Pancreatic Ductal Epithelium Research Articles

Abstract 1444: Modeling Twist1 overexpression in a pancreatic ductal adenocarcinoma mouse model

Abstract Pancreatic ductal adenocarcinoma (PDAC) is an extremely lethal cancer characterized by very poor survival outcomes. Genomic sequencing of human PDAC tissues and cell lines have identified four molecular subtypes: quasimesenchymal (QM), pancreatic progenitor, immunogenic, and aberrantly differentiated endocrine exocrine (ADEX). QM-PDAC has the worse prognosis, but no in vivo models exist for this molecular subtype. Our preliminary analysis using publicly available data demonstrated that the epithelial-to-mesenchymal transition (EMT) transcription factor TWIST1 is upregulated in QM-PDAC. We hypothesized that the TWIST1-dependent plasticity program was a key regulator of QM-PDAC subtype development. We created a tetracycline-inducible tissue specific Twist1 PDAC genetically engineered mouse model (GEMM). Tumor development in the mouse pancreatic ductal epithelium was directed using the Pdx1 promoter-Cre (P) allele leading to stable native expression of the LSL-KrasG12D oncogene (R) and LSL-rtTA-IRES-GFP (G) alleles. The non-Twist1 GEMM (PGR) was crossed with the Twist1-tetO-Luc (T) mouse to create the PGRT model which allows inducible expression of Twist1 and luciferase in pancreatic epithelium under doxycycline treatment (Tet-ON system). Tumor progression, lineage tracing and metastatic invasion are followed by fluorescence (GFP) and bioluminescence (BLI) imaging. The characterization of this novel PGRT mouse model showed decreased overall survival compared to control non-Twist1 containing mice (~35 weeks PGRT (n=17) vs ~60 weeks PGR (n=10)). Histological and immunohistochemistry analyses showed the PGRT pancreatic tumors resemble the QM-PDAC subtype and vimentin overexpression correlates with Twist1-dependent induction of EMT. We attempted to confirm the QM-PDAC profile via cellular markers: GATA6-, HNF1A-, KRT81+, KRT17+, KRT20+, P63+ and ∆P63+. The PGR and standard KPC (Kras+/LSL-G12D; Trp53+LSL-R172H; Pdx1-Cre) PDAC model were also profiled. We observed that 75% of the PGRT tumors displayed a QM-PDAC profile, contrasting with the absence of such profile in both PGR and KPC tumors. Examining the tumors from PGR and KPC, 100% of the PGR and 72.27% KPC tumors exhibited a non-squamous PDAC profile while an intermediate squamous profile was observed in 25% PGRT tumors and 27.27% KPC tumors. Furthermore, Twist1 induction resulted in intra-abdominal and lung metastases. We observed that 87.5% of the PGRT mice were positive for metastases while we observed no positivity for PGR mice and 63.64% positivity in KPC mice. In conclusion, these data suggest that Twist1 overexpression cooperates with KrasG12D for PDAC tumor development mimicking the human QM-PDAC subtype to promote progression towards metastasis and early lethality. Potential uses of this novel model include testing treatment strategies to ultimately improve patient outcomes with QM-PDAC. Citation Format: Muhammad Ajmal Khan, Jinhee Chang, Triet Nguyen, Danielle N. Council, Dipanwita Dutta Chowdhury, Amol Shetty, Yang Song, Aaron Chan, Christine Lam, Priyanshi Patel, Lucas Tran, Jiayu Chen, Katriana Nugent, Matthew Ballew, Ghali Lemtiri-Chlieh, Francesca A. Carrieri, Reem Malek, Hailun Wang, Noelle R. Thielman, Keyu Li, Lei Zheng, Kathleen Gabrielson, Phuoc T. Tran, Audrey Lafargue. Modeling Twist1 overexpression in a pancreatic ductal adenocarcinoma mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1444.

Pro-inflammatory cytokines stimulate CFTR-dependent anion secretion in pancreatic ductal epithelium.

