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.

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.

Severe obstructive colitis treated with repeated colonoscopic decompression

Obstructive colitis is an acute condition caused by colorectal strictures and requires a combination of therapeutic strategies, including surgery, endoscopic interventions, and medications. Here, we describe the case of a 69-year-old man who developed severe obstructive colitis owing to diverticular stenosis of the sigmoid colon. We immediately performed endoscopic decompression to avoid perforation. The mucosa of the dilated colon appeared black, suggesting severe ischemia. We considered surgical total colectomy owing to the extensive colitis. However, considering the invasiveness of the emergent surgery, we adopted a conservative approach as enhanced computed tomography demonstrated colonic dilation with maintained blood flow in the deeper layer of the colonic wall and no signs of colonic necrosis, such as peritoneal irritation sign or elevation of deviation enzymes, were observed. Moreover, the patient preferred a conservative approach, and surgeons in our team agreed with this conservative approach. While relapses of colonic dilation occurred several times, antibiotic treatment and repeated endoscopic decompression successfully suppressed the dilation and systemic inflammation. The colonic mucosa healed gradually, and we performed a colostomy without resecting a large portion of the colorectum. In conclusion, severe obstructive colitis with maintained blood flow can be treated with endoscopic decompression instead of emergent resection for a wide portion of the colorectum. Moreover, endoscopic images of improved colitic mucosa obtained through repeated colorectal procedures are rare and noteworthy.

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.

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.

Ventral anchoring of the conus medullaris: a new surgical technique preventing the radiographic recurrence of retethering after surgery for tethered spinal cord

OBJECTIVE

Retethering is not an unusual operation for a congenital lumbosacral dysraphic spinal lesion. The present study aimed to assess a new surgical technique for preventing retethering.

SURGICAL TECHNIQUE

After untethering the spinal cord, the pia mater or scar tissue at the caudal end of the conus medullaris is anchored to the ventral dura mater loosely using 8-0 thread, and the dura mater is closed directly. This technique is called ventral anchoring.

RESULTS

Ventral anchoring was performed in 15 patients (aged 5 to 37 years old, average age: 12.1 years old) between 2014 and 2021. All but one patient showed improvement or stabilization of the preoperative symptoms. No complication directly related to the procedure was observed. Postoperative MRI demonstrated that the dorsal subarachnoid space was restored in 14 patients but was undetectable or absent in three patients on follow-up MRI. No patients have experienced a recurrence of the tethered cord syndrome during the follow-up period.

CONCLUSION

Ventral anchoring is effective for restoring the dorsal subarachnoid space after untethering the spinal cord. This preliminary study suggested that ventral anchoring has the potential to prevent the postoperative radiographic recurrence of tethered spinal cord in patients with a congenital lumbosacral dysraphic spinal lesion.

Codelivery of Antigens and Adjuvant in Polymeric Nanoparticles Coated With Native Parasite Membranes Induces Protective Mucosal Immunity Against Giardia lamblia

The protozoan pathogen Giardia lamblia is an important worldwide cause of diarrheal disease and malabsorption. Infection is managed with antimicrobials, although drug resistance and treatment failures are a clinical challenge. Prior infection provides significant protection, yet a human vaccine has not been realized. Individual antigens can elicit partial protection in experimental models, but protection is weaker than after prior infection. Here, we developed a multivalent nanovaccine by coating membranes derived from the parasite onto uniform and stable polymeric nanoparticles loaded with a mucosal adjuvant. Intranasal immunization with the nanovaccine induced adaptive immunity and effectively protected mice from G. lamblia infection.

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 α4β7-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.

