First case report of intestinal lymphangiectasia with refractory bleeding from the duodenum, successfully treated by intra-abdominal lymphaticovenous anastomosis with venous ligation.

Intestinal lymphangiectasia (IL) is a protein-losing enteropathy (PLE) that occasionally leads to gastrointestinal bleeding (GIB). We encountered a 41-year-old female with a 9-year history of duodenal IL with PLE and GIB that progressively worsened. Despite a diet, supplemented with medium-chain triglycerides, antiplasmin therapy, oral corticosteroids, octreotides, sirolimus, and repeated endoscopic hemostasis, her symptoms remained uncontrolled, leading to blood transfusion dependence. Lymphangiography revealed significant leakage from abnormal abdominal lymph vessels into the duodenal lumen. The patient subsequently underwent an abdominal-level lymphaticovenous anastomosis combined with local venous ligation. This approach resulted in a dramatic improvement and sustained resolution of both the PLE and GIB. More than 6 months after surgery, the patient remained free of symptoms and blood transfusion dependence.

Metabolic Factors Associated with Endoscopic Atrophy, Intestinal Metaplasia, and Gastric Neoplasms in Helicobacter pylori-Positive Patients.

BACKGROUND: Previous studies demonstrate an association between metabolic factors and Helicobacter pylori-related gastric cancer. However, the association of gastric atrophy or intestinal metaplasia (IM) with these factors remains unknown. METHODS: Data on 1603 Helicobacter pylori-positive patients who underwent esophagogastroduodenoscopy between 2001 and 2021 were evaluated. The outcome measures were endoscopic atrophy, IM grade, and the incidence of endoscopically diagnosed and pathologically confirmed gastric neoplasms. Clinical factors associated with these findings were also determined. RESULTS: Advanced age; successful Helicobacter pylori eradication; and comorbidities including diabetes mellitus (DM), hypertension, dyslipidemia, and fib4 index were significantly associated with endoscopic gastric atrophy grade. Male sex; advanced age; and comorbidities including DM, hypertension, dyslipidemia, hyperuricemia, fatty liver, aortic calcification, and fib4 index were also significantly associated with endoscopic IM grade, whereas advanced age, successful Helicobacter pylori eradication, DM, fatty liver, and fib4 index were significantly associated with the incidence of gastric neoplasms. CONCLUSION: Several metabolic disorders, including DM, hypertension, dyslipidemia, hyperuricemia, and fatty liver disease, are risk factors for advanced-grade gastric atrophy, intestinal metaplasia, and gastric neoplasms. Risk stratification according to these factors, particularly those with metabolic disorders, would affect EGD surveillance for Helicobacter pylori-positive patients.

Impaired Glycosylation of Gastric Mucins Drives Gastric Tumorigenesis and Serves as a Novel Therapeutic Target.

BACKGROUND & AIMS: Gastric cancer is often accompanied by a loss of mucin 6 (MUC6), but its pathogenic role in gastric carcinogenesis remains unclear. METHODS: Muc6 knockout (Muc6-/-) mice and Muc6-dsRED mice were newly generated. Tff1Cre, Golph3-/-, R26-Golgi-mCherry, Hes1flox/flox, Cosmcflox/flox, and A4gnt-/- mice were also used. Histology, DNA and RNA, proteins, and sugar chains were analyzed by whole-exon DNA sequence, RNA sequence, immunohistochemistry, lectin-binding assays, and liquid chromatography-mass spectrometry analysis. Gastric organoids and cell lines were used for in vitro assays and xenograft experiments. RESULTS: Deletion of Muc6 in mice spontaneously causes pan-gastritis and invasive gastric cancers. Muc6-deficient tumor growth was dependent on mitogen-activated protein kinase activation, mediated by Golgi stress-induced up-regulation of Golgi phosphoprotein 3. Glycomic profiling revealed aberrant expression of mannose-rich N-linked glycans in gastric tumors, detected with banana lectin in association with lack of MUC6 expression. We identified a precursor of clusterin as a binding partner of mannose glycans. Mitogen-activated protein kinase activation, Golgi stress responses, and aberrant mannose expression are found in separate Cosmc- and A4gnt-deficient mouse models that lack normal O-glycosylation. Banana lectin-drug conjugates proved an effective treatment for mannose-rich murine and human gastric cancer. CONCLUSIONS: We propose that Golgi stress responses and aberrant glycans are important drivers of and promising new therapeutic targets for gastric cancer.

