International Consensus Recommendations for Safe Use of LAMS for On- and Off-Label Indications Using a Modified Delphi Process

INTRODUCTION

The study aimed to develop international consensus recommendations on the safe use of lumen-apposing metal stents (LAMSs) for on- and off-label indications.

METHODS

Based on the available literature, statements were formulated and grouped into the following categories: general safety measures, peripancreatic fluid collections, endoscopic ultrasound (EUS)-biliary drainage, EUS-gallbladder drainage, EUS-gastroenterostomy, and gastric access temporary for endoscopy. The evidence level of each statement was determined using the Grading of Recommendations Assessment, Development, and Evaluation methodology.International LAMS experts were invited to participate in a modified Delphi process. When no 80% consensus was reached, the statement was modified based on expert feedback. Statements were rejected if no consensus was reached after the third Delphi round.

RESULTS

Fifty-six (93.3%) of 60 formulated statements were accepted, of which 35 (58.3%) in the first round. Consensus was reached on the optimal learning path, preprocedural imaging, the need for airway protection and essential safety measures during the procedure, such as the use of Doppler, and measurement of the distance between the gastrointestinal lumen and the target structure. Specific consensus recommendations were generated for the different LAMS indications, covering, among others, careful patient selection, the preferred size of the LAMS, the need for antibiotics, the preferred anatomic location of the LAMS, the need for coaxial pigtail placement, and the appropriate management of LAMS-related adverse events.

DISCUSSION

Through a modified international Delphi process, we developed general and indication-specific experience- and evidence-based recommendations on the safe use of LAMS.

Contrast enhanced endoscopic ultrasound detects early therapy response following anti-TNF-therapy in patients with ulcerative colitis

BACKGROUND AND AIM

Though colonoscopy plays a crucial role in assessing active ulcerative colitis (aUC), its scope is limited to the mucosal surface. Endoscopic ultrasound (EUS) coupled with contrast-enhancement (dCEUS) can precisely quantify bowel wall thickness and microvascular circulation, potentially enabling the quantitative evaluation of inflammation.We conducted a prospective, longitudinal study to assess therapy response using dCEUS in aUC patients undergoing treatment with adalimumab (ADA) or infliximab (IFX).

METHODS

30 ADA- and 15 IFX-treated aUC patients were examined at baseline and at 2, 6, 14 weeks of therapy and 48 weeks of follow-up. Bowel wall thickness (BWT) was measured by EUS in the rectum. Vascularity was quantified by dCEUS using Rise Time (RT) and Time To Peak (TTP). Therapy response was defined after 14 weeks using the Mayo Score.

RESULTS

Patients with aUC displayed a mean BWT of 3.9±0.9 mm. In case of response to ADA/IFX a significant reduction in BWT was observed after 2 weeks (p=0.04), whereas non-responders displayed no significant changes. The TTP was notably accelerated at baseline and significantly normalised by week 2 in responders (p=0.001), while non-responders exhibited no significant alterations (p=0.9). At week 2, the endoscopic Mayo score did not exhibit any changes, thus failing to predict treatment responses.

CONCLUSION

dCEUS enables the early detection of therapy response in patients with aUC, which serves as a predictive marker for long term clinical success. Therefore, dCEUS serves as a diagnostic tool for assessing the probability of future therapy success.

Type 1 Autoimmune Pancreatitis in Europe: Clinical Profile and Response to Treatment

BACKGROUND & AIMS

Autoimmune pancreatitis (AIP) is an immune-mediated disease of the pancreas with distinct pathophysiology and manifestations. Our aims were to characterize type 1 AIP in a large pan-European cohort and study the effectiveness of current treatment regimens.

METHODS

We retrospectively analyzed adults diagnosed since 2005 with type 1 or not-otherwise-specified AIP in 42 European university hospitals. Type 1 AIP was uniformly diagnosed using specific diagnostic criteria. Patients with type 2 AIP and those who had undergone pancreatic surgery were excluded. The primary end point was complete remission, defined as the absence of clinical symptoms and resolution of the index radiologic pancreatic abnormalities attributed to AIP.

RESULTS

We included 735 individuals with AIP (69% male; median age, 57 years; 85% White). Steroid treatment was started in 634 patients, of whom 9 (1%) were lost to follow-up. The remaining 625 had a 79% (496/625) complete, 18% (111/625) partial, and 97% (607/625) cumulative remission rate, whereas 3% (18/625) did not achieve remission. No treatment was given in 95 patients, who had a 61% complete (58/95), 19% partial (18/95), and 80% cumulative (76/95) spontaneous remission rate. Higher (≥0.4 mg/kg/day) corticosteroid doses were no more effective than lower (<0.4 mg/kg/day) doses (odds ratio, 0.428; 95% confidence interval, 0.054-3.387) and neither was a starting dose duration >2 weeks (odds ratio, 0.908; 95% confidence interval, 0.818-1.009). Elevated IgG4 levels were independently associated with a decreased chance of complete remission (odds ratio, 0.639; 95% confidence interval, 0.427-0.955). Relapse occurred in 30% of patients. Relapses within 6 months of remission induction were independent of the steroid-tapering duration, induction treatment duration, and total cumulative dose.

CONCLUSIONS

Patients with type 1 AIP and elevated IgG4 level may need closer monitoring. For remission induction, a starting dose of 0.4 mg/kg/day for 2 weeks followed by a short taper period seems effective. This study provides no evidence to support more aggressive regimens.

