Takamitsu Ishizuka

Association Between Common Genetic Variants in Pre‐microRNAs and Gastric Cancer Risk in Japanese Population

Background:  Common single‐nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human cancers. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre‐miRNAs (miR‐196a2, miR‐146a, and miR‐499) with the risk of gastric cancer (GC) and peptic ulcer diseases, and with the severity of Helicobacter pylori‐induced gastritis in Japanese population.

Association Study of Common Genetic Variants in Pre-microRNAs in Patients with Ulcerative Colitis

BackgroundCommon single-nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human diseases. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre-miRNAs (miR-196a2, miR-146a, and miR-499) with the risk of ulcerative colitis (UC) in a Japanese population.MethodsThe rs11614913 (T > C), rs2910164 (C > G), and rs3746444 (A > G) SNPs were genotyped in 170 UC and 403 control subjects.ResultsThe rs3746444 AG genotype was significantly higher among the UC group (odds ratio (OR) = 1.51, 95% CI = 1.03–2.21, p = 0.037). The rs3746444 AG genotype was associated with onset at an older age (OR = 1.70, 95% CI = 1.04–2.78, p = 0.035), left-sided colitis and pancolitis (left-sided colitis, OR = 2.10, 95% CI = 1.12–3.94, p = 0.024; pancolitis, OR = 1.81, 95% CI = 1.09–3.01, p = 0.028, left-sided colitis + pancolitis, OR = 1.91, 95% CI = 1.26–2.92, p = 0.003), higher number of times hospitalized (OR = 2.63, 95% CI = 1.22–5.69, p = 0.017), steroid dependence (OR = 2.63, 95% CI = 1.27–5.44, p = 0.014), and refractory phenotypes (OR = 2.76, 95% CI = 1.46–5.21, p = 0.002) while the rs3746444 AA genotype was inversely associated with the number of times hospitalized (2∼, OR = 0.36, 95% CI = 0.17–0.79, p = 0.012), steroid dependence (OR = 0.42, 95% CI = 0.21–0.88, p = 0.021), and refractory phenotypes (OR = 0.38, 95% CI = 0.20–0.72, p = 0.003). The rs1161913 TT genotype also held a significantly higher risk of refractory phenotype (T/T vs. T/C + C/C, OR = 2.21, 95% CI = 1.17–4.18, p = 0.016).ConclusionsOur results provided the first evidence that rs3746444 SNP may influence the susceptibility to UC, and both rs3746444 and rs11614913 SNPs may influence the pathophysiological features of UC.

Correlation between magnifying narrow band imaging and histopathology in gastric protruding/or polypoid lesions: a pilot feasibility trial

BackgroundSeveral study showed usefulness of microscopic capillaries, seen by magnifying narrow band imaging (NBI) endoscopy for predicting histopathology among superficial depressed or flat elevated gastric neoplasia (GN). Here we assessed the diagnostic efficacy of magnifying NBI for predicting histopathology among gastric protruding/or polypoid lesions.MethodsUsing endoscopic pictures of magnifying NBI from 95 protruding/or polypoid lesions (19 fundic gland polyps: FGP, 47 hyperplastic polyps: HP, and 29 GN), fine mucosal patterns were classified into four categories: small round, prolonged, villous or ridge, and unclear patterns, and micro vascular patterns were classified into five categories: honey comb, dense vascular, fine net work, core vascular, and unclear patterns.ResultsMost suggestive micro vascular patterns for predicting FGP, and HP were honeycomb (sensitivity 94.7%, specificity 97.4%), and dense vascular patterns (sensitivity 93.6%, specificity 91.6%), respectively. Fine net work, core vascular, and unclear patterns presented higher specificity (97%, 100%, and 100%) for predicting GN, and diagnostic efficacy of combined of those patterns was favorable (sensitivity 86.2%, specificity 97.0%).ConclusionMicro vascular patterns by using magnifying NBI provides meaningful information for predicting the histopathology of gastric protruding/or polypoid lesions.

