田原 智満

Telomere shortening occurs with human aging in many organs and tissues and is accelerated by rapid cell turnover and oxidative injury. To clarify the clinical importance of telomere shortening in colonic mucosa in ulcerative colitis (UC), we measured average telomere length using quantitative real-time PCR in non-neoplastic colonic mucosa in UC patients and assessed its relationship to various clinical subtypes. Relative telomere length in genomic DNA was measured in colonic biopsies obtained from rectal inflammatory mucosa from 86 UC patients as well as paired non-inflammatory proximal colonic mucosae from 10 patients. Data were correlated with various clinical phenotypes. In paired samples, average relative telomere length of rectal inflammatory mucosa was shortened compared to normal appearing proximal colon in eight out of ten cases (p = 0.01). Telomere length shortening was significantly associated with more severe Mayo endoscopic subscore (p < 0.0001) and cases needing surgery due to toxic megacolon or cancer occurrence (p = 0.043). When the severe clinical phenotype was defined as having at least one of following phenotypes, more than two times of hospitalization, highest Mayo endoscopic subscore, steroid dependent, refractory, or needing operation, average relative telomere length was significantly shortened in the same phenotypes than the others (p = 0.003). Telomere shortening is associated with more severe clinical phenotypes of UC, reflecting severe inflammatory state in the colonic mucosa.

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.

Fusobacterium species are part of the gut microbiome in humans. Recent studies have identified overrepresentation of Fusobacterium in colorectal cancer tissues, but it is not yet clear whether this is pathogenic or simply an epiphenomenon. In this study, we evaluated the relationship between Fusobacterium status and molecular features in colorectal cancers through quantitative real-time PCR in 149 colorectal cancer tissues, 89 adjacent normal appearing mucosae and 72 colonic mucosae from cancer-free individuals. Results were correlated with CpG island methylator phenotype (CIMP) status, microsatellite instability (MSI), and mutations in BRAF, KRAS, TP53, CHD7, and CHD8. Whole-exome capture sequencing data were also available in 11 cases. Fusobacterium was detectable in 111 of 149 (74%) colorectal cancer tissues and heavily enriched in 9% (14/149) of the cases. As expected, Fusobacterium was also detected in normal appearing mucosae from both cancer and cancer-free individuals, but the amount of bacteria was much lower compared with colorectal cancer tissues (a mean of 250fold lower for Pan-fusobacterium). We found the Fusobacterium-high colorectal cancer group (FB-high) to be associated with CIMP positivity (P = 0.001), TP53 wild-type (P = 0.015), hMLH1 methylation positivity (P = 0.0028), MSI (P = 0.018), and CHD7/8 mutation positivity (P = 0.002). Among the 11 cases where whole-exome sequencing data were available, two that were FB-high cases also had the highest number of somatic mutations (a mean of 736 per case in FB-high vs. 225 per case in all others). Taken together, our findings show that Fusobacterium enrichment is associated with specific molecular subsets of colorectal cancers, offering support for a pathogenic role in colorectal cancer for this gut microbiome component. (C) 2014 AACR.

Background/Aims: Combining the magnifying endoscopy and the narrow-band imaging (NBI) system is an endoscopic imaging technique for the enhanced visualization of mucosal microscopic structure and capillaries of the superficial mucosal layer. Light blue crest (LBC) and, ridge/villous pattern have been thought to be suggestive signs for gastric intestinal metaplasia (IM) of magnifying NBI endoscopy. Since the IM is related to gastric cancer risk (GC), the prevalence of LBC and ridge/villous pattern in the nonneoplastic gastric antrum was examined in relation to gastric cancer (GC) risk and serological severity of gastritis. Methodology: In 100 subjects including 13 GC patients, gastric mucosal pattern were examined using magnifying NBI. The mucosal patterns in the antrum were classified according to the presence of LBC or ridge/villous pattern. Serum pepsinogen (PG) levels were also examined. Results: The sensitivity and specificity for predicting IM was the best when LBC and ridge/villous patterns were combined (sensitivity 95.2%, specificity 98.7%). Both LBC and ridge/villous pattern showed lower serum PGI and PGI/II ratio than those without (P = 0.046, 0.0005, respectively.) In particular, PGI/II ratio was lowest in ridge/villous pattern. The LBC and ridge/villous pattern showed higher incidence of all GC and diffuse GC compared to those without (P = 0.002, 0.002, respectively). Conclusions: LBC and ridge/villous pattern in uninvolved gastric antrum by magnifying NBI endoscopy are useful signs for predicting gastric atrophy in the entire Stomach and GC risk.

BACKGROUND & AIMS: Subgroups of colorectal carcinomas (CRCs) characterized by DNA methylation anomalies are termed CpG island methylator phenotype (CIMP)1, CIMP2, or CIMP-negative. The pathogenesis of CIMP1 colorectal carcinomas, and their effects on patients' prognoses and responses to treatment, differ from those of other CRCs. We sought to identify genetic somatic alterations associated with CIMP1 CRCs. METHODS: We examined genomic DNA samples from 100 primary CRCs, 10 adenomas, and adjacent normal-appearing mucosae from patients undergoing surgery or colonoscopy at 3 tertiary medical centers. We performed exome sequencing of 16 colorectal tumors and their adjacent normal tissues. Extensive comparison with known somatic alterations in CRCs allowed segregation of CIMP1-exclusive alterations. The prevalence of mutations in selected genes was determined from an independent cohort. RESULTS: We found that genes that regulate chromatin were mutated in CIMP1 CRCs; the highest rates of mutation were observed in CHD7 and CHD8, which encode members of the chromodomain helicase/adenosine triphosphate-dependent chromatin remodeling family. Somatic mutations in these 2 genes were detected in 5 of 9 CIMP1 CRCs. A prevalence screen showed that nonsilencing mutations in CHD7 and CHD8 occurred significantly more frequently in CIMP1 tumors (18 of 42 [43%]) than in CIMP2 (3 of 34 [9%]; P<.01) or CIMP-negative tumors (2 of 34 [6%]; P<.001). CIMP1 markers had increased binding by CHD7, compared with all genes. Genes altered in patients with CHARGE syndrome (congenital malformations involving the central nervous system, eye, ear, nose, and mediastinal organs) who had CHD7 mutations were also altered in CRCs with mutations in CHD7. CONCLUSIONS: Aberrations in chromatin remodeling could contribute to the development of CIMP1 CRCs. A better understanding of the biological determinants of CRCs can be achieved when these tumors are categorized according to their epigenetic status.