Inflammation In Pancreatic Cancer Research Articles

IL-1β+ macrophages fuel pathogenic inflammation in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with high resistance to therapies1. Inflammatory and immunomodulatory signals co-exist in the pancreatic tumour microenvironment, leading to dysregulated repair and cytotoxic responses. Tumour-associated macrophages (TAMs) have key roles in PDAC2, but their diversity has prevented therapeutic exploitation. Here we combined single-cell and spatial genomics with functional experiments to unravel macrophage functions in pancreatic cancer. We uncovered an inflammatory loop between tumour cells and interleukin-1β (IL-1β)-expressing TAMs, a subset of macrophages elicited by a local synergy between prostaglandin E2 (PGE2) and tumour necrosis factor (TNF). Physical proximity with IL-1β+ TAMs was associated with inflammatory reprogramming and acquisition of pathogenic properties by a subset of PDAC cells. This occurrence was an early event in pancreatic tumorigenesis and led to persistent transcriptional changes associated with disease progression and poor outcomes for patients. Blocking PGE2 or IL-1β activity elicited TAM reprogramming and antagonized tumourcell-intrinsic and -extrinsic inflammation, leading to PDAC control in vivo. Targeting the PGE2-IL-1β axis may enable preventive or therapeutic strategies for reprogramming of immune dynamics in pancreatic cancer.

Inflammation-Based Prognostic Scores in Pancreatic Cancer Patients—A Single-Center Analysis of 1294 Patients within the Last Decade

Inflammatory properties are known to promote tumor progression leading to an impaired median overall survival (mOS). Various small studies have focused on a wide range of inflammation-based prognostic indicators. By using sufficient data from 1294 out of 2323 patients diagnosed with pancreatic cancer between 2009 and 2021 at our cancer center, inflammatory markers such as the neutrophil to lymphocyte ratio (NRL), the platelet to lymphocyte ratio (PLR), the lymphocyte to monocyte ratio (LMR) and the CRP to albumin ratio (CAR) were evaluated. We identified a new combined score, termed the inflammatory benchmark index (IBI). We performed univariate and multivariate overall survival analyses and identified optimal prognostic cut-off values for each parameter. In univariate analyses, advanced age (p < 0.001), gender (p < 0.001), tumor stage (p < 0.001), CA19-9 (p = 0.001), NLR (p = 0.001), LMR (p = 0.004), PLR (p = 0.004), CAR (p = 0.001) and IBI (p = 0.001) were identified as prognostic markers. In multivariate analyses advanced age (p < 0.001), gender (p = 0.001), tumor stage (p < 0.001), CA19-9 (p < 0.001), NLR (p = 0.001), LMR (p = 0.038), CAR (p < 0.001) and IBI (p < 0.001) were independent prognostic markers. These findings emphasize the impact of inflammation in pancreatic cancer, provide easily accessible prognostic values for the clinician, and may be useful as stratification parameters for trials aimed at patient inflammation or immune response.

Abstract C031: Targeting granulocytic MDSC-derived inflammasome activation to overcome stromal inflammation in pancreatic cancer