Loss of CFTR-dependent anion and fluid secretion in the ducts of the exocrine pancreas is thought to contribute to the development of pancreatitis, but little is known about the impact of inflammation on ductal CFTR function. Here we used adult stem cell-derived cell cultures (organoids) obtained from porcine pancreas to evaluate the effects of pro-inflammatory cytokines on CFTR function. Organoids were cultured from porcine pancreas and used to prepare ductal epithelial monolayers. Monolayers were characterized by immunocytochemistry. Epithelial bicarbonate and chloride secretion, and the effect of IL-1β, IL-6, IFN-γ, and TNF-α on CFTR function was assessed by electrophysiology. Immunolocalization of ductal markers, including CFTR, keratin 7, and zonula occludens 1, demonstrated that organoid-derived cells formed a highly polarized epithelium. Stimulation by secretin or VIP triggered CFTR-dependent anion secretion across epithelial monolayers, whereas purinergic receptor stimulation by UTP, elicited CFTR-independent anion secretion. Most of the anion secretory response was attributable to bicarbonate transport. The combination of IL-1β, IL-6, IFN-γ, and TNF-α markedly enhanced CFTR expression and anion secretion across ductal epithelial monolayers, whereas these cytokines had little effect when tested separately. Although TNF-α triggered apoptotic signaling, epithelial barrier function was not significantly affected by cytokine exposure. Pro-inflammatory cytokines enhance CFTR-dependent anion secretion across pancreatic ductal epithelium. We propose that up-regulation of CFTR in the early stages of the inflammatory response, may serve to promote the removal of pathogenic stimuli from the ductal tree, and limit tissue injury.

β-Carotene Supplementation Improves Pancreas Function during Moderate Ethanol Consumption: Initial Characterization from a Morphological Overview.

Alcohol is believed to harm acinar cells, pancreatic ductal epithelium, and pancreatic stellate cells. After giving ethanol and/or β-carotene to C57BL/6 mice, our goal was to evaluate their biochemistry, histology, and morpho-quantitative features. There were six groups of C57BL/6 mice: 1. Group C (control), 2. Group LA (low-dose alcohol), 3. Group MA (moderate-dose alcohol), 4. Group B (β-carotene), 5. Group LA + B (low-dose alcohol combined with β-carotene), and 6. Group MA + B (moderate-dose alcohol combined with β-carotene). After the animals were euthanized on day 28, each specimen's pancreatic tissue was taken. Lipase, uric acid, and amylase were assessed using biochemical assessment. Furthermore, the examination of the pancreatic structure was conducted using Ammann's fibrosis scoring system. Finally, the morpho-quantitative characteristics of the pancreatic islets and acinar cells were determined. In the serum of the MA + B group, there were higher amounts of total amylase (825.953 ± 193.412 U/L) and lower amounts of lipase (47.139 ± 6.099 U/L) (p < 0.05). Furthermore, Ammann's fibrosis punctuation in the pancreas revealed significant variations between the groups (p < 0.001). Finally, the stereological analysis of pancreatic islets showed that the groups were different (p < 0.001). These findings suggest that antioxidant treatments might help decrease the negative effects of ethanol exposure in animal models.

Abstract C055: Activation of oncogenes within Tff2 expressing cells of the pancreatic ductal glands results in increased lineage stemness preceding tumorigenesis: Insights from an inducible mouse model and derived organoids

