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.

DPYD, down-regulated by the potentially chemopreventive agent luteolin, interacts with STAT3 in pancreatic cancer.

The 5-year survival rate of pancreatic ductal carcinoma (PDAC) patients is <10% despite progress in clinical medicine. Strategies to prevent the development of PDAC are urgently required. The flavonoids Luteolin (Lut) and hesperetin (Hes) may be cancer-chemopreventive, but effects on pancreatic carcinogenesis in vivo have not been studied. Here, the chemopreventive effects of Lut and Hes on pancreatic carcinogenesis are assessed in the BOP-induced hamster PDAC model. Lut but not Hes suppressed proliferation of pancreatic intraepithelial neoplasia (PanIN) and reduced the incidence and multiplicity of PDAC in this model. Lut also inhibited the proliferation of hamster and human pancreatic cancer cells in vitro. Multi-blot and microarray assays revealed decreased phosphorylated STAT3 (pSTAT3) and dihydropyrimidine dehydrogenase (DPYD) on Lut exposure. To explore the relationship between DPYD and STAT3 activity, the former was silenced by RNAi or overexpressed using expression vectors, and the latter was inactivated by small molecule inhibitors or stimulated by IL6 in human PDAC cells. DPYD knock-down decreased, and overexpression increased, pSTAT3 and cell proliferation. DPYD expression was decreased by inactivation of STAT3 and increased by its activation. The frequency of pSTAT3-positive cells and DPYD expression was significantly correlated and was decreased in parallel by Lut in the hamster PDAC model. Finally, immunohistochemical analysis in 73 cases of human PDAC demonstrated that DPYD expression was positively correlated with the Ki-67 labeling index, and high expression was associated with poor prognosis. These results indicate that Lut is a promising chemopreventive agent for PDAC, targeting a novel STAT3-DPYD pathway.

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.

Anti-Allergic Drug Suppressed Pancreatic Carcinogenesis via Down-Regulation of Cellular Proliferation.

Pancreatic cancer is a fatal disease, and thus its chemoprevention is an important issue. Based on the recent report that patients with allergic diseases have a low risk for pancreatic cancer, we examined the potential chemopreventive effect of anti-allergic agents using a hamster pancreatic carcinogenesis model. Among the three anti-allergic drugs administered, montelukast showed a tendency to suppress the incidence of pancreatic cancer. Further animal study revealed a significantly decreased incidence of pancreatic cancer in the high-dose montelukast group compared with controls. The development of the pancreatic intraepithelial neoplasia lesions was also significantly suppressed. The Ki-67 labeling index was significantly lower in pancreatic carcinomas in the high-dose montelukast group than in controls. In vitro experiments revealed that montelukast suppressed proliferation of pancreatic cancer cells in a dose-dependent manner with decreased expression of phospho-ERK1/2. Montelukast induced G1 phase arrest. Conversely, leukotriene D4 (LTD4), an agonist of CYSLTR1, increased cellular proliferation of pancreatic cancer cells with an accumulation of phospho-ERK1/2. In our cohort, pancreatic ductal adenocarcinoma patients with high CYSLTR1 expression showed a significantly unfavorable clinical outcome compared with those with low expression. Our results indicate that montelukast exerts a chemopreventive effect on pancreatic cancer via the LTD4-CYSLTR1 axis and has potential for treatment of pancreatic carcinogenesis.

Bleeding risk of endoscopic ultrasound-guided fine-needle aspiration in patients undergoing antithrombotic therapy.

OBJECTIVES: Bleeding events related to endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) are rare. However, for patients treated with antithrombotic agents, the bleeding risk of EUS-FNA is uncertain. Hence, the aim of this study was to assess the bleeding event rate associated with EUS-FNA in patients receiving antithrombotic treatment. METHODS: A retrospective study was conducted in 742 consecutive patients who underwent EUS-FNA for solid lesions between 2008 and 2015. We compared the bleeding event rates among patients who were not administered antithrombotic agents, those whose agent use was discontinued, those who continued treatment with aspirin or cilostazol, and those who were administered heparin as a replacement. RESULTS: There were 131 patients (17.7 %) treated with antithrombotic agents. Seven experienced bleeding events, and the overall bleeding event rate was 0.9 % (7/742). All bleeding events were intraoperative; there were no postoperative bleeding episodes. Subgroup analysis by antithrombotic agent revealed bleeding event rates of 1.0 % (6/611), 0 % (0/62), 1.6 % (1/61), and 0 % (0/8) for the non-administration, discontinuation of agents, continuation of aspirin or cilostazol, and heparin replacement groups, respectively. Only one severe bleeding event necessitated hemostatic treatment (1/742; 0.1 %); this occurred in a patient in the non-administration group, and there were no severe bleeding events in patients receiving antithrombotic treatment. CONCLUSIONS: The present study found a low incidence of EUS-FNA-related bleeding in patients receiving antithrombotic treatment. The bleeding event rate was low even in patients who underwent EUS-FNA while continuing aspirin or cilostazol.