High prevalence of incidental endoscopic findings at routine endoscopy after atrial fibrillation ablation: Do we need a screening endoscopy for the upper gastrointestinal tract in the general population?

INTRODUCTION

High-power short-duration ablation (HPSD) is an effective therapy for atrial fibrillation with thermal esophageal injury as a rare but relevant side effect.

AIM AND METHODS

In this retrospective single-center analysis we evaluated the incidence and relevance of ablation-induced findings and the prevalence of ablation-independent incidental gastrointestinal findings. For 15 months all patients undergoing ablation were screened by postablation esophagogastroduodenoscopy. Pathological findings were followed up and treated if necessary.

RESULTS

286 consecutive patients (66±10 years; 54.9% male) were included. 19.6% of patients showed ablation-associated alterations (10.8% esophageal lesions, 10.8% gastroparesis, 1.7% both findings). Logistic multivariable regression analysis confirmed an influence of lower BMI on the occurrence of RFA-associated endoscopic findings (OR 0.936, 95% CI 0.878-0.997, p<0.05). 48.3% of patients demonstrated incidental gastrointestinal findings. In 1.0% neoplastic lesions were present, 9.4% showed precancerous lesions and in 4.2% neoplastic lesions of unknown dignity were found requiring further diagnostics or therapy. 18.1% of patients demonstrated findings associated with a potentially increased risk of bleeding under anticoagulation. Patients with clinically relevant incidental findings were significantly more often male, 68.8% vs. 49.5% (p<0.01).

CONCLUSION

HPSD ablation is safe, no devasting complication occurred in any patient. It resulted in 19.6% ablation-induced thermal injury whereas incidental findings of the upper GI tract were found in 48.3% of patients. Due to the high prevalence of 14.7% of findings requiring further diagnostics, therapy, or surveillance in a cohort that is mimicking the general population, screening endoscopy of the upper GI tract seems to be reasonable in the general population.

NF-κB/RelA controlled A20 limits TRAIL-induced apoptosis in pancreatic cancer

The emergence of resistance to systemic therapies in pancreatic ductal adenocarcinoma (PDAC) is still a major obstacle in clinical practice. Both, constitutive and inducible NF-κB activity are known as key players in this context. To identify differentially expressed and TRAIL resistance mediating NF-κB target genes, TRAIL sensitive and resistant PDAC cell lines were analyzed by transcriptome assays. In this context, A20 was identified as an NF-κB/RelA inducible target gene. Translational PDAC tissue analysis confirmed the correlation of elevated A20 protein expression with activated RelA expression in PDAC patients. In in vitro experiments, an elevated A20 expression is accompanied by a specific resistance toward TRAIL-mediated apoptosis but not to chemotherapeutic-induced cell death. This TRAIL resistance was attributed to A20´s E3-ligase activity-mediating Zink finger domain. Furthermore, the ubiquitin-binding scaffold protein p62 was identified as indispensable for the TRAIL-mediated apoptosis-inducing pathway affected by A20. The results of this study identify A20 as a possible therapeutic target to affect resistance to TRAIL-induced apoptosis in PDAC cells.

Incidence of ablation-induced esophageal lesions and gastroparesis in patients undergoing ablation index guided high power short duration atrial fibrillation ablation

INTRODUCTION

Aim of this study was to evaluate the incidence of ablation-induced endoscopically detected esophageal lesions (EDEL) and gastroparesis in patients undergoing high-power short-duration (HPSD) atrial fibrillation (AF) ablation using different target ablation index (AI) values.

METHODS AND RESULTS

Consecutive patients undergoing AF ablation were included. Radiofrequency (RF) ablation was performed using HPSD ablation (50 W, target AI of 320 and 350 (group 1) and 380 (group 2) at posterior wall). Postablation endoscopy was performed in all patients. In total, 233 patients (66.8 ± 10 years; 52% male) were included consecutively (n = 137 patients in group 1 and n = 96 patients in group 2). Mean AI values und RF time at posterior wall was significantly higher and longer in group 2 compared to group 1 patients (413 ± 9 vs. 392 ± 19 AI, p < 0.01; 9.0 ± 0.8 s vs. 7.8 ± 0.7 s, p < 0.01). Esophageal endoscopy revealed esophageal lesions or gastroparesis in 43 of 233 patients (18.5%) in the total cohort (13.1% in group 1 and 26.0% in group 2; p = 0.02). Incidence of EDEL was 8.0% and 13.5% in group 1 and group 2, respectively. According to logistic analysis incidence of EDEL and/or gastroparesis was significantly lower in patients with a higher body mass index and higher in group 2 patients compared to group 1 patients.

CONCLUSION

The incidence of EDEL or gastroparesis in patients undergoing HPSD AF ablation was 18.5% in the total cohort. The risk of EDEL and gastroparesis was associated with a higher AI target value of 380 compared to 320 and 350 at posterior wall and was reversely associated with body mass index.

