Satoshi Tanida

Changes in 12-Year First-Line Eradication Rate of Helicobacter pylori Based on Triple Therapy with Proton Pump Inhibitor, Amoxicillin and Clarithromycin

A triple therapy based on a proton pump inhibitor (PPI), amoxicillin (AMPC), and clarithromycin (CAM) is recommended as a first-line therapy for Helicobacter pylori (H. pylori) eradication and is widely used in Japan. However, a decline in eradication rate associated with an increase in prevalence of CAM resistance is viewed as a problem. We investigated CAM resistance and eradication rates over time retrospectively in 750 patients who had undergone the triple therapy as first-line eradication therapy at Nagoya City University Hospital from 1995 to 2008, divided into four terms (Term 1: 1997–2000, Term 2: 2001–2003, Term 3: 2004–2006, Term 4: 2007–2008). Primary resistance to CAM rose significantly over time from 8.7% to 23.5%, 26.7% and 34.5% while the eradication rate decreased significantly from 90.6% to 80.2%, 76.0% and 74.8%. Based on the PPI type, significant declines in eradication rates were observed with omeprazole or lansoprazole, but not with rabeprazole. A decrease in the H. pylori eradication rate after triple therapy using a PPI + AMPC + CAM has been acknowledged, and an increase in CAM resistance is considered to be a factor. From now on, a first-line eradication regimen that results in a higher eradication rate ought to be investigated.

Advantages of endoscopic submucosal dissection over conventional endoscopic mucosal resection

Background:  Endoscopic mucosal resection is an established method for treating intramucosal gastric neoplasms. Conventional endoscopic mucosal resection has predominantly been performed using strip biopsy, but local recurrence sometimes occurs due to such piecemeal resection. Endoscopic submucosal dissection has recently been performed in Japan using new devices such as an insulation‐tip diathermic knife. The efficacy and problems associated with endoscopic submucosal dissection were evaluated by comparison with conventional endoscopic mucosal resection.

Mechanisms of Cisplatin-Induced Apoptosis and of Cisplatin Sensitivity: Potential of BIN1 to Act as a Potent Predictor of Cisplatin Sensitivity in Gastric Cancer Treatment

Cisplatin is the most important and efficacious chemotherapeutic agent for the treatment of advanced gastric cancer. Cisplatin forms inter- and intrastrand crosslinked DNA adducts and its cytotoxicity is mediated by propagation of DNA damage recognition signals to downstream pathways involving ATR, p53, p73, and mitogen-activated protein kinases, ultimately resulting in apoptosis. Cisplatin resistance arises through a multifactorial mechanism involving reduced drug uptake, increased drug inactivation, increased DNA damage repair, and inhibition of transmission of DNA damage recognition signals to the apoptotic pathway. In addition, a new mechanism has recently been revealed, in which the oncoprotein c-Myc suppresses bridging integrator 1 (BIN1), thereby releasing poly(ADP-ribose)polymerase 1, which results in increased DNA repair activity and allows cancer cells to acquire cisplatin resistance. The present paper focuses on the molecular mechanisms of cisplatin-induced apoptosis and of cisplatin resistance, in particular on the involvement of BIN1 in the maintenance of cisplatin sensitivity.

Adalimumab for the Treatment of Japanese Patients With Intestinal Behçet’s Disease