Gold(I) Phosphine Derivatives with Improved Selectivity as Topically Active Drug Leads to Overcome 5-Nitroheterocyclic Drug Resistance in Trichomonas vaginalis

Trichomonas vaginalis causes the most common, nonviral sexually transmitted infection. Only metronidazole (Mz) and tinidazole are approved for treating trichomoniasis, yet resistance is a clinical problem. The gold(I) complex, auranofin, is active against T. vaginalis and other protozoa but has significant human toxicity. In a systematic structure-activity exploration, we show here that diversification of gold(I) complexes, particularly as halides with simple C1-C3 trialkyl phosphines or as bistrialkyl phosphine complexes, can markedly improve potency against T. vaginalis and selectivity over human cells compared to that of the existing antirheumatic gold(I) drugs. All gold(I) complexes inhibited the two most abundant isoforms of the presumed target enzyme, thioredoxin reductase, but a subset of compounds were markedly more active against live T. vaginalis than the enzyme, suggesting that alternative targets exist. Furthermore, all tested gold(I) complexes acted independently of Mz and were able to overcome Mz resistance, making them candidates for the treatment of Mz-refractory trichomoniasis.

Click chemistry-facilitated comprehensive identification of proteins adducted by antimicrobial 5-nitroimidazoles for discovery of alternative drug targets against giardiasis

Giardiasis and other protozoan infections are major worldwide causes of morbidity and mortality, yet development of new antimicrobial agents with improved efficacy and ability to override increasingly common drug resistance remains a major challenge. Antimicrobial drug development typically proceeds by broad functional screens of large chemical libraries or hypothesis-driven exploration of single microbial targets, but both strategies have challenges that have limited the introduction of new antimicrobials. Here, we describe an alternative drug development strategy that identifies a sufficient but manageable number of promising targets, while reducing the risk of pursuing targets of unproven value. The strategy is based on defining and exploiting the incompletely understood adduction targets of 5-nitroimidazoles, which are proven antimicrobials against a wide range of anaerobic protozoan and bacterial pathogens. Comprehensive adductome analysis by modified click chemistry and multi-dimensional proteomics were applied to the model pathogen Giardia lamblia to identify dozens of adducted protein targets common to both 5'-nitroimidazole-sensitive and -resistant cells. The list was highly enriched for known targets in G. lamblia, including arginine deiminase, α-tubulin, carbamate kinase, and heat shock protein 90, demonstrating the utility of the approach. Importantly, over twenty potential novel drug targets were identified. Inhibitors of two representative new targets, NADP-specific glutamate dehydrogenase and peroxiredoxin, were found to have significant antigiardial activity. Furthermore, all the identified targets remained available in resistant cells, since giardicidal activity of the respective inhibitors was not impacted by resistance to 5'-nitroimidazoles. These results demonstrate that the combined use of click chemistry and proteomics has the potential to reveal alternative drug targets for overcoming antimicrobial drug resistance in protozoan parasites.

Composite thermoresponsive hydrogel with auranofin-loaded nanoparticles for topical treatment of vaginal trichomonad infection

Trichomonas vaginalis is responsible for the most common non-viral sexually-transmitted disease worldwide. Standard treatment is with oral nitro-heterocyclic compounds, metronidazole or tinidazole, but resistance to these drugs is emerging and adverse effects can be problematic. Topical treatment offers potential benefits for increasing local drug concentrations and efficacy, while reducing systemic drug exposure, but no topical strategies are currently approved for trichomoniasis. The anti-rheumatic drug, auranofin (AF), was recently discovered to have significant trichomonacidal activity, but has a long plasma half-life and significant adverse effects. Here, we used this drug as a model to develop a novel topical formulation composed of AF-loaded nanoparticles (NP) embedded in a thermoresponsive hydrogel for intravaginal administration. The AF-NP composite gel showed sustained drug release for at least 12 h, and underwent sol-gel transition with increased viscoelasticity within a minute. Intravaginal administration in mice showed excellent NP retention for >6 h and markedly increased local AF levels, but reduced plasma and liver levels compared to oral treatment with a much higher dose. Furthermore, intravaginal AF-NP gel greatly outperformed oral AF in eliminating vaginal trichomonad infection in mice, while causing no systemic or local toxicity. These results show the potential of the AF-NP hydrogel formulation for effective topical therapy of vaginal infections.