Abstract Objective: The major drivers of therapeutic resistance in pancreatic ductal adenocarcinoma (PDAC) are myeloid cell-derived signaling that sustains immune tolerance/exclusion, and interleukin-1 (IL-1)-mediated inflammatory polarization of cancer-associated fibroblasts (iCAF) which promotes stromal inflammation by elaborating soluble factors (i.e., CXCL1, IL-6) that further accelerate myeloid chemotaxis. Moreover, we have recently shown that enrichment of pathways related to inflammasome activation-which involves recruitment of ASC complexes culminating in IL-1β generation—is a major contributor to chemoresistance in advanced PDAC patients. However, how these disparate pathways converge to mediate stromal inflammation in PDAC is incompletely understood. Methods: Single-cell RNA sequencing (scRNAseq) and caspase-1 luminescence assays in human and genetically engineered mouse (GEM) PDAC models were interrogated to identify cellular source of inflammasome-derived IL-1β. Gene set enrichment analysis in bulk RNA-sequencing data and signal transduction studies examined novel pathways associated with inflammasome activation in granulocytic myeloid-derived suppressor cells (gMDSC). scRNAseq and ASC-speck formation via confocal microscopy in intratumoral gMDSCs was performed in PKT mice treated with a novel anti-ASC antibody. Results: scRNAseq in human and GEM PDAC models revealed gMDSCs as the dominant source of inflammasome activation-derived IL1B expression. Functionally, caspase-1 activation and ASC-speck formation was strongest in intratumoral gMDSCs, compared with tumor-cell, CAF, macrophage, T-cell, and dendritic cell, compartments. Investigating developmental trajectories of single-cell transcriptomes in intratumoral gMDSCs from Panc02 tumors revealed an activated Cd14+ gMDSC state with strong co-expression of Cxcr2 and Il1b. As such, treatment of PKT GEM and orthotopically injected KPC tumor-bearing mice with CXCR2 inhibitor AZD5069 significantly abrogated inflammasome activation in intratumoral and splenic gMDSCs. In vitro signal transduction and RNA-seq studies revealed cooperativity between Tlr4-Myd88 and Cxcr2-Tpl2-p38 signaling in activating gMDSC-restricted inflammasome signaling. Co-culture of intratumoral gMDSCs and KPC CAFs ex vivo revealed strong induction of CAF-intrinsic Il6/Cxcl1 expression, which was dependent in part on CAF-Il1r1 expression and inflammasome activation in gMDSCs. We next used antibody to target ASC-a common downstream adaptor complex inducing inflammasomes-in vivo. Treatment of PKT mice with this anti-ASC antibody significantly attenuated ASC-speck formation in intratumoral gMDSCs as well as CAF-specific Il6/Cxcl1 expression via scRNAseq. Conclusions: These data uncover granulocytic MDSCs as the dominant source of inflammasome activation derived-IL1β in the PDAC TME, which promotes stromal inflammation via iCAF polarization. Therapeutic approaches-such as anti-ASC treatment-targeting gMDSC-intrinsic inflammasome activation may mitigate stromal inflammation and overcome therapeutic resistance in PDAC. Citation Format: Nilesh Deshpande, Anna Bianchi, Iago De Castro Silva, Vanessa Garrido, Siddharth Mehra, Samara Singh, Ifeanyichukwu Ogobuiro, Nagaraj Nagathihalli, Nipun B. Merchant, Jashodeep Datta. Targeting granulocytic MDSC-derived inflammasome activation to overcome stromal inflammation in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr C031.

Expression of complement proteins C3 &amp; C5 in South African pancreatic ductal adenocarcinoma patients and their potential roles in PDAC progression

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and deadliest of human malignancies. PDAC cells have developed mechanisms to evade and suppress immune function. Despite advances, immunotherapy is still ineffective for the treatment of PDAC.We aimed to identify novel potential immune targets in South African PDAC patients. Method: Total RNA was isolated from 15 tumours and 15 adjacent corresponding “normal” tissues (Ethics-M190734). A PCR Array immune focused panel was used to identify differentially expressed genes and qPCR used for verification. ELISA was further performed on 25 PDAC, 6 chronic pancreatitis, and 3 controls. Statistical analysis was conducted using Statistica V13.5, reported as mean±SEM, with a p<0.05 considered as significant. Online databases were accessed for C3 and C5 gene/protein expression and mutation data. Results: We found 13 upregulated and 62 downregulated genes. C3 was the most overexpressed gene in tumours (fold change=562,22). Furthermore, C3 plasma levels decreased in locally-advanced and metastatic disease 0.71±0.15μg/mL) compared to resectable cancer (0.97±0.09μg/mL;p<0.05). C5 was lower in healthy controls compared to patients with pancreatic disease (chronic + cancer; p<0.05) and correlated with the inflammatory marker, C-reactive protein (CRP; p=0.0098). Missense mutations were the most commonly occurring mutations in both C3 and C5 in PDAC. Conclusion: The decrease in C3 with disease severity in PDAC may indicate the loss of innate immune response and thus a compromised immunity as the complement system plays a major role in immunosurveillance. C5 may play a role in inducing inflammation in pancreatic cancer, therefore may be a potential therapeutic target.

Cellular determinants and therapeutic implications of inflammation in pancreatic cancer.

Inflammation is a hallmark of cancer. For pancreatic ductal adenocarcinoma (PDAC), malignant cells arise in the context of a brisk inflammatory cell infiltrate surrounded by dense fibrosis that is seen beginning at the earliest stages of cancer conception. This inflammatory and fibrotic milieu supports cancer cell escape from immune elimination and promotes malignant progression and metastatic spread to distant organs. Targeting this inflammatory reaction in PDAC by inhibiting or depleting pro-tumor elements and by engaging the potential of inflammatory cells to acquire anti-tumor activity has garnered strong research and clinical interest. Herein, we describe the current understanding of key determinants of inflammation in PDAC; mechanisms by which inflammation drives immune suppression; the impact of inflammation on metastasis, therapeutic resistance, and clinical outcomes; and strategies to intervene on inflammation for providing therapeutic benefit.

Inflammation, Biomarkers and Immuno-Oncology Pathways in Pancreatic Cancer.