Abstract Introduction: Adult stem cell dysregulation can initiate cancer. Pancreatic ductal glands (PDGs) act as a stem cell niche for the pancreatic main duct epithelium (MD). Previous studies have shown that Tff2+ cells within the PDGs give rise to progeny that migrate to the MD epithelium during inflammation. In human IPMN, the PDGs have been shown to comprise the basal proliferative compartment of these neoplasms. Here we investigate the effect of oncogenic activation and tumor suppressor deletion within Tff2+ PDG cells. Methods: We utilized Tff2CreERT2;Rosa26mT/mG;KrasLSL-G12D;P53fl/fl mice (TTKP) to activate oncogenes in Tff2+ cells and GFP tag this lineage in vivo and ex vivo. Cre activity was induced by tamoxifen injection in TTKP experimental or Tff2CreERT2;Rosa26mT/mG (TT) control mice. Pancreata were collected at pre-determined time points post-tamoxifen with GFP tagged, Tff2 lineage cells quantified and compared between groups at each timepoint. For ex vivo experiments, ductal cells were isolated from tamoxifen-naïve TTKP pancreata via magnetic-assisted cell sorting, grown in 3D culture and induced via 4OHT. GFP+ cells were sorted, cultured, and orthotopically implanted in athymic nude mice. Tumors were collected before reaching 20mm in diameter. Spatial RNA sequencing (spRNAseq) was performed on frozen tissue sections and analyzed with R package Seurat. Cross-species analysis utilized human PDAC scRNAseq reference datasets. Results: TTKP mice developed lineage-traced PDAC eight weeks after tamoxifen induction. In vivo lineage tracing showed a significant increase of GFP+ Tff2-lineage cells in PDGs and MD between TTKP and TT mice at all analyzed time points (4-, 6- and 8-weeks post tamoxifen, ≥ 3 mice each). GFP-positive PDGs exhibited progressive PanIN-like changes before PDAC formation. Tff2-PDG cells in TT mice function as transient amplifying cells, expanding within PDGs and to the MD during inflammation and contracting upon resolution. Oncogenic activation (sans inflammation) in Tff2-PDG cells led to sustained GFP+ cell presence in PDGs and MD, indicating increased stem-like behavior preceding neoplasia. Orthotopic organoid experiments resulted in GFP+ tumor formation. SpRNAseq analysis indicated enrichment of "Ductal cell type 2" in TTKP tumors, particularly overlying the main duct epithelium. Conclusion: Our study demonstrates that dysregulation of the Tff2-lineage in PDGs can initiate PDAC. Oncogenic activation in Tff2+ cells increases their stemness as indicated by lineage expansion in PDGs and MD preceding PanIN and PDAC formation. Orthotopic organoid implantation experiments further validate the tumor-initiating capacity of Tff2+ ductal cells. Spatial transcriptomics analysis confirms the presence of similar cell types identified in human scRNAseq studies within TTKP tumors. These findings strongly support the role of PDGs as a potential niche of origin for human PDAC and provide additional insights into an under-studied disease initiating process. Citation Format: Kyle L. McAndrews, Pinaki Mondal, Dulce Maroni, Dongdong Wang, Michael A. Hollingsworth, Sarah P. Thayer. Activation of oncogenes within Tff2 expressing cells of the pancreatic ductal glands results in increased lineage stemness preceding tumorigenesis: Insights from an inducible mouse model and derived organoids [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 C055.

Pancreatic intraepithelial neoplasia detection and duct pathology grading using FT-IR imaging and machine learning

Pancreatic intraepithelial neoplasia (PanIN) is manifested by noninvasive lesions in the epithelium of smaller pancreatic ducts. Generally, cancer development risk from low-grade PanIN is minor, whereas, invasive pancreatic ductal adenocarcinoma (PDAC) development is highly related to high-grade PanINs. Therefore, in the case of high-grade PanIN detection, additional surgical resection may be recommended. However, even the low-grade PanINs can indicate possible progression to PDAC. The definition of PanIN is constantly changing and there is a need for new tools to better characterize and understand its behavior. We have recently developed a comprehensive pancreatic cancer classification model with biopsies collected from over 600 biopsies from 250 patients. Here, we take the next step and employ Infrared (IR) spectroscopy to build the first classification model for PanINs detection. Furthermore, we created a Partial Least Squares Regression (PLSR) model to characterize ducts from benign to cancerous. This model was then used to predict and grade PanINs accordingly to their malignancy level.

Prediction of Prognosis in Pancreatic Cancer According to Methionyl-tRNA Synthetase 1 Expression as Determined by Immunohistochemical Staining.

The serum level of CA 19-9 is a prognostic marker for pancreatic ductal adenocarcinoma (PDAC). We evaluated the ability of the expression level of methionyl-tRNA synthetase 1 (MARS1)-which facilitates cancer growth by modulating protein synthesis and the cell cycle-to predict the prognosis of PDAC. Immunohistochemical (IHC) staining was performed on pancreatic specimens obtained from patients with PDAC who were undergoing surgery. High MARS1 expression was defined as equal to, or greater than, that in normal acinar cells. Low MARS1 expression was defined as weaker than in normal acinar cells, and stronger than in the pancreatic duct epithelium. Univariate and multivariate analyses were performed on other factors related to prognosis. Among 137 PDAC patients, no significant differences in baseline characteristics were found between those with high (n = 82) and low (n = 55) MARS1 expression. The median overall survival time of patients with high MARS1 expression was shorter than that of those with low expression (15.2 versus 17.2 months, log-rank test p = 0.044). The median disease-free survival (DFS) was not significantly different between the two groups. However, the DFS was shorter in patients with high than in those with low MARS1 expression (8.9 versus 11.2 months, log-rank test p = 0.067). In a multivariate analysis, lymph node metastasis and high MARS1 expression were associated with a poor prognosis of PDAC. Elevated MARS1 expression detected by IHC staining is associated with a poor prognosis of PDAC, suggesting that MARS1 has potential as a prognostic marker.

