Neoadjuvant chemotherapy (NAT) is increasingly used in the treatment of pancreatic ductal adenocarcinoma (PDAC). However, the actual molecular impact of NAT on the tumor remains unknown, particularly on the cancer-associated fibroblasts (CAFs) remains largely unknown. Here, mass-spectrometry (MS)-based proteomic profiling of primary CAFs derived from treatment-naïve (TN) and NAT-treated resected PDAC (n = 10 in each group) was conducted to explore potential NAT-associated changes. Differentially abundant proteins (DAPs; p < 0.05) in NAT versus TN CAFs accounted for 10.6% of all 5438 proteins mapped by MS. According to gene ontology analysis, DAPs with higher abundance (273) in NAT versus TN were involved in protein transport and carbohydrate metabolism, while DAPs with lower abundance (305) were mainly related to RNA processing. Protein-protein interactions identified several cluster networks of closely linked DAPs. Exploring the correlation between DAPs abundance and survival identified a negative correlation for 30 of 42 DAPs in NAT group. In addition, several proteins were found to be differentially abundant among different NAT regimens. In conclusion, this exploratory study reveals significant NAT-associated changes in CAF proteome profiles, which are related to the fundamental biological processes of RNA processing and protein transport. Further validation of these preliminary findings using a large independent cohort is needed.

IntroductionExploiting the full potential of neoadjuvant treatment (NAT) in pancreatic ductal adenocarcinoma (PDAC) is hampered by the lack of biomarkers for treatment response. Dysregulated lipid metabolism has been suggested to promote PDAC growth and resistance to therapy.ObjectivesTo investigate lipid metabolic changes in PDAC following NAT.MethodsCross-sectional study of mass spectrometry-based global lipidomic profiling of tumour tissue (n = 35) and paired serum samples (n = 35) from treatment-na & iuml;ve (TN; n = 18) and neoadjuvant FOLFIRINOX-treated (NAT; n = 17) PDAC patients was conducted. Pre- and post-treatment CA 19-9 levels were available from 15 NAT patients. Differentially abundant lipids (DALs) in NAT versus TN were assessed for correlation with various clinical parameters and the performance of all serum DALs to distinguish NAT from TN samples was explored using receiver operating characteristic analysis.ResultsA total of 40 tissue and 35 serum DALs were identified, which mainly belonged to glycerophospholipids and sphingolipids in tissue and glycerolipids, glycerophospholipids, and fatty acyls in serum. All 19 serum glycerolipids were less abundant in NAT and 18 of these were triacylglycerols. The abundance of 26 tissue and 11 serum DALs correlated moderately with % reduction in serum CA 19-9 following NAT. The top five of 23 serum DALs with moderate discriminatory potential (AUC = 0.66-0.87) - PI(18:0_20:3), AcCa(13:0), PC(O-42:6), TG(49:6), TG(66:14), performed better together (AUC = 0.93 and 95% CI = 0.79-1) and combined with CA 19-9 (AUC = 0.99 and 95% CI = 0.81-1).ConclusionsBoth tumour tissue and serum samples from PDAC patients showed lower abundance of lipid metabolites following neoadjuvant FOLFIRINOX treatment. Moreover, a biomarker panel of CA 19-9 together with five serum DALs could potentially be used to assess NAT response in PDAC but requires further validation.

Background: Gemcitabine (GEM) remains a cornerstone in the treatment of pancreatic cancer. Upon exposure to GEM, pancreatic cancer cells (PCCs) tend to adapt quickly to outcompete drug-induced cytotoxicity, thereby contributing to treatment failure. Thus, understanding GEM-induced molecular changes in PCCs is important. Methods: Three primary PCC lines (PCC-1, PCC-2, PCC-7) and Mia PaCa-2 cultured for 40 passages (p) in the absence (control) or presence of GEM (GemR) were assessed for phenotypic changes. Proteome profiles for all PCCs at p10, p20, p25, p30, p35, and p40 were obtained using mass spectrometry (MS). Protein expression was determined using immunoblotting. Differentially abundant proteins (DAPs) were evaluated for enrichment of functional and biological attributes and protein–protein interactions. Results: GEM sensitivity and growth were both reduced in GemR versus paired controls for all four PCC lines. MS mapped > 7000 proteins in each PCC line, and the abundance of 70–83% of these was found to be significantly altered when comparing all sample groups. Proteomic changes in GemR versus paired controls differed remarkably among the PCCs and were affected by passaging and treatment duration. DAPs at p40 were mostly related to metabolic pathways, including nucleotide metabolism and diverse cell growth processes. Several closely related DAPs and multiple hub proteins in each PCC line were identified. Conclusions: Overall, this study revealed cell-line-specific, heterogeneous changes in proteome profiles of PCCs following their long-term exposure to GEM, and these were likely affected by treatment duration, dosage, and passaging.

