Development Of Pancreatic Cancer Research Articles

Transcription factor FOXF2 promotes the development and progression of pancreatic cancer by targeting MSI2.

Pancreatic cancer (PC) is a malignant tumor possessing high mortality. The role of transcription factor Forkhead Box F2 (FOXF2) in PC remains unverified. The current study investigated the roles of FOXF2 in developing PC in vitro and in vivo. A xenograft tumor model was constructed with nude mice injected using FOXF2‑overexpressing PC cells or FOXF2‑silenced PC cells. High FOXF2 expression significantly enhanced the proliferation ability of PC cells in vitro and pancreatic tumor growth in vivo. The cell cycle analysis indicated that transition of G1‑S phase was promoted by FOXF2. The cell cycle‑associated proteins cyclin D1, CDK2, phosphorylated (p)‑CDK2 and p‑RB were upregulated in the FOXF2‑overexpressing cells and downregulated in the cells with FOXF2 knockdown. Flow cytometric analysis and Hoechst staining showed that the percentage of apoptotic cells was significantly increased after FOXF2 was silenced. FOXF2 knockdown promoted expression of pro‑apoptotic proteins (Bad, Bax and cleaved caspase‑3) while suppressing the anti‑apoptotic proteins (Bcl‑2 and Bcl‑xl) at the protein level. FOXF2 improved the migration and invasion of PC cells in vitro. Moreover, luciferase and chromatin immunoprecipitation assays revealed that FOXF2 binds to the MSI2 promoter, promoting its transcriptional expression. FOXF2 knockdown inhibited the MSI2 protein translation while enhancing the translation of NUMB protein, suppressing PC development in vivo. MSI2 silencing reversed the promotive effect mediated by FOXF2 on cell proliferation. These results demonstrated that FOXF2 is essential in PC progression, and the potential mechanism includes regulating MSI2 transcription.

The serum tenascin C level is a marker of metabolic disorder-related inflammation affecting pancreatic cancer prognosis

Obesity is a risk factor for pancreatic cancer development, partly due to the tissue environment of metabolic disorder-related inflammation. We aimed to detect a tissue environment marker triggered by obesity-related metabolic disorders related to pancreatic cancer progression. In murine experiments, Bl6/j mice fed a normal diet (ND) or a high-fat diet (HFD) were orthotopically injected with mPKC1, a murine-derived pancreatic cancer cell line. We used stocked sera from 140 pancreatic cancer patients for analysis and 14 colon polyp patients as a disease control. Compared with ND-fed mice, HFD-fed mice exhibited obesity, larger tumors, and worse prognoses. RNA sequencing of tumors identified tenascin C (TNC) as a candidate obesity-related serum tissue environment marker with elevated expression in tumors of HFD-fed mice. Serum TNC levels were greater in HFD-fed mice than in ND-fed mice. In pancreatic cancer patients, serum TNC levels were greater than those in controls. The TNC-high group had more metabolic disorders and greater CA19-9 levels than did the TNC-low group. There was no relationship between serum TNC levels and disease stage. Among 77 metastatic patients treated with chemotherapy, a high serum TNC concentration was an independent poor prognostic factor. Pancreatic cancer patients with high serum TNC levels experienced progression more rapidly.

KRAS-mediated upregulation of CIP2A promotes suppression of PP2A-B56α to initiate pancreatic cancer development.

Oncogenic mutations in KRAS are present in approximately 95% of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC) and are considered the initiating event of pancreatic intraepithelial neoplasia (PanIN) precursor lesions. While it is well established that KRAS mutations drive the activation of oncogenic kinase cascades during pancreatic oncogenesis, the effects of oncogenic KRAS signaling on regulation of phosphatases during this process is not fully appreciated. Protein Phosphatase 2A (PP2A) has been implicated in suppressing KRAS-driven cellular transformation. However, low PP2A activity is observed in PDAC cells compared to non-transformed cells, suggesting that suppression of PP2A activity is an important step in the overall development of PDAC. In the current study, we demonstrate that KRASG12D induces the expression of both an endogenous inhibitor of PP2A activity, Cancerous Inhibitor of PP2A (CIP2A), and the PP2A substrate, c-MYC. Consistent with these findings, KRASG12D sequestered the specific PP2A subunit responsible for c-MYC degradation, B56α, away from the active PP2A holoenzyme in a CIP2A-dependent manner. During PDAC initiation in vivo, knockout of B56α promoted KRASG12D tumorigenesis by accelerating acinar-to-ductal metaplasia (ADM) and the formation of PanIN lesions. The process of ADM was attenuated ex vivo in response to pharmacological re-activation of PP2A utilizing direct small molecule activators of PP2A (SMAPs). Together, our results suggest that suppression of PP2A-B56α through KRAS signaling can promote the MYC-driven initiation of pancreatic tumorigenesis.

