Factor In Pancreatic Ductal Adenocarcinoma Research Articles

Blood type as a risk factor for pancreatic ductal adenocarcinoma.

10559 Background: Non-O blood type has been associated with increased risk of pancreatic ductal adenocarcinoma (PDAC), the third leading cause of cancer death in the United States (US), in largely white populations. We aimed to explore PDAC risk across blood types in the racially diverse Veteran’s Health Administration (VA), the largest integrated healthcare system in the US. Methods: We included all individuals in the VA from 2002 - 2022 with at least one inpatient or outpatient encounter and a non-missing race. We defined the index date as 1.5 years after the initial VA encounter and excluded individuals with prior PDAC. We defined the exposure by non-O (A, B, AB) or type O blood type. We defined PDAC based on a previously validated algorithm of ≥2 sources (cancer registry, hospitalizations, or outpatient oncology encounters) with 95% positive predictive value. Using time to PDAC as the outcome in a multivariable Cox regression, we evaluated the association between blood type and PDAC risk, adjusting for age, sex, BMI, smoking, alcohol use, Hepatitis C (HCV) and diabetes. We censored at time of death, 1.5 years after the last VA encounter, or the end of the study period. We performed a subgroup analysis to evaluate the association of blood type by race. Results: Of the 2.5 million individuals with an available blood type, 1.35 million (52.6%) had a non-O blood type (Table) and over a quarter of our cohort (28.2%, 725,878) were over baseline age 50. Median time to PDAC diagnosis was 8.6 years. There were 877 PDAC cases (0.03%), with 530 (60.4%) of those having a non-O blood type. Compared to those with type O blood, risk of PDAC for individuals with non-O blood type was higher overall [adjusted HR = 1.37 (95% CI 1.20-1.57)], and higher among Whites (n=1,689,092, HR 1.52, 95% CI 1.27-1.82) than Black patients (n=525,666, HR 1.15, 95% CI 0.90-1.48), though this was limited by smaller sample size. Conclusions: Non-O blood type was associated with higher risk of PDAC in a diverse population. Given the potential differences between races, we will further explore the impact of neighborhood-level socioeconomic data on PDAC risk. [Table: see text]

Pancreatic Cancer and Venous Thromboembolism.

Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% of all pancreatic cancers and is the most fatal of all cancers. The treatment response from combination chemotherapies is far from satisfactory and surgery remains the mainstay of curative strategies. These challenges warrant identifying effective treatments for combating this deadly cancer. PDAC tumor progression is associated with the robust activation of the coagulation system. Notably, cancer-associated thrombosis (CAT) is a significant risk factor in PDAC. CAT is a concept whereby cancer cells promote thromboembolism, primarily venous thromboembolism (VTE). Of all cancer types, PDAC is associated with the highest risk of developing VTE. Hypoxia in a PDAC tumor microenvironment also elevates thrombotic risk. Direct oral anticoagulants (DOACs) or low-molecular-weight heparin (LMWH) are used only as thromboprophylaxis in PDAC. However, a precision medicine approach is recommended to determine the precise dose and duration of thromboprophylaxis in clinical setting.

Physical Activity Decreases Inflammation and Delays Development of Obesity-Associated Pancreatic Ductal Adenocarcinoma.