BackgroundManaging postoperative pancreatic fistula (POPF) presents a formidable challenge after pancreatoduodenectomy. Some centers consider pancreatic duct occlusion (PDO) in reoperations following pancreatoduodenectomy as a pancreas-preserving procedure, aiming to control a severe POPF. The aim of the current study was to evaluate the short- and long-term outcomes of employing PDO for the management of the pancreatic stump during relaparotomy for POPF subsequent to pancreatoduodenectomy.MethodsRetrospective review of consecutive patients at Oslo University Hospital undergoing pancreatoduodenectomy and PDO during relaparotomy. Pancreatic stump management during relaparotomy consisted of occlusion of the main pancreatic duct with polychloroprene Faxan-Latex, after resecting the dehiscent jejunal loop previously constituting the pancreaticojejunostomy.ResultsBetween July 2005 and September 2015, 826 pancreatoduodenectomies were performed. Overall reoperation rate was 13.2% (n = 109). POPF grade B/C developed in 113 (13.7%) patients. PDO during relaparotomy was performed in 17 (2.1%) patients, whereas completion pancreatectomy was performed in 22 (2.7%) patients. Thirteen (76%) of the 17 patients had a persistent POPF after PDO, and the time from PDO until removal of the last abdominal drain was median 35 days. Of the PDO patients, 13 (76%) patients required further drainage procedures (n = 12) or an additional reoperation (n = 1). In-hospital mortality occurred in one patient (5.9%). Five (29%) patients developed new-onset diabetes mellitus, and 16 (94%) patients acquired exocrine pancreatic insufficiency.ConclusionsPDO is a safe and feasible approach for managing severe POPF during reoperation following pancreatoduodenectomy. A significant proportion of patients experience persistent POPF post-procedure, necessitating supplementary drainage interventions. The findings suggest that it is advisable to explore alternative pancreas-preserving methods before opting for PDO in the management of POPF subsequent to pancreatoduodenectomy.

Neoadjuvant chemotherapy (NAT) is increasingly used for the treatment of non‐metastatic pancreatic ductal adenocarcinoma (PDAC) and is established as a standard of care for borderline resectable and locally advanced PDAC. However, full exploitation of its clinical benefits is limited by the lack of biomarkers that assess treatment response. To address this unmet need, global metabolomic profiling was performed on tumor tissue and paired serum samples from patients with treatment‐naïve (TN; n = 18) and neoadjuvant leucovorin calcium (folinic acid), fluorouracil, irinotecan hydrochloride and oxaliplatin (FOLFIRINOX)‐treated (NAT; n = 17) PDAC using liquid chromatography mass spectrometry. Differentially abundant metabolites (DAMs) in TN versus NAT groups were identified and their correlation with various clinical parameters was assessed. Metabolomics profiling identified 40 tissue and five serum DAMs in TN versus NAT PDAC. In general, DAMs associated with amino acid and nucleotide metabolism were lower in NAT compared to TN. Four DAMs—3‐hydroxybutyric acid (BHB), 3‐carboxy‐4‐methyl‐5‐propyl‐2‐furanpropanoic acid (CMPF), glycochenodeoxycholate and citrulline—were common to both tissue and serum and showed a similar pattern of differential abundance in both groups. A strong positive correlation was observed between serum carbohydrate 19‐9 antigen (CA 19‐9) and tissue carnitines (C12, C18, C18:2) and N8‐acetylspermidine. The reduction in CA 19‐9 following NAT correlated negatively with serum deoxycholate levels, and the latter correlated positively with survival. This study revealed neoadjuvant‐chemotherapy‐induced changes in metabolic pathways in PDAC, mainly amino acid and nucleotide metabolism, and these correlated with reduced CA 19‐9 following neoadjuvant FOLFIRINOX treatment.

