Pancreatic cancer cells invasiveness is mainly affected by interleukin-1beta not by transforming growth factor-beta1

Role of Interleukins in Pancreatic Cancer: A Literature Review

PURPOSE

This review article summarizes the pathophysiological aspects of interleukins (ILs) including IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, and IL-10 in pancreatic cancer (PC).

METHODS

Science Direct, PubMed, and Google Scholar were used for the literature review. The search was conducted until August 12, 2024, and particular keywords such as "Pancreatic Cancer," "Interleukins," "Pathophysiological Aspects," "Immunosuppression," "Invasiveness," and "Metastasis" were used. Focusing on interleukins related to pancreatic cancer, 61 original studies were included: 32 studies for human patients, 16 studies for animal models, and 13 studies for both animal models and human patients. All types of PC were considered. The timeframe of 1991 to 2024 was chosen for clinical studies.

RESULTS

In epithelial pancreatic tumors, IL-1 is a major inflammation factor. Serum concentrations of soluble interleukin-2-receptor were considerably greater in patients with PC and chronic pancreatitis than in healthy individuals. In comparison to controls, pancreatic cancer patients had considerably greater levels of macrophage colony-stimulating factor and significantly lower levels of stem cell factor and IL-3. The tissues and cells of pancreatic cancer have higher concentrations of IL-4 receptors. IL-5 has a role in the accumulation of pancreatic fibrosis. For individuals with pancreatic ductal adenocarcinoma (PDAC), a high serum level of IL-6 may be a separate risk factor for the development of widespread liver metastases. PDAC patients' peripheral blood mononuclear cells exhibit a substantial upregulation of IL-7 receptor. The role of IL-8 in the growth and spread of PC in humans. The miR-200a/β-catenin axis may be the mechanism by which IL-9 stimulates the proliferation and metastasis of PC cells. Blocking IL-10 in the local microenvironment appears to result in a significant reversal of tumor-induced immunosuppression.

CONCLUSION

The article concludes that interleukins 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 played significant roles in the pathogenesis of PC.

The pro-inflammatory cytokines IL-1β and IL-6 promote upregulation of the ST6GAL1 sialyltransferase in pancreatic cancer cells

The ST6GAL1 sialyltransferase is overexpressed in multiple cancers, including pancreatic ductal adenocarcinoma (PDAC). ST6GAL1 adds an α2-6-linked sialic acid to N-glycosylated membrane receptors, which consequently modulates receptor structure and function. While many studies have investigated the effects of ST6GAL1 on cell phenotype, there is a dearth of knowledge regarding mechanisms that regulate ST6GAL1 expression. In the current study, we evaluated the regulation of ST6GAL1 by two pro-inflammatory cytokines, IL-1β and IL-6, which are abundant within the PDAC tumor microenvironment. Cytokine activity was monitored using the Suit-2 PDAC cell line and two Suit-2-derived metastatic subclones, S2-013 and S2-LM7AA. For all three cell models, treatment with IL-1β or IL-6 increased the expression of ST6GAL1 protein and mRNA. Specifically, IL-1β and IL-6 induced expression of the ST6GAL1 YZ mRNA isoform, which is driven by the P3 promoter. The ST6GAL1 H and X isoforms were not detected. Promoter reporter assays confirmed that IL-1β and IL-6 activated transcription from the P3 promoter. We then examined downstream signaling mechanisms. IL-1β is known to signal through the NFκB transcription factor, whereas IL-6 signals through the STAT3 transcription factor. CUT&RUN experiments revealed that IL-1β promoted the binding of NFκB to the ST6GAL1 P3 promoter, and IL-6 induced the binding of STAT3 to the P3 promoter. Finally, we determined that inhibitors of NFκB and STAT3 blocked the upregulation of ST6GAL1 stimulated by IL-1β and IL-6, respectively. Together, these results highlight a novel molecular pathway by which cytokines within the tumor microenvironment stimulate the upregulation of ST6GAL1 in PDAC cells.