Obesity is a risk factor for pancreatic ductal adenocarcinoma (PDAC), a deadly disease with limited preventive strategies. Lifestyle interventions to decrease obesity represent a potential approach to prevent obesity-associated PDAC. Here, we examined whether decreasing obesity through physical activity (PA) and/or dietary changes could decrease inflammation in humans and prevent obesity-associated PDAC in mice. Comparison of circulating inflammatory-associated cytokines in subjects (overweight and obese) before and after a PA intervention revealed PA lowered systemic inflammatory cytokines. Mice with pancreatic-specific inducible KrasG12D expression were exposed to PA and/or dietary interventions during and after obesity-associated cancer initiation. In mice with concurrent diet-induced obesity (DIO) and KrasG12D expression, the PA intervention led to lower weight gain, suppressed systemic inflammation, delayed tumor progression, and decreased pro-inflammatory signals in the adipose tissue. However, these benefits were not as evident when obesity preceded pancreatic KrasG12D expression. Combining PA with diet-induced weight loss (DI-WL) delayed obesity-associated PDAC progression in the genetically engineered mouse model, but neither PA alone nor combined with DI-WL or chemotherapy prevented PDAC tumor growth in orthotopic PDAC models regardless of obesity status. PA led to upregulation of IL-15ra in adipose tissue. Adipose-specific overexpression of IL-15 slowed PDAC growth but only in non-obese mice. Overall, our study suggests that PA alone or combined with DI-WL can reduce inflammation and delay obesity-associated PDAC development or progression. Lifestyle interventions that prevent or manage obesity or therapies that target weight loss-related molecular pathways could prevent progression of PDAC.

Genetic and other risk factors for pancreatic ductal adenocarcinoma (PDAC).

Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at an advanced stage, resulting in poor prognosis and low 5-year survival rates. While early evidence suggests increased long-term survival in those with screen-detected resectable cancers, surveillance imaging is currently only recommended for individuals with a lifetime risk of PDAC ≥ 5%. Identification of risk factors for PDAC provides opportunities for early detection, risk reducing interventions, and targeted therapies, thus potentially improving patient outcomes. Here, we summarize modifiable and non-modifiable risk factors for PDAC. We review hereditary cancer syndromes associated with risk for PDAC and their implications for patients and their relatives. In addition, other biologically relevant pathways and environmental and lifestyle risk factors are discussed. Future work may focus on elucidating additional genetic, environmental, and lifestyle risk factors that may modify PDAC risk to continue to identify individuals at increased risk for PDAC who may benefit from surveillance and risk reducing interventions.

Chronological pattern of venous thromboembolism (VTE) occurrence impacts in survival of pancreatic ductal adenocarcinoma (PDAC).

Limited data exist on the prognostic significance of the chronology of VTE in patients with PDAC. Medical data and survival characteristics of patients treated for PDAC from 2019 to 2021 were retrospectively reviewed. Early VTE was defined as occurring within the three months of PDAC diagnosis. 197 patients were included, 54 (27.4%) developed a VTE. Early appearanceof VTE was associated with worse prognosis: median overall survival (mOS) VTE < 3months 8.5months (HR 1.65, 95% CI 1.11-2.46; p = 0.014), mOS VTE > 3months 12.8months (HR 0.78, 95% CI 0.39-1.54; p = 0.5) and mOS patients without VTE 11.4months (95% CI 10.1-15.4). There was no significant association between the patient's VTE risk according to the Khorana risk score (KRS) (chi2 test p-value = 0.9). Early VTE is a prognostic factor in PDAC, which may identify a more aggressive subtype.

Solute carrier family 16 member 1 as a potential prognostic factor for pancreatic ductal adenocarcinoma and its influence on tumor immunity.

Solute carrier family 16 member 1 (SLC16A1) serves as a biomarker in numerous types of cancer. Tumor immune infiltration has drawn increasing attention in cancer progression and treatment. The objective of our study was to explore the association between SLC16A1 and the tumor immune microenvironment in pancreatic ductal adenocarcinoma (PDAC). Data were obtained from The Cancer Genome Atlas. The xCell web tool was used to calculate the proportion of immune cells according to SLC16A1 expression. To further explore the mechanism of SLC16A1, immunity-related genes were screened from differentially expressed genes through weighted gene coexpression network analysis, examined via Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, and filtrated using univariate Cox regression and least absolute shrinkage and selection operator regression model combined correlation analysis (P<0.05). Next, CIBERSORT was used to analyze the correlation between immune cells and five important genes. SLC16A1 expression and its clinical role in pancreatic cancer was clarified via immunohistochemical staining experiments. Finally, the effects of SLC16A1 on the results of cancer immunity were evaluated by in vitro experiments. SLC16A1 was overexpressed in PDAC tissues and could be an independent prognostic factor. SLC16A1 was significantly negatively correlated with overall survival and suppressed the tumor immunity of PDAC. In clinic, SLC16A1 expression was significantly positively correlated with tumor progression and poor prognosis. We also found that SLC16A1 could suppress the antitumor ability of CD8+ T cells. SLC16A1 is a biomarker for the prognosis of PDAC and can influence the immune environment of PDAC. These findings provide new insights into the treatment of PDAC.