Contrast-Enhanced Computed Tomography and Laboratory Parameters as Non-Invasive Diagnostic Markers of Pancreatic Fibrosis.

Pancreatic fibrosis (PF) is a part of the pathogenesis in most pancreatic disorders and plays a crucial role in chronic pancreatitis development. The aim of our study was to investigate a relationship between PF grade and signs in resected pancreatic specimens, and the results of both multidetector computed tomography (MDCT) post-processing parameters and fibronectin (FN), hyaluronic acid (HA), matrix metalloproteinase (MMP)-1, and MMP-9 serum levels. The examination results of 74 patients were analyzed. The unenhanced pancreas density (UPD) value and contrast enhancement ratio (CER) showed statistically significant differences in groups with peri- and intralobular fibrosis grades, an integrative index of fibrosis, inflammation in pancreatic tissue, and pancreatic duct epithelium metaplasia, while the normalized contrast enhancement ratio in the venous phase (NCER VP) significantly differed with the perilobular fibrosis grade, integrative fibrosis index, and inflammation (p < 0.05). The blood FN level showed a weak positive correlation with the intralobular fibrosis grade (rho = 0.32, p = 0.008). The blood level of HA positively correlated with the presence of prominent and enlarged peripheral nerves (rho = 0.28, p = 0.02) and negatively correlated with the unenhanced pancreas density value (rho = -0.42, p = 0.0001). MMP-1 and MMP-9 values' intergroup analysis and correlation did not show any statistical significance. The UPD value, NCER VP, and CER, as well as blood levels of FN and HA, could be used in non-invasive PF diagnosis.

The Forms of the Lectin Tff2 Differ in the Murine Stomach and Pancreas: Indications for Different Molecular Functions.

The lectin TFF2 belongs to the trefoil factor family (TFF). This polypeptide is typically co-secreted with the mucin MUC6 from gastric mucous neck cells, antral gland cells, and duodenal Brunner glands. Here, TFF2 fulfills a protective function by forming a high-molecular-mass complex with the MUC6, physically stabilizing the mucus barrier. In pigs and mice, and slightly in humans, TFF2 is also synthesized in the pancreas. Here, we investigated the murine stomach, pancreas, and duodenum by fast protein liquid chromatography (FPLC) and proteomics and identified different forms of Tff2. In both the stomach and duodenum, the predominant form is a high-molecular-mass complex with Muc6, whereas, in the pancreas, only low-molecular-mass monomeric Tff2 was detectable. We also investigated the expression of Tff2 and other selected genes in the stomach, pancreas, and the proximal, medial, and distal duodenum (RT-PCR analysis). The absence of the Tff2/Muc6 complex in the pancreas is due to a lack of Muc6. Based on its known motogenic, anti-apoptotic, and anti-inflammatory effects, we propose a protective receptor-mediated function of monomeric Tff2 for the pancreatic ductal epithelium. This view is supported by a report that a loss of Tff2 promotes the formation of pancreatic intraductal mucinous neoplasms.

Synergistic effects of agonists and two-pore-domain potassium channels on secretory responses of human pancreatic duct cells Capan-1

Mechanisms of synergistic agonist stimulation and modulation of the electrochemical driving force for anion secretion are still not fully explored in human pancreatic duct epithelial cells. The first objective of this study was therefore to test whether combined agonist stimulation augments anion transport responses in the Capan-1 monolayer model of human pancreatic duct epithelium. The second objective was to test the influence of H+,K+-ATPase inhibition on anion transport in Capan-1 monolayers. The third objective was to analyze the expression and function of K+ channels in Capan-1, which could support anion secretion and cooperate with H+,K+-ATPases in pH and potassium homeostasis. The human pancreatic adenocarcinoma cell line Capan-1 was cultured conventionally or as polarized monolayers that were analyzed by Ussing chamber electrophysiological recordings. Single-cell intracellular calcium was assayed with Fura-2. mRNA isolated from Capan-1 was analyzed by use of the nCounter assay or RT-PCR. Protein expression was assessed by immunofluorescence and western blot analyses. Combined stimulation with different physiological agonists enhanced anion transport responses compared to single agonist stimulation. The responsiveness of Capan-1 cells to histamine was also revealed in these experiments. The H+,K+-ATPase inhibitor omeprazole reduced carbachol- and riluzole-induced anion transport responses. Transcript analyses revealed abundant TASK-2, TWIK-1, TWIK-2, TASK-5, KCa3.1, and KCNQ1 mRNA expression. KCNE1 mRNA and TREK-1, TREK-2, TASK-2, and KCNQ1 protein expression were also shown. This study shows that the Capan-1 model recapitulates key physiological aspects of a bicarbonate-secreting epithelium and constitutes a valuable model for functional studies on human pancreatic duct epithelium.

