Hiroyuki Isshiki

Conditioned mesenchymal stem cells produce pleiotropic gut trophic factors.

BackgroundAlthough mounting evidence implicates mesenchymal stem cells (MSCs) in intestinal tissue repair, controversy remains regarding the engraftment, proliferation, and differentiation for repopulating MSCs in recipient tissues. Therefore, we investigated the paracrine and/or endocrine role of MSCs in experimental colitis.MethodsWe analyzed the therapeutic effects of MSC-conditioned medium (MSC-CM) on dextran sulfate sodium (DSS)- or 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis. We investigated the effects of MSC-CM on the epithelial cell viability, mobility, cell cycle, and cytokine production in ex vivo lamina propria/mesenteric lymphocytes, a macrophage cell line, and the mixed lymphocyte reaction. An optimal regimen against colitis was explored. The contents of MSC-CM were analyzed using a WNT signaling pathway polymerase chain reaction array, an inflammatory cytokines antibody array, and liquid chromatography-tandem mass spectrometry analysis.ResultsIndependent of the systemic administration route, MSC-CM concentrates were effective for the inductive phase of TNBS-induced colitis and for the recovery phase of DSS-induced colitis. Hypoxia appeared to be one of the optimal preconditioning factors assessed by cell motility and viability through activating the PI3K-Akt pathway in rat small intestine epithelial cells, IEC-6. Thus, Hypoxia had profound effects on the contents of MSC-CM, which comprised pleiotropic gut trophic factors involved in each wound healing process, including the anti-inflammatory, proliferative, and tissue remodeling phases.ConclusionsIdentification and optimization of potential gut trophic factors in MSC-CM is urgently needed to form the basis for new drug discovery and for optimizing cell-based therapies for inflammatory bowel disease.

Mesenchymal Stem Cells Cancel Azoxymethane‐Induced Tumor Initiation

The role of mesenchymal stem cells (MSCs) in tumorigenesis remains controversial. Therefore, our goal was to determine whether exogenous MSCs possess intrinsic antineoplastic or proneoplastic properties in azoxymethane (AOM)‐induced carcinogenesis. Three in vivo models were studied: an AOM/dextran sulfate sodium colitis‐associated carcinoma model, an aberrant crypt foci model, and a model to assess the acute apoptotic response of a genotoxic carcinogen (AARGC). We also performed in vitro coculture experiments. As a result, we found that MSCs partially canceled AOM‐induced tumor initiation but not tumor promotion. Moreover, MSCs inhibited the AARGC in colonic epithelial cells because of the removal of O6‐methylguanine (O6MeG) adducts through O6MeG‐DNA methyltransferase activation. Furthermore, MSCs broadly affected the cell‐cycle machinery, potentially leading to G1 arrest in vivo. Coculture of IEC‐6 rat intestinal cells with MSCs not only arrested the cell cycle at the G1 phase, but also induced apoptosis. The anti‐carcinogenetic properties of MSCs in vitro required transforming growth factor (TGF)‐β signaling because such properties were completely abrogated by absorption of TGF‐β under indirect coculture conditions. MSCs inhibited AOM‐induced tumor initiation by preventing the initiating cells from sustaining DNA insults and subsequently inducing G1 arrest in the initiated cells that escaped from the AARGC. Furthermore, tumor initiation perturbed by MSCs might potentially dysregulate WNT and TGF‐β‐Smad signaling pathways in subsequent tumorigenesis. Obtaining a better understanding of MSC functions in colon carcinogenesis is essential before commencing the broader clinical application of promising MSC‐based therapies for cancer‐prone patients with inflammatory bowel disease. Stem Cells 2014;32:913–925