AP1/Fra1 confers resistance to MAPK cascade inhibition in pancreatic cancer

Targeting KRAS downstream signaling remains an important therapeutic approach in pancreatic cancer. We used primary pancreatic ductal epithelial cells and mouse models allowing the conditional expression of oncogenic Kras^G12D, to investigate KRAS signaling integrators. We observed that the AP1 family member FRA1 is tightly linked to the KRAS signal and expressed in pre-malignant lesions and the basal-like subtype of pancreatic cancer. However, genetic-loss-of-function experiments revealed that FRA1 is dispensable for Kras^G12D-induced pancreatic cancer development in mice. Using FRA1 gain- and loss-of-function models in an unbiased drug screen, we observed that FRA1 is a modulator of the responsiveness of pancreatic cancer to inhibitors of the RAF-MEK-ERK cascade. Mechanistically, context-dependent FRA1-associated adaptive rewiring of oncogenic ERK signaling was observed and correlated with sensitivity to inhibitors of canonical KRAS signaling. Furthermore, pharmacological-induced degradation of FRA1 synergizes with MEK inhibitors. Our studies establish FRA1 as a part of the molecular machinery controlling sensitivity to MAPK cascade inhibition allowing the development of mechanism-based therapies.

Role of Epithelial-to-Mesenchymal Transition for the Generation of Circulating Tumors Cells and Cancer Cell Dissemination

Tumor-related death is primarily caused by metastasis; consequently, understanding, preventing, and treating metastasis is essential to improving clinical outcomes. Metastasis is mainly governed by the dissemination of tumor cells in the systemic circulation: so-called circulating tumor cells (CTCs). CTCs typically arise from epithelial tumor cells that undergo epithelial-to-mesenchymal transition (EMT), resulting in the loss of cell-cell adhesions and polarity, and the reorganization of the cytoskeleton. Various oncogenic factors can induce EMT, among them the transforming growth factor (TGF)-β, as well as Wnt and Notch signaling pathways. This entails the activation of numerous transcription factors, including ZEB, TWIST, and Snail proteins, acting as transcriptional repressors of epithelial markers, such as E-cadherin and inducers of mesenchymal markers such as vimentin. These genetic and phenotypic changes ultimately facilitate cancer cell migration. However, to successfully form distant metastases, CTCs must primarily withstand the hostile environment of circulation. This includes adaption to shear stress, avoiding being trapped by coagulation and surviving attacks of the immune system. Several applications of CTCs, from cancer diagnosis and screening to monitoring and even guided therapy, seek their way into clinical practice. This review describes the process leading to tumor metastasis, from the generation of CTCs in primary tumors to their dissemination into distant organs, as well as the importance of subtyping CTCs to improve personalized and targeted cancer therapy.

Endoscopic Management of Anastomotic Leakage after Esophageal Surgery - Ten Year Analysis in a Tertiary University Center

Background/Aims

Anastomotic leakage after esophageal surgery remains a feared complication. During the last decade, management of this complication changed from surgical revision to a more conservative and endoscopic approach. However, the treatment remains controversial as the indications for conservative, endoscopic, and surgical approaches remain non-standardized.

Methods

Between 2010 and 2020, all patients who underwent Ivor Lewis esophagectomy for underlying malignancy were included in this study. The data of 28 patients diagnosed with anastomotic leak were further analyzed.

Results

Among 141 patients who underwent resection, 28 (19.9%) developed an anastomotic leak, eight (28.6%) of whom died. Thirteen patients were treated with endoluminal vacuum therapy (EVT), seven patients with self-expanding metal stents (SEMS) four patients with primary surgery, one patient with a hemoclip, and three patients were treated conservatively. EVT achieved closure in 92.3% of the patients with a large defect and no EVT-related complications. SEMS therapy was successful in clinically stable patients with small defect sizes.

Conclusions

EVT can be successfully applied in the treatment of anastomotic leakage in critically ill patients, while SEMS should be limited to clinically stable patients with a small defect size. Surgery is only warranted in patients with sepsis with graft necrosis.

Stem Cells and Organoid Technology in Precision Medicine in Inflammation: Are We There Yet?

Individualised cellular models of disease are a key tool for precision medicine to recapitulate chronic inflammatory processes. Organoid models can be derived from induced pluripotent stem cells (iPSCs) or from primary stem cells ex vivo. These models have been emerging over the past decade and have been used to reconstruct the respective organ-specific physiology and pathology, at an unsurpassed depth. In cancer research, patient-derived cancer organoids opened new perspectives in predicting therapy response and provided novel insights into tumour biology. In precision medicine of chronic inflammatory disorders, stem-cell based organoid models are currently being evaluated in pre-clinical pharmacodynamic studies (clinical studies in a dish) and are employed in clinical studies, e.g., by re-transplanting autologous epithelial organoids to re-establish intestinal barrier integrity. A particularly exciting feature of iPSC systems is their ability to provide insights into organ systems and inflammatory disease processes, which cannot be monitored with clinical biopsies, such as immune reactions in neurodegenerative disorders. Refinement of differentiation protocols, and next-generation co-culturing methods, aimed at generating self-organised, complex tissues in vitro, will be the next logical steps. In this mini-review, we critically discuss the current state-of-the-art stem cell and organoid technologies, as well as their future impact, potential and promises in combating immune-mediated chronic diseases.

Coming in the Air: Hypoxia Meets Epigenetics in Pancreatic Cancer

With a five-year survival rate under 9%, pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest tumors. Although the treatment options are slightly improving, PDAC is the second leading cause of cancer related death in 2020 in the US. In addition to a pronounced desmoplastic stroma reaction, pancreatic cancer is characterized by one of the lowest levels of oxygen availability within the tumor mass and these hypoxic conditions are known to contribute to tumor development and progression. In this context, the major hypoxia associated transcription factor family, HIF, regulates hundreds of genes involved in angiogenesis, metabolism, migration, invasion, immune escape and therapy resistance. Current research implications show, that hypoxia also modulates diverse areas of epigenetic mechanisms like non-coding RNAs, histone modifications or DNA methylation, which cooperate with the hypoxia-induced transcription factors as well as directly regulate the hypoxic response pathways. In this review, we will focus on hypoxia-mediated epigenetic alterations and their impact on pancreatic cancer.