The first case report of de novo Crohn's disease after heart transplantation successfully treated with ustekinumab.

Inflammatory bowel disease (IBD) is a complex chronic inflammatory intestinal disease. The development of de novo IBD after solid organ transplantation with immunosuppressive agents has been rarely reported. We present the case of a 65-year-old man with repeated colitis after heart transplantation (HTx) who was diagnosed with Crohn's disease (CD). The patient underwent HTx due to non-ischemic dilated cardiomyopathy. Six months after HTx, he developed serious diarrhea and a transient fever, which persisted for about 6 months. Valganciclovir or any antibiotic agents were not effective for his symptoms and longitudinal ulcers in colonoscopy aggravated during the course, so that we made a diagnosis of CD. We started 5-aminosalicylic acid and found improvement in his symptoms and colonoscopic findings. However, 7 months after improvement, CD worsened. We started ustekinumab by which his condition successfully went into remission again. While oral immunosuppressive drugs are thought to suppress autoimmune diseases in general, IBD should be included in the differential diagnoses for recurring enterocolitis after HTx. Poorly controlled CD can lead to serious and potentially fatal complications, but in this case, ustekinumab has been used safely and effectively for the treatment of CD. Learning objective: Colitis is a common complication after heart transplantation (HTx). Although cytomegalovirus colitis or posttransplant lymphoproliferative disorder are observed commonly, de novo inflammatory bowel disease (IBD) should be considered when serious refractory colitis occurs. Not only 5-aminosalicylic acid but also ustekinumab, which is a monoclonal antibody to the p40 subunit of interleukin (IL)-12 and IL-23, may be a safe and effective treatment for de novo IBD after HTx.

Association Between Vonoprazan and the Risk of Gastric Cancer After Helicobacter pylori Eradication.

BACKGROUND & AIMS: Potassium-competitive acid blockers (PCABs) have been increasingly used to treat upper gastrointestinal disorders, replacing proton pump inhibitors (PPIs). Whereas PPIs are associated with an increased risk of gastric cancer (GC) after Helicobacter pylori (Hp) eradication, it is uncertain whether PCABs carry the same risk. METHODS: Using a population-based claims database in Japan, we identified patients who were prescribed a clarithromycin-based first regimen of Hp eradication between 2015 and 2018. Patients who failed this regimen and those diagnosed with GC before or within 1 year after Hp eradication were excluded. We compared GC incidence between PCAB users and histamine type-2 receptor antagonist (H2RA) users, matching them on the basis of propensity scores calculated with considerations for age, sex, smoking, alcohol consumption, comorbidities, and co-administered medications. PCABs included only vonoprazan in this study. RESULTS: Among 54,055 patients, 568 (1.05%) developed GC during the follow-up period (mean, 3.65 years). The cumulative incidence of GC was 1.64% at 3 years, 2.02% at 4 years, and 2.36% at 5 years in PCAB users and 0.71% at 3 years, 1.04% at 4 years, and 1.22% at 5 years in H2RA users. The use of PCABs was associated with a higher GC risk (matched hazard ratio, 1.92; 95% confidence interval, 1.13-3.25; P = .016). Longer PCAB use and high-dose PCAB use were significantly associated with higher incidence of GC. Sensitivity analyses showed the risk of GC incidence among PCAB users was comparable with that of PPI users. CONCLUSIONS: The use of PCABs was associated with an increased risk of GC among Hp-eradicated patients, with duration/dose response effects.

Upper gastrointestinal involvement of Behçet's disease in Japan: endoscopic findings and clinical features.