Perineural invasion score system and clinical outcomes in resected pancreatic cancer patients

Background/objectivesPerineural invasion (PNI), classified according to its presence or absence in tumor specimens, is recognized as a poor prognostic factor in pancreatic ductal adenocarcinoma (PDAC) patients. Herein, we identified five histological features of PNI and investigated their impact on survival outcomes of PDAC resected patients. MethodsFive histopathological features of PNI (diameter, number, site, sheath involvement, and mitotic figures within perineural invasion) were combined in an additional final score (ranging from 0 to 8), and clinical data of PDAC patients were retrospectively analyzed. PNI + patients were stratified in two categories according to the median score value (<6 and ≥ 6, respectively). Impact of PNI on disease-free survival (DFS) and overall survival (OS) were analyzed. ResultsForty-five patients were enrolled, of whom 34 with PNI (PNI+) and 11 without PNI (PNI-). The DFS was 11 months vs. not reached (NR) (p = 0.258), while the OS was 19 months vs. NR (p = 0.040) in PNI+ and PNI- patients, respectively. A ≥6 PNI was identified as an independent predictor of worse OS vs. <6 PNI + patients (29 vs. 11 months, p < 0.001) and <6 PNI+ and PNI- patients (43 vs. 11 months, p < 0.001). PNI ≥6 was an independent negative prognostic factor of DFS vs. <6 PNI+ and PNI- patients (13 vs. 6 months, p = 0.022). ConclusionsWe report a PNI scoring system that stratifies surgically-treated PDAC patients in a graded manner that correlates with patient prognosis better than the current dichotomous (presence/absence) definition. However, further and larger studies are needed to support this PNI scoring system.

Carfilzomib relieves pancreatitis-initiated pancreatic ductal adenocarcinoma by inhibiting high-temperature requirement protein A1

Pancreatitis is a crucial risk factor for pancreatic ductal adenocarcinoma (PDAC), and our previous study had proved high-temperature requirement protein A1 (HTRA1) exacerbates pancreatitis insult; however, the function and mechanism of HTRA1 in pancreatitis-initiated PDAC is still unclear. In the present paper, we clarified the expression of HTRA1 in PDAC using bioinformatics and immunohistochemistry of tissue chip, and found that HTRA1 is significantly upregulated in PDAC. Moreover, the proliferation, migration, invasion and adhesion of PANC-1 and SW1990 cells were promoted by overexpression of HTRA1, but inhibited by knockdown of HTRA1. Meanwhile, we found that HTRA1 arrested PANC-1 and SW1990 cells at G2/M phase. Mechanistically, HTRA1 interacted with CDK1 protein, and CDK1 inhibitor reversed the malignant phenotype of PANC-1 and pancreatitis-initiated PDAC activated by HTRA1 overexpression. Finally, we discovered a small molecule drug that can inhibit HTRA1, carfilzomib, which has been proven to inhibit the biological functions of tumor cells in vitro and intercept the progression of pancreatitis-initiated PDAC in vivo. In conclusion, the activation of HTRA1-CDK1 pathway promotes the malignant phenotype of tumor cells by blocking the cell cycle at the G2/M phase, thereby accelerating pancreatitis-initiated PDAC. Carfilzomib is an innovative candidate drug that can inhibit pancreatitis-initiated PDAC through targeted inhibition of HTRA1.

