Shinsaku Fukuda

Mesenchymal stromal cells promote tumor growth through the enhancement of neovascularization.

Mesenchymal stromal cells (MSCs), also called mesenchymal stem cells, migrate and function as stromal cells in tumor tissues. The effects of MSCs on tumor growth are controversial. In this study, we showed that MSCs increase proliferation of tumor cells in vitro and promote tumor growth in vivo. We also further analyzed the mechanisms that underlie these effects. For use in in vitro and in vivo experiments, we established a bone marrow-derived mesenchymal stromal cell line from cells isolated in C57BL/6 mice. Effects of murine MSCs on tumor cell proliferation in vitro were analyzed in a coculture model with B16-LacZ cells. Both co-culture with MSCs and treatment with MSC-conditioned media led to enhanced growth of B16-LacZ cells, although the magnitude of growth stimulation in cocultured cells was greater than that of cells treated with conditioned media. Co-injection of B16-LacZ cells and MSCs into syngeneic mice led to increased tumor size compared with injection of B16-LacZ cells alone. Identical experiments using Lewis lung carcinoma (LLC) cells instead of B16-LacZ cells yielded similar results. Consistent with a role for neovascularization in MSC-mediated tumor growth, tumor vessel area was greater in tumors resulting from co-injection of B16-LacZ cells or LLCs with MSCs than in tumors induced by injection of cancer cells alone. Co-injected MSCs directly supported the tumor vasculature by localizing close to vascular walls and by expressing an endothelial marker. Furthermore, secretion of leukemia inhibitory factor, macrophage colony-stimulating factor, macrophage inflammatory protein-2 and vascular endothelial growth factor was increased in cocultures of MSCs and B16-LacZ cells compared with B16-LacZ cells alone. Together, these results indicate that MSCs promote tumor growth both in vitro and in vivo and suggest that tumor promotion in vivo may be attributable in part to enhanced angiogenesis.

High Prevalence of the CagA-positive Helicobacter pylori Strains in Japanese Asymptomatic Patients and Gastric Cancer Patients

BACKGROUND Several studies have shown that infection of Helicobacter pylori strains possessing cagA is associated with atrophic gastritis and gastric cancers. METHOD In 58 pairs of early gastric cancer patients and sex- and age-matched controls, isolated H. pylori strains were tested for possession of cagA. The presence of atrophic gastritis was also examined. RESULTS Proportions of cagA-positive strains were 100% in cancer patients and 92.3% in controls. Atrophic gastritis was seen in 96.7% and 95.8% of cancer and control patients in whom cagA-positive strains (NS) were detected. However, it was seen in only 20% of H. pylori-negative control patients (P < 0.01). CONCLUSIONS The present results do not suggest any specific association between cagA-positive strains and gastric cancer. However, frequent prevalence of cagA-positive strains might be associated with the high incidence of atrophic gastritis in Japanese populations.

Methylation of the KEAP1 gene promoter region in human colorectal cancer

BackgroundThe Keap1-Nrf2 pathway has been reported to be impaired in several cancers. However, the status of Keap1-Nrf2 system in human colorectal cancer (CRC) has not been elucidated.MethodsWe used colorectal cancer (CRC) cell lines and surgical specimens to investigate the methylation status of the KEAP1 promoter region as well as expression of Nrf2 and its downstream antioxidative stress genes, NQO-1 and AKR1C1.ResultsDNA sequencing analysis indicated that all mutations detected were synonymous, with no amino acid substitutions. We showed by bisulfite genomic sequencing and methylation-specific PCR that eight of 10 CRC cell lines had hypermethylated CpG islands in the KEAP1 promoter region. HT29 cells with a hypermethylated KEAP1 promoter resulted in decreased mRNA and protein expression but unmethylated Colo320DM cells showed higher expression levels. In addition, treatment with the DNA methyltransferase inhibitor 5-Aza-dC combined with the histone deacetylase inhibitor trichostatin A (TSA) increased KEAP1 mRNA expression. These result suggested that methylation of the KEAP1 promoter regulates its mRNA level. Time course analysis with the Nrf2-antioxidant response element (ARE) pathway activator t-BHQ treatment showed a rapid response within 24 h. HT29 cells had higher basal expression levels of NQO-1 and AKR1C1 mRNA than Colo320DM cells. Aberrant promoter methylation of KEAP1 was detected in 53% of tumor tissues and 25% of normal mucosae from 40 surgical CRC specimens, indicating that cancerous tissue showed increased methylation of the KEAP1 promoter region, conferring a protective effect against cytotoxic anticancer drugs.ConclusionHypermethylation of the KEAP1 promoter region suppressed its mRNA expression and increased nuclear Nrf2 and downstream ARE gene expression in CRC cells and tissues.