The safety and efficacy of a new 20-mm lumen apposing metal stent (lams) for the endoscopic treatment of pancreatic and peripancreatic fluid collections: a large international, multicenter study

BACKGROUND

Lumen apposing metal stent (LAMS) allows an easy access to peripancreatic fluid collections (PPFCs) and the possibility of performing direct endoscopic necrosectomy (DEN). The aim of our study was to evaluate the safety and efficacy of a new 20-mm LAMS in the management of PPFCs. This novel stent represents the largest diameter LAMS available on the market to date.

METHODS

This is an international, multicenter retrospective study involving 20 centers. Consecutive patients who underwent EUS-guided PPFC drainage using a 20-mm LAMS were included. Primary outcomes were technical and clinical success. Secondary outcomes were rate and the severity of adverse events.

RESULTS

A total 105 patients underwent PPFC drainage using the new 20-mm LAMS and 106 LAMS were placed. Technical success was 100% (106/106). 7/105 patients died due to causes not related to the stent. Clinical success was achieved in 92/98 patients (93.9%). Significant adverse events occurred in 8/98 patients (8.16%): 4 cases (4.08%) of bleeding, 3 cases (3.06%) of suprainfection, 1 case of gastric outlet obstruction.

CONCLUSIONS

This multicenter study demonstrated acceptable rates of technical and clinical success using a new 20-mm LAMS for PPFC, including walled-off pancreatic necrosis (WOPN). The results of our study suggest that a new 20-mm LAMS is non-inferior in terms of safety, efficacy, and adverse events as compared to smaller diameter LAMS in the management of PPFCs, including pancreatic psuedocysts (PP) and WOPN. Randomized controlled studies will be needed to determine the ideal size of LAMS need to achieve the greatest clinical benefit with the minimized risk exposure for this high-risk patient population.

Endoscopic ultrasound-guided drainage of pancreatic walled-off necrosis using 20-mm versus 15-mm lumen-apposing metal stents: an international, multicenter, case-matched study

BACKGROUNDS

Endoscopic ultrasound (EUS)-guided placement of lumen-apposing metal stents (LAMSs) has gained popularity for the treatment of pancreatic walled-off necrosis (WON). We compared the 20-mm and 15-mm LAMSs for the treatment of symptomatic WON in terms of clinical success and adverse events.

METHODS

We conducted a retrospective, case-matched study of 306 adults at 22 tertiary centers from 04/2014 to 10/2018. A total of 102 patients with symptomatic WON who underwent drainage with 20-mm LAMS (cases) and 204 patients who underwent drainage with 15-mm LAMS (controls) were matched by age, sex, and drainage approach. Conditional logistic regression analysis was performed to compare clinical success (resolution of WON on follow-up imaging without reintervention) and adverse events (according to American Society for Gastrointestinal Endoscopy criteria).

RESULTS

Clinical success was achieved in 92.2 % of patients with 20-mm LAMS and 91.7 % of patients with 15-mm LAMS (odds ratio 0.92; P = 0.91). Patients with 20-mm LAMS underwent fewer direct endoscopic necrosectomy (DEN) sessions (mean 1.3 vs. 2.1; P < 0.001), despite having larger WON collections (transverse axis 118.2 vs. 101.9 mm, P = 0.003; anteroposterior axis 95.9 vs. 80.1 mm, P = 0.01). There was no difference in overall adverse events (21.6 % vs. 15.2 %; P = 0.72) and bleeding events (4.9 % vs. 3.4 %; P = 0.54) between the 20-mm and 15-mm LAMS groups, respectively.

CONCLUSIONS

The 20-mm LAMS showed comparable clinical success and safety profile to the 15-mm LAMS, with the need for fewer DEN sessions for WON resolution.

NF-κB Dependent Chemokine Signaling in Pancreatic Cancer

Pancreatic cancer is one of the carcinomas with the worst prognoses, as shown by its five-year survival rate of 9%. Although there have been new therapeutic innovations, the effectiveness of these therapies is still limited, resulting in pancreatic ductal adenocarcinoma (PDAC) becoming the second leading cause of cancer-related death in 2020 in the US. In addition to tumor cell intrinsic resistance mechanisms, this disease exhibits a complex stroma consisting of fibroblasts, immune cells, neuronal and vascular cells, along with extracellular matrix, all conferring therapeutic resistance by several mechanisms. The NF-κB pathway is involved in both the tumor cell-intrinsic and microenvironment-mediated therapeutic resistance by regulating the transcription of a plethora of target genes. These genes are involved in nearly all scenarios described as the hallmarks of cancer. In addition to classical regulators of apoptosis, NF-κB regulates the expression of chemokines and their receptors, both in the tumor cells and in cells of the microenvironment. These chemokines mediate autocrine and paracrine loops among tumor cells but also cross-signaling between tumor cells and the stroma. In this review, we will focus on NF-κB-mediated chemokine signaling, with an emphasis on therapy resistance in pancreatic cancer.