The Role of Pretreatment Serum Interleukin 6 in Predicting Short-Term Mortality in Patients with Advanced Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is notorious for its aggressive progression and dismal survival rates, with this study highlighting elevated interleukin 6 (IL-6) levels in patients as a key marker of increased disease severity and a potential prognostic indicator. Analyzing pre-treatment serum from 77 advanced PDAC patients via ELISA, the research determined optimal cutoff values for IL-6 and the IL-6:sIL-6Rα ratio using receiver operating characteristic curve analysis, which then facilitated the division of patients into low and high IL-6 groups, showing significantly different survival outcomes. Notably, high IL-6 levels correlated with adverse features such as poorly differentiated histology, higher tumor burden, and low albumin levels, indicating a stronger likelihood of poorer prognosis. With a median follow-up of 9.28 months, patients with lower IL-6 levels experienced markedly better median overall survival and progression-free survival than those with higher levels, underscoring IL-6's role in predicting disease prognosis. Multivariate analysis further confirmed IL-6 levels, alongside older age, and elevated neutrophil-to-lymphocyte ratio, as predictors of worse outcomes, suggesting that IL-6 could be a critical biomarker for tailoring treatment strategies in advanced PDAC, warranting further investigation into its role in systemic inflammation and the tumor microenvironment.

Predictive Value of MUC5AC Signature in Pancreatic Ductal Adenocarcinoma: A Hypothesis Based on Preclinical Evidence

Mucin 5AC (MUC5AC) glycoprotein plays a crucial role in carcinogenesis and drug sensitivity in pancreatic ductal adenocarcinoma (PDAC), both individually and in combination with other mucins. Its function and localization are glycoform-specific. The immature isoform (detected by the CLH2 monoclonal antibody, or mab) is usually in the perinuclear (cytoplasmic) region, while the mature (45 M1, 2-11, Nd2) variants are in apical and extracellular regions. There is preclinical evidence suggesting that mature MUC5AC has prognostic and predictive (response to treatment) value. However, these findings were not validated in clinical studies. We propose a MUC5AC signature with three components of MUC5AC-localization, variant composition, and intensity-suggesting a reliable marker in combination of variants than with individual MUC5AC variants alone. We also postulate a theory to explain the occurrence of different MUC5AC variants in abnormal pancreatic lesions (benign, precancerous, and cancerous). We also analyzed the effect of mature MUC5AC on sensitivity to drugs often used in PDAC management, such as gemcitabine, 5-fluorouracil, oxaliplatin, irinotecan, cisplatin, and paclitaxel. We found preliminary evidence of its predictive value, but there is a need for large-scale studies to validate them.

Prognostic association between NLRP3 inflammasome expression level and operable pancreatic adenocarcinoma

BACKGROUND

The NLRP3 inflammasome is significantly associated with tumor development and metastasis in various malignancies. However, the significance of the NLRP3 inflammasome in pancreatic adenocarcinoma has not been fully determined. Therefore, we try to evaluate the expression of the NLRP3 inflammasome in pancreatic adenocarcinoma and analyzed its prognostic significance.

METHODS

This cohort study enrolled 98 patients with primary pancreatic adenocarcinoma who received curative surgery. The NLRP3 inflammasome expression levels in cancer tissue were determined by immunohistochemistry, and compared with that of adjacent normal tissues. The association between NLRP3 inflammasome expression levels and baseline clinicopathological characteristics were also analyzed. Moreover, the correlation between NLRP3 inflammasome expression levels and survival was analyzed by log-rank test, and the survival curve was made by the Kaplan-Meier survival analysis.

RESULTS

Expression of each NLRP3 inflammasome component in cancer tissue was higher than that in the adjacent normal tissues (all P < 0.05), including NLRP3, IL-1β, ASC, and Caspase-1. All four components of the NLRP3 inflammasome were closely associated with clinical stage and lymph node status (all P < 0.05). The Kaplan-Meier log rank test showed that the high expression level of the NLRP3 inflammasome was significantly related to poor overall survival in pancreatic adenocarcinoma patients.

CONCLUSIONS

NLRP3 inflammasome expression was upregulated in cancer tissue and closely associated with the prognosis of operable pancreatic adenocarcinoma.

Inflammatory Cytokine: An Attractive Target for Cancer Treatment

The relationship between inflammation and cancer has attracted attention for a long time. The inflammatory tumor microenvironment consists of inflammatory cells, chemokines, cytokines, and signaling pathways. Among them, inflammatory cytokines play an especially pivotal role in cancer development, prognosis, and treatment. Interleukins, tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta (TGF-β), interferons, and vascular endothelial growth factor (VEGF) are the representative inflammatory cytokines in various cancers, which may promote or inhibit cancer progression. The pro-inflammatory cytokines are associated with advanced cancer stages, resistance to immunotherapy, and poor prognoses, such as in objective response and disease control rates, and progression-free and overall survival. In this review, we selected colorectal, pancreatic, breast, gastric, lung, and prostate cancers, which are well-reported for an association between cancer and inflammatory cytokines. The related cytokines and their effects on each cancer’s development and prognosis were summarized. In addition, the treatment strategies targeting inflammatory cytokines in each carcinoma were also described here. By understanding the biological roles of cancer-related inflammatory cytokines, we may modulate the inflammatory tumor microenvironment for potential cancer treatment.