Oncogenic DDX46 promotes pancreatic cancer development and gemcitabine resistance by facilitating the JMJD6/CDK4 signaling pathway.

Pancreatic cancer (PAAD) is a fatal malignancy with a poor prognosis. The treatment strategies are quite limited and gemcitabine is the canonical one, which has been proven to improve the prognosis of PAAD patients. However, the treatment efficiency of gemcitabine is far from satisfactory and remains to be further improved. DEAD-Box Helicase 46 (DDX46) is a kind of RNA helicase, which promotes multiple cancers development. However, its role in PAAD is largely unknown. In the present study, we found DDX46 was highly expressed in PAAD tissues and correlated with poor prognosis. Knockdown of DDX46 repressed PAAD cell growth in vitro and in vivo and sensitized PAAD cells to gemcitabine treatment. Mechanically, DDX46 bound to JMJD6 and promoted JMJD6/CDK4 signaling pathway. Overexpression of JMJD6 reversed the anti-tumor function of DDX46 knockdown. Our study found a novel pathological mechanism of PAAD progression and provided a potential therapeutic target to improve gemcitabine efficiency.

Apolipoprotein E is a prognostic factor for pancreatic cancer and associates with immune infiltration

BackgroundThe expression level of apolipoprotein E (APOE) in pancreatic ductal adenocarcinoma (PDAC) and its effect on the prognosis of PDAC patients are not clear. The effect of APOE on the immune status of patients with PDAC has not been elucidated. MethodsWe obtained pancreatic cancer data from the TCGA and GETx databases. Patients with PDAC who underwent pancreatic surgery at the Second Affiliated Hospital of Jiaxing University between 2012 and 2021 were included. Clinical pathological data were recorded, plasma APOE levels were measured, and tissue samples were collected. A tissue microarray was generated using the collected tissue samples. APOE and CD4 staining was performed to determine immunoreactive scores (IRSs). The expression of APOE in the plasma and tumour tissues of pancreatic cancer patients was analysed and compared. The correlations between plasma APOE levels, tissue APOE levels and clinicopathological characteristics were analysed. Survival prognosis was analysed using Kaplan-Meier survival analysis and Cox multivariate regression analysis. The correlations between APOE expression levels and immune biomarkers and immune cells were further analysed. Single-cell analysis of APOE distribution in various cells was performed on the TISCH website. ResultsAPOE was highly expressed in the tumour tissue of pancreatic cancer patients, and high plasma APOE levels were associated with poor prognosis. Females, patients with high-grade disease and patients with pancreatic head carcinoma had high plasma APOE levels. High APOE expression in tumour tissues was associated with good prognosis. Mononuclear macrophages in the pancreatic cancer microenvironment primarily expressed APOE. APOE levels positively correlated with immune biomarkers, such as CD8A, PDCD1, GZMA, CXCL10, and CXCL9, in the tumour microenvironment. APOE promoted CD4 + T cell or dendritic cell infiltration in the tumour microenvironment. ConclusionsAPOE may affect the occurrence and development of pancreatic cancer by regulating the infiltration of immune cells in the tumour microenvironment.

OTUB1/NDUFS2 axis promotes pancreatic tumorigenesis through protecting against mitochondrial cell death

Pancreatic cancer is one of the most fatal cancers in the world. A growing number of studies have begun to demonstrate that mitochondria play a key role in tumorigenesis. Our previous study reveals that NDUFS2 (NADH: ubiquinone oxidoreductase core subunit S2), a core subunit of the mitochondrial respiratory chain complex I, is upregulated in Pancreatic adenocarcinoma (PAAD). However, its role in the development of PAAD remains unknown. Here, we showed that NDUFS2 played a critical role in the survival, proliferation and migration of pancreatic cancer cells by inhibiting mitochondrial cell death. Additionally, protein mass spectrometry indicated that the NDUFS2 was interacted with a deubiquitinase, OTUB1. Overexpression of OTUB1 increased NDUFS2 expression at the protein level, while knockdown of OTUB1 restored the effects in vitro. Accordingly, overexpression and knockdown of OTUB1 phenocopied those of NDUFS2 in pancreatic cancer cells, respectively. Mechanically, NDUFS2 was deubiquitinated by OTUB1 via K48-linked polyubiquitin chains, resulted in an elevated protein stability of NDUFS2. Moreover, the growth of OTUB1-overexpressed pancreatic cancer xenograft tumor was promoted in vivo, while the OTUB1-silenced pancreatic cancer xenograft tumor was inhibited in vivo. In conclusion, we revealed that OTUB1 increased the stability of NDUFS2 in PAAD by deubiquitylation and this axis plays a pivotal role in pancreatic cancer tumorigenesis and development.