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, Apc^flox/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.

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.

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-Kras^G12D 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-Kras^G12D mice exhibited accelerated growth and abnormal differentiation with a loss of chief and parietal cell markers. Tff1-Cre;Pten^flox/flox mice displayed similar changes to those seen in Tff1-Cre;LSL-Kras^G12D mice, both with aberrant ERK activation within 3 months. In contrast, Tff1-Cre;Cdh1^flox/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;Cdh1^flox/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-β 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.

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.

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.

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.

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 Ptf1a^Cre/+;Kras^G12D/+ mice with JNK1^−/− mice to generate Ptf1a^Cre/+;Kras^G12D/+;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.

TGF-β in inflammatory bowel disease: a key regulator of immune cells, epithelium, and the intestinal microbiota

Inflammatory bowel disease (IBD) is defined as chronic intestinal inflammation, and includes ulcerative colitis and Crohn's disease. Multiple factors are involved in the pathogenesis of IBD, and the condition is characterized by aberrant mucosal immune reactions to intestinal microbes in genetically susceptible hosts. Transforming growth factor-β (TGF-β) is an immune-suppressive cytokine produced by many cell types and activated by integrins. Active TGF-β binds to its receptor and regulates mucosal immune reactions through the TGF-β signaling pathway. Dysregulated TGF-β signaling is observed in the intestines of IBD patients. TGF-β signal impairment in specific cell types, such as T-cells and dendritic cells, results in spontaneous colitis in mouse models. In addition, specific intestinal microbes contribute to immune homeostasis by modulating TGF-β production. In this review, we describe the role of TGF-β in intestinal immunity, focusing on immune cells, epithelium, and intestinal microbes. In addition, we present potential therapeutic strategies for IBD that target TGF-β.

TGF-β Signaling in Dendritic Cells Governs Colonic Homeostasis by Controlling Epithelial Differentiation and the Luminal Microbiota

Dendritic cells (DCs) mediate host immune responses to gut microbes and play critical roles in inflammatory bowel disease. In this study, we examined the role of TGF-β signaling in DCs in colonic homeostasis. CD11c-cre Tgfbr2fl/fl mice developed spontaneous colitis, and CD11c-cre Tgfbr2fl/+ mice exhibited susceptibility to dextran sulfate sodium–induced colitis. Colitis in these mice was characterized by goblet cell depletion and dysbiosis caused by Enterobacteriaceae enrichment. Wild-type mice gavaged with Enterobacteriaceae from CD11c-cre Tgfbr2fl/fl mice feces showed severe colitis after dextran sulfate sodium treatment, whereas those treated with Notch inhibitor exhibited attenuated colonic injury with increased goblet cell numbers, thickened mucus layer, and fewer fecal Enterobacteriaceae. Wild-type mice transplanted with CD11c-cre Tgfbr2fl/fl bone marrow developed colitis showing increased Jagged1 and Jagged2 in DCs, increased Hes1 levels in epithelium, and goblet cell depletion. These findings suggest that TGF-β signaling in DCs regulates intestinal homeostasis by modulating epithelial cell differentiation and fecal microbiota.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

Inhibition of autophagy exerts anti-colon cancer effects via apoptosis induced by p53 activation and ER stress

BACKGROUND

Although some molecularly targeted drugs for colorectal cancer are used clinically and contribute to a better prognosis, the current median survival of advanced colorectal cancer patients is not sufficient. Autophagy, a basic cell survival mechanism mediated by recycling of cellular amino acids, plays an important role in cancer. Recently, autophagy has been highlighted as a promising new molecular target. The unfolded protein response (UPR) reportedly act in complementary fashion with autophagy in intestinal homeostasis. However, the roles of UPR in colon cancer under autophagic inhibition remain to be elucidated. We aim to clarify the inhibitory effect of autophagy on colon cancer.