Long-term outcomes of endoscopic gallbladder stenting in high-risk surgical patients with calculous cholecystitis (with videos).

BACKGROUND AND AIMS: Recently, endoscopic gallbladder stenting (EGBS) has been performed to prevent recurrences in high-risk surgical patients with cholecystitis. However, evidence regarding the long-term outcomes of EGBS is sparse. We investigated the cholecystitis recurrence rate in high-risk surgical patients with acute calculous cholecystitis and compared the cholecystitis recurrence rates in patients in whom EGBS was performed with those in patients who were observed after percutaneous drainage. METHODS: We studied 64 consecutive high-risk surgical patients with acute calculous cholecystitis who required gallbladder decompression between 2007 and 2014. We divided the patient cohort into patients who underwent observation after percutaneous drainage between 2007 and 2011 (OAPD group) and those who underwent EGBS between 2012 and 2014 (EGBS group), and we compared the groups. RESULTS: The technical success rate of EGBS was 82.9% based on the intention-to-treat analysis. The cholecystitis recurrence rates were 17.2% in the OAPD group and 0% in the EGBS group, a difference that was significant (P = .043). There was also a significant difference between the groups with respect to the time to recurrent cholecystitis, which was determined by using Kaplan-Meier analysis (P = .015). The overall biliary event rates were 24.1% in the OAPD group and 9.1% in the EGBS group, and no significant difference was noted (P = .207). CONCLUSION: EGBS reduced the recurrence of cholecystitis in high-risk surgical patients with calculous cholecystitis. However, stent-related adverse events may occur, and modifications are necessary to reduce these.

Feasibility of the placement of a novel 6-mm diameter threaded fully covered self-expandable metal stent for malignant hilar biliary obstructions (with videos).

BACKGROUND AND AIMS: Uncovered self-expandable metal stents (USEMSs) are used to treat unresectable malignant hilar biliary obstructions (MHBOs). However, ingrowth is not prevented, and reintervention is often troublesome. A novel 6-mm threaded fully covered self-expandable metal stent (T-FCSEMS) is available that may mitigate these issues. We aimed to clarify the safety and efficacy of T-FCSEMS placement for MHBO. METHODS: Thirty patients underwent T-FCSEMS placements for MHBOs between 2014 and 2015. T-FCSEMSs were used for initial stenting in 17 patients (initial group) and for reinterventions for USEMS occlusions caused by ingrowth in 13 patients (reintervention group). The technical success rates, times to recurrent biliary obstruction, and the reintervention success rates were evaluated. RESULTS: The technical success rates were 94% (16/17) and 92% (12/13) in the initial group and reintervention group, respectively. Intrahepatic bile duct occlusions caused liver abscesses 8 days and 22 days after T-FCSEMS placements in 2 cases (7%) in the initial group, in which T-FCSEMSs were placed across the intrahepatic bile duct bifurcation. The median times to recurrent biliary obstruction were 210 days in the initial group after bilateral placement and 112 days and 152 days in the reintervention group after bilateral and unilateral placements, respectively. During reintervention, T-FCSEMS removal was successful in all patients in whom it was attempted, and the success rate of endoscopic reintervention was 100% in both groups. CONCLUSIONS: T-FCSEMS placement is a promising option for both initial stenting and reintervention for MHBO. However, we should consider the possibility of intrahepatic bile duct occlusion.

Difficult diagnoses of two cases of double cancer involving malignant lymphoma with peritoneal localization and malignant abdominal tumor.

We encountered two cases of malignant lymphoma with peritoneal localization complicated by sigmoid colon cancer and hepatocellular carcinoma. Multiple primary cancers were suspected on the basis of differences in absorption values on computed tomography (CT) and differences in the degree of accumulation on positron emission tomography CT; however, a definitive diagnosis based on these findings alone was difficult. Endoscopic ultrasound-guided fine-needle aspiration was useful for determining the diagnosis and treatment strategy. In cases of double cancers involving malignant lymphoma with peritoneal localization and malignant abdominal tumor, differentiation and staging are often difficult, which increases the risk of selecting the wrong treatment strategy. Therefore, care must be taken when diagnosing these diseases.