Inspired by the current transdisciplinary debate about decolonisation, this article raises the fundamental question of how medicine can manage its own history in a way that safeguards the drive for decolonisation, but without eradicating the traces of previous misconceptions. We will do so by reconsidering a case from the complex records of physical anthropology, more specifically, a selected corpus of texts written by the two Norwegian physicians Kristian Emil Schreiner and Alette Schreiner in the early twentieth century, and their relation to race and racism. By teasing out the conceptual nuances and specificities in these texts, we do not attempt to exonerate the Schreiner couple of accusations of racism. Rather, we argue that it is essential to approach the past with caution, avoiding oversimplification when striving to distance ourselves from past thinking

BACKGROUND:Profound resistance to chemotherapy remains a major challenge in achieving better clinical outcomes for patients with pancreatic ductal adenocarcinoma (PDAC). Recent studies indicate that gemcitabine (GEM) resistance is promoted both by pancreatic stellate cells (PSCs) and through increased glycolysis. However, it remains unknown whether PSCs affect GEM sensitivity via glycolytic regulation.METHODS:Human pancreatic cancer cell (PCC) lines (BxPC-3, Capan-2, HPAF-II, Mia PaCa-2, Panc-1, SW-1990) were exposed to three different PSC-conditioned media (PSC-CM; PSC-1, PSC-2, HPaSteC), following either pre-treatment with glycolysis inhibitor NV-5440 or transfection for transient silencing of key glycolytic regulators (LDHA and MCT4). Proliferation, glucose transport, extracellular lactate, and GEM sensitivity were assessed. Protein expression was determined by Western blot and immunostaining. Moreover, secreted proteins in PSC-CMs were profiled by mass spectrometry (MS).RESULTS:While exposure to PSC-CMs did not affect glucose transport in PCCs, it increased their lactate release and proliferation, and reduced the sensitivity for GEM. Both NV-5440 treatment and transient silencing of LDHA and MCT4 inhibited these PSC-induced changes in PCCs. MS analysis identified 688 unique proteins with differential expression, of which only 87 were common to the three PSC-CMs. Most PSC-secreted proteins were extracellular matrix-related, including SPARC, fibronectin, and collagens. Moreover, exposure to PSC-CMs increased the phosphorylation of ERK in PCCs, but the treatment of PCCs with the MEK/ERK inhibitor PD98059 resulted in a reduction of PSC-CM-induced glycolysis and improved GEM sensitivity.CONCLUSIONS:The study findings suggest that PSC-secreted factors promote both glycolysis and GEM resistance in PCCs, and that glycolysis inhibition by NV-5440 and blocking of ERK phosphorylation by PD98059 protect PCCs from PSC-CM-induced loss of GEM sensitivity. Taken together, PSCs appear to promote GEM resistance in PDAC via glycolysis. Thus, targeting glycolysis may improve the effect of chemotherapy in PDAC.

BACKGROUND:Despite therapeutic advances, the prognosis of pancreatic ductal adenocarcinoma (PDAC) remains extremely poor. Metabolic reprogramming is increasingly recognized as a key contributor to tumor progression and therapy resistance in PDAC. One of the main metabolic changes essential for tumor growth is altered cholesterol flux. Targeting cholesterol flux appears an attractive therapeutic approach, however, the complex regulation of cholesterol balance in PDAC cells remains poorly understood.METHODS:The lipid content in human pancreatic duct epithelial (HPDE) cells and human PDAC cell lines (BxPC-3, MIA PaCa-2, and PANC-1) was determined. Cells exposed to eight different inhibitors targeting different regulators of lipid flux, in the presence or absence of oleic acid (OA) stimulation were assessed for changes in viability, proliferation, migration, and invasion. Intracellular content and distribution of cholesterol was assessed. Lastly, proteome profiling of PANC-1 exposed to the sterol O-acyltransferase 1 (SOAT1) inhibitor avasimibe, in presence or absence of OA, was performed.RESULTS:PDAC cells contain more free cholesterol but less cholesteryl esters and lipid droplets than HPDE cells. Exposure to different lipid flux inhibitors increased cell death and suppressed proliferation, with different efficiency in the tested PDAC cell lines. Avasimibe had the strongest ability to suppress proliferation across the three PDAC cell lines. All inhibitors showing cell suppressive effect disturbed intracellular cholesterol flux and increased cholesterol aggregation. OA improved overall cholesterol balance, reduced free cholesterol aggregation, and reversed cell death induced by the inhibitors. Treatment with avasimibe changed the cellular proteome substantially, mainly for proteins related to biosynthesis and metabolism of lipids and fatty acids, apoptosis, and cell adhesion. Most of these changes were restored by OA.CONCLUSIONS:The study reveals that disturbing the cholesterol flux by inhibiting the actions of its key regulators can yield growth suppressive effects on PDAC cells. The presence of fatty acids restores intracellular cholesterol balance and abrogates the alternations induced by cholesterol flux inhibitors. Taken together, targeting cholesterol flux might be an attractive strategy to develop new therapeutics against PDAC. However, the impact of fatty acids in the tumor microenvironment must be taken into consideration.