AIM: Behçet's disease (BD) can involve any gastrointestinal (GI) tract site. We analyzed the characteristics, risk factors, and treatment responses to upper GI (UGI) involvement in patients with BD. METHODS: This retrospective cohort study analyzed UGI findings in 101 patients with BD who underwent endoscopy between April 2005 and December 2022 at the University of Tokyo Hospital. The patients were divided into two groups based on the presence or absence of UGI findings. Patient backgrounds, clinical symptoms, colonoscopy (CS) findings, and blood test findings were compared between the groups. RESULTS: In total, 18.8% (19/101) of the patients had UGI lesions. The prevalence rates in the esophagus, stomach, and duodenum were 6.9%, 6.9%, and 8.9%, respectively. Of these 19 patients, BD treatment were intensified in 10 (52.6%) patients after esophagogastroduodenoscopy (EGD), and all showed improvement in symptoms or endoscopic findings. In the multivariate analysis, symptoms (OR: 37.1, P < 0.001), CRP > 1 mg/dL (OR: 11.0, P = 0.01), and CS findings (OR: 5.16, P = 0.04) were independent predictors of UGI involvement in BD patients. The prediction model for UGI involvement using these three factors was highly accurate, with an AUC of 0.899 on the ROC curve. In the subgroup analysis of intestinal BD, symptoms (OR: 12.8, P = 0.01) and ESR > 20 mm/h (OR: 11.5, P = 0.007) were independent predictors. CONCLUSIONS: EGD should be conducted in BD patients with high CRP, GI symptoms, and lower GI involvement, which leads to better management of BD in terms of improving symptoms and endoscopic findings.

Conserved metabolic enzymes as vaccine antigens for giardiasis.

Giardia lamblia is a leading protozoal cause of diarrheal disease worldwide. Infection is associated with abdominal pain, malabsorption and weight loss, and protracted post-infectious syndromes. A human vaccine is not available against G. lamblia. Prior studies with human and murine immune sera have identified several parasite antigens, including surface proteins and metabolic enzymes with intracellular functions. While surface proteins have demonstrated vaccine potential, they can exhibit significant variation between G. lamblia strains. By comparison, metabolic enzymes show greater conservation but their vaccine potential has not been established. To determine whether such proteins can serve as vaccine candidates, we focused on two enzymes, α-enolase (ENO) and ornithine carbamoyl transferase (OCT), which are involved in glycolysis and arginine metabolism, respectively. We show in a cohort of patients with confirmed giardiasis that both enzymes are immunogenic. Intranasal immunization with either enzyme antigen in mice induced strong systemic IgG1 and IgG2b responses and modest mucosal IgA responses, and a marked 100- to 1,000-fold reduction in peak trophozoite load upon oral G. lamblia challenge. ENO immunization also reduced the extent and duration of cyst excretion. Examination of 44 cytokines showed only minimal intestinal changes in immunized mice, although a modest increase of CCL22 was observed in ENO-immunized mice. Spectral flow cytometry revealed increased numbers and activation state of CD4 T cells in the small intestine and an increase in α4ß7-expressing CD4 T cells in mesenteric lymph nodes of ENO-immunized mice. Consistent with a key role of CD4 T cells, immunization of CD4-deficient and Rag-2 deficient mice failed to induce protection, whereas mice lacking IgA were fully protected by immunization, indicating that immunity was CD4 T cell-dependent but IgA-independent. These results demonstrate that conserved metabolic enzymes can be effective vaccine antigens for protection against G. lamblia infection, thereby expanding the repertoire of candidate antigens beyond primary surface proteins.

Alpha-Blockers As Colorectal Cancer Chemopreventive: Findings from a Case-Control Study, Human Cell Cultures, and In Vivo Preclinical Testing.

A retrospective case-controlled analysis was performed to identify drug candidates in the current use that may prevent colorectal cancer, outside of aspirin. A total of 37,510 patients aged ≥20 years were assessed to identify subjects who had been diagnosed with colorectal cancer by colonoscopy without a previous diagnosis of colorectal cancer, inflammatory bowel disease (IBD), or gastrointestinal symptoms; 1,560 patients were identified who were diagnosed with colorectal cancer by colonoscopy. The patients with colorectal cancer were matched with 1,560 age, gender, family history of colorectal cancer and comorbidity-matched control patients who were not diagnosed with colorectal cancer at colonoscopy. The medication histories were compared between the two groups. Next, candidate drugs that were more frequently used by the control patients were selected and their effects on human colorectal cancer cell lines in vitro and an inflammation-induced mouse model of colorectal cancer were tested. Putative colorectal cancer preventative agents were identified, including aspirin, vitamin D, vitamin B, vitamin C, vitamin E, xanthine oxidase inhibitor, alpha-blockers, angiotensin receptor blocker, nateglinide, probiotics, thienopyridine, folic acid, nitrovasodilators, bisphosphonates, calcium channel blockers, steroids, and statins (P < 0.05). Alpha-blockers and xanthine oxidase inhibitors were selected for further study because these agents have not been analyzed previously as factors that may affect colorectal cancer outcomes. In vitro doxazosin (alpha-blocker), but not febuxostat (xanthine oxidase inhibitor), suppressed the proliferation of human colorectal cancer cells. Doxazosin also decreased tumorigenesis in an AOM/DSS mouse colorectal cancer model. Alpha-blockers may prevent colorectal cancer.