Acute sedation-associated complications in GI endoscopy (ProSed 2 Study): results from the prospective multicentre electronic registry of sedation-associated complications

OBJECTIVES

Sedation has been established for GI endoscopic procedures in most countries, but it is also associated with an added risk of complications. Reported complication rates are variable due to different study methodologies and often limited sample size.

DESIGNS

Acute sedation-associated complications were prospectively recorded in an electronic endoscopy documentation in 39 study centres between December 2011 and August 2014 (median inclusion period 24 months). The sedation regimen was decided by each study centre.

RESULTS

A total of 368 206 endoscopies was recorded; 11% without sedation. Propofol was the dominant drug used (62% only, 22.5% in combination with midazolam). Of the sedated patients, 38 (0.01%) suffered a major complication, and overall mortality was 0.005% (n=15); minor complications occurred in 0.3%. Multivariate analysis showed the following independent risk factors for all complications: American Society of Anesthesiologists class >2 (OR 2.29) and type and duration of endoscopy. Of the sedation regimens, propofol monosedation had the lowest rate (OR 0.75) compared with midazolam (reference) and combinations (OR 1.0-1.5). Compared with primary care hospitals, tertiary referral centres had higher complication rates (OR 1.61). Notably, compared with sedation by a two-person endoscopy team (endoscopist/assistant; 53.5% of all procedures), adding another person for sedation (nurse, physician) was associated with higher complication rates (ORs 1.40-4.46), probably due to higher complexity of procedures not evident in the multivariate analysis.

CONCLUSIONS

This large multicentre registry study confirmed that severe acute sedation-related complications are rare during GI endoscopy with a very low mortality. The data are useful for planning risk factor-adapted sedation management to further prevent sedation-associated complications in selected patients.

TRIAL REGISTRATION NUMBER

DRKS00007768; Pre-results.

Vedolizumab is associated with changes in innate rather than adaptive immunity in patients with inflammatory bowel disease

OBJECTIVE

Vedolizumab, a monoclonal antibody directed against the integrin heterodimer α4β7, is approved for the treatment of Crohn's disease and ulcerative colitis. The efficacy of vedolizumab has been suggested to result from inhibition of intestinal T cell trafficking although human data to support this conclusion are scarce. We therefore performed a comprehensive analysis of vedolizumab-induced alterations in mucosal and systemic immunity in patients with inflammatory bowel disease (IBD), using anti-inflammatory therapy with the TNFα antibody infliximab as control.

DESIGN

Immunophenotyping, immunohistochemistry, T cell receptor profiling and RNA sequencing were performed using blood and colonic biopsies from patients with IBD before and during treatment with vedolizumab (n=18) or, as control, the anti-TNFα antibody infliximab (n=20). Leucocyte trafficking in vivo was assessed using single photon emission computed tomography and endomicroscopy.

RESULTS

Vedolizumab was not associated with alterations in the abundance or phenotype of lamina propria T cells and did not affect the mucosal T cell repertoire or leucocyte trafficking in vivo. Surprisingly, however, α4β7 antibody treatment was associated with substantial effects on innate immunity including changes in macrophage populations and pronounced alterations in the expression of molecules involved in microbial sensing, chemoattraction and regulation of the innate effector response. These effects were specific to vedolizumab, not observed in response to the TNFα antibody infliximab, and associated with inhibition of intestinal inflammation.

CONCLUSION

Our findings suggest that modulation of innate immunity contributes to the therapeutic efficacy of vedolizumab in IBD.

TRIAL REGISTRATION NUMBER

NCT02694588.

The antioxidant transcription factor Nrf2 modulates the stress response and phenotype of malignant as well as premalignant pancreatic ductal epithelial cells by inducing expression of the ATF3 splicing variant ΔZip2

Pancreatic ductal adenocarcinoma (PDAC) exhibits one of the worst survival rates of all cancers. While death rates show declining trends in the majority of cancers, PDAC registers rising rates. Based on the recently described crosstalk between TGF-β1 and Nrf2 in the PDAC development, the involvement of ATF3 and its splice variant ΔZip2 in TGF-β1- and Nrf2-driven pancreatic tumorigenesis was investigated. As demonstrated here, PDAC (Panc1, T3M4) cells or premalignant H6c7 pancreatic ductal epithelial cells differentially express ΔZip2- and ATF3, relating to stronger Nrf2 activity seen in Panc1 cells and TGF-ß1 activity in T3M4 or H6c7 cells, respectively. Treatment with the electrophile/oxidative stress inducer tBHQ or the cytostatic drug gemcitabine strongly elevated ΔZip2 expression in a Nrf2-dependent fashion. The differential expression of ATF3 and ΔZip2 in response to Nrf2 and TGF-ß1 relates to differential ATF3-gene promoter usage, giving rise of distinct splice variants. Nrf2-dependent ΔZip2 expression confers resistance against gemcitabine-induced apoptosis, only partially relating to interference with ATF3 and its proapoptotic activity, e.g., through CHOP-expression. In fact, ΔZip2 autonomously activates expression of cIAP anti-apoptotic proteins. Moreover, ΔZip2 favors and ATF3 suppresses growth and clonal expansion of PDAC cells, again partially independent of each other. Using a Panc1 tumor xenograft model in SCID-beige mice, the opposite activities of ATF3 and ΔZip2 on tumor-growth and chemoresistance were verified in vivo. Immunohistochemical analyses confirmed ΔZip2 and Nrf2 coexpression in cancerous and PanIN structures of human PDAC and chronic pancreatitis tissues, respectively, which to some extent was reciprocal to ATF3 expression. It is concluded that depending on selective ATF3-gene promoter usage by Nrf2, the ΔZip2 expression is induced in response to electrophile/oxidative (here through tBHQ) and xenobiotic (here through gemcitabine) stress, providing apoptosis protection and growth advantages to pancreatic ductal epithelial cells. This condition may substantially add to pancreatic carcinogenesis driven by chronic inflammation.