Abstract B053: Physical activity regulates targetable transcriptomic changes in the adipose tissue of obese PDAC mice

Abstract Background: Obesity is a risk factor for pancreatic ductal adenocarcinoma (PDAC), a highly aggressive cancer with a low 5-year survival rate. The association between obesity and PDAC could be attributed to the inflammatory effects of obesity and its impact on the adipose microenvironment. Physical activity (PA) is a potential approach to counteract obesity and its associated inflammation. Moreover, a recent study revealed that exercise-induced interleukin (IL)-15 in tumors has an anti-tumor response. However, there is still limited understanding of the mechanisms underlying how PA impacts the adipose-tumor microenvironments in PDAC. In this study, we hypothesized that PA could upregulate anti-inflammatory signaling in the adipose tissue and that targeting some of these signaling pathways could be a novel therapy for obesity-associated PDAC. Methods: Transcriptomic analysis was performed on adipose tissue obtained from a genetically engineering mouse model of obesity-associated PDAC. The mice were fed an obesogenic high-fat diet and divided into groups with and without PA intervention for one month. An adipose-specific recombinant adeno-associated vector (rAAV) was generated and mouse IL-15 cDNA was subcloned into the vector. C57BL/6J mice were administered intraperitoneal injections of either the rAAV/empty or rAAV/IL-15 vectors. Three weeks after rAAV intraperitoneal injection, mice were orthotopically injected with mouse KRasG12D/Trp53−/−/PDX-1-CRE cells expressing firefly luciferase to monitor growth in vivo and expression of IL-15 in the adipose tissue was confirmed via qPCR. Results: PA intervention increased the expression of genes related to metabolic and inflammation-related pathways. The administration of a novel adipose-targeted rAAV resulted in the upregulation of IL-15 within the adipose tissue and not the tumor. Increasing IL-15 expression in the adipose tissue led to a notable delay in tumor growth in an orthotopic mouse model. Conclusions: Here, we show that PA modulates gene expression in the adipose tissue and the beneficial impact of adipose tissue molecular remodeling on anti-tumor effects. However, more studies are needed to characterize the full extent of the adipose-tumor interactions and how they can be effectively targeted for therapeutic interventions. Citation Format: Hsiang-Yin Hsueh, Valentina Pita-Grisanti, Ericka Vélez-Bonet, Lei Cao, Wei Huang, Zobeida Cruz-Monserrate. Physical activity regulates targetable transcriptomic changes in the adipose tissue of obese PDAC mice [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B053.

Abstract C048: Obesity transforms the gut microbiome to invoke a cancer permissive state