[Two cases of distal duodenal gastrointestinal stromal tumor diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy].

Gastrointestinal stromal tumor (GIST) of the duodenum is rare. Obtaining tissue samples of GIST in the duodenum is difficult, especially when the tumor is located in the distal duodenum. Thus, preoperative pathological diagnosis often becomes difficult. We performed endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy for two cases with submucosal tumors in the third portion of the duodenum. Tissue samples were successfully obtained and diagnosed as GIST. Partial duodenectomy was performed in the two patients. Thus, we believe that EUS-FNA is a potentially useful diagnostic aid for submucosal tumors in the third portion of the duodenum, and it should be attempted before more invasive approaches.

[Gadolinium as an alternative radiocontrast agent in patients with allergy to iodine-based contrast provide for useful diagnostic imagings and safely treatment of biliary tract diseases].

Diagnosis and treatment of biliary tract disease requires an intraductal radiocontrast agent. Although iodine-based contrast medium is commonly used, some patients show severe allergy to iodinated contrast agent. We have retrospectively reviewed the usefulness and safety of gadolinium as an alternative radiocontrast agent in 3 patients with allergy to iodine-based contrast medium in the diagnosis and treatment of biliary tract diseases. In case 1, percutaneous transhepatic biliary drainage and cholangiography were performed successfully and it was possible to visualize an intrahepatic bile duct stone. Percutaneous transhepatic cholangioscopic lithotomy was performed and the intrahepatic bile duct stone was removed. In case 2, endoscopic biliary lithotripsy was performed. In case 3, percutaneous transhepatic cholangiography and cholangioscopy provided a diagnosis of moderately differentiated carcinoma. He underwent pancreatoduodenectomy. Postoperative cholangiograms were also obtained successfully. Gadolinium contrast agent is an alternative to iodine-based cholangiography for the patients with allergy to iodine.

[A case of intraductal papillary mucinous carcinoma found with acute obstructive suppurative pancreatic ductitis and liver abscess, and associated with a pancreatobiliary fistula].

We report a rare case of intraductal papillary mucinous carcinoma (IPMC) with acute obstructive suppurative pancreatic ductitis (AOSPD), liver abscess, and pancreatobiliary fistula formation. A man in his sixties was admitted to our hospital with a chief complain of high grade fever and anorexia. CT and MRI revealed a multilocular cystic lesion in the pancreatic head, fistula formation between the common bile duct and this cystic lesion, and multiple liver abscess. We performed endoscopic nasopancreatic drainage for the AOSPD, endoscopic biliary drainage for the biliary flow obstruction, and percutaneous transhepatic drainage for the liver abscess. Klebsiella pneumoniae was detected in the culture of pancreatic juice and liver abscess, but not in the bile and blood culture. These culture studies revealed that the liver abscess was caused by AOSPD. The patient underwent pancreaticoduodenectomy for the IPMC. The pathological diagnosis was IPMC.

Theoretical step approach with 'Three-pillar' device assistance for successful endoscopic transpapillary gallbladder drainage.

BACKGROUND: Endoscopic transpapillary gallbladder drainage (ETGBD) has been reported as an alternative procedure for acute cholecystitis but remains a challenging procedure. AIMS: To elucidate the efficacy of a strategic approach for ETGBD that utilizes a four-step classification system and the optional use of 'Three-pillar' assistance with the following devices: cholangioscopy (SpyGlass DS, SG), a flex-type guidewire (Flex-GW), and a 3-Fr microcatheter (3-Fr Micro). METHODS: A total of 115 patients undergoing ETGBD were studied retrospectively. Characteristics and technical outcomes were compared between conventional ETGBD technique (Classical ETGBD, N = 50) and strategic ETGBD with optional Three-pillar assistance (Strategic ETGBD, N = 65). RESULTS: SG-assistance (15/65, 23.1%) was as an excellent troubleshooter in Category 1 (failure to identify the cystic duct [CD] orifice) and Category 2 (failure to advance the GW across the CD takeoff due to unfavorable angle). Flex-GW (19/65, 29.2%) worked for Category 3b (failure of GW access to the GB due to multiple tortuosities). 3-Fr Micro (11/65, 16.9%) was effective for Category 3a (failure of GW access to the GB due to CD obstruction) and Category 4 (failure of drainage stent insertion to the GB). The overall technical success rate was significantly higher for Strategic ETGBD (63/65, 96.9%) compared with Classical ETGBD (36/50, 72.0%) (p = 0.0001). CONCLUSIONS: Strategic ETGBD, which includes the Three-pillar assistance options of SG in the initial steps, Flex-GW for tortuous CD, and 3-Fr Micro for stenotic CD, achieved a significantly higher success rate than for Classical ETGBD.