METHODS

We crossed K19 (CreERT) and Atg5 (flox/flox) mice to generate Atg5 (flox/flox)/K19 (CreERT) mice. Atg5 (flox/flox)/K19 (CreERT) mice were first treated with azoxymethane/dextran sodium sulfate and then injected with tamoxifen to inhibit autophagy in CK19-positive epithelial cells. To examine the anti-cancer mechanisms of autophagic inhibition, we used colon cancer cell lines harboring different p53 gene statuses, as well as small interfering RNAs (siRNAs) targeting Atg5 and immunoglobulin heavy-chain binding protein (BiP), a chaperone to aid folding of unfolded proteins.

RESULTS

Colon tumors in Atg5 (flox/flox)/K19 (CreERT) mice showed loss of autophagic activity and decreased tumor size (the total tumor diameter was 28.1 mm in the control and 20.7 mm in Atg5 (flox/flox)/K19 (CreERT) mice, p = 0.036). We found that p53 and UPR/endoplasmic reticulum (ER) stress-related proteins, such as cleaved caspase 3, and CAAT/enhancer-binding protein homologous protein, are up-regulated in colon tumors of Atg5 (flox/flox)/K19 (CreERT) mice. Although Atg5 and BiP silencing, respectively, increased apoptosis in p53 wild type cells, Atg5 silencing alone did not show the same effect on apoptosis in p53 mutant cells. However, co-transfection of Atg5 and BiP siRNAs led to increased apoptosis in p53 mutant cells.

CONCLUSIONS

Blocking autophagy has potential in the treatment of colon cancer by inducing apoptosis via p53 and ER stress, and suppressing the UPR pathway is a valid strategy to overcome resistance to autophagic inhibition.

Simple model of pH-induced protein denaturation

The pH-induced conformational changes of proteins are systematically studied in the framework of a hydrophobic-polar (HP) model, in which proteins are dramatically simplified as chains of hydrophobic (H) and polar (P) beads on a lattice. We express the electrostatic interaction, the principal driving force of pH-induced unfolding that is not included in the conventional HP model, as the repulsive energy term between P monomers. As a result of the exact enumeration of all of the 14- to 18-mers, it is found that lowest-energy states in many sequences change from single "native" conformations to multiple sets of "denatured" conformations with an increase in the electrostatic repulsion. The switching of the lowest-energy states occurs in quite a similar way to real proteins: it is almost always between two states, while in a small fraction of ≥16-mers it is between three states. We also calculate the structural fluctuations for all of the denatured states and find that the denatured states contain a broad range of incompletely unfolded conformations, similar to "molten globule" states referred to in acid or alkaline denatured real proteins. These results show that the proposed model provides a simple physical picture of pH-induced protein denaturation.

Characterization of a new small bowel adenocarcinoma cell line and screening of anti-cancer drug against small bowel adenocarcinoma

Small bowel adenocarcinoma (SBA) is a rare, aggressive malignancy with a poor prognosis, and the mechanisms of carcinogenesis in SBA remain unclear. Our aims were to investigate the molecular mechanisms underlying SBA and to identify treatments by establishing and characterizing an SBA cell line and performing anti-cancer drug screening. SIAC1 cells, established from jejunal SBA, showed epithelial characteristics and formed organoids in 3D culture. SIAC1 cells had a heterozygous β-catenin deletion mutation, resulting in a stable β-catenin protein with enhanced Wnt/β-catenin activity. SIAC1 cells lacked MLH1 and MSH6 expression, and target genes such as TGFBR2 and ACVR2 showed frameshift mutations. Among 10 clinical SBA samples, 2 (20%) had interstitial deletions in β-catenin, expression of mismatch repair protein was aberrant in 4 (40%), and heterozygous frameshift mutations of three target genes were found in all 10 samples. On screening assay using 140 compounds, eribulin significantly inhibited SIAC1 cell growth both in vitro and in vivo by inhibition of the Wnt/β-catenin pathway via enhanced degradation of β-catenin. In conclusion, we established an SBA cell line with molecular characteristics similar to those of clinical SBA samples, including β-catenin deletion and mismatch repair protein deficiency, that will be useful for SBA research. Eribulin might be a candidate for SBA treatment due to its inhibitory effect on Wnt/β-catenin signaling.