Nardilysin-regulated scission mechanism activates polo-like kinase 3 to suppress the development of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) develops through step-wise genetic and molecular alterations including Kras mutation and inactivation of various apoptotic pathways. Here, we find that development of apoptotic resistance and metastasis of KrasG12D-driven PDAC in mice is accelerated by deleting Plk3, explaining the often-reduced Plk3 expression in human PDAC. Importantly, a 41-kDa Plk3 (p41Plk3) that contains the entire kinase domain at the N-terminus (1-353 aa) is activated by scission of the precursor p72Plk3 at Arg354 by metalloendopeptidase nardilysin (NRDC), and the resulting p32Plk3 C-terminal Polo-box domain (PBD) is removed by proteasome degradation, preventing the inhibition of p41Plk3 by PBD. We find that p41Plk3 is the activated form of Plk3 that regulates a feed-forward mechanism to promote apoptosis and suppress PDAC and metastasis. p41Plk3 phosphorylates c-Fos on Thr164, which in turn induces expression of Plk3 and pro-apoptotic genes. These findings uncover an NRDC-regulated post-translational mechanism that activates Plk3, establishing a prototypic regulation by scission mechanism.

Oral bacteria accelerate pancreatic cancer development in mice

ObjectiveEpidemiological studies highlight an association between pancreatic ductal adenocarcinoma (PDAC) and oral carriage of the anaerobic bacterium Porphyromonas gingivalis, a species highly linked to periodontal disease. We analysed the potential...

Abstract CT022: Mutant KRAS peptide-based vaccine in patients at high risk of developing pancreatic cancer: Preliminary analysis from a phase I study

Abstract Background: The development of pancreatic ductal adenocarcinoma (PDAC) from the first driver event takes >10 years, providing a unique window of opportunity for early interception. As a frequent alteration identified in both PDAC and pancreatic premalignancy, mutant KRAS (mKRAS) has emerged as a potential target for immune-based interception strategies in individuals at high risk of developing pancreatic cancer. Methods: This is a single-arm, open-label, second-in-human phase I study of a pooled synthetic long peptide (SLP) vaccine with poly-ICLC adjuvant targeting up to six mKRAS subtypes (G12D, G12R, G12V, G12A, G12C, G13D) in patients with hereditary predisposition to developing PDAC (NCT05013216). Key inclusion: radiographic evidence of a pancreatic abnormality and eligibility under at least one of three high-risk groups based on family history of PDAC and/or germline mutation status. Vaccination schema: mKRAS vaccine given on weeks 1, 3, 5, and 13. Peripheral blood collected at baseline and weeks 5, 13, and 17 for analysis of immunogenicity by IFN-gamma ELISpot. Co-primary endpoints: safety and mKRAS-specific T cell response. Results: At the time of data cutoff (November 15, 2023), 15 out of 20 planned patients were vaccinated on study and evaluable for immunogenicity. All 15 patients achieved a mKRAS-specific T cell response, defined by the maximal fold change in the pooled average IFN-gamma-producing mKRAS-specific T cell density within 17 weeks post-vaccination (median: 12.3, range: 3.1-167). Differential immunogenicity elicited by individual mKRAS epitopes was noted in this cohort. Specifically, the mKRAS G12V peptide induced the highest fold change increase in antigen-specific T cell expansion (median: 32.6, range: 2.9-243) while the mKRAS G12D peptide was the least immunogenic (median: 7.6, range: 0.4-104). Regarding safety, all adverse events were grade 1 or grade 2 in severity per NCI CTCAE v5.0. The most frequent vaccine-related adverse events were injection site reactions (93.8%), fatigue (62.5%), chills (43.8%), and headache (37.5%). No safety signals were observed. Conclusions: For the first time, we demonstrate mKRAS-specific T cell responses induced by vaccination in a cohort of high-risk individuals with inherited predisposition to PDAC. These findings directly serve as proof-of-concept to advance vaccine strategies focused on intercepting the development of pancreatic cancer in high-risk populations. Support: Stand Up To Cancer, Lustgarten Foundation, and NIH/NCI. Citation Format: Saurav D. Haldar, Amanda Huff, Elizabeth Abou Diwan, Anna Ferguson, Carol Judkins, Jiayun Lu, Hao Wang, Hassan Sinan, Christopher Thoburn, Katherine M. Bever, Mark Yarchoan, Amy M. Thomas, Julie M. Nauroth, Daniel A. Laheru, Michael G. Goggins, Elizabeth M. Jaffee, Nilofer S. Azad, Neeha Zaidi. Mutant KRAS peptide-based vaccine in patients at high risk of developing pancreatic cancer: Preliminary analysis from a phase I study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT022.