TNFSF9 promotes metastasis of pancreatic cancer by regulating M2 polarization of macrophages through Src/FAK/p-Akt/IL-1β signaling

The effect of tumor necrosis factor superfamily member 9 (TNFSF9) on the metastasis of pancreatic cancer (PC) and the underlying mechanism remain unclear. We studied the expression of TNFSF9 in pancreatic cancer and its relationship with immune cells. We further explored the effect of TNFSF9 on pancreatic cancer metastasis by inducing macrophage polarization, and evaluated the expression of Src/FAK/p-Akt/IL-1β signals in macrophages after knocking down TNFSF9. The data shows that TNFSF9 expression is elevated in pancreatic cancer and is related to the poor prognosis of patients with pancreatic cancer. In addition, TNFSF9 may induce the M2 polarization of macrophages through Src/FAK/p-Akt/IL-1β signals, thereby promoting the migration of pancreatic cancer cells. In conclusion, our data reveals that TNFSF9 may become a predictive biomarker of pancreatic cancer and provides a new intervention target for the immunotherapy of pancreatic cancer.

Apoptosis-associated speck-like protein containing a CARD regulates the growth of pancreatic ductal adenocarcinoma

Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is a key adaptor protein of inflammasomes and a proapoptotic molecule; however, its roles in signal transduction in pancreatic ductal adenocarcinoma (PDAC) cells remain unknown. Here, we clarified the role and mechanisms of action of ASC in PDAC using clinical evidence and in vitro data. ASC expression in PDAC tissues was analyzed using public tumor datasets and immunohistochemistry results of patients who underwent surgery, and PDAC prognosis was investigated using the Kaplan-Meier Plotter. ASC expression in PDAC cells was downregulated using small-interfering RNA, and gene expression was assessed by RNA sequencing. Review of the Oncomine database and immunostaining of surgically removed tissues revealed elevated ASC expression in PDAC tumors relative to non-tumor tissue, indicating poor prognosis. We observed high ASC expression in multiple PDAC cells, with ASC silencing subsequently inhibiting PDAC cell growth and altering the expression of cell cycle-related genes. Specifically, ASC silencing reduced cyclin D1 levels and stopped the cell cycle at the G1 phase but did not modulate the expression of any apoptosis-related molecules. These results show that ASC inhibited tumor progression via cell cycle modulation in PDAC cells and could be a potential therapeutic target.

Interleukin-1β-induced pancreatitis promotes pancreatic ductal adenocarcinoma via B lymphocyte-mediated immune suppression

OBJECTIVE

Long-standing chronic pancreatitis is an established risk factor for pancreatic ductal adenocarcinoma (PDAC). Interleukin-1β (IL-1β) has been associated in PDAC with shorter survival. We employed murine models to investigate the mechanisms by which IL-1β and chronic pancreatitis might contribute to PDAC progression.

DESIGN

We crossed LSL-Kras^+/G12D;Pdx1-Cre (KC) mice with transgenic mice overexpressing IL-1β to generate KC-IL1β mice, and followed them longitudinally. We used pancreatic 3D in vitro culture to assess acinar-to-ductal metaplasia formation. Immune cells were analysed by flow cytometry and immunohistochemical staining. B lymphocytes were adoptively transferred or depleted in Kras-mutant mice. B-cell infiltration was analysed in human PDAC samples.

RESULTS

KC-IL1β mice developed PDAC with liver metastases. IL-1β treatment increased Kras^+/G12D pancreatic spheroid formation. CXCL13 expression and B lymphocyte infiltration were increased in KC-IL1β pancreata. Adoptive transfer of B lymphocytes from KC-IL1β mice promoted tumour formation, while depletion of B cells prevented tumour progression in KC-IL1β mice. B cells isolated from KC-IL1β mice had much higher expression of PD-L1, more regulatory B cells, impaired CD8⁺ T cell activity and promoted tumorigenesis. IL-35 was increased in the KC-IL1β pancreata, and depletion of IL-35 decreased the number of PD-L1⁺ B cells. Finally, in human PDAC samples, patients with PDAC with higher B-cell infiltration within tumours showed significantly shorter survival.

