Potential of Anti-Leukotriene Drugs as New Therapeutic Agents for Inhibiting Cholangiocarcinoma Progression.

Cholangiocarcinoma (CCA) is a cancer with a poor prognosis due to difficulties in diagnosis and limited treatment options, highlighting the urgent need for new targeted therapies. In a clinical setting, we found that leukotriene levels in bile were higher than in serum. Immunohistochemical analysis of surgically resected samples also revealed that CysLT receptor 1 (CysLTR1) was more highly expressed in CCA than in normal bile duct tissue, prompting us to investigate leukotriene as a potential therapeutic target in CCA. In vitro studies using CCA cell lines expressing CysLTR1 showed that leukotriene D4, a major ligand of CysLTR1, promoted cell proliferation, with increased phosphorylation of AKT and extracellular signal-regulated kinase 1/2 (ERK1/2). Additionally, treatment with two clinically available anti-allergic drugs-zileuton, an inhibitor of CysLT formation, and montelukast, a CysLTR1 inhibitor-had inhibitory effects on cell proliferation and migratory capacity, accompanied by the reduced phosphorylation of AKT and ERK1/2. Furthermore, the simultaneous administration of both drugs synergistically enhanced the inhibitory effect on cell proliferation. Our study suggests that use of these drugs may represent a novel approach to treat CCA through drug repositioning.

Dual role of autotaxin as novel biomarker and therapeutic target in pancreatic neuroendocrine neoplasms.

Pancreatic neuroendocrine neoplasms (panNENs) are rare pancreatic neoplasms, and descriptions of treatment remain limited. Autotaxin (ATX) is a secreted autocrine motility factor involved in the production of lysophosphatidic acid (LPA), a lipid mediator that promotes the progression of various cancers. The aim of this study was to clarify the importance of the ATX-LPA axis in panNENs and to confirm its contribution to panNEN progression using clinical data, cell lines, and a mouse model. Serum ATX level was higher in patients with panNEN than in patients with other pancreatic diseases (chronic pancreatitis, pancreatic ductal adenocarcinoma [PDAC], intraductal papillary mucinous neoplasm, autoimmune pancreatitis) and healthy controls, and 61% of clinical specimens stained strongly for ATX. In a case we encountered, serum ATX level fluctuated with disease progression. An in vitro study showed higher ATX mRNA expression in panNEN cell lines than in PDAC cell lines. Cell proliferation and migration in panNEN cell lines were stimulated via the ATX-LPA axis and suppressed by RNA interference or inhibitors. An in vivo study showed that intraperitoneal injection of GLPG1690, an ATX inhibitor, suppressed tumor progression in a xenograft model. These findings revealed that ATX expression is significantly elevated in panNEN and is related to the progression of panNEN. We showed the potential of ATX as a novel biomarker and therapeutic target.

Clinical impact of bile-derived exosomal microRNAs as novel diagnostic and prognostic biomarkers for biliary tract cancers.

Sampling of bile juice during endoscopic retrograde cholangiopancreatography (ERCP) has potential benefit of being amenable to the identification of novel biomarkers in liquid biopsy. This study reports the results of a global investigation of exosomal microRNAs (miRNAs) in bile to identify potential biomarkers for biliary tract cancers (BTCs). Eighty-eight bile samples collected during ERCP (45 BTC and 43 noncancer control samples) were enrolled in this study. Eleven BTC samples and nine control samples were assigned as the discovery set. Exosomes in bile and serum samples were collected using a glass membrane column with size-controlled macroporous glass (MPG), and exosomal miRNA expression profiles were evaluated using comprehensive miRNA microarray analysis (3D-Gene). For validation, exosomal miRNA in the bile samples of 34 BTCs and 34 controls were comprehensively evaluated using 3D-Gene. In the discovery set, eight exosomal miRNAs in bile were identified as significant aberrant expression markers, while no miRNA with aberrant expression in serum was identified. In a comparison of the discovery and validation sets, miR-451a and miR-3619-3p were identified as reproducible upregulated markers, and the combination of the two bile miRNAs showed an excellent area under the curve (0.819) value for diagnosing BTCs. In addition, high miR-3619-3p expression in bile reflects poorer prognosis of BTCs (hazard ratio = 2.89). The MPG-extracted exosomal miRNAs in bile aspirated during ERCP provide a convenient new approach for diagnosing biliary diseases. Bile-derived miRNA analysis with miR-451a and miR-3619-3p represents a potentially valuable diagnostic strategy for identifying BTCs as well as a predictive indicator of BTC prognosis.