BHLHA15-Positive Secretory Precursor Cells Can Give Rise to Tumors in Intestine and Colon in Mice.

BACKGROUND & AIMS: The intestinal epithelium is maintained by long-lived intestinal stem cells (ISCs) that reside near the crypt base. Above the ISC zone, there are short-lived progenitors that normally give rise to lineage-specific differentiated cell types but can dedifferentiate into ISCs in certain circumstances. However, the role of epithelial dedifferentiation in cancer development has not been fully elucidated. METHODS: We performed studies with Bhlha15-CreERT, Lgr5-DTR-GFP, Apcflox/flox, LSL-Notch (IC), and R26-reporter strains of mice. Some mice were given diphtheria toxin to ablate Lgr5-positive cells, were irradiated, or were given 5-fluorouracil, hydroxyurea, doxorubicin, or dextran sodium sulfate to induce intestinal or colonic tissue injury. In intestinal tissues, we analyzed the fate of progeny that expressed Bhlha15. We used microarrays and reverse-transcription PCR to analyze gene expression patterns in healthy and injured intestinal tissues and in tumors. We analyzed gene expression patterns in human colorectal tumors using The Cancer Genome Atlas data set. RESULTS: Bhlha15 identified Paneth cells and short-lived secretory precursors (including pre-Paneth label-retaining cells) located just above the ISC zone in the intestinal epithelium. Bhlha15+ cells had no plasticity after loss of Lgr5-positive cells or irradiation. However, Bhlha15+ secretory precursors started to supply the enterocyte lineage after doxorubicin-induced epithelial injury in a Notch-dependent manner. Sustained activation of Notch converts Bhlha15+ secretory precursors to long-lived enterocyte progenitors. Administration of doxorubicin and expression of an activated form of Notch resulted in a gene expression pattern associated with enterocyte progenitors, whereas only sustained activation of Notch altered gene expression patterns in Bhlha15+ precursors toward those of ISCs. Bhlha15+ enterocyte progenitors with sustained activation of Notch formed intestinal tumors with serrated features in mice with disruption of Apc. In the colon, Bhlha15 marked secretory precursors that became stem-like, cancer-initiating cells after dextran sodium sulfate-induced injury, via activation of Src and YAP signaling. In analyses of human colorectal tumors, we associated activation of Notch with chromosome instability-type tumors with serrated features in the left colon. CONCLUSIONS: In mice, we found that short-lived precursors can undergo permanent reprogramming by activation of Notch and YAP signaling. These cells could mediate tumor formation in addition to traditional ISCs.

Three types of metaplasia model through Kras activation, Pten deletion, or Cdh1 deletion in the gastric epithelium.