Fluorinated triphenylphosphonium analogs improve cell selectivity and invivo detection of mito-metformin.

Triphenylphosphonium (TPP+) conjugated compounds selectively target cancercells by exploiting their hyperpolarized mitochondrial membrane potential. Todate, studies have focused on modifying either the linker or the cargo of TPP+-conjugated compounds. Here, we investigated the biological effects ofdirect modification to TPP+ to improve the efficacy and detection of mito-metformin (MMe), a TPP+-conjugated probe we have shown to have promising preclinical efficacy against solid cancer cells. We designed, synthesized, and tested trifluoromethyl and methoxy MMe analogs (pCF3-MMe, mCF3-MMe, and pMeO-MMe) against multiple distinct human cancer cells. pCF3-MMe showed enhanced selectivity toward cancer cells compared to MMe, while retaining thesame signaling mechanism. Importantly, pCF3-MMe allowed quantitative monitoring of cellular accumulation via 19F-NMR invitro and invivo. Furthermore, adding trifluoromethyl groups to TPP+ reduced toxicity invivo while retaining anti-tumor efficacy, opening an avenue to de-risk these next-generation TPP+-conjugated compounds.

Predictive and Prognostic Value of SUOX Expression in Pancreatic Ductal Adenocarcinoma

Sulphite oxidase (SUOX) is a metalloenzyme that catalyses ATP synthesis via oxidative phosphorylation in the mitochondria. Although SUOX has been reported to affect the invasiveness and differentiation of cancer cells, its clinicopathological significance in pancreatic adenocarcinoma (PDAC) remains unclear. In this study, we investigated the utility of SUOX expression as a prognostic factor in PDAC. This study included 56 patients with PDAC who underwent pancreatic resection at the Kurume University Hospital between 2014 and 2018. SUOX immunohistochemistry was evaluated using tissue microarray specimens from patients. Patients were classified into a high SUOX expression group (≥10% of cells stained) or a low SUOX expression group (<10% of cells stained), and the associations of SUOX with clinicopathological characteristics and survival were analysed. Statistical analysis was performed using Cox regression analysis, the Kaplan-Meier method, and log-rank test. SUOX was expressed in the cytoplasm of normal pancreatic ductal epithelium, pancreatic acinar cells, and islets of Langerhans. Although we did not find any significant correlation between SUOX expression and clinicopathological factors, SUOX was identified as an independent prognostic factor based on univariate and multivariate analyses. Pathological stage was also an independent prognostic factor. The high SUOX expression group showed a significantly poorer prognosis than the low SUOX expression group (p=0.018). SUOX-mediated mitochondrial metabolism in PDAC may be a factor influencing prognosis and SUOX may be a potential novel prognostic biomarker.

Expression of matrix metalloproteinase-2 and survivin in pancreatic carcinoma

Background and Aim Matrix metalloproteinase (MMP) is a member of the MMP family, which is a zinc-dependent endopeptidase that degrades all extracellular matrix components and vascular basement membrane. Survivin plays a leading role in the process of apoptosis regulation. Survivin is unique for its expression in human malignancies but not in normal adult cells. This study aimed to assess immunoexpression of MMP-2 and survivin in pancreatic carcinoma. Patients and methods A total of 25 pancreatic carcinomas were evaluated for immunohistochemical expression of MMP-2 and survivin. The expression was evaluated by immunoreactive score that combines the intensity of immunoreactions with the percentage of positive cells. Results In this study, 24/25 of the cases were pancreatic ductal adenocarcinoma (PDAC) and 1/25 was acinar cell carcinoma. Regarding tumor differentiation, PDAC included five cases of adenocarcinoma that were well differentiated, 16 cases were moderately differentiated, and three cases were poorly differentiated. Pancreatic carcinoma specimens showed positive cytoplasmic MMP-2 staining with high expression in 22/25 (88%) studied specimens ranging from 6/9 to 9/9 with high extent and intensity. Survivin staining with high expression was seen in 23/25 (92%) studied specimens, ranging from 9/12 to 12/12 with high extent and intensity. Conclusion MMP-2 and survivin expressions were positive in pancreatic carcinoma with various grades but negative in non-neoplastic parenchymal, acinar, and pancreatic ductal epithelium. There were significant positive relationships between MMP-2 and survivin expression and poor histological grade in PDAC (P&lt;0.024 and 0.021, respectively).