It is estimated that pancreatic cancer will be the second leading cause of cancer-related deaths globally by 2030, highlighting the ongoing lack of effective treatment options for this devastating condition. There is a lack of reliable prognostic or predictive markers in pancreatic cancer to guide management decisions, whether for systemic chemotherapy, molecularly targeted therapies, or immunotherapies. To date, the results for targeted agents and immunotherapies in unselected populations of chemo-refractory pancreatic cancer have not met expectations. The reasons for this lack of efficacy of immunotherapy in pancreatic cancer are not completely understood. The challenges in pancreatic cancer include the physical barrier created by the dense desmoplastic stroma surrounding the tumor, chemokine-mediated exclusion of T cells, relatively poorer antigenicity compared to other solid tumors, paucity of infiltrating T cells within the tumor, ultimately leading to an immunosuppressive microenvironment. A better understanding of the role of inflammation in pancreatic cancer, its tumor microenvironment and individualized patient-related features, be they molecular, clinical or histopathological, would enable a more effective tailored approach to the management of pancreatic cancer. In this review, the role of inflammation, the immune tumor microenvironment and potential immune biomarkers in pancreatic cancer are explored.

Targeting inflammation in pancreatic cancer: Clinical translation.

Preclinical modelling studies are beginning to aid development of therapies targeted against key regulators of pancreatic cancer progression. Pancreatic cancer is an aggressive, stromally-rich tumor, from which few people survive. Within the tumor microenvironment cellular and extracellular components exist, shielding tumor cells from immune cell clearance, and chemotherapy, enhancing progression of the disease. The cellular component of this microenvironment consists mainly of stellate cells and inflammatory cells. New findings suggest that manipulation of the cellular component of the tumor microenvironment is possible to promote immune cell killing of tumor cells. Here we explore possible immunogenic therapeutic strategies. Additionally extracellular stromal elements play a key role in protecting tumor cells from chemotherapies targeted at the pancreas. We describe the experimental findings and the pitfalls associated with translation of stromally targeted therapies to clinical trial. Finally, we discuss the key inflammatory signal transducers activated subsequent to driver mutations in oncogenic Kras in pancreatic cancer. We present the preclinical findings that have led to successful early trials of STAT3 inhibitors in pancreatic adenocarcinoma.

Impact of Intratumoral Inflammation on Survival After Pancreatic Cancer Resection.

Pancreatic cancer (PaC) frequently results in death despite surgical resection. We sought to evaluate whether inflammation in the primary tumor was associated with early death after surgical resection. In this case-control study, we identified 21 individuals who died less than 12 months after surgery for PaC and 42 controls who survived more than 36 months after surgery. Differences in the composition of host inflammatory response between the groups were evaluated with univariate comparisons and odds ratios for early death were calculated using logistic regression modeling. Cases were more likely to have a high tumor grade (90.5% vs 26.2%; P < 0.01). The odds of early death were increased in those with a high-grade tumor (unadjusted odds ratio, 26.77; 95% confidence interval, 5.35-134.07; P < 0.01). Conversely, the density (high vs low) of inflammatory cells in tumors was similar between the groups, and odds of early death were not associated with any inflammatory marker. High tumor grade, but not altered density of inflammatory cells in the intratumoral compartment, is associated with increased odds of early death after PaC resection. Future studies evaluating the host response in multiple tumor compartments with advanced histologic techniques is needed to further elucidate the role of inflammation in PaC.

Abstract 293: Therapeutic effects of the bromodomain inhibitors JQ1 and I-BET 762 on pancreatic cancer