Chronic inflammation and intestinal metaplasia are strongly associated with gastric carcinogenesis. Kras activation and Pten deletion are observed in intestinal-type gastric cancer, and Cdh1 mutation is associated with diffuse-type gastric cancer. Although various mouse models of gastric carcinogenesis have been reported, few mouse lines enable gene manipulation selectively in the stomach. Here we established a Tff1-Cre bacterial artificial chromosome transgenic mouse line in an attempt to induce gene modification specifically in the gastric pit lineage. In the stomach, Tff1-Cre-mediated recombination was most evident in the pit lineage in the corpus and in entire antral glands; recombination was also observed in a few gastric chief and parietal cells. Outside the stomach, recombination was patchy throughout the intestines, and particularly frequently in the duodenum (Brunner glands), cecum, and proximal colon. In the stomachs of Tff1-Cre;LSL-KrasG12D mice, proliferating cell clusters expanded throughout the corpus glands, with foveolar cell expansion with ectopic Alcian blue-positive mucins, oxyntic atrophy, and pseudopyloric changes with spasmolytic polypeptide-expressing metaplasia; however, gastric cancer was not observed even at 12 months of age. Corpus-derived organoids from Tff1-Cre;LSL-KrasG12D mice exhibited accelerated growth and abnormal differentiation with a loss of chief and parietal cell markers. Tff1-Cre;Ptenflox/flox mice displayed similar changes to those seen in Tff1-Cre;LSL-KrasG12D mice, both with aberrant ERK activation within 3 months. In contrast, Tff1-Cre;Cdh1flox/flox mice initially showed signet ring-like cells that were rapidly lost with disruption of the mucosal surface, and later developed gastric epithelial shedding with hyperproliferation and loss of normal gastric lineages. Eventually, the glandular epithelium in Tff1-Cre;Cdh1flox/flox mice was completely replaced by squamous epithelium which expanded from the forestomach. Tff1-Cre mice offer an additional useful tool for studying gastric carcinogenesis both in vivo and in vitro. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Adhesive Interactions between Mononuclear Phagocytes and Intestinal Epithelium Perturb Normal Epithelial Differentiation and Serve as a Therapeutic Target in Inflammatory Bowel Disease.

BACKGROUND AND AIMS: Disturbance of intestinal homeostasis is associated with the development of inflammatory bowel disease [IBD], and TGF-ß signalling impairment in mononuclear phagocytes [MPs] causes murine colitis with goblet cell depletion. Here, we examined an organoid-MP co-culture system to study the role of MPs in intestinal epithelial differentiation and homeostasis. METHODS: Intestinal organoids were co-cultured with lamina propria leukocytes and bone marrow-derived dendritic cells [BMDCs] from CD11c-cre Tgfbr2fl/fl mice. Organoid-MP adhesive interactions were evaluated by microscopy, RT-PCR, and flow cytometry. Murine colitis models (dextran sodium sulphate [DSS], CD11c-cre Tgfbr2fl/fl, T-cell-transfer) were used for histological and immunohistochemical analysis. Anti-E-cadherin antibody treatment or CD11c+-cell-specific CDH1 gene deletion were performed for E-cadherin neutralization or knockout. Colonic biopsies from patients with ulcerative colitis were analysed by flow cytometry. RESULTS: Intestinal organoids co-cultured with CD11c+ lamina propria leukocytes or BMDCs from CD11c-cre Tgfbr2fl/fl mice showed morphological changes and goblet cell depletion with Notch signal activation, analogous to CD11c-cre Tgfbr2fl/fl colitis. E-cadherin was upregulated in CD11c+ MPs, especially CX3CR1+CCR2+ monocytes, of CD11c-cre Tgfbr2fl/fl mice. E-cadherin-mediated BMDC adhesion promoted Notch activation and cystic changes in organoids. Anti-E-cadherin antibody treatment attenuated colitis in CD11c-cre Tgfbr2fl/fl and T-cell-transferred mice. In addition, E-cadherin deletion in CD11c+ cells attenuated colitis in both CD11c-cre Tgfbr2fl/fl and DSS-treated mice. In patients with ulcerative colitis, E-cadherin expressed by intestinal CD11c+ leukocytes was enhanced compared with that in healthy controls. CONCLUSIONS: E-cadherin-mediated MP-epithelium adhesion is associated with the development of colitis, and blocking these adhesions may have therapeutic potential for IBD.

Extranodal NK/T-cell lymphoma of the nasal cavity developed in a patient with intestinal Epstein-Barr virus-positive T/NK-cell lymphoproliferative disorder.

Extranodal NK/T cell lymphoma, nasal type (ENKL) developed in a patient with intestinal Epstein-Barr virus (EBV)-positive T/NK-cell lymphoproliferative disorder (LPD). The patient was a 46-year-old Chinese man who complained of diarrhea and abdominal pain without immune-deficiency. Endoscopy demonstrated ileum ulcers like Crohn's disease, without histological granulomas. His symptoms continued waxing and waning for 3 years until he developed overt lymphoma (ENKL) in the nasal cavity. The ileum lesions exacerbated into a large deep ulcer, and the biopsy specimens from the ileum, including the one 3 years ago, showed infiltration of small lymphocytes containing many EBV-positive T/NK cells without atypia. Thus, the patient illness of intestine was revealed as intestinal EBV-positive T/NK-cell LPD, which might be closely associated with development of ENKL in this patient. In cases of inflammatory bowel disease without typical clinical courses and histological findings, check-up of EBV in the biopsy might help correct diagnosis.