Study on Lgr5 expression in pancreas tissues and organoids by lineage tracing.

Leucine rich repeat containing G protein-coupled receptor 5(Lgr5) is widely expressed in multiple tissues and can be used as a stem cell marker in a variety of epithelial organs (including the small intestine, colon, stomach and hair follicles). In this study, we used Lgr5-CreERT2+/- and Rosa26-mTmG hybridized transgenic mice to investigate the expression of Lgr5 in both ductal epithelial cells during pancreas development and in vitro cultured pancreatic duct organoids. After induction with Tamoxifen, the Lgr5 expression was analyzed by detecting the enhanced green fluorescence protein in the pancreatic tissue sections in adult animals and embryos at different developmental stages. The results showed that Lgr5 expression was detected neither in adult pancreatic duct epithelia nor in the embryonic pancreatic tissues at day 15.5 or in newborn mice. However, when 4-hydroxy-Tamoxifen was supplemented to the culture medium, EGFP could be detected in the primary pancreatic duct organoids from Lgr5-Cre ERT2+/-; Rosa26-mTmG mice. These results suggested that Lgr5 was not expressed in adult and embryonic pancreatic tissues; but could be expressed in the cultured pancreas ductal organoids. The research lays the foundation for exploring specific gene expression patterns in stem/progenitor cells during pancreatic development.

Dynamic Interplay between Structural Variations and 3D Genome Organization in Pancreatic Cancer.

Structural variations (SVs) are the greatest source of variations in the genome and can lead to oncogenesis. However, the identification and interpretation of SVs in human cancer remain technologically challenging. Here, long‐read sequencing is first employed to depict the signatures of structural variations in carcinogenesis of human pancreatic ductal epithelium. Then widespread reprogramming of the 3D chromatin architecture is revealed by an in situ Hi‐C technique. Integrative analyses indicate that the distribution pattern of SVs among the 3D genome is highly cell‐type specific and the bulk remodeling effects of SVs in the chromatin organization partly depend on intercellular genomic heterogeneity. Meanwhile, contact domains tend to minimize these disrupting effects of SVs within local adjacent genomic regions to maintain overall stability. Notably, complex genomic rearrangements involving two key driver genes CDKN2A and SMAD4 are identified, and their influence on the expression of oncogenes MIR31HG, MYO5B, etc., are further elucidated from both a linear view and 3D perspective. Overall, this work provides a genome‐wide resource and highlights the impact, complexity, and dynamicity of the interplay between structural variations and high‐order chromatin organization, which expands the current understanding of the pathogenesis of SVs in human cancer.

Effects of Lipolysis-Stimulated Lipoprotein Receptor on Tight Junctions of Pancreatic Ductal Epithelial Cells in Hypertriglyceridemic Acute Pancreatitis.

Objective We investigated the effects of lipolysis-stimulated lipoprotein receptor (LSR) on the tight junctions (TJs) of pancreatic ductal epithelial cells (PDECs) in hypertriglyceridemic acute pancreatitis (HTGAP). Methods Sprague-Dawley rats were fed standard rat chow or a high-fat diet and injected with sodium taurocholate to obtain normal and HTGAP rats, respectively. Serum triglyceride (TG) levels, pathological changes, TJ proteins in the pancreas, and TJ ultrastructure of PDECs were assessed. LSR overexpression (OE) and knockdown (KD) HPDE6-C7 models were designed and cultured in a high-fat environment. Protein levels were quantified by Western blotting. Cell monolayer permeability was detected using FITC-Dextran. Results Serum TG concentration and pancreatic scores were higher in the HTGAP group than in the normal group. Among the TJ proteins, LSR protein expression was significantly lower in the HTGAP group than in the acute pancreatitis (AP) group. Tricellulin (TRIC) expression in the pancreatic ductal epithelia was higher in the HTGAP group than in the AP group. The HTGAP group had lower TJ protein levels, wider intercellular space, and widespread cellular necrosis with disappearance of cell junction structures. In the cell study, TJ proteins were downregulated and the cellular barrier was impaired by palmitic acid (PA), which was reversed by LSR-OE, whereas LSR-KD downregulated the TJ proteins and aggravated PA-induced cellular barrier impairment. Conclusions Hypertriglyceridemia downregulates the TJ proteins in PDECs, which may impair the pancreatic ductal mucosal barrier function. LSR regulation can change the effects of HTG on cellular barrier function by upregulating the TJ proteins.