BACKGROUND & AIMS Behçets disease is a chronic, relapsing inflammatory disease that can involve the mouth, skin, eyes, genitals, and intestines. Active intestinal Behçets disease can be complicated by gastrointestinal (GI) bleeding and perforation. We performed a multicenter, open-label, uncontrolled study to evaluate the efficacy and safety of adalimumab, a fully human monoclonal antibody against tumor necrosis factor α, in patients with intestinal Behçets disease who were refractory to corticosteroid and/or immunomodulator therapies. METHODS The study was conducted at 12 sites in Japan, from November 2010 through October 2012. Twenty patients were given 160 mg adalimumab at the start of the study and 80 mg 2 weeks later, followed by 40 mg every other week for 52 weeks; for some patients, the dose was increased to 80 mg every other week. A composite efficacy index, combining GI symptom and endoscopic assessments, was used to evaluate efficacy. The primary efficacy end point was the percentage of patients with scores of 1 or lower for GI symptom and endoscopic assessments at week 24. Secondary end points included complete remission and resolution of non-GI Behçets-related symptoms. RESULTS Nine patients (45%) had GI symptom and endoscopic assessment scores of 1 or lower at week 24 of treatment, and 12 patients (60%) had these scores by week 52. Four patients (20%) achieved complete remission at weeks 24 and 52. Individual global GI symptom and endoscopic scores improved for most patients at weeks 24 and 52. Two thirds of patients with oral aphthous ulcers, skin symptoms, and genital ulcers, and 88% of patients with erythema nodosum had complete resolution of these conditions at week 52. A total of 9 of 13 patients (69%) taking steroids at baseline were able to taper (n = 1) or completely discontinue steroids (n = 8) during the study. No new safety signals were observed. CONCLUSIONS Adalimumab is a potentially effective treatment for intestinal Behçets disease in Japanese patients who are refractory to conventional treatments. ClinicalTrials.gov number: NCT01243671.

Helicobacter pylori-Stimulated Interleukin-8 (IL-8) Promotes Cell Proliferation Through Transactivation of Epidermal Growth Factor Receptor (EGFR) by Disintegrin and Metalloproteinase (ADAM) Activation

Helicobacter pylori infection increases the risk of hyperplastic polyps and gastric cancer, but the mechanisms remain to be elucidated. H. pylori was recently shown to transactivate epidermal growth factor receptor (EGFR) through metalloprotease stimulation. The present study was designed to investigate the effect of interleukin-8 (IL-8) induced by H. pylori infection on EGFR transactivation and epithelial cell growth. H. pylori Sydney strain 1 (SS1) having wild-type cag+A was used. Phospho-EGFR assay was performed by immunoprecipitation using anti-human EGFR and anti-phosphotyrosine antibodies. DNA synthesis was evaluated by [3H]thymidine uptake using the human gastric cancer cell line, KATO III. H. pylori induced EGFR phosphorylation, and a disintegrin and metalloproteinase (ADAM) inhibitor, KB-R7785, completely suppressed EGFR phosphorylation. IL-8 also induced EGFR phosphorylation, while anti-IL-8 and anti-IL-8 receptor (CXCR1) neutralizing antibodies suppressed EGFR phosphorylation. [3H]Thymidine uptake analysis demonstrated that H. pylori increased DNA synthesis in gastric epithelial cells, and tyrosine kinase inhibitor, MEK inhibitor, and ADAM inhibitor suppressed the DNA synthesis induced by H. pylori. H. pylori-stimulated IL-8 accelerates processing of EGFR ligands through ADAM activation, and cleaved EGFR ligands bind and stimulate EGFR in paracrine and autocrine manners to induce cell proliferation. This may be one of the mechanisms of hyperplastic polyp and gastric cancer development in H. pylori-infected gastric mucosa.

Tumor suppressor, AT motif binding factor 1 (ATBF1), translocates to the nucleus with runt domain transcription factor 3 (RUNX3) in response to TGF-β signal transduction