CONCLUSION

We show here that IL-1β promotes tumorigenesis in part by inducing an expansion of immune-suppressive B cells. These findings point to the growing significance of B suppressor cells in pancreatic tumorigenesis.

Galectin-3 Expression in Pancreatic Cell Lines Under Distinct Autophagy-Inducing Stimulus

Hypoxia and nutrient deprivation are responsible for inducing malignant behavior in neoplastic cells. In these conditions, metabolic stress leads the cells to enhance their autophagic flux and to activate key molecules for homeostasis maintenance. Galectin-3 (Gal-3) is upregulated in pancreatic cancer and it is activated under the hypoxic atmosphere. We aimed to analyze the most effective autophagic-inducing conditions in pancreatic ductal adenocarcinoma cells and the effect exerted under these conditions in association with hypoxia on the Gal-3 expression. Gal-3 and the microtubule-associated protein light chain 3 beta (LC3) were accessed through western blot and immunofluorescence. Degradative vacuole quantification was analyzed by transmission electronic microscopy, and inhibition of Gal-3 was performed using siRNA. According to the analyses, the most effective conditions in the inducement of autophagy for PANC-1 and MIA PaCa-2 cells were nutritional deprivation and complete amino acid/glucose deprivation, respectively. PANC-1 cells presented higher Gal-3 when they were submitted to 24 h of nutritional deprivation alone and simultaneously nutritional and oxygen deprivation. Inhibition of Gal-3 causes a decrease of LC3 levels in all experimental conditions. These results confirm that Gal-3 is modulated by microenvironment factors and the possibility of Gal-3 participating in an adaptive response from PDAC cells to extreme conditions.

Inflammatory cytokines in the pathogenesis of cardiovascular disease and cancer

Inflammatory cytokines are highly inducible small glycoproteins or regulatory proteins of low molecular weight secreted by different cell types. They regulate intercellular communication and mediate a number of physiological functions in the human immune system. Numerous prospective studies report that inflammatory cytokines strongly predict coronary artery disease, myocardial infarction, heart failure and other adverse cardiac events. Inflammatory cascade is believed to be a causative factor in the development of atherosclerotic process. Several aspects of atherogenesis are accelerated by cytokines. This article provides an overall overview of current understanding of cytokines in various cardiovascular events. Besides, inflammatory cytokines trigger cellular events that can induce malignancy and carcinogenesis. Elevated expression of several cytokines such as interleukin-1, interleukin-6, interleukin-10, tumor necrosis factor-α, macrophage migration inhibitory factor and transforming growth factor-β are involved in tumor initiation and progression. Thus, they exert a pivotal role in cancer pathogenesis. This review highlights the role of several cytokines in various events of tumorigenesis. Actually, this article summarizes the contributions of cytokines in the pathogenesis of cardiovascular disease and cancer.

Immune Cells Combined With NLRP3 Inflammasome Inhibitor Exert Better Antitumor Effect on Pancreatic Ductal Adenocarcinoma

Pancreatic cancer is among the most aggressive malignancies associated with chronic inflammation. Moreover, cellular immunity can be inhibited by inflammation induced by nucleotide-binding domain, leucine-rich family, pyrin-containing 3 (NLRP3) inflammasome. Accordingly, NLRP3 inhibition combining cytokine-induced killer (CIK) cells may improve antitumor efficacy. 3,4-Methylenedioxy-β-nitrostyrene (MNS) was selected as a specific NLRP3 inflammasome inhibitor. Western blot was used to evaluate the NLRP3 inflammasome expression in pancreatic cancer cell lines SW1990 and PANC-1. The impact of NLRP3 inhibition on migration, invasiveness, and proliferation of pancreatic cancer cells was analyzed through wound healing assay, Transwell assay, and Cell Counting Kit-8 (CCK-8) assay, respectively. The combining antitumor effect in vivo of CIK and NLRP3 inhibition was evaluated in a subcutaneous human pancreatic cancer BALB/c nude mouse model. Western blot analysis showed significant expression of NLRP3 inflammasome in human pancreatic cancer lines SW1990 and PANC-1, and MNS did significantly inhibit the expression of NLRP3 inflammasome in cell lines. Moreover, NLRP3 inhibition could significantly decrease the migration, invasiveness, and proliferation of pancreatic cancer cells. In vivo experiments showed that combination treatment with MNS and CIK cells had the greatest antitumor effect among the four treatment groups including control, MNS, and CIK. Combination treatment with NLRP3 inflammasome inhibition and CIK cells showed greater antitumor efficacy through inflammation inhibition and immunity restoration.