Identification and prevalence of potentially therapeutic targetable variants of major cancer driver genes in ampullary cancer patients in India through deep sequencing

Ampulla is a complex region located at the confluence of pancreatic and common bile duct and intestinal epithelium. Tumors arising in this region are anatomically and morphologically heterogenous, however they show unique as well as overlapping molecular features. Cancers of both these anatomic sites share morphological as well as genetic profile despite having few unique differences. Targeted therapies are currently emerging as one of the demanding approaches for treatment in most cancer types especially for malignant epithelial tumors and therefore genetic profiling of cancers is the key for identification of potentially therapeutic targetable mutations to know their prevalence and prognostic impact.We studied 97 resected cases of formalin fixed paraffin-embedded AC by deep targeted sequencing using Ampliseq cancer hotspot panel comprising of 50 oncogenes and tumor suppressor genes.Potentially therapeutic targetable mutations were observed in 58/83 (70%) cases. Fourteen patients did not show any pathogenic mutation. TP53 (48.1%), KRAS (37.3%), APC (25.3%), SMAD4 (22.8%), MET (16.8%), CTNNB1 (15.6%) and PIK3CA (10.8%) were the major mutated potential therapeutic targets. KRAS mutation (43.2 Vs. 32.6%) was more prevalent in pancreatobiliary subtype, while TP53 (58.6 Vs 35.1), APC (36.9 Vs 10.8), SMAD4 (28.2 Vs 16.2), MET (21.7 Vs 10.8) and CTNNB1 (19.5 Vs 10.8) were more prevalent in intestinal subtype. WNT signaling pathway was the major altered pathway in intestinal subtype. These mutated genes and pathways may be targeted with currently available drugs and may be explored for future development of targetable agents to improve the disease course in patients of AC.

Lack of CFTR alters the ferret pancreatic ductal epithelial secretome and cellular proteome: Implications for exocrine/endocrine signaling

BackgroundCystic fibrosis (CF) related diabetes is the most common comorbidity for CF patients and associated with islet dysfunction. Exocrine pancreas remodeling in CF alters the microenvironment in which islets reside. Since CFTR is mainly expressed in pancreatic ductal epithelium, we hypothesized altered CF ductal secretions could impact islet function through paracrine signals. MethodWe evaluated the secretome and cellular proteome of polarized WT and CF ferret ductal epithelia using quantitative ratiometric mass spectrometry. Differentially secreted proteins (DSPs) or expressed cellular proteins were used to mine pathways, upstream regulators and the CFTR interactome to map candidate CF-associated alterations in ductal signaling and phenotype. Candidate DSPs were evaluated for their in vivo pancreatic expression patterns and their functional impact on islet hormone secretion. ResultsThe secretome and cellular proteome of CF ductal epithelia was significantly altered relative to WT and implicated dysregulated TGFβ, WNT, and BMP signaling pathways. Cognate receptors of DSPs from CF epithelia were equally distributed among endocrine, exocrine, and stromal pancreatic cell types. IGFBP7 was a downregulated DSP in CF ductal epithelia in vitro and exhibited reduced CF ductal expression in vivo. IGFBP7 also altered WT islet insulin secretion in response to glucose. Many CFTR-associated proteins, including SLC9A3R1, were differentially expressed in the CF cellular proteome. Upstream regulators of the differential CF ductal proteome included TGFβ, PDX1, AKT/PTEN, and INSR signaling. Data is available via ProteomeXchange with identifier PXD025126. ConclusionThese findings provide a proteomic roadmap for elucidating disturbances in autocrine and paracrine signals from CF pancreatic ducts and how they may alter islet function and maintenance.

A Surface Plasmon Resonance Plastic Optical Fiber Biosensor for the Detection of Pancreatic Amylase in Surgically-Placed Drain Effluent.