First case report of de novo ulcerative colitis developing after orthotopic liver transplantation successfully treated by granulocyte and monocyte apheresis

BACKGROUND

Immunosuppressants such as tacrolimus and cyclosporine are prescribed long-term after orthotopic liver transplantation (OLT) to prevent allograft rejection. Although these immunosuppressants are known to effectively control ulcerative colitis (UC), some post-OLT patients develop exacerbation of preexisting UC or de novo UC. Although aminosalicylates and corticosteroid courses are usually effective to treat such UC, several patients have developed uncontrollable disease and required colectomies.

CASE REPORT

We have reported a patient who developed de novo UC after OLT to treat liver cirrhosis and hepatocellular carcinoma associated with hepatitis B virus (HBV) infection. Existence of the HBV infection made us avoid to increase the corticosteroid dose or to use other immunosuppressants such as azathioprine or infliximab.

CONCLUSIONS

In this patient, granulocyte and monocyte apheresis was highly effective in terms of inducing remission of de novo UC. No adverse event was noted.

Chemosensory signals and their receptors in the olfactory neural system

Chemical communication is widely used among various organisms to obtain essential information from their environment required for life. Although a large variety of molecules have been shown to act as chemical cues, the molecular and neural basis underlying the behaviors elicited by these molecules has been revealed for only a limited number of molecules. Here, we review the current knowledge regarding the signaling molecules whose flow from receptor to specific behavior has been characterized. Discussing the molecules utilized by mice, insects, and the worm, we focus on how each organism has optimized its reception system to suit its living style. We also highlight how the production of these signaling molecules is regulated, an area in which considerable progress has been recently made.

Production and characterization of recombinant human anti-HBs Fab antibodies

Recombinant human Fab antibodies were generated with different reactivities against the hepatitis B virus surface (HBs) antigen. To isolate the antibodies, a method was used that combined transformation of human B cells by Epstein-Barr virus (EBV) infection with a primer-vector system developed for isolating DNA fragments of human Ig Fab portions. With this method, monoclonal and oligoclonal cell lines producing anti-HBs antibodies were established and three anti-HBs Fab antibodies were isolated from two of these cell lines. From analysis of affinity characteristics, immunohistochemical activity, and cytolysis activity, these three Fab antibodies were classified into three different groups. The first group had high affinity for HBs, the second had the ability to kill HBV-infected cells, and the third was applicable to immunohistochemical staining with HBV-infected cells. The combined effect of these antibodies was also investigated by complement-dependent cytotoxicity assay.

Multidimensional support vector machines for visualization of gene expression data

MOTIVATION

Since DNA microarray experiments provide us with huge amount of gene expression data, they should be analyzed with statistical methods to extract the meanings of experimental results. Some dimensionality reduction methods such as Principal Component Analysis (PCA) are used to roughly visualize the distribution of high dimensional gene expression data. However, in the case of binary classification of gene expression data, PCA does not utilize class information when choosing axes. Thus clearly separable data in the original space may not be so in the reduced space used in PCA.

RESULTS

For visualization and class prediction of gene expression data, we have developed a new SVM-based method called multidimensional SVMs, that generate multiple orthogonal axes. This method projects high dimensional data into lower dimensional space to exhibit properties of the data clearly and to visualize a distribution of the data roughly. Furthermore, the multiple axes can be used for class prediction. The basic properties of conventional SVMs are retained in our method: solutions of mathematical programming are sparse, and nonlinear classification is implemented implicitly through the use of kernel functions. The application of our method to the experimentally obtained gene expression datasets for patients' samples indicates that our algorithm is efficient and useful for visualization and class prediction.