Usefulness of Magnifying Narrow-Band Imaging Endoscopy in the Helicobacter pylori-Related Chronic Gastritis

Combining the narrow-band imaging (NBI) system and magnifying endoscopy allows simple and clear visualization of microscopic structures of the superficial mucosa and its capillary patterns, which may be useful for precise endoscopic diagnosis in the gastrointestinal tract, being more closely to histopathological diagnosis. In the non-neoplastic gastric mucosa, there have been reports showing a potential usefulness of magnifying NBI for the diagnosis of Helicobacter pylori infection, degree of histological gastritis, and intestinal metaplasia. We have shown that magnifying NBI appearances in the non-neoplastic gastric mucosa also predicts pepsinogen levels, which indicates extension of gastric atrophy in the entire stomach, and gastric cancer occurrence. Furthermore, we have shown that magnifying NBI appearances predicts the result of H. pylori treatment. Clear visualization of fine mucosal and capillary patterns, obtained by magnifying NBI, allows prediction of the histological condition, more in detail without biopsy, and it may also be useful for less invasive, and cost-effective endoscopic gastric cancer surveillance, and prediction of H. pylori eradication.

DNA Methylation Status of Epithelial-Mesenchymal Transition (EMT) - Related Genes Is Associated with Severe Clinical Phenotypes in Ulcerative Colitis (UC)

Background Epithelial-to-mesenchymal transition (EMT) is a phenomenon that allows the conversion of adherent epithelial cells to a mesenchymal cell phenotype, which enhances migratory capacity and invasiveness. Recent studies have suggested that EMT contributes to the pathogenesis of ulcerative colitis (UC). We investigated the promoter DNA methylation status of EMT-related genes in the colonic mucosa in UC. Methods Colonic biopsies were obtained from the rectal inflammatory mucosa of 86 UC patients and the non-inflammatory proximal colonic mucosa of 10 paired patients. Bisulfite pyrosequencing was used to quantify the methylation of 5 candidate CpG island promoters (NEUROG1, CDX1, miR-1247, CDH1, and CDH13) and LINE1. Results Using an unsupervised hierarchical clustering analysis, inflamed rectal mucosa was well separated from mucosa that appeared normal. The CDH1 and CDH13 promoters were significantly associated with patient age (p = 0.04, 0.03, respectively). A similar trend was found between those genes and the duration of disease (CDH1: p = 0.07, CDH13: p = 0.0002, mean of both: p<0.00001). Several positive associations were found between hypermethylation and severe clinical phenotypes (CDX1 and miR-1247 and a refractory phenotype: p = 0.04 and 0.006, respectively. miR-1247 and CDH1 hyper methylation and a more severe Mayo endoscopic subscore: miR-1247: p = 0.0008, CDH1: p = 0.03, mean of both: p = 0.003). When the severe clinical phenotype was defined as having any of five phenotypes (hospitalized more than twice, highest Mayo endoscopic subscore, steroid dependence, refractory, or a history of surgery) miR-1247 hypermethylation was associated with the same phenotype (p = 0.008). Conclusions Our data suggest that variability in the methylation status of EMT-related genes is associated with more severe clinical phenotypes in UC.

Mutation spectrum of TP53 gene predicts clinicopathological features and survival of gastric cancer

Background and aim TP53 gene is frequently mutated in gastric cancer (GC), but the relationship with clinicopathological features and prognosis is conflicting. Here, we screened TP53 mutation spectrum of 214 GC patients in relation to their clinicopathological features and prognosis. Results TP53 nonsilent mutations were detected in 80 cases (37.4%), being frequently occurred as C:G to T:A single nucleotide transitions at 5′-CpG-3′ sites. TP53 mutations occurred more frequently in differentiated histologic type than in undifferentiated type in the early stage (48.6% vs. 7%, P=0.0006), while the mutations correlated with venous invasion among advanced stage (47.7% vs. 20.7%, P=0.04). Subset of GC with TP53 hot spot mutations (R175, G245, R248, R273, R282) presented significantly worse overall survival and recurrence free survival compared to others (both P=0.001). Methods Matched biopsies from GC and adjacent tissues from 214 patients were used for the experiment. All coding regions of TP53 gene (exon2 to exon11) were examined using Sanger sequencing. Conclusion Our data suggest that GC with TP53 mutations seems to develop as differentiated histologic type and show aggressive biological behavior such as venous invasion. Moreover, our data emphasizes the importance of discriminating TP53 hot spot mutations (R175, G245, R248, R273, R282) to predict worse overall survival and recurrence free survival of GC patients.