Postoperative pancreatic fistula (POPF), the major driver of morbidity and mortality following pancreatectomy, is caused by an abnormal communication between the pancreatic ductal epithelium and another epithelial surface containing pancreas-derived, enzyme-rich fluid. There is a strong correlation between the amylase content in surgically-placed drains early in the postoperative course and the development of POPF. A simple and cheap method to determine the amylase content from the drain effluent has been eagerly advocated. Here, we developed an amylase optical biosensor, based on a surface plasmon resonance (SPR) plastic optical fiber (POF), metallized with a 60 nm layer of gold and interrogated with white light. The sensor was made specific by coupling it with an anti-amylase antibody. Each surface derivatization step was optimized and studied by XPS, contact angle, and fluorescence. The POF-biosensor was tested for its response to amylase in diluted drain effluents. The volume of sample required was 50 µL and the measurement time was 8 min. The POF-biosensor showed selectivity for amylase, a calibration curve log-linear in the range of 0.8–25.8 U/L and a limit of detection (LOD) of ~0.5 U/L. In preliminary tests, the POF-biosensor allowed for the measurement of the amylase content of diluted surgically-placed drain effluents with an accuracy of >92% with respect to the gold standard. The POF-biosensor allows for reliable measurement and could be implemented to allow for a rapid bedside assessment of amylase value in drains following pancreatectomy.

Establishment of a Macrophage Phenotypic Switch Related Prognostic Signature in Patients With Pancreatic Cancer.

IntroductionMacrophage phenotype switch plays a vital role in the progression of malignancies. We aimed to build a prognostic signature by exploring the expression pattern of macrophage phenotypic switch related genes (MRGs) in the Cancer Genome Atlas (TCGA)—pancreatic adenocarcinoma (PAAD), Genotype-Tissue Expression (GTEx)-Pancreas, and Gene Expression Omnibus (GEO) databases.MethodsWe identified the differentially expressed genes between the PAAD and normal tissues. We used single factor Cox proportional risk regression analysis, Least Absolute Shrinkage and Selection Operator (LASSO) analysis, and multivariate Cox proportional hazard regression analysis to establish the prognosis risk score by the MRGs. The relationships between the risk score and immune landscape, “key driver” mutations and clinicopathological factors were also analyzed. Gene-set enrichment analysis (GSEA) analysis was also performed.ResultsWe detected 198 differentially expressed MRGs. The risk score was constructed based on 9 genes (KIF23, BIN1, LAPTM4A, ERAP2, ATP8B2, FAM118A, RGS16, ELMO1, RAPGEFL1). The median overall survival time of patients in the low-risk group was significantly longer than that of patients in the high-risk group (P < 0.001). The prognostic value of the risk score was validated in GSE62452 dataset. The prognostic performance of nomogram based on risk score was superior to that of TNM stage. And GSEA analysis also showed that the risk score was closely related with P53 signaling pathway, pancreatic cancer and T cell receptor signaling pathway. qRT-PCR assay showed that the expressions of the 9 MRGs in PDAC cell lines were higher than those in human pancreatic ductal epithelium cell line.ConclusionsThe nine gene risk score could be used as an independent prognostic index for PAAD patients. Further studies validating the prognostic value of the risk score are warranted.

Effectiveness of Focal Pancreatic Parenchymal Atrophy in Diagnosing High-Grade Pancreatic Intraepithelial Neoplasia/Carcinoma in Situ

To improve the poor prognosis of pancreatic ductal adenocarcinoma (PDAC), the diagnosis of early-stage PDAC is essential. In particular, the diagnosis of high-grade intraepithelial pancreatic neoplasia/carcinoma in situ (HG-PanIN/CIS) is the best option. However, it is almost impossible to directly observe HG-PanIN/CIS. Thus, identifying a secondary imaging finding due to the disorder is important. Focal pancreatic parenchymal atrophy (FPPA) and hypoechoic area have been reported as preferred secondary signs. We studied 50 patients to clarify the effectiveness of FPPA in diagnosing HG-PanIN/CIS. Most patients had the opportunity to undergo further examination due to the presence of a cyst. Among the 50 patients, 23 (46%) had positive results for serial pancreatic-juice aspiration cytologic examination (SPACE), which has high sensitivity and specificity for diagnosing PADC; 20 of the 23 (87.0%) patients underwent surgery to resect the pancreatic part including the FPPA. Distal pancreatectomy and pancreatoduodenectomy were performed in 19 patients and one patient, respectively. In 13 of the 20 (65%) patients, histopathological examination revealed HG-PanIN/CIS in the pancreatic ductal epithelium of the resected specimens. FPPA could indicate HG-PanIN/CIS, but not satisfactorily. One of the factors for the unsatisfactory results might be the difficulty in identifying FPPA in the pancreatic head area. On the other hand, a pancreatic cyst, especially in the area of FPPA, could lead to the diagnosis of HG-PanIN/CIS. The size of the cyst does not affect the diagnosis of HG-PanIN/CIS.