Abstract Obesity – an established, modifiable risk factor for pancreatic ductal adenocarcinoma (PDAC) – has increased in prevalence worldwide yet the precise mechanisms underlying its propensity to promote cancer have remained an enigma. Alterations to the gut microbiota, the microorganisms that colonize the intestinal tract of humans and mice, may provide a link between obesity and PDAC, offering a previously untapped target to develop novel anti-cancer strategies in this highly lethal disease. To ascertain the importance of the obesity-associated microbiome in PDAC progression, we leveraged our previously established autochthonous model of obesity-associated PDAC (Pdx1-Cre; KrasLSL-G12D/+; LepOb/Ob) (KCO) which allows for rapid and reversible weight gain in a Kras-driven mouse tumor model that closely mimics the genetic and histologic features of human PDAC progression. Ablation of the gut microbiome via broad-spectrum antibiotics intercepted tumor development in KCO mice highlighting the importance of the gut microbiome in obesity-driven PDAC. By correlating microbial composition to tumor burden in antibiotic-treated and control mice via 16S rRNA sequencing, we are identifying microbial communities that may be causal for tumor development. In parallel studies, we performed 16S rRNA sequencing on feces serially collected from wild-type, LepOb/Ob ad libitum-fed mice (AL), and LepOb/Ob mice on calorie restriction (CR), which induces rapid weight loss. We found that obesity causes reversible changes to gut microbial composition including an increase in Proteobacteria, a phylum that holds the most known species to secrete histamine, a bioamine implicated in pancreatitis, a PDAC risk factor, and PDAC development itself. Concordant with these findings, Parallel Receptorome Expression and Screening via Transcriptional Output-SALSA (PRESTO-SALSA), a novel high-throughput system that allows for sensitive detection of microbial metabolites that exhibit mammalian GPCR agonism, feces from LepOb/Ob AL mice showed robust activation of histamine receptors (HRHs), while feces from obese mice subject to CR exhibited reduced Proteobacteria species and decreased capacity to activate mammalian HRHs, suggesting weight loss by CR mitigates microbe-derived histamine. Ongoing studies are testing whether microbe-derived histamine is necessary and sufficient for the tumor-promoting effects of obesity. Collectively, our results establish a dependency for the gut microbiome in obesity-driven PDAC, identify reversible obesity-induced microbial communities in the gut, and nominate microbial metabolites capable of activating pro-tumorigenic GPCR pathways as potential causative mechanisms. Citation Format: Christian F. Ruiz, Rylee McDonnell, Lauren Lawres, Yiyun Cao, Deguange Song, Nicole Sonnert, Noah Palm, Mandar D. Muzumdar. Obesity transforms the gut microbiome to invoke a cancer permissive state [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C048.

Comparison of single and combination risk factors in pancreatic ductal adenocarcinoma with control and benign hepatobiliary disease groups

Comparison of single and combination risk factors in pancreatic ductal adenocarcinoma with control and benign hepatobiliary disease groups

Regnase-1 downregulation promotes pancreatic cancer through myeloid-derived suppressor cell-mediated evasion of anticancer immunity

BackgroundPancreatitis is known to be an important risk factor for pancreatic ductal adenocarcinoma (PDAC). However, the exact molecular mechanisms of how inflammation promotes PDAC are still not fully understood. Regnase-1, an endoribonuclease, regulates immune responses by degrading mRNAs of inflammation-related genes. Herein, we investigated the role of Regnase-1 in PDAC.MethodsClinical significance of intratumor Regnase-1 expression was evaluated by immunohistochemistry in 39 surgically-resected PDAC patients. The functional role of Regnase-1 was investigated by pancreas-specific Regnase-1 knockout mice and Kras-mutant Regnase-1 knockout mice. The mechanistic studies with gene silencing, RNA immunoprecipitation sequencing (RIP-seq) and immune cell reconstitution were performed in human/mouse PDAC cell lines and a syngeneic orthotopic tumor transplantation model of KrasG12D-mutant and Trp53-deficient PDAC cells.ResultsRegnase-1 expression was negatively correlated with the clinical outcomes and an independent predictor of poor relapse-free and overall survival in PDAC patients. Pancreas-specific Regnase-1 deletion in mice promoteed pancreatic cancer with PMN-MDSC infiltration and shortened their survival. A syngeneic orthotopic PDAC model exhibited that Regnase-1 downregulation accelerated tumor progression via recruitment of intratumor CD11b+ MDSCs. Mechanistically, Regnase-1 directly negatively regulated a variety of chemokines/cytokines important for MDSC recruitment and activation, including CXCL1, CXCL2, CSF2, and TGFβ, in pancreatic cancer cells. We subsequently showed that IL-1β-mediated Regnase-1 downregulation recruited MDSCs to tumor sites and promoted pancreatic cancer progression via mitigation of cytotoxic T lympohocytes-mediated antitumor immunity.ConclusionsIL-1b-mediated Regnase-1 downregulation induces MDSCs and promotes pancreatic cancer through the evasion of anticancer immunity.