Abstract Pancreatic cancer is expected to be the second most deadly cancer by 2030 with very few effective therapeutic options to improve patient survival. Bromodomain inhibitors (JQ1 and I-BET 762) are a new generation of chemotherapeutic drugs that target BET proteins, impairing their ability to bind to acetyl modified lysines and therefore interfering with transcriptional initiation and elongation. BET proteins regulate several genes responsible for cell cycle, apoptosis and inflammation. I-BET 762 is currently in clinical trials for cancer and has the advantage of oral administration. Kras is one of the most common mutated genes in pancreatic cancer (90%); however its protein is a difficult drug target. p-Erk, responsible for several pathways regulating cell survival, is a downstream effector of Kras that has been shown to be essential for the progression and maintenance of pancreatic cancer. LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre (KPC) and LSL-KrasG12D/+;Pdx-1-Cre (KC) mouse models are commonly used to study pancreatic cancer. KPC mice develop the full spectrum of pancreatic cancer by an average age of 20 weeks. The KC mouse model is commonly used to study pancreatic cancer progression after stimulation with a pancreatic inflammatory agent, such as cerulein. JQ1 and I-BET 762 reduce the protein levels of p-ERK 1/2 in cells lines derived from a pancreatic tumor or ascites of KPC animals. JQ1 and I-BET 762 are also effective at inhibiting cell growth in human pancreatic cells harboring Kras mutations. When KC mice are injected with LPS to induce inflammation and pancreatitis, p-ERK 1/2 protein levels are significantly increased. This model is being used to test the effects of JQ1 and I-BET 762 after a single LPS injection, in KC mice. Pancreatic cancer is driven by several cytokines and chemokines, including CCL2 and IL-6, which recruit and regulate the inflammatory cells (macrophages, T cells and MDSC (Myeloid derived suppressor cells) cells) in the tumor. Levels of IL-6 and CCL2 in cell lines developed from KPC mice are reduced when treated with JQ1 and I-BET 762. KC mice stimulated with LPS also have higher levels of CCL2 and IL-6 than mice stimulated with saline. In conclusion this study showed that the bromodomain inhibitors JQ1 and I-BET 762 had positive effects in suppressing targets of inflammation in pancreatic cancer. We thank James Bradner for the generous gift of JQ1. Citation Format: Ana S. Leal, Charlotte R. Williams, Michael B. Sporn, Karen T. Liby. Therapeutic effects of the bromodomain inhibitors JQ1 and I-BET 762 on pancreatic cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 293. doi:10.1158/1538-7445.AM2015-293

Abstract B56: Inactivation of LKB1-AMPK pathway is mediated by inflammation in pancreatic cancer

Abstract Goal: The goal of this project is to determine if there is link between cancer cell metabolism and inflammation. LKB1is a known serine/threonine kinase tumor suppressor gene and it functions by sensing changes in cellular energy homeostasis and modulates anabolic and catabolic processes by activating its downstream kinase, AMP-activated protein kinase (AMPK). It is associated with Peutz-Jeghers syndrome, as well as various cancers including pancreatic cancer. Thus; it is a unique link between cell metabolism and inflammation. Hypothesis: Our hypothesis is that LKB1-AMK succumbs to inactivation processes because of increased NF-κB expression in pancreatic cancer cells and is associated with increased pancreatic cancer growth. Results: We tested five pancreatic cancer cells that express constitutive active NF-κB (pp65) and LKB1proteins by western blot analysis. In these cancer cells there was loss of active AMPK, phospho AMK (pAMPK) protein and its substrate pACC protein, suggesting a negative correlation between inflammation and loss of active AMPK. To strengthen this observation, we treated macrophage with LPS/IFNγ to create inflammatory environment and examined the protein levels of pp65, NF-κB regulated inflammatory gene (COX-2), pAMPK and pACC. We found that induction of pp65 and COX-2 are negatively correlated with pAMPK and pACC. To further support this observation we treated the pancreatic cancer cells with Metformin, a known activator of AMPK and our results clearly indicates that Metformin inhibits the proliferation of pancreatic cancer cells in a time-dependent manner. Metformin activates AMPK and ACC in pancreatic cancer cells. These data indicate that, compounds that activates LKB1-AMPK pathway can be beneficial in pancreatic cancer treatment. Citation Format: Sita Aggarwal, Qingxia Wang, Shailendra Giri, William Hansel. Inactivation of LKB1-AMPK pathway is mediated by inflammation in pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B56.

The role of inflammation in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with an extremely poor prognosis. Inflammatory processes have emerged as key mediators of pancreatic cancer development and progression. In genetically engineered mouse models, induction of pancreatitis accelerates PDAC development, and patients with chronic pancreatitis are known to have a higher risk of developing pancreatic cancer. In recent years, much effort has been given to identify the underlying mechanisms that contribute to inflammation-induced tumorigenesis. Many inflammatory pathways have been identified and inhibitors have been developed in order to prevent cancer development and progression. In this chapter, we discuss the role of inflammatory pathways in the initiation and progression of pancreatic cancer as well as the role of inhibitors used in treatment and prevention of pancreatic cancer.

