Current perspectives on the diversification of endoscopic ultrasound-guided fine-needle aspiration and biopsy.

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has undergone significant advancements since it was first reported in 1992. Initially focused on the pancreas, EUS-guided fine-needle aspiration (FNA) has now been extended to encompass all organs proximal to the gastrointestinal system. Recently, a novel fine-needle biopsy (FNB) needle with an end-cut tip was developed, allowing for the collection of specimens suitable for histological assessment, a feat hard to achieve with traditional needles. The FNB needle holds promise for applications in immunohistochemistry staining and genetics evaluation, and it has the potential to yield specimens of comparable quality to core needle biopsy during percutaneous puncture, especially for lesions beyond the pancreas, such as lymph nodes. This review focuses on the efficacy of EUS-FNA/FNB for extended target regions, specifically lymph nodes, spleen, adrenal gland, and ascites. The indications for EUS-FNA have greatly expanded beyond the pancreas over the years, and future improvements and innovations in puncture needles will allow for the collection of higher-quality specimens, which is expected to play a significant part in personalized cancer treatment.

Novel anti-reflux biliary metal stent with a distal tapered end for distal malignant biliary obstruction: a feasibility study.

Background and study aims We developed a self-expandable metallic stent (SEMS) with a distal tapered end to reproduce the physiological bile flow with a pressure gradient due to the difference in the diameter. We aimed to evaluate the safety and efficacy of the newly developed distal tapered covered metal stent (TMS) for distal malignant biliary obstruction (DMBO). Patients and methods This single-center, prospective, single-arm study was conducted in patients with DMBO. The primary endpoint was time to recurrent biliary obstruction (TRBO), and the secondary endpoints were the survival time and incidence of adverse events (AEs). Results Thirty-five patients (15 men, 20 women; median age, 81 years [range: 53-92]) were enrolled between December 2017 and December 2019. The primary diseases were pancreatic head cancer in 25 cases, bile duct cancer in eight cases, and ampullary cancer in two cases. TMS was successfully placed in all cases. Acute cholecystitis occurred as an early AE (within 30 days) in two cases (5.7 %). The median TRBO was 503 days, median survival time was 239 days. RBO was observed in 10 cases (28.6 %), and the causes were distal migration in six cases, proximal migration in two cases, biliary sludge in one case, and tumor overgrowth in one case. Conclusions Endoscopic placement of the newly developed TMS in patients with DMBO is technically feasible and safe, and the TRBO was remarkably long. The anti-reflux mechanism based on the difference in diameter may be effective, and a randomized controlled trial with a conventional SEMS is required.

Quantitative analysis of tissue area of endoscopic ultrasound-guided liver biopsy specimens using 19-gauge fine-needle biopsy needle in patients with diffuse liver disease: A single-center retrospective study.

BACKGROUND/PURPOSE: Endoscopic ultrasound-guided liver biopsy (EUS-LB) is a novel liver biopsy technique. We aimed to evaluate the efficacy and safety of EUS-LB in comparison with percutaneous liver biopsy (PLB). METHODS: This retrospective study evaluated the safety and efficacy of EUS-LB using a 19-gauge fine needle biopsy (FNB) needle compared with PLB using a spring-loaded 16-gauge needle in patients with diffuse liver disease at our hospital from April 2017 to December 2020. The primary outcomes included the total hepatic tissue surface area and the total number of portal tracts. Secondary outcomes included the success and adverse event rates. RESULTS: Twenty patients each underwent EUS-LB and PLB. There was no statistical difference in the sum of liver tissue surface area (22 mm2 vs 22.6 mm2 , P = .910) and the total number of portal tracts (29 vs 25, P = .916). The success rate was 95% (19/20) for EUS-LB and 100% (20/20) for PLB (P = 1). There were two adverse events in the PLB group but none in the EUS-LB group (P = .487). CONCLUSIONS: Endoscopic ultrasound-guided liver biopsy using FNB has an optimal tissue yield and success rate and is safe compared to PLB. Thus, EUS-LB may be a new alternative to PLB.

Importance of Telomere Shortening in the Pathogenesis of Ulcerative Colitis: A New Treatment From the Aspect of Telomeres in Intestinal Epithelial Cells.