Cyst Fluid Biosignature to Predict Intraductal Papillary Mucinous Neoplasms of the Pancreas with High Malignant Potential

BACKGROUND

Current standard-of-care technologies, such as imaging and cyst fluid analysis, are unable to consistently distinguish intraductal papillary mucinous neoplasms (IPMNs) of the pancreas at high risk of pancreatic cancer from low-risk IPMNs. The objective was to create a single-platform assay to identify IPMNs that are at high risk for malignant progression.

STUDY DESIGN

Building on the Verona International Consensus Conference branch duct IPMN biomarker review, additional protein, cytokine, mucin, DNA, and microRNA cyst fluid targets were identified for creation of a quantitative polymerase chain reaction-based assay. This included messenger RNA markers: ERBB2, GNAS, interleukin 1β, KRAS, MUCs1, 2, 4, 5AC, 7, prostaglandin E2R, PTGER2, prostaglandin E synthase 2, prostaglandin E synthase 1, TP63; microRNA targets: miRs 101, 106b, 10a, 142, 155, 17, 18a, 21, 217, 24, 30a, 342, 532, 92a, and 99b; and GNAS and KRAS mutational analysis. A multi-institutional international collaborative contributed IPMN cyst fluid samples to validate this platform. Cyst fluid gene expression levels were normalized, z-transformed, and used in classification and regression analysis by a support vector machine training algorithm.

RESULTS

From cyst fluids of 59 IPMN patients, principal component analysis confirmed no institutional bias/clustering. Lasso (least absolute shrinkage and selection operator)-penalized logistic regression with binary classification and 5-fold cross-validation used area under the curve as the evaluation criterion to create the optimal signature to discriminate IPMNs as low risk (low/moderate dysplasia) or high risk (high-grade dysplasia/invasive cancer). The most predictive signature was achieved with interleukin 1β, MUC4, and prostaglandin E synthase 2 to accurately discriminate high-risk cysts from low-risk cysts with an area under the curve of up to 0.86 (p = 0.002).

CONCLUSIONS

We have identified a single-platform polymerase chain reaction-based assay of cyst fluid to accurately predict IPMNs with high malignant potential for additional studies.

Inflammation and Pancreatic Cancer: Focus on Metabolism, Cytokines, and Immunity

Systemic and local chronic inflammation might enhance the risk of pancreatic ductal adenocarcinoma (PDAC), and PDAC-associated inflammatory infiltrate in the tumor microenvironment concurs in enhancing tumor growth and metastasis. Inflammation is closely correlated with immunity, the same immune cell populations contributing to both inflammation and immune response. In the PDAC microenvironment, the inflammatory cell infiltrate is unbalanced towards an immunosuppressive phenotype, with a prevalence of myeloid derived suppressor cells (MDSC), M2 polarized macrophages, and T_reg, over M1 macrophages, dendritic cells, and effector CD4⁺ and CD8⁺ T lymphocytes. The dynamic and continuously evolving cross-talk between inflammatory and cancer cells might be direct and contact-dependent, but it is mainly mediated by soluble and exosomes-carried cytokines. Among these, tumor necrosis factor alpha (TNFα) plays a relevant role in enhancing cancer risk, cancer growth, and cancer-associated cachexia. In this review, we describe the inflammatory cell types, the cytokines, and the mechanisms underlying PDAC risk, growth, and progression, with particular attention on TNFα, also in the light of the potential risks or benefits associated with anti-TNFα treatments.

Inflammation and Epithelial-Mesenchymal Transition in Pancreatic Ductal Adenocarcinoma: Fighting Against Multiple Opponents

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and one of the most lethal human cancers. Inflammation is a critical component in PDAC initiation and progression. Inflammation also contributes to the aggressiveness of PDAC indirectly via induction of epithelial-mesenchymal transition (EMT), altogether leading to enhanced resistance to chemotherapy and poor survival rates. This review gives an overview of the key pro-inflammatory signaling pathways involved in PDAC pathogenesis and discusses the role of inflammation in induction of EMT and development of chemoresistance in patients with PDAC.