Role of SGLT2 Inhibitors, DPP-4 Inhibitors, and Metformin in Pancreatic Cancer Prevention.

Pancreatic carcinoma is a highly aggressive tumor that usually presents when it has already metastasized. Therapeutic options for cure remain scarce and rely on combination chemotherapy with limited sustainability. Diabetes is considered an important risk factor for the development of pancreatic cancer due to the production of proinflammatory cytokines, which result in increased cell proliferation. More than half of patients diagnosed with pancreatic cancer eventually develop diabetes due to the destruction of insulin-producing cells. The interlinkage of both diseases might identify a possible preventative strategy for reducing the incidence of pancreatic carcinoma. This study reviewed the recent literature on the association between pancreatic cancer risk and SGLT2 inhibitors, GLP-1 RA, DPP-4 inhibitors, and biguanides. There are mixed data regarding the relationship between GLP-1 RA and DPP-4 inhibitors and pancreatic cancer, with some trials suggesting that they might increase the risk. In contrast, studies have mostly revealed that SGLT2 inhibitors have an antiproliferative effect on various tumors, such as liver, pancreatic, prostate, bowel, lung, and breast carcinoma, which might be due to their mechanism of blockage of reabsorption of glucose by cells, lowering the amount of available glucose for the growth of tumor cells. Metformin, the first-line agent for diabetes, has also been shown to be associated with decreasing pancreatic cancer risk and improving prognosis in those who already have the disease. Dedicated trials are needed to further delineate the association of antidiabetic drugs with the risk of pancreatic cancer in the general population, as previous studies have mostly focused on diabetic patients.

Inoculation of Pan02 cells produces tumor nodules in mouse pancreas: Characterization of a novel orthotopic pancreatic ductal adenocarcinoma tumor model for interventional studies.

Preclinical models of cancer are vital for assessing and predicting efficacies and toxicities of novel treatments prior to testing in human subjects. Current pancreatic tumor models exhibit variable growth rates, unpredictable tumor size after implantation in non-native tissues, or require surgical implantation. Surgical implantation in the pancreas may produce not only unpredictable tumor uptake but could also elicit additional inflammatory responses. In searching for a pancreatic carcinoma cell that can be introduced into a mouse via simple injection, we found that Pan02, a murine ductal pancreatic adenocarcinoma derived from a pancreatic lesion of a C57BL/6 mouse, inoculated peritoneally can consistently produce pancreatic tumors. This intraperitoneal, but not intravenous, introduction of Pan02 cells leads to the attachment and growth of Pan02 in the pancreas before spreading to other tissues. Time-course tissue analysis indicates that the Pan02 cells first find, infiltrate, and grow within the pancreas, producing a pancreatic tumor model. This model appears to mimic pancreatic cancer development in humans and is the first reported use of Pan02 cells to produce orthotopic pancreatic and metastatic neoplasms in a mouse model without the need for tumor implantation within matrices or survival surgeries. This orthotopic pancreatic tumor model, with consistent tumor uptake, synchronized tumor development and survival, and predictable outcomes may enable and accelerate the preclinical evaluation of treatment candidates for pancreatic cancer.

IFIT1 modulates the proliferation, migration and invasion of pancreatic cancer cells via Wnt/β-catenin signaling.

Previously, Interferon-induced Protein with Tetratricopeptide Repeats 1 (IFIT1) has been shown to promote cancer development. Here, we aimed to explore the role of IFIT1 in the development and progression of pancreatic cancer, including the underlying mechanisms. We explored IFIT1 expression in pancreatic cancer samples using The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. Cell Counting Kit-8 (CCK8), colony formation, scratch wound-healing and Transwell assays were performed to assess the proliferation, migration and invasion abilities of pancreatic cancer cells. Gene Set Enrichment Analysis (GSEA) and Western blotting were performed to assess the regulatory effect of IFIT1 on the Wnt/β-catenin pathway. We found that upregulation of IFIT1 expression is common in pancreatic cancer and is negatively associated with overall patient survival. Knockdown of IFIT1 expression led to decreased proliferation, migration and invasion of pancreatic cancer cells. We also found that IFIT1 could regulate Wnt/β-catenin signaling, and that a Wnt/β-catenin agonist could reverse this effect. In addition, we found that IFIT1 can promote epithelial-mesenchymal transition (EMT) of pancreatic cancer cells. Our data indicate that IFIT1 increases pancreatic cancer cell proliferation, migration and invasion by activating the Wnt/β-catenin pathway. In addition, we found that EMT could be regulated by IFIT1. IFIT1 may serve as a potential therapeutic target for pancreatic cancer.