CONTACT

komura@hal.rcast.u-tokyo.ac.jp.

Characteristics of coated copper wire specimens using high frequency ultrasonic complex vibration welding equipments

Welding characteristic of thin coated copper wires were studied using 40, 60, 100 kHz ultrasonic complex vibration welding equipments with elliptical to circular vibration locus. The complex vibration systems consisted of a longitudinal-torsional vibration converter and a driving longitudinal vibration system. Polyurethane coated copper wires of 0.036 mm outer diameter and copper plates of 0.3 mm thickness and the other dimension wires were used as welding specimens. The copper wire part is completely welded on the copper substrate and the insulated coating material is driven from welded area to outsides of the wire specimens by high frequency complex vibration.

[Irrigation for the post-pneumonectomy empyema infected by methicillin-resistant Staphylococcus aureus without broncho-pleural fistula; report of a successful case]

It has been known that treatments of post-pneumonectomy empyema are difficult. We report a successful case of irrigation for the post-pneumonectomy. The patient was 68-year-old man with advanced lung cancer. He underwent induction chemoradiotherapy following by pneumonectomy of the right side. A few days later after the chest drain was withdrawn, spike fever appeared. Empyema was suspected, so a 28 Fr diameter double lumen chest drain was intubated again. Turbid effusion was discharged through the drain, in which methicillin-resistant staphylococcus aureus (MRSA) was cultured. Irrigation using a lot of saline and acid electrolyzed water started. A month later, irrigator through the drain was looking clear, however, MRSA was cultured so far. After putting minomycine into the irrigator, MRSA died away. This physical and chemical irrigations were effective.

Cell Simulation for Circadian Rhythm Based on Michaelis-MentenModel

We report here the development of a cell biological simulation systembased on ordinary differential equations and the results on the simulationof the heat pulses' effects on the circadian rhythm in Drosophila.The simulator implements intra-cellular processes: transcription,translation, transport, modification (association, disassociation),degradation. It simulates the temporal behavior of concentrations ofproteins and mRNA involved in various biological phenomena. Moreover, thesystem is able to determine the exact type of reaction for a givenregulatory pathway. In order to prove the usefulness of the simulator weconstruct a model of the circadian rhythm in Drosophilaand wesimulate the effect of the heat pulses applied in early afternoon on thecircadian clock proteins PER and TIM. Our simulation results show therobustness of the genetic network as well as the important role playedby dClk mRNA in the mechanism of phase-shift responses.

Cloning and expression of human anti-tumor necrosis factor-alpha monoclonal antibodies from Epstein-Barr virus transformed oligoclonal libraries

Peripheral blood was obtained from a healthy human volunteer and transformed with Epstein-Barr virus (EBV). This produced an oligoclonal cell library in culture medium that was screened by ELISA for anti-human tumor necrosis factor-alpha (TNFalpha) activity. RNA from two positive clones was applied to RT-PCR using antibody-specific primers, and the light (kappa and lambda) and heavy chain genes (gamma and mu) were cloned into the plasmid vector pFab1-His2. The antibodies produced in Escherichia coli as Fab fragments were assayed for anti-TNFalpha activity utilizing ELISA. Two IgG1/kappa anti-TNFalpha antibodies and two IgM/kappa anti-TNFalpha antibodies were isolated. DNA sequence analysis showed that the VL and VH gene families of IgM and IgG were the same. Both the antibodies showed almost the same activity on ELISA-testing. Ten clones randomly selected from light (kappa and lambda) and heavy (gamma and mu) chain genes in the oligoclonal cell library 1D5 were sequenced, and each gene (kappa, lambda, gamma, and mu) was found to be composed of one to three different genes. These data support the conclusion that the cell clone is oligoclonal at the molecular level.