Seasonal changes in mortality rates from main causes of death in Japan

Background: It is well recognized that the season of the year exerts an influence on some diseases and causes of death such as coronary heart diseases, stroke, infectious diseases and so on. Methods: We evaluated the influence of seasonal changes on diseases and causes of death in Japan using the Japan Vital Statistics from 1970 to 1999 and recorded weather data (mean temperature), by a Fourier decomposition in a log linear regression model.Results: Major influences of seasonal change with the highest rates in winter were seen on the following: the overall causes of death; infectious and parasitic diseases including tuberculosis; respiratory disease, including pneumonia and influenza; heart and cerebrovascular diseases; diabetes; and digestive diseases and accidents. Two peaks were seen in suicides, a large peak in April and a small peak in autumn. Cancer and homicides were little or not at all influenced by seasonality. There was no major difference in changes between the years studied, except for respiratory disease and tuberculosis, which showed a clear reduction in the seasonality effect from 1970 to 1999. Conclusions: To reduce the overall mortality rate and to prolong life expectancy in Japan, measures must be taken to reduce those mortality rates associated with seasonal differences, especially those causes of death which show a strong correlation with seasonal change: respiratory, heart, cerebrovascular, diabetes and infectious diseases.

Dietary fat attenuates the benefits of an elemental diet in active Crohn's disease: a randomized, controlled trial.

Objectives Although an elemental diet has been established as the primary treatment for patients with Crohns disease, the influence of dietary fat on the elemental diet remains unclear. We have designed the first randomized, controlled trial for elemental diets containing different fat percentages in patients with active Crohns disease. Methods Each patient was randomized to receive one of three dose levels of fat in an elemental diet (Elental) for 4 weeks: 10 patients received low fat (3.06 g/day), 10 patients received medium fat (16.56 g/day) and eight patients received high fat (30.06 g/day). The additional fat was composed of long-chain fatty acids. All patients were evaluated using the International Organization of Inflammatory Bowel Disease rating, plus C-reactive protein level and erythrocyte sedimentation rate, which were measured at weekly intervals. Results Although the International Organization of Inflammatory Bowel Disease rating, C-reactive protein level and erythrocyte sedimentation rate in the low-fat group decreased, the values in the medium- and high-fat groups fluctuated during the study. The remission rate after 4 weeks in each group was 80%, 40% and 25% for patients in the low-, medium- and high-fat groups, respectively. Conclusions When the fat consisted of long-chain triglycerides, a high amount of this fat in the elemental diet formula decreased its therapeutic effect against active Crohns disease.

CagA seropositivity associated with development of gastric cancer in a Japanese population.

BACKGROUND/AIMS: Infection with Helicobacter pylori strains possessing the cagA gene is associated with increased risk of gastric cancer of the intestinal type. The aims of this study were to investigate whether CagA seropositivity is associated with increasing risk of gastric cancer in a Japanese population that has a much higher incidence of gastric cancer than western populations. METHODS: Eighty one gastric cancer patients and 81 sex and age matched endoscopically evaluated controls were studied. Histologically, 62 cancers were of the intestinal type and 76 were early gastric cancer. Serum CagA IgG antibodies were assayed by enzyme linked immunosorbent assay (ELISA) using purified recombinant CagA protein as antigen. Polymerase chain reaction (PCR) analysis for cagA in H pylori isolates (n = 80) showed that the CagA ELISA had a sensitivity of 83.3% (controls) and 72.5% (cancers). RESULTS: CagA seropositivity was 60% (49 of 81) in cancer patients and 44% (36 of 81) in controls. The odds ratio for the risk of cancer if CagA seropositive was 1.93 (95% confidence interval (CI) 1.01 to 3.68; p < 0.05). In the 57 H pylori positive cancer patients and their matched H pylori positive controls, the odds ratio for the risk of cancer if CagA seropositive was 2.2 (95% CI 1.04 to 4.65; p < 0.05). CONCLUSIONS: These results suggest that CagA seropositivity is associated with increased risk of gastric cancer in Japanese populations.