[Inflammation and Cancer Development in Pancreatic and Biliary Tract Cancer]

Chronic inflammation has been known to be a risk for many kinds of cancers, including pancreatic and biliary tract cancer. Recently, inflammatory process has emerged as a key mediator of cancer development and progression. Many efforts with experimental results have been given to identify the underlying mechanisms that contribute to inflammation-induced tumorigenesis. Diverse inflammatory pathways have been investigated and inhibitors for inflammation-related signaling pathways have been developed for cancer treatment. This review will summarize recent outcomes about this distinctive process in pancreatic and biliary tract cancer. Taking this evidence into consideration, modulation of inflammatory process will provide useful options for pancreatic and biliary tract cancer treatment.

The small heat shock protein αA-crystallin negatively regulates pancreatic tumorigenesis

Our recent study has shown that αA-crystallin appears to act as a tumor suppressor in pancreas. Here, we analyzed expression patterns of αA-crystallin in the pancreatic tumor tissue and the neighbor normal tissue from 74 pancreatic cancer patients and also pancreatic cancer cell lines. Immunocytochemistry revealed that αA-crystallin was highly expressed in the normal tissue from 56 patients, but barely detectable in the pancreatic tumor tissue. Moreover, a low level of αA-crystallin predicts poor prognosis for patients with pancreatic duct adenocarcinoma (PDAC). In the 12 pancreatic cell lines analyzed, except for Capan-1 and Miapaca-2 where the level of αA-crystallin was about 80% and 65% of that in the control cell line, HPNE, the remaining pancreatic cancer cells have much lower αA-crystallin levels. Overexpression of αA-crystallin in MiaPaca-1 cells lacking endogenous αA-crystallin significantly decreased its tumorigenicity ability as shown in the colony formation and wound healing assays. In contrast, knockdown of αA-crystallin in the Capan-1 cells significantly increased its tumorigenicity ability as demonstrated in the above assays. Together, our results further demonstrate that αA-crystallin negatively regulates pancreatic tumorigenesis and appears to be a prognosis biomarker for PDAC.

The inflammatory milieu within the pancreatic cancer microenvironment correlates with clinicopathologic parameters, chemoresistance and survival

Background

The tumor microenvironment impacts pancreatic cancer (PC) development, progression and metastasis. How intratumoral inflammatory mediators modulate this biology remains poorly understood. We hypothesized that the inflammatory milieu within the PC microenvironment would correlate with clinicopathologic findings and survival.

Methods

Pancreatic specimens from normal pancreas (n = 6), chronic pancreatitis (n = 9) and pancreatic adenocarcinoma (n = 36) were homogenized immediately upon resection. Homogenates were subjected to multiplex analysis of 41 inflammatory mediators.

Results

Twenty-three mediators were significantly elevated in adenocarcinoma specimens compared to nonmalignant controls. Increased intratumoral IL-8 concentrations associated with larger tumors (P = .045) and poor differentiation (P = .038); the administration of neoadjuvant chemotherapy associated with reduced IL-8 concentrations (P = .003). Neoadjuvant therapy was also associated with elevated concentrations of Flt-3 L (P = .005). Elevated levels of pro-inflammatory cytokines IL-1β (P = .017) and TNFα (P = .033) were associated with a poor histopathologic response to neoadjuvant therapy. Elevated concentrations of G-CSF (P = .016) and PDGF-AA (P = .012) correlated with reduced overall survival. Conversely, elevated concentrations of FGF-2 (P = .038), TNFα (P = .031) and MIP-1α (P = .036) were associated with prolonged survival.

Conclusion

The pancreatic cancer microenvironment harbors a unique inflammatory milieu with potential diagnostic and prognostic value.

Oxidative stress and cytokines in the pathogenesis of pancreatic cancer

Pancreatic cancer is one of the most aggressive, drug-resistant and lethal types of cancer with poor prognosis. Various factors including reactive oxygen species, cytokines, growth factors, and extracellular matrix proteins are reported to be involved in the development of pancreatic cancer. However, the pathogenesis of pancreatic cancer has not been completely elucidated. Oxidative stress has been shown to contribute to the development of pancreatic cancer. Evidences supporting the role of reactive oxygen species and cytokines as a risk for pancreatic cancer and the concept of antioxidant supplementation as a preventive approach for pancreatic cancer have been proposed. Here, we review the literature on oxidative stress, cytokine expression, inflammatory signaling, and natural antioxidant supplementation in relation to pancreatic cancer.