Various innovative roles for 3-Fr microcatheters in pancreaticobiliary endoscopy.

With the development of newer devices and technical innovations, pancreaticobiliary endoscopy is expanding to assume more advanced therapeutic roles. As with other devices, slimmed-down "3-Fr microcatheters" are considered to be opening new windows toward entirely new therapeutic techniques for various purposes. Our practical experience with a total of 34 consecutive patients in whom 3-Fr microcatheters were applied during pancreaticobiliary endoscopic procedures clarified the potential roles of this instrument in pancreaticobiliary endoscopy. The major benefits of 3-Fr microcatheters involve their slimness and flexibility. Applications of 3-Fr microcatheters could be categorized into three groups according to the characteristics of usage: (1) utilization as a cannulation catheter for peroral digital cholangioscopy (n = 15); (2) selective advancement through deep flexures or severely stenotic ducts (n = 11); or (3) two-devices-in-one-channel technique (n = 8). The microcatheter worked successfully for cannulation of cholangioscopy in all but one case (14/15, 93.3%). For selective advancement, the microcatheter worked for troubleshooting in 9 of 11 cases (81.8%). With the two-devices-in-one-channel technique, the microcatheter proved satisfactory in all cases (8/8, 100%). In total, the microcatheter was successfully maneuvered in 31 of 34 cases (91.1%), following the failure of procedures using conventional endoscopic techniques. In terms of adverse events, cystic duct injury was only observed in two cases (5.8%), who recovered under conservative observation, because its slimness could minimize the damage. We believe that 3-Fr microcatheters offer effective and safe salvage troubleshooting during various endoscopic pancreaticobiliary procedures that face troublesome situations with conventional strategies.

Autotaxin in ascites promotes peritoneal dissemination in pancreatic cancer.

Peritoneal dissemination and malignant ascites in pancreatic ductal adenocarcinoma (PDAC) patients represent a major clinical issue. Lysophosphatidic acid (LPA) is a lipid mediator that modulates the progression of various cancers. Based on the increasing evidence showing that LPA is abundant in malignant ascites, we focused on autotaxin (ATX), which is a secreted enzyme that is important for the production of LPA. This study aimed to elucidate the importance of the ATX-LPA axis in malignant ascites in PDAC and to determine whether ATX works as a molecular target for treating peritoneal dissemination. In a PDAC peritoneal dissemination mouse model, the amount of ATX was significantly higher in ascites than in serum. An in vitro study using two PDAC cell lines, AsPC-1 and PANC-1, showed that ATX-LPA signaling promoted cancer cell migration via the activation of the downstream signaling, and this increased cell migration was suppressed by an ATX inhibitor, PF-8380. An in vivo study showed that PF-8380 suppressed peritoneal dissemination and decreased malignant ascites, and these results were validated by the biological analysis as well as the in vitro study. Moreover, there was a positive correlation between the amount of ATX in ascites and the degree of disseminated cancer progression. These findings demonstrated that ATX in ascites works as a promotor of peritoneal dissemination, and the targeting of ATX must represent a useful and novel therapy for peritoneal dissemination of PDAC.

Classic chronic pancreatitis is associated with prior acute pancreatitis in only 50% of patients in a large single-institution study.

BACKGROUND: The sentinel acute pancreatitis event (SAPE) hypothesis for pathogenesis of chronic pancreatitis (CP) postulates that acute pancreatitis (AP), especially recurrent AP (RAP), precedes development of CP. However, in a recent population-based study, 52/89 (58.4%) of CP had no prior episodes of AP. In a large clinic-based CP cohort, we aimed to determine the incidence and timing of prior AP in patients diagnosed with CP. METHODS: We retrospectively identified 499 consecutive patients with classic CP diagnosed at our institution from January 2013 through December 2015. We abstracted their demographic and clinical data, especially regarding prior AP. RESULTS: We identified 3 cohorts: 1) CP with no AP (n = 231 [46.3%]), 2) AP before CP (n = 250 [50.1%]), and 3) AP after CP (n = 18 [3.6%]). At CP diagnosis, 249 patients (49.9%) had no prior AP. Compared with the "CP preceded by AP" cohort, the "CP without AP"' cohort was older (59.2 ±â€¯13.9 vs 48.6 ±â€¯15.7 years; P < .001), had a higher prevalence of diabetes mellitus (30.3% vs 12.4%; P < .001), reported less pain (52.8% vs 87.6%; P < .001), and had a lower rate of endoscopic interventions (16.0% vs 39.2%; P < .001). In the "CP preceded by AP" cohort, 117 (46.8%) had a single episode of AP and 133 (53.2%) had RAP. CONCLUSION: Nearly half the patients with classic CP did not have prior AP. Only a quarter of patients had CP that could potentially have evolved from prior RAP. Development of CP may be attributable to an altogether different pathogenesis (a non-SAPE pathway) for a considerable proportion of patients.