Decline in perception of acid regurgitation symptoms from gastroesophageal reflux disease in diabetes mellitus patients.

OBJECTIVES: To determine if a discrepancy exists between subjective symptoms and the grade of endoscopic gastroesophageal reflux disease (GERD) in diabetes mellitus (DM) patients. METHODS: All 2,884 patients who underwent esophagogastroduodenoscopy completed the modified Gastrointestinal Symptom Rating Scale (GSRS), an interview-based rating scale consisting of 16 items including a question on acid regurgitation. Patients were divided into DM and non-DM groups (1,135 and 1,749 patients, respectively). GERD was diagnosed endoscopically and graded according to the Los Angeles classification. Grade B or more severe GERD was defined as severe endoscopic GERD. The intergroup GSRS score was compared statistically. RESULTS: In severe endoscopic GERD patients, the prevalence of patients with a positive GSRS score in the acid regurgitation question was statistically lower in DM patients than non-DM patients. Of the 60 non-DM patients with severe endoscopic GERD, 40 patients (67%) had a positive GSRS score for acid regurgitation; however, of the 51 DM patients with severe endoscopic GERD, 23 patients (45%) had a positive GSRS score. Multivariate analysis showed that severe endoscopic GERD (OR: 2.01; 95% CI: 1.21-3.33; p = 0.0066), non-DM (OR: 0.74; 95% CI: 0.54-0.94; p = 0.0157), younger age (OR: 0.98; 95% CI: 0.97-0.99; p = 0.0125), and hiatal hernia (OR: 1.46; 95% CI: 1.12-1.90; p = 0.0042) were associated with acid regurgitation symptoms. CONCLUSIONS: There is a discrepancy between subjective symptoms and endoscopic GERD grade in DM patients. The ability of DM patients to feel acid regurgitation may be decreased.

Distinct Chemopreventive Effects of Aspirin in Diffuse and Intestinal-Type Gastric Cancer.

Introduction: Although aspirin/NSAIDs may have potential preventive effects on several cancers, it remains unclear on gastric cancer. The purpose of this study is to compare the risk of developing gastric cancer and the histologic changes of intestinal metaplasia and neutrophil infiltration, between aspirin/NSAID users and nonusers.Methods: Using an electronic endoscopy database in two hospitals from 1996 to 2017, we analyzed the data from patients with chronic gastritis who received aspirin or NSAIDs prior to upper gastrointestinal endoscopy. One-to-one propensity score matching was performed to compare the proportion of gastric cancer, intestinal metaplasia, and neutrophil infiltration between these drug users and nonusers.Results: We analyzed 2,082 aspirin users and 2,082 nonusers as well as 898 NSAID users and 898 nonusers. Six diffuse-type and 19 intestinal-type gastric cancer, 1,243 intestinal metaplasia, and 1,503 neutrophil infiltration patients were identified. The proportion of diffuse-type gastric cancer (0.05%) was 80% lower in aspirin users compared with the nonusers (0.24%), and there was no case of diffuse-type cancer in patients who took aspirin for more than 2 years. In contrast, intestinal-type gastric cancer incidence was significantly higher in aspirin users (0.72%) compared with nonusers (0.14%). No significant differences in the incidence of gastric cancer were found between NSAID use and nonusers. NSAID use was significantly associated with decreased proportion of neutrophil infiltration compared with nonusers.Conclusion: Aspirin may have distinct effects between intestinal-type and diffuse-type gastric cancer development. Cancer Prev Res; 11(5); 279-86. ©2018 AACR.

Mature gastric chief cells are not required for the development of metaplasia.