Blood-based Migration Signature Biomarker Panel Discriminates Early Stage New Onset Diabetes related Pancreatic Ductal Adenocarcinoma from Type 2 Diabetes

Background and aimsWhile type 2 diabetes is a well-known risk factor for pancreatic ductal adenocarcinoma (PDAC), PDAC-induced new-onset diabetes (PDAC-NOD) is a manifestation of underlying PDAC. In this study, we sought to identify potential blood-based biomarkers for distinguishing PDAC-NOD from type 2 diabetes (T2DM) without PDAC. Materials and methodsBy ELISA analysis, a migration signature biomarker panel comprising tissue factor pathway inhibitor (TFPI), tenascin C (TNC-FNIII-C) and CA 19–9 was analyzed in plasma samples from 50 PDAC-NOD and 50 T2DM controls. ResultsBoth TFPI (area under the curve (AUC) 0.71) and TNC-FNIII-C (AUC 0.69) outperformed CA 19–9 (AUC 0.60) in distinguishing all stages of PDAC-NOD from T2DM controls. The combined panel showed an AUC of 0.82 (95% CI = 0.73–0.90) (p = 0.002). In the PDAC-NOD early stage II samples, the three biomarkers had an AUC of 0.84 (95% CI = 0.73–0.93) vs CA 19-9, AUC = 0.60, (95% CI = 0.45–0.73), which also improved significance (p = 0.0123). ConclusionThe migration signature panel adds significantly to CA 19–9 to discriminate PDAC-NOD from T2DM controls and warrants further validation for high-risk group stratification.

Osteopontin secreted from obese adipocytes enhances angiogenesis and promotes progression of pancreatic ductal adenocarcinoma in obesity.

Obesity is a risk factor and poor prognostic factor for pancreatic ductal adenocarcinoma (PDAC), but the underlying mechanisms remain unclear. PDAC cells and obese visceral adipocytes (O-Ad) derived from mice and humans were used to analyze interactions between the two cell types, and human microvascular endothelial cells were used for angiogenesis assay. A xenograft mouse model with subcutaneously injected PDAC cells was used for animal studies. The relationship between visceral fat and prognosis was analyzed using resected tissues from PDAC patients with and without obesity. Conditioned media (CM) from O-Ad significantly increased PDAC cell growth and migration and angiogenic capacity in both human and mice cells, and blocking osteopontin (OPN) in O-Ad canceled O-Ad-induced effects in both mouse and human cells. In addition, O-Ad directly increased the migratory and tube-forming capacities of endothelial cells, while blocking OPN canceled these effects. O-Ad increased AKT phosphorylation and VEGFA expression in both PDAC and endothelial cells, and OPN inhibition in O-Ad canceled those O-Ad-induced effects. In the xenograft model, PDAC tumor volume was significantly increased in obese mice compared with lean mice, whereas blocking OPN significantly inhibited obesity-accelerated tumor growth. OPN expression in adipose tissues adjacent to human PDAC tumor was significantly higher in obese patients than in non-obese patients. In PDAC patients with obesity, high OPN expression in adipose tissues was significantly associated with poor prognosis. Obese adipocytes trigger aggressive transformation in PDAC cells to induce PDAC progression and accelerate angiogenesis via OPN secretion.

Exploring the Neandertal legacy of pancreatic ductal adenocarcinoma risk in Eurasians

BackgroundThe genomes of present-day non-Africans are composed of 1–3% of Neandertal-derived DNA as a consequence of admixture events between Neandertals and anatomically modern humans about 50–60 thousand years ago. Neandertal-introgressed single nucleotide polymorphisms (aSNPs) have been associated with modern human disease-related traits, which are risk factors for pancreatic ductal adenocarcinoma (PDAC), such as obesity, type 2 diabetes, and inflammation. In this study, we aimed at investigating the role of aSNPs in PDAC in three Eurasian populations.ResultsThe high-coverage Vindija Neandertal genome was used to select aSNPs in non-African populations from 1000 Genomes project phase 3 data. Then, the association between aSNPs and PDAC risk was tested independently in Europeans and East Asians, using existing GWAS data on more than 200 000 individuals. We did not find any significant associations between aSNPs and PDAC in samples of European descent, whereas, in East Asians, we observed that the Chr10p12.1-rs117585753-T allele (MAF = 10%) increased the risk to develop PDAC (OR = 1.35, 95%CI 1.19–1.54, P = 3.59 × 10–6), with a P-value close to a threshold that takes into account multiple testing.ConclusionsOur results show only a minimal contribution of Neandertal SNPs to PDAC risk.