A case of plummer-vinson syndrome showing rapid improvement of Dysphagia and esophageal web after two weeks of iron therapy.

Plummer-Vinson syndrome (PVS) is a rare entity characterized by upper esophageal webs and iron deficiency anemia. We report a case of PVS whose esophageal web was rapidly improved by iron therapy. A 77-year-old woman was admitted to our hospital with complaints of dysphagia, vomiting, shortness of breath and weight loss for 1 month. Physical examination revealed conjunctival pallor, koilonychia, angular cheilitis and smooth tongue, and laboratory findings were consistent with microcytic hypochromic anemia with iron deficiency. Gastrointestinal endoscopy and barium-swallow esophagography detected a web that prevented passage of the endoscope into the upper portion of the esophagus. The patient received oral iron therapy daily; the hemoglobin concentration rose to 8.9 g/dl and the complaints of dysphagia were dramatically improved after 2 weeks, with improvement of luminal stenosis confirmed by gastrointestinal endoscopy and barium-swallow esophagography. The PVS described in this report had a distinct clinical course, showing very rapid improvement of dysphagia and esophageal web after 2 weeks of oral iron therapy.

Potential link between Fusobacterium enrichment and DNA methylation accumulation in the inflammatory colonic mucosa in ulcerative colitis

BACKGROUND AND AIM Fusobacterium enrichment has been associated with colorectal cancer development. Ulcerative colitis (UC) associated tumorigenesis is characterized as high degree of methylation accumulation through continuous colonic inflammation. The aim of this study was to investigate a potential link between Fusobacterium enrichment and DNA methylation accumulation in the inflammatory colonic mucosa in UC. METHODS In the candidate analysis, inflamed colonic mucosa from 86 UC patients were characterized the methylation status of colorectal a panel of cancer related 24 genes. In the genome-wide analysis, an Infinium HumanMethylation450 BeadChip array was utilized to characterize the methylation status of >450,000 CpG sites for fourteen UC patients. Results were correlated with Fusobacterium status. RESULTS UC with Fusobacterium enrichment (FB-high) was characterized as high degree of type C (for cancer-specific) methylation compared to other (FB-low/neg) samples (P<0.01). Genes hypermethylated in FB-high samples included well-known type C genes in colorectal cancer, such as MINT2 and 31, P16 and NEUROG1. Multivariate analysis demonstrated that the FB high status held an increased likelihood for methylation high as an independent factor (odds ratio: 16.18, 95% confidence interval: 1.94-135.2, P=0.01). Genome-wide methylation analysis demonstrated a unique methylome signature of FB-high cases irrespective of promoter, outside promoter, CpG and non-CpG sites. Group of promoter CpG sites that were exclusively hypermethylated in FB-high cases significantly codified the genes related to the catalytic activity (P=0.039). CONCLUSION Our findings suggest that Fusobacterium accelerates DNA methylation in specific groups of genes in the inflammatory colonic mucosa in UC.BACKGROUND AND AIM Fusobacterium enrichment has been associated with colorectal cancer development. Ulcerative colitis (UC) associated tumorigenesis is characterized as high degree of methylation accumulation through continuous colonic inflammation. The aim of this study was to investigate a potential link between Fusobacterium enrichment and DNA methylation accumulation in the inflammatory colonic mucosa in UC. METHODS In the candidate analysis, inflamed colonic mucosa from 86 UC patients were characterized the methylation status of colorectal a panel of cancer related 24 genes. In the genome-wide analysis, an Infinium HumanMethylation450 BeadChip array was utilized to characterize the methylation status of >450,000 CpG sites for fourteen UC patients. Results were correlated with Fusobacterium status. RESULTS UC with Fusobacterium enrichment (FB-high) was characterized as high degree of type C (for cancer-specific) methylation compared to other (FB-low/neg) samples (P<0.01). Genes hypermethylated in FB-high samples included well-known type C genes in colorectal cancer, such as MINT2 and 31, P16 and NEUROG1. Multivariate analysis demonstrated that the FB high status held an increased likelihood for methylation high as an independent factor (odds ratio: 16.18, 95% confidence interval: 1.94-135.2, P=0.01). Genome-wide methylation analysis demonstrated a unique methylome signature of FB-high cases irrespective of promoter, outside promoter, CpG and non-CpG sites. Group of promoter CpG sites that were exclusively hypermethylated in FB-high cases significantly codified the genes related to the catalytic activity (P=0.039). CONCLUSION Our findings suggest that Fusobacterium accelerates DNA methylation in specific groups of genes in the inflammatory colonic mucosa in UC.