BACKGROUND AND AIMS: Ulcerative colitis [UC] is a chronic inflammatory disease of the colon with frequent relapses. Telomere shortening in intestinal epithelial cells has been reported in severe or longstanding cases. However, its influence on UC pathogenesis remains unelucidated. To this end, we evaluated telomere shortening using a long-term organoid inflammation model that we had originally established. METHODS: A UC model using human colon organoids was established to assess telomere changes chronologically. MST-312 was used for the telomerase inhibition assay. The potential of telomerase activators as a novel UC treatment was evaluated with an in vitro model, including microarray analysis, and histological changes were assessed using xenotransplantation into mouse colonic mucosa. RESULTS: Our UC model reproduced telomere shortening in vitro, which was induced by the continuous suppression of telomerase activity via P53. MST-312-based analysis revealed that telomere shortening was involved in the pathogenesis of UC. Madecassoside [MD] improved the telomere length of the UC model and UC patient-derived organoids, which further promoted cell proliferation in vitro and improved the graft take-rate of xenotransplantation. Moreover, histological analysis revealed that MD induced normal crypt structure with abundant goblet cells. CONCLUSIONS: This study is the first to reveal the mechanism and importance of telomere shortening in the pathogenesis of UC. MD could be a novel candidate for UC treatment beyond endoscopic mucosal healing.

Chemotherapy with gemcitabine for unresectable intrahepatic cholangiocarcinoma in a patient undergoing maintenance hemodialysis.

A 56-year-old man with chronic renal failure due to diabetic nephropathy had received maintenance dialysis (every 4 h, three times/week). A hypoechoic tumor measuring 67 × 50 mm in the right lobe of the liver was discovered following routine abdominal ultrasonography. Dynamic computed tomography showed a low-density liver tumor, enlarged hilar lymph node, and a small nodule on the dorsal side of the lower lobe of the left lung. Histopathological examination of the liver tumor revealed intrahepatic cholangiocarcinoma. We developed a chemotherapy treatment plan with gemcitabine, which can be performed concurrently with hemodialysis. Gemcitabine (1000 mg/m2, three times/cycle) was administered on Friday afternoon, and hemodialysis was performed on Tuesday, Thursday, and Saturday. Anemia and hypotension occurred after gemcitabine administration. Therefore, the dose of darbepoetin alpha was increased, and packed red blood cells were transfused. The patient was treated with gemcitabine for approximately 5 and a half months until computed tomography findings showed progressive disease; the survival time after treatment start was 8 months. Chemotherapy using gemcitabine has not been established in dialysis patients and has little evidence. We report a case of unresectable intrahepatic cholangiocarcinoma that developed during maintenance dialysis and was treated using gemcitabine chemotherapy.

Influence of chronic inflammation on the malignant phenotypes and the plasticity of colorectal cancer cells.

Sporadic adenoma or adenocarcinoma is often detected during endoscopic surveillance of patients with ulcerative colitis (UC). However, it is occasionally difficult to distinguish these neoplasms from dysplasia or colitis-associated cancers because of the influence of inflammation. However, the influence of inflammation on sporadic neoplasms is not well characterised. To assess this influence, we established a long-term inflammation model of colon cancer cells by inflammatory stimulation with tumour necrosis factor-α, flagellin and interleukin-1ß for 60 weeks. Then, the malignant phenotypes were evaluated using the MTS assay, Annexin V fluorescence assay, cell migration assay and sphere formation assay. The influence of P53 function on these phenotypes was assessed with a TP53 mutation model using the CRISPR/Cas9 system. A long-term inflammation model of LS174T cells was established for the first time with continuous inflammatory signalling. Chronic inflammation induced apoptosis and suppressed the proliferation and stemness of these cancer cells via the action of P53. It also enhanced the invasiveness of LS174T cells. Moreover, these phenotypic changes and changes in inflammatory signalling were recoverable after the removal of inflammatory stimuli, suggesting that colon cancer cells have higher plasticity than normal intestinal epithelial cells. In conclusion, our results suggest that sporadic neoplasms in patients with UC are affected by chronic inflammation but are not essentially altered.

Schlafen 11 Is a Novel Target for Mucosal Regeneration in Ulcerative Colitis.