Feasibility and safety of duodenal covered self-expandable metallic stent fixation: an experimental study.

BACKGROUND AND AIMS: Migration of duodenal covered self-expandable metallic stents (C-SEMS) is the main cause of stent dysfunction in patients with malignant gastric outlet obstruction. However, the ideal method to prevent migration has not been clarified. We aimed to evaluate the feasibility and safety of duodenal C-SEMS fixation in this experimental study. METHODS: We used the over-the-scope clip (OTSC), suture, and clip methods to fix duodenal C-SEMS and evaluated the gripping force of each device and invasion depth based on pathological findings. RESULTS: The OTSC and suturing systems had a significantly higher mean gripping force compared with the clipping system (OTSC vs. clip: 13.2 vs. 1.0 Newtons [N], P < 0.001; suture vs. clip: 8.5 vs. 1.0 N, P < 0.001). OTSC compression was stronger compared with suturing (OTSC vs. suture: 13.2 vs. 8.5 N, P = 0.006). The submucosal layer, but not the muscle layer, was compressed more widely and deeply by OTSC compared with clips based on pathological findings by hematoxylin and eosin staining. CONCLUSION: Both OTSC and suturing methods used for duodenal C-SEMS fixation were feasible compared with the clipping method. The pathological evaluation of invasion depth indicated that OTSC may be safe even for preventive use. This study suggested that these methods can be applied clinically for duodenal C-SEMS fixation.

Covered duodenal self-expandable metal stents prolong biliary stent patency in double stenting: The largest series of bilioduodenal obstruction.

BACKGROUND AND AIM: Endoscopic biliary and duodenal stenting (DS; double stenting) is widely accepted as a palliation therapy for malignant bilioduodenal obstruction. The aim of the current study was to investigate the patency and adverse events of duodenal and biliary stents in patients with DS. METHODS: Patients who underwent DS from April 2004 to March 2017 were analyzed retrospectively with regard to clinical outcomes and predictive factors of recurrent biliary and duodenal obstruction (recurrent biliary obstruction [RBO] and recurrent duodenal obstruction [RDO]). RESULTS: A total of 109 consecutive patients was enrolled. Technical success of DS was achieved in 108 patients (99.1%). Symptoms due to biliary and duodenal obstruction were improved in 89 patients (81.7%). RBO occurred in 25 patients (22.9%) and RDO in 13 (11.9%). The median times to RBO and RDO from DS were 87 and 76 days, respectively. Placement of a duodenal uncovered self-expandable metal stent (U-SEMS) was significantly associated with RBO in the multivariable analysis (P = 0.007). Time to RBO was significantly longer in the duodenal covered self-expandable metal stent group than in the U-SEMS group (P = 0.003). No predictive factors of RDO were detected, and duodenal stent type was not associated with the time to RDO (P = 0.724). CONCLUSIONS: Double stenting was safe and effective for malignant bilioduodenal obstruction. Duodenal U-SEMS is a risk factor for RBO. The covered self-expandable metal stent is the preferred type of duodenal SEMS in patients with DS (Clinical trial registration number: UMIN000027606).

The utility and efficacy of self-expandable metal stents for treating malignant gastric outlet obstructions in patients under best supportive care.