During human gastric carcinogenesis, intestinal metaplasia is frequently seen in the atrophic stomach. In mice, a distinct type of metaplasia known as spasmolytic polypeptide-expressing metaplasia (SPEM) is found in several inflammatory and genetically engineered models. Given the diversity of long- and short-term models of mouse SPEM, it remains unclear whether all models have a shared or distinct molecular mechanism. The origin of SPEM in mice is presently under debate. It is postulated that stem or progenitor cells acquire genetic alterations that then supply metaplastic cell clones, whereas the possibility of transdifferentiation or dedifferentiation from mature gastric chief cells has also been suggested. In this study, we report that loss of chief cells was sufficient to induce short-term regenerative SPEM-like lesions that originated from chief cell precursors in the gastric neck region. Furthermore, Lgr5+ mature chief cells failed to contribute to both short- and long-term metaplasia, whereas isthmus stem and progenitor cells efficiently contributed to long-term metaplasia. Interestingly, multiple administrations of high-dose pulsed tamoxifen induced expansion of Lgr5 expression and Lgr5-CreERT recombination within the isthmus progenitors apart from basal chief cells. Thus we conclude that short-term SPEM represents a regenerative process arising from neck progenitors following chief cell loss, whereas true long-term SPEM originates from isthmus progenitors. Mature gastric chief cells may be dispensable for SPEM development. NEW & NOTEWORTHY Recently, dedifferentiation ability in gastric chief cells during metaplasia development has been proposed. Our findings reveal that lesions that were thought to be acute metaplasia in fact represent normal regeneration supplied from neck lineage and that isthmus stem/progenitors are more responsible for sustained metaplastic changes. Cellular plasticity in gastric chief cells may be more limited than recently highlighted.

c-Jun N-terminal kinase in pancreatic tumor stroma augments tumor development in mice.

Pancreatic ductal adenocarcinoma (PDAC) is a life-threatening disease and there is an urgent need to develop improved therapeutic approaches. The role of c-Jun N-terminal kinase (JNK) in PDAC stroma is not well defined even though dense desmoplastic reactions are characteristic of PDAC histology. We aimed to explore the role of JNK in PDAC stroma in mice. We crossed Ptf1aCre/+ ;KrasG12D/+ mice with JNK1-/- mice to generate Ptf1aCre/+ ;KrasG12D/+ ;JNK1-/- (Kras;JNK1-/- ) mice. Tumor weight was significantly lower in Kras;JNK1-/- mice than in Kras;JNK1+/- mice, whereas histopathological features were similar. We also transplanted a murine PDAC cell line (mPC) with intact JNK1 s.c. into WT and JNK1-/- mice. Tumor diameters were significantly smaller in JNK1-/- mice. Phosphorylated JNK (p-JNK) was activated in α-smooth muscle actin (SMA)-positive cells in tumor stroma, and mPC-conditioned medium activated p-JNK in tumor-associated fibroblasts (TAF) in vitro. Relative expression of Ccl20 was downregulated in stimulated TAF. Ccl20 is an important chemokine that promotes CD8+ T-cell infiltration by recruitment of dendritic cells, and the number of CD8+ T cells was decreased in Kras;JNK1+/- mice compared with Kras;JNK1-/- mice. These results suggest that the cancer secretome decreases Ccl20 secretion from TAF by activation of JNK, and downregulation of Ccl20 secretion might be correlated with reduction of infiltrating CD8+ T cells. Therefore, we concluded that inhibition of activated JNK in pancreatic tumor stroma could be a potential therapeutic target to increase Ccl20 secretion from TAF and induce accumulation of CD8+ T cells, which would be expected to enhance antitumor immunity.

Prevalence of pks-positive Escherichia coli in Japanese patients with or without colorectal cancer.