Characteristics of Japanese inflammatory bowel disease susceptibility loci

BackgroundThere are substantial differences in inflammatory bowel disease (IBD) genetics depending on the populations examined. We aimed to identify Japanese population-specific or true culprit susceptibility genes through a meta-analysis of past genetic studies of Japanese IBD.MethodsFor this study, we reviewed 2,703 articles. The review process consisted of three screening stages: we initially searched for relevant studies and then relevant single nucleotide polymorphisms (SNPs). Finally, we adjusted them for the meta-analysis. To maximize our chances of analysis, we introduced proxy SNPs during the first stage. To minimize publication bias, no significant SNPs and solitary SNPs without pairs were combined to be reconsidered during the third stage. Additionally, two SNPs were newly genotyped. Finally, we conducted a meta-analysis of 37 published studies in 50 SNPs located at 22 loci corresponding to the total number of 4,853 Crohn’s disease (CD), 5,612 ulcerative colitis (UC) patients, and 14,239 healthy controls.ResultsWe confirmed that the NKX2–3 polymorphism is associated with common susceptibility to IBD and that HLA-DRB1*0450 alleles increase susceptibility to CD but reduce risk for UC while HLA-DRB1*1502 alleles increase susceptibility to UC but reduce CD risk. Moreover, we found individual disease risk loci: TNFSF15 and TNFα to CD and HLA-B*5201, and NFKBIL1 to UC. The genetic risk of HLA was substantially high (odds ratios ranged from 1.54 to 2.69) while that of common susceptibility loci to IBD was modest (odds ratio ranged from 1.13 to 1.24).ConclusionsResults indicate that Japanese IBD susceptibility loci identified by the meta-analysis are closely associated with the HLA regions.

Contextual niche signals towards colorectal tumor progression by mesenchymal stem cell in the mouse xenograft model

BackgroundThe role of mesenchymal stem/stromal cells (MSCs) in tumorigenesis remains controversial. This study aimed to determine whether heterotypic interactions between MSCs and colon cancer cells can supply contextual signals towards tumor progression.MethodsXenografts consisting of co-implanted human colorectal cancer cells with rat MSCs in immunodeficient mice were evaluated by tumor progression, angiogenic profiles, and MSC fate. Furthermore, we investigated how MSCs function as a cancer cell niche by co-culture experiments in vitro.ResultsTumor growth progressed in two ways, either independent of or dependent on MSCs. Such cell line-specific dependency could not be explained by host immune competency. COLO 320 xenograft angiogenesis was MSC-dependent, but less dependent on vascular endothelial growth factor (VEGF), whereas HT-29 angiogenesis was not MSC-dependent, but was VEGF-dependent. MSCs and COLO 320 cells established a functional positive feedback loop that triggered formation of a cancer cell niche, leading to AKT activation. Subsequently, MSCs differentiated into pericytes that enhanced angiogenesis as a perivascular niche. In contrast, the MSC niche conferred an anti-proliferative property to HT-29 cells, through mesenchymal–epithelial transition resulting in p38 activation.ConclusionsIn conclusion, MSCs demonstrate pleiotropic capabilities as a cancer cell or perivascular niche to modulate colorectal cancer cell fate in a cell line-dependent manner in a xenogeneic context.

Polypectomy to Eradicate Cap Polyposis With Protein-Losing Enteropathy

16894. Committee On Quality Of Health Care In A, Medicine I . Crossing the Quality Chasm: A New Health System for the 21st Century Ntioanal Aademies c Pess ; r 2001 . 1Division of Gastroenterology, University of Michigan , Ann Arbor 2Michigan , USA ; Division of Gastroenterology, Northwestern University , Chicago , Illinois , USA . Correspondence: Neehar D. Parikh, MD, MS, Division of Gastroenterology, University of Michigan, 3912 Taubman Center, 1500 E Medical Center Dr , Ann Arbor , Michigan 48104 , USA . E-mail: ndparikh@med.umich.edu

Low-Frequency IL23R Coding Variant Associated with Crohn’s Disease Susceptibility in Japanese Subjects Identified by Personal Genomics Analysis