Abstract 524: Myxomaviral Anti-angiogenesis Protein Serp-1 Inhibits Pancreatic Cancer Growth in Mice

Modification of the tumor microenvironment by inflammatory cells represents a newly recognized driving force in cancer with a critical role in tumor invasion, growth, angiogenesis, and metastasis. Increased serine proteases in the thrombolytic cascade, specifically urokinase-type plasminogen activator and its receptor, correlate with inflammatory cell invasion, angiogenesis, cancer growth and invasion. Inflammation in pancreatic cancer is linked with myeloid-derived suppressor cell activity and cancer progression. Myxomavirus is a complex DNA virus encoding highly potent immune modulators such as Serp-1, which inhibits uPA, tPA, plasmin and coagulation factor X. Serp-1 has also been demonstrated to inhibit angiogenesis in a chicken chorioallantoic membrane (CAM) model. To explore the potential use of anti-inflammatory, anti-angiogenesis proteins that target thrombotic and thrombolytic as well as inflammatory pathways, for cancer treatment, severe combined immunodeficient (SCID) mice engrafted with human cancer cells were treated with Serp-1 and neuroserpin, a selective mammalian inhibitor of thrombolytic proteases or control saline. Proteins were tested for efficacy in preventing human pancreatic and breast cancer cell growth in NOD/SCID mice (n=67 total) at 4 weeks after implantation. Serp-1 and neuroserpin inhibited pancreatic cancer Hs766t (n=27; P=0.03 and P=0.01, respectively), but not breast cancer MDA231 growth (n=11) when compared to saline controls (N =5). Serpin inhibition of pancreatic tumor growth was associated with decreased MDSC as shown by flow cytometry analysis of splenocyte (P=0.009). Serpin-mediated anti-inflammatory activity in pancreatic tumor growth was also demonstrated by reduced macrophage infiltration in tumors (P=0.001). Furthermore, RT-PCR array analysis revealed a five-fold decrease in the expression of inducible nitric oxide synthase (iNOS), which has been shown to play important role in tumor angiogenesis. Conclusions Anti-inflammatory protease inhibitors, virus-derived Serp-1 and mammalian neuroserpin, may provide new treatment approaches by targeting the angiogenesis and inflammatory responses that support cancer cell growth.

Myxomaviral Anti-Inflammatory Serpin Reduces Myeloid-Derived Suppressor Cells and Human Pancreatic Cancer Cell Growth in Mice.

Modification of the tumor microenvironment by inflammatory cells represents a newly recognized driving force in cancer with critical roles in tumor invasion, growth, angiogenesis, and metastasis. Increased thrombolytic cascade serine proteases, specifically urokinase-type plasminogen activator and its receptor, correlate with inflammatory cell migration, pancreatic cancer growth, invasion and unfavorable outcomes. Inflammation in pancreatic cancer is linked with myeloid-derived suppressor cell (MDSC) activity and cancer progression. Myxomavirus is a complex DNA virus encoding highly potent immune modulators. Serp-1 and M-T7 are two such secreted anti-inflammatory myxomaviral proteins. Serp-1 inhibits uPA, plasmin and coagulation factor X while M-T7 inhibits C, CC, and CXC chemokines. We have explored the potential use of these viral proteins for treatment of a range of human cancer isolates engrafted in severe combined immunodeficient (SCID) mice. Engrafted tumors were treated with either Serp-1, neuroserpin, a related mammalian serpin that inhibits thrombolytic proteases, or M-T7. Serp-1 and neuroserpin inhibited growth of the pancreatic cancer cell line Hs766t (P=0.03 and P=0.01, respectively) at 4 weeks after implantation. Serp-1 also inhibited growth of a second pancreatic cancer cell line MIA PaCa-2 in mice (P=0.02). Growth of the human breast cancer line MDA231 was not inhibited by Serp-1. M-T7, in contrast, did not alter growth of any of the cancer cell lines tested after implant into SCID mice. Serpin inhibition of pancreatic tumor growth was associated with a significant decrease in splenocyte MDSC counts by flow cytometry (P=0.009), without detected change in other splenocyte subpopulations. Serp-1 and NSP treatment also significantly reduced macrophage infiltration in tumors (P=0.001). In summary two anti-inflammatory serpins reduced inflammatory macrophage invasion and pancreatic tumor cell growth, suggesting potential therapeutic efficacy.

Pancreatic Cancer and Inflammation

The association between cancer and inflammation is arguably undeniable. However, it is uncertain whether inflammation leads to cancer development or oncogenic changes result in inflammatory conditions. Regardless of the debate surrounding this argument, inflammation in the immediate vicinity of the tumor promotes its development and makes inflammatory markers attractive targets both for prevention as well as treatment. This review discusses the role of inflammation in pancreatic cancer, one of the most lethal cancers with the lowest survival rates. Risk factors associated with pancreatic cancer have an underlying inflammatory pathology. The mechanisms that influence cellular damage including signaling pathways in pancreatitis and pancreatic cancer will be briefly discussed.

293 Cyclooxygenase 2-driven inflammation in pancreatic cancer

293 Cyclooxygenase 2-driven inflammation in pancreatic cancer