Abstract 2802: Enterococcus faecalis-derived X facilitates pancreatic tumor by regulating immune microenvironment

Abstract Previous research in human samples has found a link between the intratumoral microbiome and the development and progression of pancreatic cancer. Nevertheless, the bacterial strains that may have an effect, and the underlying mechanisms, are largely unknown. To identify potential bacterial species, microbiome sequencing was performed on fecal and tumor samples obtained from KPC mice and patients with pancreatic tumors in this study. To identify metabolites associated with bacteria, untargeted metabolomics were analyzed on serum and tumor samples. Furthermore, advanced and high-throughput techniques, such as single-cell RNA sequencing, tumor organoids, engineered bacteria and germ-free mouse models, were used to elucidate the specific influence on the immune microenvironment of pancreatic tumors. Our findings reveal an increased abundance of Enterococcus faecalis (E. faecalis) in the gut during the development of pancreatic cancer, accompanied by its accumulation in the tumor. Patient-derived E. faecalis strain and its metabolite X, facilitated pancreatic tumor growth, reduced the recruitment of CD8+T cells, and caused their dysfunction in the tumor, relying heavily on E. faecalis intratumoral colonization. We found that X inhibits the production of anti-tumor chemokines like CCL21 and CCL8 in tumor cells, reducing peripheral CD8+ T cell infiltration into the tumor. Furthermore, X was found to inhibit glycolysis and compromise the function of tumor-infiltrating CD8+ T cells by decreasing the activity of lactate dehydrogenase (LDH) in CD8+ T cells. Additionally, oral doxycycline, an antibiotic that targets intratumoral E. faecalis, effectively enhanced the therapeutic effect of gemcitabine in pancreatic cancer. Finally, we present evidence that X may predicts efficacy and survival in pancreatic cancer patients. Together, our findings provide new insights into the role of E. faecalis in mediating the immune environment of pancreatic tumors, highlighting E. faecalis and X as potential therapeutic targets for pancreatic cancer patients. Citation Format: Bin Wang, Chao Yang, Yongjie Xie, Tianxing Zhou, Jun Yu, Jihui Hao. Enterococcus faecalis-derived X facilitates pancreatic tumor by regulating immune microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2802.

Abstract 1206: Three-dimensional immune atlas of pancreatic cancer precursor lesions reveals large inter- and intra-lesion heterogeneity

Abstract Immunotherapies are generally ineffective in pancreatic ductal adenocarcinoma (PDAC). Paradoxically, inflammation is believed to play a key role in PDAC development and invasion: patients suffering from chronic pancreatitis have a 13-fold increase in risk of developing PDAC. PDAC cells are surrounded by a dense network of fibrotic tissue containing immunosuppressive cells such as regulatory T cells, tumor-associated macrophages, and cancer-associated fibroblasts. Better understanding of the role of inflammation in PDAC could lead to the design of effective immunotherapies. Pancreatic intraepithelial neoplasia (PanIN) is a precursor to PDAC. While most of us will develop PanINs, few of these lesions will progress to invasive cancer. Efforts to determine which PanINs are likely to progress have shown that the size, incidence, and genetic variation of these lesions is high. Here, we add to these efforts through in-depth quantitative analysis of the pancreatic immune microenvironment. CODA is a novel 3D imaging technique used extensively to study the structure, transcriptomic signatures, and genetic heterogeneity of PanINs. In serial histological samples, CODA integrates image registration, cell detection, and segmentation of nine pancreatic structures: PanIN, normal ducts, islets, acini, nerves, vasculature, fat, stroma, and immune aggregates. Through integration with CD45, CD3, and FoxP3 labelled images, we explored immune infiltration in 48 large (cm3) samples of human pancreas tissues containing >1,000 PanIN lesions to describe spatial correlations between local immune hotspots, 3D tumor morphology, and the surrounding pancreas structures. We quantified inter- and intra-sample heterogeneity in immune response to pancreatic cancer precursor lesions. We determined that this cohort varied greatly in both the number of PanIN (range 3 - 92 per cm3) and overall immune cell density (range 3,000 - 40,000 immune cells/mm3). We determined that, while PanIN size is not related to local immune cell density, overall PanIN burden is highly correlated to global immune cell density. This suggests that PanIN content does not have a short-range relationship to inflammation, but does have a long-range relationship with pancreatic structures and immune infiltration. As chronic inflammation in the pancreas shows correlation with development of pancreatic cancer, increased knowledge of the heterogeneous, local immune cell environment in precancerous samples will help us determine the role of inflammation in reacting to and controlling malignant progression. Citation Format: Ashley L. Kiemen, Cristina Almagro-Pérez, Valentina Matos-Romero, Alicia M. Braxton, Jaanvi Mahesh-Babu, Elizabeth D. Thompson, Toby C. Cornish, PeiHsun Wu, Laura D. Wood, Arrate Muñoz-Barrutia, Ralph H. Hruban, Denis Wirtz. Three-dimensional immune atlas of pancreatic cancer precursor lesions reveals large inter- and intra-lesion heterogeneity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1206.