BACKGROUND: Recent studies show that some Escherichia coli strains possessing a gene cluster named the pks island might have a causative role in the development of human colorectal cancer (CRC). In several reports from Europe, they are found more prevalently in colon tissue specimens derived from CRC patients compared to those from controls. In this study we sought to clarify the difference in pks prevalence between CRC patients and non-CRC controls in the Japanese population, by using non-invasive sample collection technique during colonoscopy. METHODS: Colonic lavage samples were collected during diagnostic colonoscopy, and bacterial DNA within each sample was extracted. Fecal DNA samples were then examined for pks island genes using conventional qualitative PCR and real-time quantitative PCR. In some patients biopsy samples were also collected in the same session of colonoscopy, and the correlation between the pks status of the colonic lavage sample and the biopsy sample of the same patients was evaluated. RESULTS: Twelve out of thirteen patients (92%) showed the same pks status by colonic lavage sample and biopsy sample, suggesting the usefulness of colonic lavage samples as a surrogate for biopsy samples. A total of 98 colonic lavage samples were collected, which included 35 from CRC patients, 37 from adenoma patients, and 26 from controls. The pks-positive bacterial DNA was detected in 43, 51, and 46% of colonic lavage samples from CRC, adenoma, and control patients, respectively, and there was no significant difference among diseases. Real-time quantitative PCR showed no significant difference in the relative concentrations of pks-positive bacterial DNA among diseases. Age, gender, location of CRC, CRC staging, or k-ras gene status was not associated with pks prevalence. CONCLUSIONS: Although the method of collecting fecal DNA from colonic lavage samples was safe and technically feasible, factors other than pks-positive bacteria appear to play more important roles in CRC development in this cohort.

Biliary epithelial injury-induced regenerative response by IL-33 promotes cholangiocarcinogenesis from peribiliary glands.

The carcinogenic mechanism of extrahepatic cholangiocarcinoma (ECC) is unclear, due at least in part to the lack of an appropriate mouse model. Because human studies have reported frequent genetic alterations in the Ras- and TGFß/SMAD-signaling pathways in ECC, mice with tamoxifen-inducible, duct-cell-specific Kras activation and a TGFß receptor type 2 (TGFßR2) deletion were first generated by crossing LSL-KrasG12D , Tgfbr2flox/flox , and K19CreERT mice (KT-K19CreERT ). However, KT-K19CreERT mice showed only mild hyperplasia of biliary epithelial cells (BECs) in the extrahepatic bile duct (EHBD) and died within 7 wk, probably a result of lung adenocarcinomas. Next, to analyze the additional effect of E-cadherin loss, KT-K19CreERT mice were crossed with CDH1flox/flox mice (KTC-K19CreERT ). Surprisingly, KTC-K19CreERT mice exhibited a markedly thickened EHBD wall accompanied by a swollen gallbladder within 4 wk after tamoxifen administration. Histologically, invasive periductal infiltrating-type ECC with lymphatic metastasis was observed. Time-course analysis of EHBD revealed that recombined BECs lining the bile duct lumen detached due to E-cadherin loss, whereas recombined cells could survive in the peribiliary glands (PBGs), which are considered a BEC stem-cell niche. Detached dying BECs released high levels of IL-33, as determined by microarray analysis using biliary organoids, and stimulated inflammation and a regenerative response by PBGs, leading eventually to ECC development. Cell lineage tracing suggested PBGs as the cellular origin of ECC. IL-33 cooperated with Kras and TGFßR2 mutations in the development of ECC, and anti-IL-33 treatment suppressed ECC development significantly. Thus, this mouse model provided insight into the carcinogenic mechanisms, cellular origin, and potential therapeutic targets of ECC.

CXCR4-expressing Mist1+ progenitors in the gastric antrum contribute to gastric cancer development.

Mist1 was recently shown to identify a discrete population of stem cells within the isthmus of the oxyntic gland within the gastric corpus. Chief cells at the base of the gastric corpus also express Mist1. The relevance of Mist1 expression as a marker of specific cell populations within the antral glands of the distal stomach, however, is unknown. Using Mist1-CreERT mice, we revealed that Mist1+ antral cells, distinct from the Mist1+ population in the corpus, comprise long-lived progenitors that reside within the antral isthmus above Lgr5+ or CCK2R+ cells. Mist1+ antral progenitors can serve as an origin of antral tumors induced by loss of Apc or MNU treatment. Mist1+ antral progenitors, as well as other antral stem/progenitor population, express Cxcr4, and are located in close proximity to Cxcl12 (the Cxcr4 ligand)-expressing endothelium. During antral carcinogenesis, there is an expansion of Cxcr4+ epithelial cells as well as the Cxcl12+ perivascular niche. Deletion of Cxcl12 in endothelial cells or pharmacological blockade of Cxcr4 inhibits antral tumor growth. Cxcl12/Cxcr4 signaling may be a potential therapeutic target.