BACKGROUND AND AIMS AT motif binding factor 1 (ATBF1), a homeotic transcription factor, was identified as a tumor suppressor, and loss of heterozygosity at ATBF1 locus occurs frequently in gastric cancers. We previously showed that ATBF1 expression inversely correlated with the malignant character of gastric cancer and that ATBF1 enhanced the promoter activity of p21Waf1/Cip1. We also found that ATBF1 moves between cytoplasm and nucleus, but the precise mechanism of translocation is unknown. In this study, we investigated the mechanism of ATBF1 translocation to the nucleus with the runt domain transcription factor 3 (RUNX3) in cooperation with TGF-beta signal transduction. MATERIALS AND METHODS To analyze the expression of ATBF1 and RUNX3 in gastric cancer cells, we performed immunohistochemistry on 98 resected gastric cancer tissue samples and scored the nuclear staining intensity as grade 0 to grade 5. Co-immunoprecipitation (co-IP) of ATBF1 and RUNX3 was performed. Dual luciferase assays were performed by transfecting ATBF1 and RUNX3 with a p21Waf1/Cip1 reporter vector. To investigate the nuclear translocation of endogenous ATBF1 and RUNX3 in response to TGF-beta signal, we examined the subcellular localization of ATBF1 and RUNX3 in gastric cancer cells treated with recombinant TGF-beta1 using confocal laser scanning microscopy. RESULTS Strong immunohistochemical nuclear staining of ATBF1 was observed in 37 (37.8%) of the gastric cancer tissue samples, and RUNX3 nuclear staining was observed in 15 (15.3%). There was a statistically significant correlation between ATBF1 and RUNX3 nuclear localization (rs=0.433, p<0.001). Co-IP revealed a physical association between ATBF1 and RUNX3. ATBF1 and RUNX3 up-regulated p21Waf1/Cip1 promoter activity synergistically. In SNU16 gastric cancer cells, ATBF1 and RUNX3 were cytoplasmic before TGF-beta1 stimulation, but after 24h of TGF-beta1 stimulation, endogenous ATBF1 and RUNX3 translocated to the nucleus. CONCLUSION ATBF1 associates with RUNX3 and translocates to the nucleus in response to TGF-beta signal transduction and might function in the nucleus as tumor suppressor and transcriptional regulator.

Suppression of proHB-EGF Carboxy-Terminal Fragment Nuclear Translocation: A New Molecular Target Therapy for Gastric Cancer

Purpose: Inactivation of epidermal growth factor (EGF) receptor (EGFR) represents a promising strategy for the development of selective therapies against epithelial cancers and has been extensively studied as a molecular target for cancer therapy. However, little attention has been paid to remnant cell-associated domains created by cleavage of EGFR ligands. The present study focused on recent findings that cleavage of membrane-anchored heparin-binding EGF-like growth factor (proHB-EGF), an EGFR ligand, induces translocation of the carboxyl-terminal fragment (CTF) of HB-EGF from the plasma membrane to the nucleus and regulates cell cycle. Experimental Design: Two gastric cancer cell lines, MKN28 and NUGC4, were used. KB-R7785, an inhibitor of proHB-EGF shedding, was used to suppress HB-EGF-CTF nuclear translocation with cetuximab, which inhibits EGFR phosphorylation. Cell growth was analyzed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assay, apoptosis was evaluated by assay of caspase-3 and caspase-7, and cell cycle was investigated by flow cytometry. Results: Immunofluorescence study confirmed that KB-R7785 inhibited HB-EGF-CTF nuclear translocation under conditions of proHB-EGF shedding induction by 12-O-tetradecanoylphorbol-13-acetate in gastric cancer cells. KB-R7785 inhibited cell growth in a dose-dependent manner and high-dose KB-R7785 induced apoptosis. Moreover, KB-R7785 induced cell cycle arrest and increased sub-G1 DNA content. KB-R7785 suppressed cyclin A and c-Myc expression. All effects of KB-R7785 were reinforced by combination with cetuximab. Conclusions: These results suggest that both inhibition of EGFR phosphorylation and inhibition of HB-EGF-CTF nuclear translocation play crucial roles in inhibitory regulation of cancer cell growth. Suppression of HB-EGF-CTF nuclear translocation might offer a new strategy for treating gastric cancer.

BCL6 degradation caused by the interaction with the C-terminus of pro-HB-EGF induces cyclin D2 expression in gastric cancers

BCL6 is a transcriptional repressor that has important functions in lymphocyte differentiation and lymphomagenesis, but there have been no reports of BCL6 expression in gastric cancers. In the present study, we investigated the BCL6 function in gastric cancers. Treatment with TPA resulted in BCL6 degradation and cyclin D2 upregulation. This phenomenon was inhibited by the suppression of the nuclear translocation of HB-EGF-CTF (C-terminal fragment of pro-HB-EGF). The HB-EGF-CTF nuclear translocation leads to the interaction of BCL6 with HB-EGF-CTF and the nuclear export of BCL6, and after that BCL6 degradation was mediated by ubiquitin/proteasome pathway. Real-time RT–PCR and siRNA targeting BCL6 revealed that BCL6 suppresses cyclin D2 expression. Our data indicate that BCL6 interacts with nuclear-translocated HB-EGF-CTF and that the nuclear export and degradation of BCL6 induces cyclin D2 upregulation. We performed immunohistochemical analyses of BCL6, HB-EGF and cyclin D2 in human gastric cancers. The inverse correlation between BCL6 and cyclin D2 was also found in HB-EGF-positive human gastric cancers. BCL6 degradation caused by the HB-EGF-CTF also might induce cyclin D2 expression in human gastric cancers. Inhibition of HB-EGF-CTF nuclear translocation and maintenance of BCL6 function are important for the regulation of gastric cancer progression.