Abstract 1403: The role of Dclk1-expression cells in normal pancreas and in pancreatic tumor progression

Abstract Background: Tuft cells, marked by Doublecortin-like kinase-1 (Dclk1), are rare in the healthy pancreas but increase markedly during pancreatic tumorigenesis. While Group 2 innate lymphoid cells (ILC2s) are known to modulate inflammation and immunity, their specific roles in cancer-related immunity and immunotherapy interactions with pancreatic tuft cells remain unknown. Methods: To investigate tuft cells during early pancreatic neoplasia, we used a Dclk1 reporter mouse model and single-cell RNA-seq to study Dclk1-expressing cells in normal pancreas and neoplasia using Mist1/Kras mouse. We treated mice with IL-13 peptides and anti-IL-13 antibodies to explore the IL-13-ILC2 axis in tuft cell regulation. Results: Within the normal pancreas, Dclk1 expression marked several specialized epithelial cell types, including tuft-like cells, neuroendocrine cells, and a small number of acinar progenitor cells. A notable increase in Dclk1-expressing cells was observed at the onset of early PanIN lesions, with a subsequent decline in advanced PanIN stages and PDAC. Using flow cytometric analysis, we observed an increase in ILC2 cells in the Mist1/Kras pancreas in response to IL33 produced by pancreatic cancer-associated fibroblasts (CAFs). Blocking ILC2 activation with anti-IL33 antibodies reduced Dclk1 cell hyperplasia during PanIN progression. Given the known association between tuft cells, ILC2 cells, and the IL13/IL4 signaling pathways in the intestine, we discovered that Dclk1-expressing cells highly expressed the IL4 receptor (IL4ra). IL-13 levels increased during PanIN progression, and we found that ILC2s comprised the primary source of IL-13 within pancreatic tumors. In vitro, studies showed that the presence of IL-13 maintained the expansion of Dclk1-expressing tuft-like cells in pancreatic organoids derived from Dclk1-DTR-ZsGreen mice. Correspondingly, the in vivo administration of anti-IL-13 resulted in reduced Dclk1 expression. Conclusion: Previous studies have shown that pancreatic tuft cells inhibit pancreatic cancer progression. Our study reveals a novel regulatory mechanism wherein IL-13 secreted by ILC2s modulates Dclk1 tuft cell expression during pancreatic tumorigenesis. The IL13-ILC2 axis appears to be a potential therapeutic target to regulate Dclk1 cell activity, which could influence the course of pancreatic tumorigenesis. Future investigations will further explore the interaction between the IL13/ILC2 axis and Dclk1 in pancreatic cancer development. Citation Format: Giovanni Valenti, Pasquale Laise, Feijing Wu, Hiroki Kobayashi, Quin T. Waterbury, Ryota Takahashi, Tuo Ruan, Zhengyu Jiang, Yosuke Ochiai, Leah B. Zamechek, Timothy C. Wang. The role of Dclk1-expression cells in normal pancreas and in pancreatic tumor progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1403.

Abstract 4978: Genomic characterization of metastatic pancreatic cancer according to tumor sample sites

Abstract Background: Our research aimed to evaluate and compare the genetic variations in the primary and metastatic sites of patients with metastatic pancreatic cancer. Methods: In this study, we selected individuals with metastatic pancreatic cancer from the data provided by the American Association for Cancer Research Project GENIE (version 14.1). The comparison of genetic mutations between primary and metastatic tumor sites was conducted using the Fisher exact test, augmented with the Benjamini-Hochberg adjustment technique. Results: In a study of 3,108 patients with metastatic pancreatic cancer, 38.9% had metastatic site tumor samples, while 61.1% had samples from the primary tumor. The most frequent mutations were KRAS (89.4%), TP53 (72.9%), SMAD4 (21.2%), and CDKN2A (17.4%). Metastatic samples showed higher rates of CDKN2A, CDKN2B, and MTAP mutations compared to primary site samples (40.1% vs. 29.1%; 20.3% vs. 10.4%; and 20.8% vs. 8.9%, respectively, all with p<0.001 and q<0.001). In patients with young-onset pancreatic cancer (younger than 50 years), there was no notable difference in gene mutations between the two sample groups. Conclusion: Our findings corroborate the notion that identifying the precise genes that contribute to the development of metastatic pancreatic cancer is vital for gaining a more comprehensive understanding of the biological mechanisms. Moreover, genomic profiling could be a key in pinpointing potential biomarkers for diagnosis and therapy. Citation Format: Suleyman Y. Goksu, Muhammet Ozer, Busra Bacik Goksu, Nina N. Sanford, Amy Jones, Nilesh Verma, Syed Kazmi. Genomic characterization of metastatic pancreatic cancer according to tumor sample sites [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4978.