Background The common disease-common variant hypothesis is insufficient to explain the complexities of Crohn’s disease (CD) genetics; therefore, rare variants are expected to be important in the disease. We explored rare variants associated with susceptibility to CD in Japanese individuals by personal genomic analysis. Methods Two-step analyses were performed. The first step was a trio analysis with whole-exome sequence (WES) analysis and the second was a follow-up case-control association study. The WES analysis pipeline comprised Burrows-Wheeler Aligner, Picard, Genome Analysis Toolkit, and SAMTOOLS. Single nucleotide variants (SNVs)/indels were annotated and filtered by using programs implemented in ANNOVAR in combination with identity-by-descent (IBD), subsequently were subjected to the linkage based, and de novo based strategies. Finally, we conducted an association study that included 176 unrelated subjects with CD and 358 healthy control subjects. Results In family members, 234,067–297,523 SNVs/indels were detected and they were educed to 106–146 by annotation based filtering. Fifty-four CD variants common to both individuals of the affected sib pair were identified. The linkage based strategy detected five candidate variants whereas the de novo based strategy identified no variants. Consequently, five candidates were analyzed in the case-control association study. CD showed a significant association with one variant in exon 4 of IL23R, G149R [rs76418789, P = 3.9E-5, odds ratio (OR) 0.21, 95% confidence interval (CI) 0.09–0.47 for the dominant model (AA + AG versus GG), and P = 7.3E-5, OR 0.21, 95% CI 0.10–0.48 for AG versus GG, and P = 7.2E-5, OR 0.23, 95% CI 0.10–0.50 for the allele model]. Conclusions The present study, using personal genomics analysis of a small CD pedigree, is the first to show that the low-frequency non-synonymous variant of IL23R, rs76418789, protects against CD development in Japanese subjects.

HER2-positive gastric cancer identified by serum HER2: A case report

Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are the current standards methods for the determination of tissue human epidermal growth factor receptor 2 (HER2) status in gastric cancer, as for breast cancer. However, HER2-positive gastric cancer occasionally exhibits heterogeneous tissue HER2 overexpression, raising concern regarding false-negative results in unresectable cases diagnosed by biopsy samples. Serum HER2, the concentration of the extracellular domain of HER2 protein shed into the bloodstream, has the potential to supplement the use of IHC or FISH to determine HER2 status. However, the clinical significance of serum HER2 has not been well studied in gastric cancer. The present study describes an illustrative case of metastatic gastric cancer initially diagnosed as HER2-negative (IHC score 1+). The patient exhibited an elevated serum HER2 level, which prompted a reevaluation of the tissue by IHC, using an alternative antibody, and FISH; re-biopsy analyses confirmed the case as HER2-positive, and trastuzumab was subsequently added to the combination chemotherapy with capecitabine and cisplatin. Serum HER2 may aid in avoiding false-negative diagnoses of HER2 gastric cancer.

Mo1168 Mesenchymal Stem Cells Partially Cancel Azoxymethane-Induced Tumor Initiation

Background: Western-style diet (WD) is known to be associated with insulin resistance and colonic inflammation which contributes to carcinogenesis. Biguanide metformin (M) and probiotics VSL#3 (V) can reduce insulin resistance and intestinal inflammation to inhibit tumor growth. We investigated the chemopreventive effect and the mechanism of the agents in WD-induced colitis associated carcinogenesis Methods: Male BALB/c mice were fed a control diet (CD) or WD for 8 weeks and WD groups were divided into groups of no treatment, M alone, V alone and combination therapy (CT). They were exposed to azoxymethane (AOM, 10mg/kg) and followed by 2 % dextran sodium sulfate (DSS) for 7 days. Tumor mass area was measured and tumor nodules were counted in colon of sacrificed mice. Disease activity index (DAI) was checked for 7 days during DSS exposure. Plasma glucose and insulin levels were measured and F4/80, Ki-67, claudin-1 and AMPK expressions were evaluated. Results: Tumor mass area and number of tumor nodules (.4 mm) were significantly decreased in CT group compared with WD group (p,0.01, p=0.016, respectively) and CT group showed low Ki-67 proliferation index (p,0.01). Plasma insulin and glucose levels in treatment groups (M, V, and CT group) were lower than those in WD group. CT group revealed low scores of DAI and decreased F4/80 positive cells accumulation during colitis compared with WD group (p=0.03, p,0.05, respectively). CT group showed maintained epithelial integrity by claudin-1 expression and increased AMPK activation. Conclusions: These results provide that combination therapy with metformin and VSL#3 attenuates tumor growth in WD induced colitic cancer model, which suggest that the treatment strategy could be useful in chemoprevention of colon cancer. The possible mechanisms were AMPK activation and inhibiting macrophage infiltration by maintaining epithelial integrity during colitis. Key word: colitic cancer, chemoprevention, metformin, VSL#3, western-style diet