BACKGROUND AND AIMS: Ulcerative colitis [UC] is a chronic inflammatory disease of the colon with an intractable course. Although the goal of UC therapy is to achieve mucosal healing, the pathogenesis of mucosal injury caused by chronic inflammation remains unknown. We therefore aim to elucidate molecular mechanisms of mucosal injury by establishing in vitro and in vivo humanised UC-mimicking models. METHODS: An in vitro model using human colon organoids was established by 60 weeks of inflammatory stimulation. The key gene for mucosal injury caused by long-term inflammation was identified by microarray analysis. An in vivo model was established by xenotransplantation of organoids into mouse colonic mucosa. RESULTS: An in vitro model demonstrated that long-term inflammation induced irrecoverable changes in organoids: inflammatory response and apoptosis with oxidative stress and suppression of cell viability. This model also mimicked organoids derived from patients with UC at the gene expression and phenotype levels. Microarray analysis revealed Schlafen11 [SLFN11] was irreversibly induced by long-term inflammation. Consistently, SLFN11 was highly expressed in UC mucosa but absent in normal mucosa. The knockdown of SLFN11 [SLFN11-KD] suppressed apoptosis of intestinal epithelial cells [IECs] induced by inflammation. Moreover, SLFN11-KD improved the take rates of xenotransplantation and induced the regenerative changes of crypts observed in patients with UC in remission. CONCLUSIONS: In vitro and in vivo UC-mimicking models were uniquely established using human colonic organoids. They revealed that SLFN11 is significant for mucosal injury in UC, and demonstrated its potential as a novel target for mucosal regeneration.

Intestinal phenotype is maintained by Atoh1 in the cancer region of intraductal papillary mucinous neoplasm.

Intraductal papillary mucinous neoplasm (IPMN) is a precancerous lesion of pancreatic cancer. Although there are 4 types of IPMN, among which intestinal-type IPMN is likely to progress into invasive cancer known as colloid carcinoma, no information regarding the involvement of the intestinal phenotype in the carcinogenesis of IPMN exists. The present study was conducted to explore how the intestinal differentiation system is maintained during the tumor progression of intestinal-type IPMN using surgical resection specimens. Results showed that Atoh1, a critical transcriptional factor for intestinal differentiation toward the secretory lineages of intestinal epithelial cells, was expressed in an invasive-grade IPMN. To determine the function of Atoh1 in pancreatic cancer, we generated a pancreatic ductal adenocarcinoma (PDAC) cell line overexpressing Atoh1. In a xenograft model, we successfully induced an IPMN phenotype in PDAC cells via Atoh1 induction. Finally, for the first time, we discovered that GPA33 is expressed in intestinal-type IPMN, thereby suggesting a novel target for cancer therapy. In conclusion, the intestinal differentiation system might be maintained during tumor progression of intestinal-type IPMN. Further analysis of the function of Atoh1 in IPMN might be useful for understanding the molecular mechanism underlying the malignant potential during the tumor progression of IPMN.

TP53 Mutation by CRISPR System Enhances the Malignant Potential of Colon Cancer.

Tumor protein p53 (TP53) mutation is a well-known occurrence at the late phase of carcinogenesis during the adenoma-carcinoma sequence of a sporadic colon cancer. Although numerous reports about clinical information of the patients with colon cancer have suggested that TP53 mutation might be related to various types of malignant potential, the direct effects of this mutation on the malignant potential of colon cancer remain unknown. Notably, no previous report has described a relationship between TP53 mutation and cancer stemness. We therefore aimed to assess the function of a TP53 mutant induced by the CRISPR-Cas9 system in colon cancer cells. In this study, two TP53 mutations, corresponding to exon 3 (TP53E3) and 10 (TP53E10), were generated in LS174T cells derived from a wild-type TP53 human colon cancer via a lentiviral CRISPR-Cas9 system. The loss of function of TP53 resulting from both mutations manifested as resistance to Nutlin3a-induced apoptosis and the downregulation of target genes of TP53. TP53 mutants exhibited an enhanced malignant potential, characterized by accelerated cell growth, invasiveness, chemoresistance, and cancer stemness. Interestingly, TP53E10 but not TP53E3 cells exhibited aberrant transcriptional activity of regenerating family member 1-α (REG1A) and expression of REG1A, resulting in the acquisition of enhanced malignant potential. In conclusion, we demonstrated for the first time that TP53 genomic mutation into human colon cancer cells affects the malignant potential. IMPLICATIONS: These findings suggest that both a loss of function and an aberrant gain of function of TP53 might promote high malignant potentials at the late phase of carcinogenesis in colon cancer.

A case of intraductal papillary neoplasm of the bile duct preoperatively diagnosed using contrast-enhanced endoscopic ultrasonography.

A 71-year-old man was referred to our hospital and was diagnosed with jaundice and a liver function disorder. Although we suspected an intraductal papillary neoplasm of the bile duct (IPNB)-derived caudate branches on the basis of contrast-enhanced CT, MRI, and endoscopic retrograde cholangiopancreatography, we could not clearly identify the tumor. Therefore, we examined the lesion using endoscopic ultrasonography (EUS). We could visualize an iso-hyperechoic elevated tumor in the caudate branches. The tumor was observed as a hypervascular lesion using contrast-enhanced EUS, which is useful in preoperatively diagnosing IPNB and detecting the presence of lesions.