Incidence of gastrointestinal bleeding in patients with cardiovascular disease: buffered aspirin versus enteric-coated aspirin

Abstract Objective. Aspirin-induced enteropathy is increasing, but whether the type of aspirin affects the gastrointestinal (GI) bleeding, especially small intestine, is unclear. The incidence of GI bleeding for buffered aspirin and enteric-coated aspirin was evaluated in patients receiving long-term low-dose aspirin (LDA) for cardiovascular (CV) diseases. Methods. This retrospective cohort study assessed overt GI bleeding, decreased hemoglobin levels suspecting small bowel blood loss, and CV death in patients taking LDA for more than 1 year (LDA group) and in patients not taking LDA (control group). The LDA group was divided into two subgroups, patients taking either buffered aspirin (buffered subgroup) or enteric-coated aspirin (enteric subgroup), and their outcomes were compared. Results. A total of 1402 patients (LDA group 701, control group 701; median follow-up duration 1778 ± 747 days) were assessed. The incidences of overt GI bleeding and decreased hemoglobin were 3.9% and 1.4% in LDA group, respectively, significantly higher than the control group (p < 0.01; p < 0.01). In the LDA group, 3% died during the follow-up period. Ten (3.7%) in the buffered subgroup (n = 267) and 17 (3.9%) in the enteric subgroup (n = 434) developed GI bleeding (p = 0.92). One (0.3%) in the buffered subgroup and nine (2%) in the enteric subgroup developed decreased hemoglobin (p = 0.06, log-rank test). Conclusions. The type of aspirin does not affect the incidence of overt GI bleeding and decreased hemoglobin, but enteric-coated aspirin may be associated with an increased incidence of decreased hemoglobin.

Blockage of angiotensin II type 1 receptor regulates TNF-α-induced MAdCAM-1 expression via inhibition of NF-κB translocation to the nucleus and ameliorates colitis

Mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1) is an important target in the treatment of inflammatory bowel disease (IBD). Recently, treatment of IBD with an antibody to alpha4beta7-integrin, a ligand for MAdCAM-1, has been an intense focus of research. Our aim was to clarify the mechanism by which MAdCAM-1 is regulated via angiotensin II type 1 receptor (AT1R), and to verify if AT1R might be a novel target for IBD treatment. The role of AT1R in the expression of MAdCAM-1 in SVEC (a murine high endothelial venule cell) and MJC-1 (a mouse colonic endothelial cell) was examined following cytokine stimulation. We further evaluated the effect of AT1R on the pathogenesis of immune-mediated colitis using AT1R-deficient (AT1R-/-) mice and a selective AT1R blocker. AT1R blocker significantly suppressed MAdCAM-1 expression induced by TNF-alpha, but did not inhibit phosphorylation of p38 MAPK or of IkappaB that modulate MAdCAM-1 expression. However, NF-kappaB translocation into the nucleus was inhibited by these treatments. In a murine colitis model induced by dextran sulfate sodium, the degree of colitis, judged by body weight loss, histological damage, and the disease activity index, was much milder in AT1R-/- than in wild-type mice. The expression of MAdCAM-1 was also significantly lower in AT1R-/- than in wild-type mice. These results suggest that AT1R regulates the expression of MAdCAM-1 under colonic inflammatory conditions through regulation of the translocation of NF-kappaB into the nucleus. Furthermore, inhibition of AT1R ameliorates colitis in a mouse colitis model. Therefore, AT1R might be one of new therapeutic target of IBD via regulation of MAdCAM-1.