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.

Inflammatory cytokines in human pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal types of cancer with poor prognosis. Despite extensive efforts, the current treatment methods have limited success. Therefore, novel therapeutic approaches are required. The pancreatic tumor microenvironment is rich in growth factors and inflammatory cytokines that support tumor growth, and it is highly immunosuppressive. Up-regulation of cytokine pathways has been shown to modulate PDAC progression and immune evasion; therefore targeting cytokines may have therapeutic benefits. In this review we provide an overview of current understanding of pro- and anti-inflammatory cytokines in pancreatic cancer and their potential as therapeutic targets.

Role of Peroxisome Proliferator-Activated Receptor β/δ and B-Cell Lymphoma-6 in Regulation of Genes Involved in Metastasis and Migration in Pancreatic Cancer Cells

PPARβ/δ is a ligand-activated transcription factor that regulates various cellular functions via induction of target genes directly or in concert with its associated transcriptional repressor, BCL-6. Matrix remodeling proteinases are frequently over-expressed in pancreatic cancer and are involved with metastasis. The present study tested the hypothesis that PPARβ/δ is expressed in human pancreatic cancer cells and that its activation could regulate MMP-9, decreasing cancer cells ability to transverse the basement membrane. In human pancreatic cancer tissue there was significantly higher expression of MMP-9 and PPARβ/δ, and lower levels of BCL-6 mRNA. PPARβ/δ activation reduced the TNF α -induced expression of various genes implicated in metastasis and reduced the invasion through a basement membrane in cell culture models. Through the use of short hairpin RNA inhibitors of PPARβ/δ, BCL-6, and MMP-9, it was evident that PPARβ/δ was responsible for the ligand-dependent effects whereas BCL-6 dissociation upon GW501516 treatment was ultimately responsible for decreasing MMP-9 expression and hence invasion activity. These results suggest that PPARβ/δ plays a role in regulating pancreatic cancer cell invasion through regulation of genes via ligand-dependent release of BCL-6 and that activation of the receptor may provide an alternative therapeutic method for controlling migration and metastasis.

Interleukin 1β gene single-nucleotide polymorphisms and susceptibility to pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are rare neoplasms with not fully understood etiology. Interleukin 1β (IL1β) plays an important role in pancreatic pathology, especially carcinogenesis, but its role in pNET development remains unknown. The aim of this study was to analyze the association between IL1β polymorphisms and susceptibility to pNETs. IL1β -511 C/T and +3954 C/T single-nucleotide polymorphisms (SNPs) were analyzed by real-time polymerase chain reaction-SNP analysis. IL1β serum values in pNET patients were also determined. Association between high-expression C/T -511 IL1β genotype and susceptibility to pNET (p=0.042) was found, especially with functional pNET (p=0.014), where it was associated with the T allele (p=0.016). Combination of genotype analyses confirmed carriers of -511/+3954 CTCT to be at risk of developing functional pNETs (p=0.006) and carriers of -511/+3954 CTCC at risk of developing nonfunctional pNETs (p=0.019). IL1β serum levels of all patients were below the limit of detection. Our results suggest IL1β involvement in pNET development, and we also found association between the IL1β -511 SNP and susceptibility to pNET, especially functional pNETs. Nonfunctional pNETs seem to have inferior prognosis when compared with functional pNETs. It is possible that they differ in tumor microenvironment and that nonfunctional tumors share similarities with adenocarcinoma. We believe that our findings will contribute to understanding of the etiology and possible novel prognostic markers for pNETs when future studies investigating the serum and tumor tissue IL1β levels are done.

Cyst fluid interleukin-1beta (IL1beta) levels predict the risk of carcinoma in intraductal papillary mucinous neoplasms of the pancreas

PURPOSE

Biomarkers for high-grade dysplasia in patients with radiographically identified intraductal papillary mucinous neoplasms (IPMN) have not been described. We hypothesized that dysplasia in IPMN invokes an immunogenic/proinflammatory microenvironment that can be identified by cyst fluid cytokine levels.