The modest clinical benefits of neoadjuvant chemotherapy (NAT) in pancreatic ductal adenocarcinoma (PDAC) are associated with a lack of robust data on treatment‐induced changes in the tumor. To this end, comparative proteomic profiling of tumor tissue samples from treatment‐naïve (TN, n = 20) and NAT‐treated ( n = 22) PDACs was performed. Differentially expressed proteins were identified and correlation with overall survival (OS) was performed. Tumors were also examined for histopathological changes and expression of cancer stem cell (CSC) markers. Serum from 33 matched patients was analyzed for metabolic markers. Cytotoxicity, proliferation, and expression of CSC markers were assessed in chemoresistant Panc‐1 and Mia PaCa‐2 cells. Of the 2265 proteins identified, 227 and 144 proteins showed significantly altered expression and differential phosphorylation, respectively, in NAT compared with TN samples. The majority of these were metabolism‐related proteins, and 14 of these correlated moderately with OS. NAT‐treated tumors and chemoresistant cancer cells showed increased expression of CSC markers. Serum ALDH1A1 was higher in NAT compared with TN. Differentially phosphorylated proteins were mainly involved in cytoskeleton organization, cell locomotion, motility, and migration, and 17 of these showed a strong positive correlation with OS. This study provides evidence of the effects of NAT on PDAC metabolism at both the tumor and the systemic levels. NAT‐treated tumors showed significantly lower expression of metabolic proteins, and patients who underwent NAT showed reduced serum lactate and high‐density lipoprotein‐cholesterol. Lastly, cancer cells that survived cytotoxic treatment expressed higher CSC markers, both in vivo and in vitro .

Inter- and intratumor heterogeneity is an important cause of treatment failure. In human pancreatic cancer (PC), heterogeneity has been investigated almost exclusively at the genomic and transcriptional level. Morphological heterogeneity, though prominent and potentially easily assessable in clinical practice, remains unexplored. This proof-of-concept study aims at demonstrating that morphological heterogeneity reflects structural and functional divergence. From the wide morphological spectrum of conventional PC, four common and distinctive patterns were investigated in 233 foci from 39 surgical specimens. Twenty-six features involved in key biological processes in PC were analyzed (immuno-)histochemically and morphometrically: cancer cell proliferation (Ki67) and migration (collagen fiber alignment, MMP14), cancer stem cells (CD44, CD133, ALDH1), amount, composition and spatial arrangement of extracellular matrix (epithelial proximity, total collagen, collagen I and III, fibronectin, hyaluronan), cancer-associated fibroblasts (density, αSMA), and cancer-stroma interactions (integrins α2, α5, α1; caveolin-1). All features differed significantly between at least two of the patterns. Stromal and cancer-cell-related features co-varied with morphology and allowed prediction of the morphological pattern. In conclusion, morphological heterogeneity in the cancer-cell and stromal compartments of PC correlates with structural and functional diversity. As such, histopathology has the potential to inform on the operationality of key biological processes in individual tumors.