Abstract 4112: Identification of Th1-specific epitopes from non-mutated KRAS lesions for off-the-shelf cancer vaccines

Abstract Background KRAS is crucial for cell growth, differentiation, and signaling. Mutations in the KRAS gene (i.e., codon 12 or 13) are frequently associated with the development and progression of cancer, particularly lung, colorectal, and pancreatic cancers. Recently, it has been captured that KRAS targeting cancer vaccine research and clinical trials have been conducted in certain tumor types and vaccine approaches are encouraged to move forward. It has been well known that the tumor-eradicating efficacy of cancer vaccines arises from Th1 epitope selection. While tumor growth may persist after immunization with non-selected epitopes (including full-length), immunization with a highly selected Th1-specific epitope vaccine can lead to tumor regression by suppressing the activation of immune inhibitory cells. The Th-Vac® discovery platform uses a combination of in-silico, in-vitro, and in-vivo studies to precisely identify Th1-specific epitopes. It consists of two modules: module 1 (in-silico) and module 2 (in-vitro and efficacy evaluation). The aim is to identify MHC class II epitopes that are specific to antigens for CD4+ T cells, displaying the most favorable binding affinity across diverse alleles. Th1-specific epitope vaccines aim to boost and sustain T cell immunity against tumor antigens, overcoming the lack of a precise T cell response or pre-existing tolerance in the immunosuppressive TME. This study aimed to explore Th1-specific epitopes for KRAS vaccine to be potentially effective in numerous KRAS mutation-driven cancers. Methods Peptide sequence candidates that have highly potential of MHC class II binding affinity were comprehensively predicted via a module 1 (ASEP program). All of peptides selected in ASEP were synthesized as 15 mers. Each peptide was evaluated for immunogenicity using ELISpot and/or FACS analysis in module 2 (2a for in vitro and 2b for in vivo immunologic evaluation) of the Th-Vac® discovery platform. Specifically, in Module 2b, immunogenicity was evaluated using a 38-mer peptide formed by combining five overlapping peptides selected in 2a. These kinds of immunogenicity evaluations were conducted using type 1 and/or type 2 cytokine(s) produced by CD4+ T cells. Results In ASEP prediction, twelve peptides were selected as potential candidates demonstrating a high affinity to MHC class II, which were in different lesions of common mutation of KRAS. In module 2 using ELISpot and FACS analysis, two epitopes (non-mutated sequences) were finally selected as Th1-specific epitopes based on the type 1 T cell response. Conclusion Unlike previous vaccines using mutant lesions, in this study, two non-mutated Th1-specific epitopes are under the in-vivo efficacy studies as mono and combining regimen(s) in certain tumor types. Additionally, the Th-Vac® platform was fully validated in terms of the performance and its application would be expanded beyond a cancer vaccine. Citation Format: Youngki Choi, Jinback Lim, Hyo-Hyun Park, Jinho Kang, Hun Jung. Identification of Th1-specific epitopes from non-mutated KRAS lesions for off-the-shelf cancer vaccines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4112.

Abstract 5904: Targeting NaV1.7 channels in pancreatic cancer: Implications for EF2K and P-Src/P-Fak/integrin β1 signaling pathways