Modifiable Pancreatic Ductal Adenocarcinoma (PDAC) Risk Factors.

This study aims to summarize the modifiable risk factors for pancreatic ductal adenocarcinoma (PDAC) that have been known for a long time, as well as information from the most recent reports. As a cancer with a late diagnosis and poor prognosis, accurate analysis of PDAC risk factors is warranted. The incidence of this cancer continues to rise, and the five-year survival rate is the lowest with respect to other tumors. The influence of cigarette smoking, alcohol consumption, and chronic pancreatitis in increasing the risk of pancreatic ductal adenocarcinoma is continually being confirmed. There are also newly emerging reports relating to the impact of lifestyle, including physical activity, the gut and oral microbiome, and hepatotropic viruses. A precise understanding of PDAC risk factors can help to identify groups of high-risk patients, and this may contribute to population awareness and education as well as earlier diagnoses with possible better treatment outcomes.

Dual epigenetic changes in diabetes mellitus-associated pancreatic ductal adenocarcinoma correlate with downregulation of E-cadherin and worsened prognosis.

Diabetes mellitus (DM) is a risk factor for pancreatic ductal adenocarcinoma (PDAC) that promotes the promoter methylation of CDH1. It is still unclear whether DM can exert other epigenetic effects, such as altering microRNA (miR) expression, in PDAC. The expression of miR-100-5p is known to be changed in DM patients and can suppress the expression of E-cadherin. In this study, the correlation between DM status and dual epigenetic changes was evaluated in PDAC specimens from patients who underwent radical surgical resection. A total of 132 consecutive patients with PDAC were clinicopathologically evaluated. E-cadherin and nuclear β-catenin expression was measured using immunohistochemistry. DNA and miRs were extracted from the main tumor site on formalin-fixed paraffin-embedded tissue sections. TaqMan miR assays were applied to assess miR-100-5p expression. Bisulfite modification was conducted on the extracted DNA, which was then subjected to methylation-specific polymerase chain reaction. Immunohistochemistry revealed that decreased E-cadherin expression and increased nuclear β-catenin expression were significantly associated with DM and poor tumor cell differentiation. The presence of long-duration DM (≥3 years) was a significant factor contributing to CDH1 promoter methylation (p < 0.01), while miR-100-5p expression was proportionally correlated with the preoperative HbA1c level (R = 0.34, p < 0.01), but not the duration of DM. The subjects with high miR-100-5p expression and CDH1 promoter methylation showed the highest level of vessel invasion and prevalence of tumor size ≥30 mm. PDAC subjects with dual epigenetic changes showed poorer overall survival (OS) than those with a single epigenetic change. miR-100-5p expression ≥4.13 and CDH1 promoter methylation independently predicted poor OS and disease-free survival (DFS) in the multivariate analysis. OS and DFS worsened in DM subjects with both HbA1c ≥ 6.5% and DM duration ≥3 years. Thus, DM is associated with two modes of epigenetic change by independent mechanisms and worsens prognosis.

Polymorphic variants involved in methylation regulation: a strategy to discover risk loci for pancreatic ductal adenocarcinoma

IntroductionOnly a small number of risk factors for pancreatic ductal adenocarcinoma (PDAC) has been established. Several studies identified a role of epigenetics and of deregulation of DNA methylation. DNA methylation...