Pancreatic ductal adenocarcinoma (PDAC), also known as pancreatic cancer (PC), is characterized by an overall poor prognosis and a five-year survival that is less than 10%. Characteristic features of the tumor are the presence of a prominent desmoplastic stromal response, an altered metabolism, and profound resistance to cancer drugs including gemcitabine, the backbone of PDAC chemotherapy. The pancreatic stellate cells (PSCs) constitute the major cellular component of PDAC stroma. PSCs are essential for extracellular matrix assembly and form a supportive niche for tumor growth. Various cytokines and growth factors induce activation of PSCs through autocrine and paracrine mechanisms, which in turn promote overall tumor growth and metastasis and induce chemoresistance. To maintain growth and survival in the nutrient-poor, hypoxic environment of PDAC, tumor cells fulfill their high energy demands via several unconventional ways, a process generally referred to as metabolic reprogramming. Accumulating evidence indicates that activated PSCs not only contribute to the therapy-resistant phenotype of PDAC but also act as a nutrient supplier for the tumor cells. However, the precise molecular links between metabolic reprogramming and an acquired therapy resistance in PDAC remain elusive. This review highlights recent findings indicating the importance of PSCs in aiding growth-permissive metabolic reprogramming and gemcitabine chemoresistance in PDAC.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an extremely poor prognosis, and its treatment remains a challenge. As the existing in vitro experimental models offer only a limited resemblance to human PDAC, there is a strong need for additional research tools to better understand PDAC tumor biology, particularly the impact of the tumor stroma. Here, we report for the first time the establishment and characterization of human PDAC-derived paired primary monolayer cultures of (epithelial) cancer cells (PCCs) and mesenchymal stellate cells (PSCs) derived from the same tumor by the outgrowth method. Characterization of cell morphology, cytostructural, and functional profiles and proteomics-based secretome analysis were performed. All PCCs harbored KRAS and TP53 mutations, and expressed cytokeratin 19, ki-67, and p53, while the expression of EpCAM and vimentin was variable. All PSCs expressed α-smooth muscle actin (α-SMA) and vimentin. PCCs showed a significantly higher growth rate and proliferation than PSCs. Secretome analysis confirmed the distinct nature of PCCs as compared to PSCs and allowed identification of potential molecular regulators of PSC-conditioned medium (PSC-CM)-induced migration of PCCs. Paired primary cultures of PCCs and PSCs derived from the same tumor specimen represent a novel experimental model for basic research in PDAC tumor biology.

Gemcitabine resistance in pancreatic ductal adenocarcinoma (PDAC) is attributed to cancer cell-intrinsic drug processing and the impact of the tumor microenvironment, especially pancreatic stellate cells (PSCs). This study uses human PDAC-derived paired primary cancer cells (PCCs) and PSCs from four different tumors, and the PDAC cell lines BxPC-3, Mia PaCa-2, and Panc-1, to assess the fate of gemcitabine by measuring its cellular uptake, cytotoxicity, and LC-MS/MS-based metabolite analysis. Expression analysis and siRNA-mediated knockdown of key regulators of gemcitabine (hENT1, CDA, DCK, NT5C1A) was performed. Compared to PSCs, both the paired primary PCCs and cancer cell lines showed gemcitabine-induced dose-dependent cytotoxicity, high uptake, as well as high and variable intracellular levels of gemcitabine metabolites. PSCs were gemcitabine-resistant and demonstrated significantly lower drug uptake, which was not influenced by co-culturing with their paired PCCs. Expression of key gemcitabine regulators was variable, but overall strong in the cancer cells and significantly lower or undetectable in PSCs. In cancer cells, hENT1 inhibition significantly downregulated gemcitabine uptake and cytotoxicity, whereas DCK knockdown reduced cytotoxicity. In conclusion, heterogeneity in gemcitabine processing among different pancreatic cancer cells and stellate cells results from the differential expression of molecular regulators which determines the effect of gemcitabine.

Background: Pancreatoduodenectomy with venous resection is considered standard of care for patients with tumour involvement of the superior mesenteric/portal vein (SMV/PV) and deemed justified if an R0-resection can be achieved. The aim of this study was to provide a detailed pathology assessment of the site and extent of margin involvement in specimens resulting from pancreatoduodenectomy with venous resection. Methods: Retrospective observational study including patients undergoing pancreatoduodenectomy with or without venous resection for pancreatic ductal adenocarcinoma between 2015 and 2017. Detailed histopathological mapping of the tumour and its relationship to the margins was undertaken. Results: 98 patients met the inclusion criteria. An R0-resection, based on 1 mm clearance, was achieved in 16 of 73 patients without venous resection and in 1 of 25 patients with venous resection (p = 0.063). The surface of the SMV-groove was the most frequently involved margin (23 of 25 patients with venous resection, 37 of 73 patients without venous resection; p < 0.001). The broad invasive tumour front as well as the absence of peripancreatic fat at the SMV-groove were the reasons for these findings. Conlusion: An R0-resection following pancreatoduodenectomy with venous resection for ductal adenocarcinoma can rarely be achieved due to microscopical involvement of the SMV-groove.