EXPERIMENTAL DESIGN

Pancreatic cyst fluid aspirates were collected at resection (2005-2009). Samples were grouped into low-risk [low-grade (n = 6) or moderate dysplasia (n = 15)] and high-risk groups [high-grade dysplasia (n = 13) or carcinoma (n = 6)]. Cytokine expression was determined using a multiplex sandwich immunoassay. Differences in cytokine expression were evaluated using the 2-sample t test. Sample classification was performed using a logistic regression adjusting for sample covariates.

RESULTS

IL5 and IL8 concentrations were higher in the cyst fluid from patients in the high-risk group than the low-risk group. Interleukin (IL)-1β concentrations were also higher in the cyst fluid from patients with high-grade dysplasia or cancer (n = 19) than those with low- or moderate-grade dysplasia (n = 21, 539 ± 255 pg/mL vs. 0.2 ± 0.1 pg/mL; P < 0.0001). IL1β remained a significant predictor of high-risk cysts after multivariate analysis. There was no significant difference in levels of IL2, IL4, IL10, IL12, IL13, TNF-α, or IFN-γ between the groups. That IL1β levels identified cysts at a high risk of malignancy was confirmed in an independent validation set.

CONCLUSIONS

Cyst fluid levels of IL1β can differentiate low- from high-risk IPMN. This study introduces IL1β as a potential biomarker for validation in larger clinical studies.

Linking L1CAM-mediated signaling to NF-κB activation

The cell adhesion molecule L1 (L1CAM) was originally identified as a neural adhesion molecule essential for neurite outgrowth and axon guidance. Many studies have now shown that L1CAM is overexpressed in human carcinomas and associated with poor prognosis. So far, L1CAM-mediated cellular signaling has been largely attributed to an association with growth factor receptors, referred to as L1CAM-'assisted' signaling. New data demonstrate that L1CAM can signal via two additional mechanisms: 'forward' signaling via regulated intramembrane proteolysis and 'reverse' signaling via the activation of the transcription factor nuclear factor (NF)-κB. Taken together, these findings lead to a new understanding of L1CAM downstream signaling that is fundamental for the development of anti-L1CAM antibody-mediated therapeutics in human tumor cells.

Phenotype and genotype of pancreatic cancer cell lines

The dismal prognosis of pancreatic adenocarcinoma is due in part to a lack of molecular information regarding disease development. Established cell lines remain a useful tool for investigating these molecular events. Here we present a review of available information on commonly used pancreatic adenocarcinoma cell lines as a resource to help investigators select the cell lines most appropriate for their particular research needs. Information on clinical history; in vitro and in vivo growth characteristics; phenotypic characteristics, such as adhesion, invasion, migration, and tumorigenesis; and genotypic status of commonly altered genes (KRAS, p53, p16, and SMAD4) was evaluated. Identification of both consensus and discrepant information in the literature suggests careful evaluation before selection of cell lines and attention be given to cell line authentication.

Transforming growth factor-beta1 (TGF-beta1) and acetylcholine (ACh) alter nitric oxide (NO) and interleukin-1beta (IL-1beta) secretion in human colon adenocarcinoma cells

Colon adenocarcinoma is one of the most common fatal malignancies in Western countries. Progression of this cancer is dependent on tumor microenvironmental signaling molecules such as transforming growth factor-beta (TGF-beta) or acetylcholine (ACh). The present study was conducted to assess the influence of recombinant human transforming growth factor (rhTGF)-beta1 or ACh on nitric oxide (NO) and interleukin-1beta (IL-1beta) secretion by three human colon adenocarcinoma cell lines: HT29, LS180, and SW948, derived from different grade tumors (Duke's stage). The cells were cultured in 2D and 3D (spheroids) conditions. Colon carcinoma cells exhibited different sensitivities to rhTGF-beta1 or ACh dependent on the tumor grade and the culture model. ACh exhibited significant inhibitory effects towards NO, endothelial nitric oxide synthase (eNOS), and IL-1beta secretion especially by tumor cells derived form Duke's C stage of colon carcinoma. rhTGF-beta1 also decreased NO, IL-1beta, and eNOS expression, but its effect was lower than that observed after the administration of ACh. The inhibition of NO and IL-1beta production was more striking in 3D tumor spheroids than in 2D culture monolayers. Taken together, the TGF-beta1-ACh axis may regulate colon carcinoma progression and metastasis by altering NO secretion and influence inflammatory responses by modulating IL-1beta production.