Preserved correlation matrices pinpoint extracellular matrix organization as a critical factor in pancreatic ductal adenocarcinoma

Background Gene co-expression correlations frequently signal shared biological functions with coordinated regulation. We hypothesized that maintained correlations might be essential for cellular survival, representing potential vulnerabilities of cancer cells. We aimed to reveal correlations preserved in pancreatic ductal adenocarcinomas (PDAC) across normal and tumor tissues. Methods: We searched the NCBI GEO for raw microarray data and the TCGA project for RNA-seq data. The microarray dataset consisted of 248 tumors and 108 normal samples, allowing the analysis of 12,210 genes. The RNA-seq dataset incorporated 177 tumors, four normal samples from TCGA, and 248 normal samples from GTEx, enabling the analysis of 21,479 genes. Genes with an altered expression were identified with a Mann-Whitney U test at p&lt;0.01, and a Pearson correlation was performed to identify preserved correlations. Results: Altogether 371 significant correlations involving 262 genes were preserved across normal samples and tumors in both RNA-seq and gene chip platforms. The identified close-knit gene network is mainly responsible for extracellular matrix organization. Seven genes (SPARC, COL6A3, MMP2, HTRA1, FN1, PALLD, and COL3A1) were heavily overrepresented in maintained correlations, some of them participating in as many as 58 interactions. High expression of 28 genes was linked to poor disease outcome at FDR ≤ 10%, out of which FN1, an extracellular matrix component, was both overrepresented in maintained correlations and associated with worse overall survival (p = 0.00097, FDR ≤ 5%). The growing expression of two genes, MYL12A and MYL12B, across normal tissues, primary, and metastatic tumors may drive the acquisition of motility by cancer cells. Conclusions: Our results propose novel prognostic biomarkers of PDAC and pinpoint fundamental cellular interactions as potential targets for combination therapies. Furthermore, the presence of significant correlations across different data platforms substantiates the validity of our findings.

Urokinase-Type Plasminogen Activator Receptor (uPAR) Cooperates with Mutated KRAS in Regulating Cellular Plasticity and Gemcitabine Response in Pancreatic Adenocarcinomas.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers. Given the currently limited therapeutic options, the definition of molecular subgroups with the development of tailored therapies remains the most promising strategy. Patients with high-level gene amplification of urokinase plasminogen activator receptor (uPAR/PLAUR) have an inferior prognosis. We analyzed the uPAR function in PDAC to understand this understudied PDAC subgroup's biology better. A total of 67 PDAC samples with clinical follow-up and TCGA gene expression data from 316 patients were used for prognostic correlations. Gene silencing by CRISPR/Cas9, as well as transfection of uPAR and mutated KRAS, were used in PDAC cell lines (AsPC-1, PANC-1, BxPC3) treated with gemcitabine to study the impact of these two molecules on cellular function and chemoresponse. HNF1A and KRT81 were surrogate markers for the exocrine-like and quasi-mesenchymal subgroup of PDAC, respectively. High levels of uPAR were correlated with significantly shorter survival in PDAC, especially in the subgroup of HNF1A-positive exocrine-like tumors. uPAR knockout by CRISPR/Cas9 resulted in activation of FAK, CDC42, and p38, upregulation of epithelial makers, decreased cell growth and motility, and resistance against gemcitabine that could be reversed by re-expression of uPAR. Silencing of KRAS in AsPC1 using siRNAs reduced uPAR levels significantly, and transfection of mutated KRAS in BxPC-3 cells rendered the cell more mesenchymal and increased sensitivity towards gemcitabine. Activation of uPAR is a potent negative prognostic factor in PDAC. uPAR and KRAS cooperate in switching the tumor from a dormant epithelial to an active mesenchymal state, which likely explains the poor prognosis of PDAC with high uPAR. At the same time, the active mesenchymal state is more vulnerable to gemcitabine. Strategies targeting either KRAS or uPAR should consider this potential tumor-escape mechanism.