MTOR inhibitor-based combination therapies for pancreatic cancer

Background:

Although the mechanistic target of rapamycin (MTOR) kinase, included in the mTORC1 and mTORC2 signalling hubs, has been demonstrated to be active in a significant fraction of patients with pancreatic ductal adenocarcinoma (PDAC), the value of the kinase as a therapeutic target needs further clarification.

Methods:

We used Mtor floxed mice to analyse the function of the kinase in context of the pancreas at the genetic level. Using a dual-recombinase system, which is based on the flippase-FRT (Flp-FRT) and Cre-loxP recombination technologies, we generated a novel cellular model, allowing the genetic analysis of MTOR functions in tumour maintenance. Cross-species validation and pharmacological intervention studies were used to recapitulate genetic data in human models, including primary human 3D PDAC cultures.

Results:

Genetic deletion of the Mtor gene in the pancreas results in exocrine and endocrine insufficiency. In established murine PDAC cells, MTOR is linked to metabolic pathways and maintains the glucose uptake and growth. Importantly, blocking MTOR genetically as well as pharmacologically results in adaptive rewiring of oncogenic signalling with activation of canonical extracellular signal-regulated kinase and phosphoinositide 3-kinase-AKT pathways. We provide evidence that interfering with such adaptive signalling in murine and human PDAC models is important in a subgroup.

Conclusions:

Our data suggest developing dual MTORC1/TORC2 inhibitor-based therapies for subtype-specific intervention.

Identification and characterization of two functional variants in the human longevity gene FOXO3

FOXO3 is consistently annotated as a human longevity gene. However, functional variants and underlying mechanisms for the association remain unknown. Here, we perform resequencing of the FOXO3 locus and single-nucleotide variant (SNV) genotyping in three European populations. We find two FOXO3 SNVs, rs12206094 and rs4946935, to be most significantly associated with longevity and further characterize them functionally. We experimentally validate the in silico predicted allele-dependent binding of transcription factors (CTCF, SRF) to the SNVs. Specifically, in luciferase reporter assays, the longevity alleles of both variants show considerable enhancer activities that are reversed by IGF-1 treatment. An eQTL database search reveals that the alleles are also associated with higher FOXO3 mRNA expression in various human tissues, which is in line with observations in long-lived model organisms. In summary, we present experimental evidence for a functional link between common intronic variants in FOXO3 and human longevity.

FOXO3 is one of the few established longevity genes. Here, the authors fine-map the FOXO3-longevity association to two intronic SNPs and, using luciferase assays and EMSAs, show that these SNPs affect binding of transcription factors CTCF and SRF and associate with FOXO3 expression.

[Hyponatremia: Differential Diagnosis and Treatment]

Hyponatremia is the most common electrolyte abnormality seen in hospitalized patients, with up to 30 % having a plasma sodium concentration below 135 mmol/l. It is now clear that the clinical problem extends beyond the neurological symptoms, which can be explained by intracerebral osmotic fluid shifts and brain edema. Instead, chronic hyponatremia is associated with impaired gait stability and an increased risk of bone fragility fractures. Moreover, hyponatremia has been demonstrated to be an indicator of poor prognosis in a variety of conditions.Hyponatremia can be a life-threatening disorder due to increased intracranial pressure, thus requiring prompt and efficacious treatment. However, overly rapid correction may be complicated by osmotic demyelination syndrome with catastrophic clinical sequelae, i. e., spastic quadriparesis, or even coma or death.To avoid inappropriate treatment, the underlying pathophysiology in each case as well as the time course (acute vs. chronic) and the clinical and biochemical severity must be considered.The purpose of this review is to provide the reader with a systematic approach to the correct diagnosis and management of hyponatremia based on available European and international guidelines.

Management of patients with pancreatic cystic lesions: A case-based survey

BACKGROUND

Pancreatic cystic lesions (PCL), including intraductal papillary mucinous neoplasia (IPMN), harbor different malignant potential and the optimal management is often challenging. The present study aims to depict the compliance of experts with current consensus guidelines and the accuracy of treatment recommendations stratified by the medical specialty and hospital volume.

METHODS

An international survey was conducted using a set of 10 selected cases of PCL that were presented to a cohort of international experts on pancreatology. All presented cases were surgically resected between 2004 and 2015 and histopathological examination was available. Accuracy of the treatment recommendations was based on the European and international consensus guideline algorithms, and the histopathological result.

RESULTS

The response rate of the survey was 26% (46 of 177 contacted experts), consisting of 70% surgeons and 30% gastroenterologists/oncologists (GI/Onc). In the case of main-duct IPMN (MD-IPMN), surgeons preferred more often the surgical approach in comparison with the GI/Onc (55 versus 44%). The mean accuracy rate based on the European and international consensus guidelines, and the histopathological result, were 71/76/38% (surgeons), and 70/73/34% (GI/Onc), respectively. High-volume centers achieved insignificantly higher accuracy scores with regard to the histopathology. Small branch-duct IPMN with cysts <2 cm and malignant potential were not identified by the guideline algorithms.