Effect of Helicobacter pylori eradication in the treatment of Japanese patients with chronic idiopathic urticaria

BackgroundInfection with Helicobacter pylori has been associated with chronic idiopathic urticaria (CIU). The aim of this study was to investigate the efficacy of H. pylori eradication in the treatment of patients with CIU.MethodsFifty patients with CIU (16 men and 34 women; age 25–75 years) and 100 sex- and age-matched control subjects were enrolled in the study. Presence of IgG antibody to H. pylori was examined by serology. H. pylori-seropositive patients with CIU received endoscopy to confirm H. pylori infection. Patients infected with H. pylori received eradication therapy comprising lansoprazole, amoxicillin, and either clarithromycin or metronidazole. At least 2 months after finishing the eradication therapy, a 13C-urea breath test was performed, and the effect of eradication therapy on the CIU was scored, using a three-point scale, as complete remission, partial remission, or no improvement.ResultsIn the 50 patients with CIU, 26 (52%) were H. pylori-seropositive, while 48% (48/100) of the control subjects were seropositive (statistically not significant). Nineteen out of the 26 patients with CIU infected with H. pylori received eradication therapy, and eradication was successful in 17 patients. In the 17 H. pylori-eradicated patients, 6 (35%) had complete remission and 11 (65%) had complete remission or partial remission. On the other hand, in the 9 patients without H. pylori eradication, only 2 (22%) showed partial remission and 7 (78%) had no improvement.ConclusionsEradication of H. pylori would be a valid choice for patients with CIU, although the prevalence of H. pylori infection is not higher in patients with CIU than it is in controls.

Spatial distribution and histogenesis of colorectal Paneth cell metaplasia in idiopathic inflammatory bowel disease

Background and Aim: Colorectal Paneth cell metaplasia (PCM) is known to be a sign of idiopathic inflammatory bowel disease (IBD), although its distribution and histogenesis are not fully understood. Objectives of this research were to investigate the spatial distribution of PCM in IBD and other forms of colitis (non‐IBD), and to find stimuli causing PCM.

Endoscopic ligation by means of clip and detachable snare for management of colonic postpolypectomy hemorrhage

Postpolypectomy hemorrhage, the most common complication of polypectomy, can be classified as immediate or delayed bleeding. Immediate bleeding can be controlled with various endoscopic methods (regrasping the stalk, epinephrine injection, coagulation with hot biopsy forceps or heater probe, rubber band ligation).1 Delayed bleeding seems to be more common.2,3 Most delayed hemorrhaging stops spontaneously and can be managed with conservative therapy. However, delayed arterial bleeding may necessitate transfusion, angiography, or surgical intervention. Injection of the stalk with epinephrine or sclerosants before transection is recommended to diminish risk for postpolypectomy hemorrhage. Epinephrine injection, however, may prevent only immediate bleeding, and use of sclerosants may increase risk for perforation.4 A detachable snare5-7 has been developed for the prevention of postpolypectomy hemorrhage. We performed endoscopic placement of a detachable snare to ligate a site of postpolypectomy arterial bleeding in the sigmoid colon.

Cyclooxygenase-2 expression is increased in early intestinal-type gastric cancer and gastric mucosa with intestinal metaplasia

Objective Cyclooxygenase-2 (COX-2) expression is increased in gastric cancer. We examined COX-2 expression in early stage gastric cancer and background mucosa to elucidate the role of COX-2 in gastric carcinogenesis. Methods Thirty-three early gastric cancers obtained from 30 patients infected with Helicobacter pylori were studied. Twenty-three patients had an intestinal, four patients had a diffuse, and three patients had both an intestinal and a diffuse type cancer. Expression of COX-2 protein was detected by immunohistochemistry by counting the number of positive staining cells per 100 cells. Results Mean COX-2 expression was 84.1 (SD 11.4) in 26 intestinal type cancers and was significantly higher than that in seven diffuse type cancers (23.1 ± 9.7) (P < 0.001). In three patients who had both the intestinal and the diffuse type cancer, COX-2 expression was 92, 90 and 83 in the intestinal type cancer and only 25, 24 and 7 in the corresponding diffuse type cancer. In 18 patients who had intestinal metaplasia (15 had incomplete metaplasia), COX-2 expression was 60.2 (24.2) in the crypts with metaplasia while it was only 16.8 (10.7) in the crypts without metaplasia (P < 0.001). Conclusions COX-2 expression may be associated with the carcinogenesis of the intestinal type gastric cancer and, speculatively, inhibition of COX-2 might have preventative effects on the intestinal type gastric cancer.