Abstract Pancreatic cancer (PaCa) ranks as the fourth leading cause of cancer-related deaths in the United States and is among the top five worldwide. Its hallmark characteristics include early invasion, metastasis, resistance to chemotherapy and radiotherapy, and aggressive tumor progression. Evaluating new generation treatments with significant potential in this ongoing battle against cancer is crucial. Voltage-gated sodium channels (VGSC), long detected in various metastatic cell lines and tissue samples beyond breast, lung, and prostate cancer, are of particular interest. This study aimed to explore the therapeutic effects of inhibiting NaV1.7 and its neonatal variant, nNaV1.7, in pancreatic cancer cells. The study utilized human normal keratinocyte cell line HaCaT and pancreatic cancer cell lines PANC-1 and MiaPaCa-2. It investigated the roles and effects of adult and neonatal isoforms of the NaV1.7 channel in pancreatic cancer proliferation, invasion, and metastasis. The findings revealed significantly higher adult and neonatal NaV1.7 mRNA expressions in PANC-1 and MiaPaCa-2 cell lines compared to HaCaT cells. Specific siRNAs effectively downregulated channel mRNA and protein expressions. Notably, NaV1.7 siRNA treatments significantly inhibited cell proliferation and colony-forming capacity in PANC-1 and MiaPaCa-2 cells, without cytotoxic effects on HaCaT cells. Combining gemcitabine with specific NaV1.7 siRNAs enhanced drug efficacy in the PANC-1 cell line. Furthermore, NaV1.7 siRNAs significantly reduced cell invasion, migration, and wound healing in both cell lines. These siRNAs also induced apoptosis and G1 arrest in the cell cycle. They inhibited protein expressions involved in key signaling pathways, including P-Src/P-Fak/Integrin β1, EF2K, P-Akt, P-mTOR, PARP, Caspase-3/9, Cyclin D1/E1. This study is pioneering, as literature lacks research on the expression and function of NaV1.7 and nNaV1.7 in pancreatic cancer cells or tissue samples. In conclusion, NaV1.7 channel isoforms play a significant role in the development, progression, and metastasis of pancreatic cancer and present as a potential therapeutic target in PaCa. Citation Format: Mumin Alper Erdogan, Ayse Caner. Targeting NaV1.7 channels in pancreatic cancer: Implications for EF2K and P-Src/P-Fak/integrin β1 signaling pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5904.

Abstract 3378: Acinar cell susceptibility for tumor development in the pancreas: Targeting the critical regulators for therapy

Abstract Acinar to ductal metaplasia (ADM) or acinar cell dedifferentiation is one of the most notable features of chronic pancreatitis. It is also considered the initial step of pancreatic cancer development when oncogenic mutations accumulate. However, its precise mechanism and regulatory pathways remain unclear. This study profiled the transcriptome of dedifferentiated acinar cells from both humans and mice. Differential expression analysis integrated with a systematic literature search revealed several potential regulators (e.g., GDF15, GFRA1, MXRA5, CXCL17), of which the expression pattern over time was validated by qRT-PCR. We also focused on multiple conserved pathways of cell survival, among which SLC7A11 (xCT) is transiently upregulated in both species. The xCT subunit, integral to the cystine/glutamate antiporter system xc-, plays a critical role in cell survival across various cell types. To elucidate its role in acinar dedifferentiation, we employed gene silencing, pharmacological inhibition, and a knock-out mouse model. Acinar cells with diminished xCT function exhibit increased ferroptosis linked to lipid peroxidation. Antioxidants such as N-acetylcysteine and ferroptosis inhibitors like Ferrostatin-1 can mitigate lower glutathione levels and lipid ROS accumulation. Similarly, in mouse acute pancreatitis, xCT prevents lipid peroxidation. Our findings indicate that xCT fuels the glutathione pool and maintains ROS balance during ADM, thereby preventing pancreatic acinar cells from ferroptosis, a form of cell death rarely reported in relation to ADM. Next to xCT, a future and similar comprehensive study of the aforementioned genes could provide valuable insights into the dynamic changes that occur during acinar cell dedifferentiation and pave the way to the discovery of new intervention targets to suppress tumorigenesis in chronic pancreatitis. Citation Format: Zhaolong Pan, Jan-Lars Van den Bossche, Eva Rodriguez-Aznar, Pauline Janssen, Olaya Lara, Gamze Ates, Ann Massie, Diedert Luc De Paep, Isabelle Houbracken, Marco Mambretti, Ilse Rooman. Acinar cell susceptibility for tumor development in the pancreas: Targeting the critical regulators for therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3378.

Macrophage-induced reactive oxygen species in the initiation of pancreatic cancer: a mini-review.

Pancreatic inflammation is a risk factor for the development of pancreatic cancer. Increased presence of inflammatory macrophages can be found in response to a KRAS mutation in acinar cells or in response to experimentally-induced pancreatitis. Inflammatory macrophages induce pancreatic acinar cells to undergo dedifferentiation to a duct-like progenitor stage, a process called acinar-to-ductal metaplasia (ADM). Occurrence of ADM lesions are believed to be the initiating event in tumorigenesis. Here we will discuss how macrophage-induced oxidative stress contributes to ADM and how ADM cells shape the fibrotic stroma needed for further progression.