PURPOSE: Self-expandable metallic stents (SEMSs) may be used to effectively palliate malignant gastric outlet obstructions (GOOs), but their utility and efficacy in patients under best supportive care (BSC) have not been explored. METHOD: In this multicenter retrospective study, we reviewed data on patients under BSC who underwent endoscopic SEMS placement to treat malignant GOO without chemotherapy. We evaluated the safety and efficacy of the procedure. RESULTS: We enrolled a total of 208 patients. SEMS placement was technically successful in 207 (99.5%) and clinically successful in 164 (78.8%). The mean procedure time was 25.6 ± 2.8 min. Stent dysfunction later developed in 30 (14.4%) patients, of whom 90% (27/30) underwent reintervention. The procedure-related mortality rate was 1.44%; all deaths were due to pneumonia. Subgroup analysis by Karnofsky performance status (KPS) revealed that neither technical success, stent dysfunction, reintervention rate, procedure-related pneumonia or death, nor death within 14 days differed between patients with good and poor KPS. However, the clinical success rate and the median survival time were significantly lower and shorter, respectively, in those with poor KPS (p < 0.001). CONCLUSIONS: Duodenal SEMS placement is an effective palliative treatment for malignant GOO in BSC patients. Although the GOO score did not dramatically improve in patients with poor KPS, the procedure was safe and palliatively feasible. Procedure-related pneumonia was fatal; thus, it is essential to proceed with great caution. TRIAL REGISTRATION: Clinical trial registration number: UMIN000028367.

An Increased Chromosome 7 Copy Number in Endoscopic Bile Duct Biopsy Specimens Is Predictive of a Poor Prognosis in Cholangiocarcinoma.

BACKGROUND: The ability of fluorescence in situ hybridization (FISH) assays in endoscopic transpapillary bile duct biopsy specimens to predict the prognosis of cholangiocarcinoma (CCA) has not been elucidated. AIMS: We aimed to clarify the association between the results of UroVysion FISH assays and the prognosis of CCA. METHODS: We retrospectively reviewed 49 specimens obtained by transpapillary forceps biopsy from consecutive patients with CCA. The copy numbers of chromosomes 3, 7, and 17 were evaluated by FISH assay using UroVysion. We compared the overall survival (OS) of CCA patients with and without increased copy numbers of chromosomes 3, 7, and 17. Furthermore, we evaluated the association between OS and the clinicopathological parameters of CCA patients. RESULTS: The OS was significantly shorter in patients with than without an increased chromosome 7 copy number (log-rank p = 0.015; median OS 11.9 vs. 20.7 months). In the univariate analyses, age (p = 0.012), ECOG performance status (p = 0.046), tumor stage (p = 0.046), surgery (p = 0.006), and an increased chromosome 7 copy number (p = 0.017) were significantly associated with OS. The multivariate analysis revealed that an increased chromosome 7 copy number (hazard ratio, 2.46; 95% CI 1.15-5.27; p = 0.021) and advanced clinical stage (hazard ratio, 2.26; 95% CI 1.11-4.63; p = 0.025) were independently predictive of a poor OS. CONCLUSIONS: Detection by FISH assay of an increased chromosome 7 copy number in transpapillary forceps biopsy specimens is predictive of a poor prognosis in CCA patients.

Predictors of outcomes in patients undergoing covered and uncovered self-expandable metal stent placement for malignant gastric outlet obstruction: a multicenter study.

BACKGROUND AND AIMS: Uncovered self-expandable metal stents (U-SEMSs) and covered self-expandable metal stents (C-SEMSs) are available for palliative therapy for malignant gastric outlet obstruction (GOO). However, clinical differences and indications between the 2 types of SEMSs have not been elucidated. METHODS: We retrospectively compared 126 patients with U-SEMS and 126 patients with C-SEMSs with regard to clinical outcome and factors predictive of clinical improvement after SEMSs placement. RESULTS: No significant difference was observed between the U-SEMS and C-SEMS groups with respect to technical success, clinical success, GOO score, or time to stent dysfunction. Stent migration was significantly more frequent in patients with C-SEMSs (U-SEMSs, .79%; C-SEMSs, 8.73%; P = .005). Karnofsky performance status, chemotherapy, peritoneal dissemination, and stent expansion ≤ 30% were associated significantly with poor GOO score improvement in multivariable analyses, but stent type was not (P = .213). In subgroup analyses, insufficient (≤30%) stent expansion was an independent factor in patients with U-SEMSs (P = .041) but not C-SEMSs. In the insufficient stent expansion subgroup, C-SEMSs was associated significantly with superior clinical improvement compared with U-SEMSs (P = .01). Insufficient stent expansion was observed more frequently in patients with GI obstruction because of anastomotic sites or metastatic cancer (44.8% [13/29], P = .001). CONCLUSIONS: No clinical difference, apart from stent migration, was observed between patients with U-SEMSs and C-SEMSs. GI obstruction because of an anastomotic site or metastatic cancer may be an indication for C-SEMS use to improve oral intake after SEMSs placement.