CONCLUSION

The survey underlines the complexity of treatment decisions for patients with PCL; less than 40% of the recommendations were in line with the final histopathology in this selected case panel. Experts and consensus guidelines may fail to predict malignant potential in small PCL.

Role of CCL20 mediated immune cell recruitment in NF-κB mediated TRAIL resistance of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest cancers. From a clinical view, the transcription factor NF-κB is of particular importance, since this pathway confers apoptosis resistance and limits drug efficacy. Whereas the role of the most abundant NF-κB subunit p65/RelA in therapeutic resistance is well documented, only little knowledge of the RelA downstream targets and their functional relevance in TRAIL mediated apoptosis in PDAC is available. In the present study TRAIL resistant and sensitive PDAC cell lines were analyzed for differentially expressed RelA target genes, to define RelA downstream targets mediating TRAIL resistance. The most upregulated target gene was then further functionally characterized. Unbiased genome-wide expression analysis demonstrated that the chemokine CCL20 represents the strongest TRAIL inducible direct RelA target gene in resistant PDAC cells. Unexpectedly, targeting CCL20 by siRNA, blocking antibodies or by downregulation of the sole CCL20 receptor CCR6 had no effect on PDAC cell death or cancer cell migration, arguing against an autocrine role of CCL20 in PDAC. However, by using an ex vivo indirect co-culture system we were able to show that CCL20 acts paracrine to recruit immune cells. Importantly, CCL20-recruited immune cells further increase TRAIL resistance of CCL20-producing PDAC cells. In conclusion, our data show a functional role of a RelA-CCL20 pathway in PDAC TRAIL resistance. We demonstrate how the therapy-induced cross-talk of cancer cells with immune cells affects treatment responses, knowledge needed to tailor novel bi-specific treatments, which target tumor cell as well as immune cells.

Phase-transfer catalyzed asymmetric synthesis of α,β-unsaturated γ,γ-disubstituted γ-lactams

The direct, γ-selective vinylogous Michael addition of unsaturated γ-monosubstituted γ-lactams was realized by using chiral phase-transfer catalysis.

Discovery of Rigidified α,β-Unsaturated Imines as New Resistance-breaking Insecticides for Malaria Vector Control

During our continuous search for new resistance-breaking insecticides applicable to malaria vector control, a new class of α,β-unsaturated imines was identified by applying the principle of conformational rigidification as a powerful tool for compound optimisation. Herein we describe the successful synthesis of these compounds and their biological test results. Our lead compound 16 from this insecticidal class outperforms market standards, notably for the control of mosquito strains that exhibit either metabolic or target-site resistance to these established insecticides. In our model system for insecticide-treated mosquito nets the compound reveals long-lasting efficacy for up to several months.

Open Surgical versus Minimal Invasive Necrosectomy of the Pancreas-A Retrospective Multicenter Analysis of the German Pancreatitis Study Group

Background

Necrotising pancreatitis, and particularly infected necrosis, are still associated with high morbidity and mortality. Since 2011, a step-up approach with lower morbidity rates compared to initial open necrosectomy has been established. However, mortality and complication rates of this complex treatment are hardly studied thereafter.

Methods

The German Pancreatitis Study Group performed a multicenter, retrospective study including 220 patients with necrotising pancreatitis requiring intervention, treated at 10 hospitals in Germany between January 2008 and June 2014. Data were analysed for the primary endpoints "severe complications" and "mortality" as well as secondary endpoints including "length of hospital stay", "follow up", and predisposing or prognostic factors.

Results

Of all patients 13.6% were treated primarily with surgery and 86.4% underwent a step-up approach. More men (71.8%) required intervention for necrotising pancreatitis. The most frequent etiology was biliary (41.4%) followed by alcohol (29.1%). Compared to open necrosectomy, the step-up approach was associated with a lower number of severe complications (primary composite endpoint including sepsis, persistent multiorgan dysfunction syndrome (MODS) and erosion bleeding: 44.7% vs. 73.3%), lower mortality (10.5% vs. 33.3%) and lower rates of diabetes mellitus type 3c (4.7% vs. 33.3%). Low hematocrit and low blood urea nitrogen at admission as well as a history of acute pancreatitis were prognostic for less complications in necrotising pancreatitis. A combination of drainage with endoscopic necrosectomy resulted in the lowest rate of severe complications.

Conclusion

A step-up approach starting with minimal invasive drainage techniques and endoscopic necrosectomy results in a significant reduction of morbidity and mortality in necrotising pancreatitis compared to a primarily surgical intervention.