Demonstration of potential link between helicobacter pylori related promoter CpG island methylation and telomere shortening in human gastric mucosa

Background Telomere length shortening in Helicobacter pylori (H. pylori) infected gastric mucosa constitutes the earliest steps toward neoplastic transformation. In addition to this genotoxic changes, epigenetic changes such as promoter CpG island (PCGI) methylation are frequently occurred in H. pylori infected gastric mucosa. The aim of this study was to investigate a potential link between H. pylori related PCGI methylation and telomere length shortening in the human gastric mucosa. Methods Telomere length was measured in non-neoplastic gastric mucosa from 106 cancer-free subjects. To identify H. pylori related PCGI methylation, bisulfite pyrosequencing was used to quantify the methylation of 49 PCGIs from 47 genes and LINE1 repetitive element Results We identified five PCGIs (IGF2, SLC16A12, SOX11, P2RX7 and MYOD1), which the methylation is closely associated with H. pylori infection. Hypermethylation of all these PCGIs was associated with development of pathological state from normal to mild, active, and atrophic gastritis (P<0.001) and lower pepsinogen I/II ratio (P<0.05), an indicator for gastric mucosal atrophy. Telomere shortening was significantly associated with mean Z score methylation of five PCGIs (R=−0.39, P<0.0001) and four of these locus (IGF2: R=−0.35, P=0.0003, SLC16A12: R=−0.35, P=0.0002, P2RX7: R=−0.29, P=0.003, and MYOD1: R=−0.33, P=0.0005). Multivariate analysis revealed that telomere shortening held an increased risk for hypermethylation (odds ratio: 1.71, 95% confidence interval: 1.11-2.63, P=0.016). Conclusion Potential link between H. pylori related PCGI methylation and telomere shortening emphasize the importance of genotoxic-epigenetic interaction in the pathological state of H. pylori infected gastric mucosa.

Change in DNA methylation patterns of SLC6A4 gene in the gastric mucosa in functional dyspepsia.

Background The neurochemical serotonin (5-HT) is an important signaling molecule in the gastrointestinal motor and sensory functions. A key regulator of 5-HT levels is the transmembrane serotonin transporter (5-HTT; SLC6A4) that governs the reuptake of 5-HT. Recent studies have indicated 5-HTT expression may be regulated by epigenetic mechanisms. We investigated DNA methylation status of SLC6A4 gene in the gastric mucosa from functional dyspepsia (FD) because of their potential role in dyspeptic symptoms. Methods Endoscopic gastric biopsies were obtained from 78 subjects with no upper abdominal symptoms and 79 patients with FD. Bisulfite Pyrosequencing was carried out to determine the methylation status of promoter CpG islands (PCGIs), promoter non-CpG islands (PNCGIs) and gene body non-CpG islands (NPNCGIs) in the SLC6A4 gene. Gene expression was examined by real-time PCR. Results In overall, methylation level of PCGIs was significantly lower in FD compared to control subjects (p = 0.04). On the other hand, methylation level of NPNCGIs was significantly higher in FD compared to control subjects (p = 0.03). Lower methylation level in PNCGIs was highlighted in the patients with PDS (p = 0.01), while higher methylation level in NPNCGIs was more prominent in the patients with EPS (p = 0.017). Methylation levels of PCGIs and PNCGIs were inversely correlated, while methylation levels of NPNCGIs was positively correlated with SLC6A4 mRNA levels in FD patients. Conclusions Our data suggest that change in DNA methylation pattern of SLC6A4 in the gastric mucosa may have a role for developing FD. A role of epigenetics for developing FD needs to be further evaluated.