Concomitant Pancreatic Ductal Adenocarcinoma and Type 1 Autoimmune Pancreatitis: A Potential Issue in the Diagnosis of Carcinoma by Endoscopic Ultrasound-guided Fine-needle Biopsy.

We herein report a 64-year-old man with concomitant pancreatic ductal adenocarcinoma (PDAC) and type 1 autoimmune pancreatitis (AIP). An endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) from the pancreatic head mass revealed level 2 histology of AIP and atypical glands. We diagnosed definitive focal AIP using the clinical diagnostic criteria. Computed tomography revealed that the pancreatic mass had not been reduced by steroid therapy. Surgery was performed after a histological PDAC diagnosis was made via a transpapillary biliary biopsy. The resected specimen revealed PDAC associated with AIP. It is important to consider the cooccurrence of PDAC and AIP even if the histological diagnosis via an EUS-FNB is AIP.

Incidence of pancreatic injury and pancreatitis in patients treated with immune checkpoint inhibitors.

OBJECTIVES: Immune checkpoint inhibitors (ICIs) are being increasingly used to treat advanced malignancies. ICI-induced pancreatic injury (ICI-PI), which is an immune-related adverse event that may be a risk factor for ICI-associated pancreatitis, is not well documented in the literature. METHODS: Consecutive patients who received ICIs for advanced malignancies from August 2015 through October 2022 were analyzed with regard to the incidence of ICI-PI based on the Common Terminology Criteria for Adverse Events and ICI-associated pancreatitis. The imaging, clinical, and pathological findings of ICI-associated pancreatitis were also assessed. RESULTS: This study enrolled 843 patients. In multivariable analyses, dual or simultaneous immunotherapy and ≥10 cycles of ICI administration were significant predictive factors for all grades of pancreatic injury, including grade ≥ 3. Notably, patients who received simultaneous immunotherapy exhibited a higher incidence of grade ≥ 3 pancreatic injuries compared to those receiving asynchronous immunotherapy in univariable analysis (p = 0.032). One-fifth of the patients (16/70) with grade ≥ 3 pancreatic injuries had imaging evidence of pancreatitis similar to mild acute pancreatitis. ICI-associated pancreatitis was observed in 5.7% (48/843) of patients, including 1.8% (15/843) with moderate-to-severe pancreatitis (grade ≥ 2). Symptomatic cases (0.36%, 3/843) were treated with steroids with favorable outcomes. Immunohistochemistry for CD4 and CD8 revealed greater infiltration of CD8+ than CD4+ lymphocytes. CONCLUSION: Simultaneous immunotherapy and dual immunotherapy are risk factors for ICI-PI. Although most patients diagnosed with ICI-PI and ICI-associated pancreatitis were asymptomatic and had a low mortality likelihood, long-term outcomes, including endocrine and exocrine function should be carefully monitored.

Urolithin A targets the AKT/WNK1 axis to induce autophagy and exert anti-tumor effects in cholangiocarcinoma.

Urolithin A (UA; 3,8-dihydroxybenzo[c]chromen-6-one), a metabolite generated by intestinal bacteria during the biotransformation of ellagitannins, has gained considerable attention in treating several cancers. Cholangiocarcinoma (CCA) remains one of the most lethal cancers; it grows in a special environment constantly exposed to both blood and bile. Since UA is known to undergo enterohepatic recirculation, we hypothesized that UA might have significant antitumor effects in CCA. Here, we investigated the therapeutic potential of UA in CCA and aimed to elucidate its mechanisms, including autophagy. UA treatment inhibited cell proliferation and induced G2/M phase cell cycle arrest in CCA cells. UA also suppressed cell migration and invasion, but did not cause apoptosis. Furthermore, Western blotting and immunocytochemistry demonstrated increased LC3-II accumulation, while electron microscopy demonstrated induced autophagosomes after UA treatment, suggesting that UA upregulated autophagy in CCA cells. In xenograft mice treated with UA, tumor growth was inhibited with increased LC3-II levels. On the other hand, phospho-kinase array demonstrated downregulation of the AKT/WNK1 pathway. LC3-II expression was elevated in WNK1 knocked down cells, indicating that WNK1 is the key signal for regulating autophagy. Thus, UA exerted antitumor effects by suppressing the AKT/WNK1 signaling pathway and inducing autophagy. In conclusion, UA, a natural, well-tolerated compound, may be a promising therapeutic candidate for advanced CCA.