Limits of and Complications after Embolization of the Hepatic Artery and Portal Vein to Induce Segmental Hypertrophy of the Liver: A Large Mini-Pig Study

Background: The aim of this study was to compare arterial embolization (AE) with portal vein embolization (PVE) for the induction of segmental hypertrophy regarding procedural efficacy, safety and outcome. Methods: A total of 29 mini pigs were subjected to PVE, AE or assigned to the sham (SO) group. Correspondingly, 75% of the hepatic artery or portal vein branches were embolized. Growth and atrophy of the liver lobes, calculating the liver-to-body weight index (LBWI), laboratory data, arteriography, portography, Doppler ultrasound (US) and histopathology were analyzed. Results: After PVE, 2 animals had to be excluded due to technical problems. After AE, 4 animals had to be excluded because of technical problems and early sacrifice. Postprocedural US demonstrated effective AE and PVE of the respective lobes. Four weeks after PVE, portography showed a slow refilling of the embolized lobe by collateral portal venous vessels. Four weeks after AE, arteriography revealed a slight revascularization of the embolized lobes by arterial neovascularization. Segmental AE led to extensive necrotic and inflammatory alterations in the liver and bile duct parenchyma. Significant hypertrophy of the non-embolized lobe was only noted in the PVE group (LBWI: 0.91 ± 0.28%; p = 0.001). There was no increase in the non-embolized lobe in the AE (LBWI: 0.45 ± 0.087%) and SO group (LBWI: 0.45 ± 0.13%). Conclusion: PVE is safe and effective to induce segmental hypertrophy. Portal reperfusion by collateral vessels may limit hypertrophy. AE did not increase the segmental hepatic volume but carries the risk of extensive necrotic inflammatory damage.

Endoscopic ultrasound-guided biliary drainage using a lumen-apposing self-expanding metal stent: a case series

Endoscopic ultrasound-guided biliary drainage (EUS-BD) might be an alternative to percutaneous or transpapillary biliary drainage in unresectable pancreatic or biliary cancer. A lumen-apposing, fully covered, self-expanding metal stent, which creates a sealed transluminal conduit between the biliary and gastrointestinal tract may offer advantages over conventional plastic and metal stents. In this retrospective, observational, open-label case study, five patients underwent EUS-BD for obstructive jaundice in pancreatic cancer (n = 4) or distal cholangiocarcinoma (n = 1). Technical and functional success was achieved in all patients without complications. The development of specialized stent and delivery systems may render EUS-BD an effective and safe alternative to percutaneous or transpapillary approaches.

Antibiosis of Necrotizing Pancreatitis

BACKGROUND

Necrotizing pancreatitis is a life-threatening presentation of acute pancreatitis. The mortality of 20-80% initially depends on the persistence of organ failure and systemic inflammatory response syndrome (SIRS) and, in the later course of the disease, on secondary infection of the necrosis. The questions whether prophylactic antibiotics aiming to prevent this infection should be administered and which antibiotic is the best to use, as well as the problem of fungal infection under antibiotic treatment are still intriguing and insufficiently solved.

METHODS

A search of the literature using PubMed was carried out, supplemented by a review of the programmes of the Digestive Disease Week (DDW) and the United European Gastroenterology Week (UEGW).

RESULTS

Despite the widely practised prophylactic antibiotic administration in severe pancreatitis, no evidence for the benefit of this strategy exists. One of the drawbacks might be a tendency for disastrous fungal infection under prophylactic antibiotics. Bacterial translocation from the gut in the second week after the onset of symptoms is the major source for infection of pancreatic necrosis and provides a clear indication for antibiotic treatment. However, routine fine-needle aspiration for a calculated antibiotic therapy cannot be recommended, and all other tests offer only indirect signs. Important factors such as enteral versus parenteral feeding and the method of necrosectomy are mostly neglected in the trials but seem to be essential for the outcome of the patient.

CONCLUSIONS

Even though most meta-analyses including the newer double-blind, placebo-controlled trials on prophylactic antibiotics showed no beneficial effects in the prevention of infection of necrosis and/or outcome of the patients, this strategy is still widely used in clinical routine. Since nearly all trials published so far show systematic problems (i.e. inaccurate definition of the severity of the disease, poor statistical testing, and neglect of differences in the route of nutrition), there is a need for randomized controlled prospective trials with exact definitions of the disease.

Abstract B114: c-Rel is a critical mediator of NF-κB dependent TRAIL resistance of pancreatic cancer cells

NF-κB has been shown to be critical for resistance of pancreatic ductal adenocarcinoma (PDAC) against chemotherapeutic drug and death receptor induced apoptosis, but little is known about the role of the c-Rel subunit.

In the present study, by analysis of genome-wide patterns of c-Rel dependent gene expression we were able to establish c-Rel as a critical regulator of TRAIL induced apoptosis in PDAC. Transfection with siRNA against c-Rel sensitized the TRAIL resistant PDAC cells and EMSA revealed that c-Rel is part of the TRAIL inducible NF-κB complex. Array analysis identified NFATc2 as a critical downstream target of c-Rel in PDAC. In line, siRNA targeting c-Rel strongly reduced TRAIL induced NFATc2 activity and siRNA targeting NFATc2 sensitized PDAC cells against TRAIL induced apoptosis. Finally, TRAIL induced expression of COX-2 was diminished through siRNA targeting c-Rel or NFATc2 and pharmacological inhibition of COX-2 with celecoxib enhanced TRAIL apoptosis.

In conclusion, we were able to delineate a novel c-Rel, NFATc2 and COX-2 dependent anti-apoptotic signalling pathway in PDAC with broad clinical implications for pharmaceutical intervention strategies.

Citation Format: Claudia Geismann, Frauke Grohmann, Robert Häsler, Philip Rosenstiel, Günter Schneider, Sebastian Zeissig, Stefan Schreiber, Heiner Schäfer, Alexander Arlt. c-Rel is a critical mediator of NF-κB dependent TRAIL resistance of pancreatic cancer cells. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Innovations in Research and Treatment; May 18-21, 2014; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2015;75(13 Suppl):Abstract nr B114.