells harboring a hyperactive variant of p53 display increased resistance to developing acute pancreatitis induced by cerulein (a secretagogue which mimics cholecystokinin). Here, we show that p53 activation using the drug Nutlin-3a can repair the damage caused by cerulein-induced pancreatitis, and reduce the formation of PanIN lesions. This repair is achieved exclusively at low doses of Nutlin-3a, which cause a mild p53 activation, and is entirely dependent on the presence of the p53 gene. We have also identified novel p53 target genes relevant to acinar identity from ChIP-seq and RNA-seq data, and validated their dependence on p53 in mouse embryonic fibroblasts and in pancreatic precancerous lesions. Lastly, we have observed expression of p53 in the developing pancreas at embryonic day 15.5, indicating a potential function of p53 in pancreatic development. Our findings suggest a novel role of p53 in rescuing acinar cells from damage, and that p53 activation may be used as a treatment for pancreatitis and pancreatic cancer prevention.

Citation Format: Jennifer J. Twardowski, Stephano S. Mello, Thomas I. Heist. A novel role of p53 in pancreatic acinar cell identity [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C089.