The double stranded RNA analog poly-IC elicits both robust IFN-λ production and oncolytic activity in human gastrointestinal cancer cells.

Purpose: Type III IFN (IFN-λ) is the dominant frontline response over type I IFN in human normal intestinal epithelial cells upon viral infection, this response being mimicked by the dsRNA analog poly-IC. Poly-IC also induces cell death in murine intestinal crypts . Here we examined whether these innate defense functions of normal intestinal epithelial cells are recapitulated in gastrointestinal carcinoma cells so that they could be harnessed to exert both immunoadjuvant and oncolytic functions, an unknown issue yet.

Mapping clinicopathological entities within colorectal mucinous adenocarcinomas: a hierarchical clustering approach.

The aim of this study was to interrogate the heterogeneity of colorectal mucinous adenocarcinomas. This study is based on hierarchical clustering approach combining clinicopathological and molecular patterns known to be relevant to oncogenesis and therapeutic management of patients with colorectal carcinoma, ie, microsatellite instability, O6-methylguanine-DNA methyltransferase (MGMT) status, KRAS, and BRAF mutations and wnt signaling pathway activation. Comparison of the study group of 60 mucinous adenocarcinomas defined according to World Health Organization classification with control group of 136 colorectal adenocarcinomas successively removed shows higher frequency of BRAF and KRAS mutations and microsatellite instability-high status and lower frequency of wnt signaling pathway activation in mucinous adenocarcinomas.

Interferon-Alpha Promotes Th1 Response and Epithelial Apoptosis via Inflammasome Activation in Human Intestinal Mucosa.

Backgound & Aims: Several lines of investigation suggest that interferon (IFN) alpha can alter human intestinal mucosa homeostasis. These include the endogenous production of IFN alpha in celiac disease or inflammatory bowel diseases, as well as the occurrence of intestinal side effects of exogenous IFN alpha used as a therapeutic tool. Here, we present an ex vivo translational approach to investigate the effects of IFN alpha on the human normal intestinal mucosa, as well as its underlying mechanisms.

Heterogeneity of subordination of the IL-18/IFN-γ axis to caspase-1 among patients with Crohn's disease.

In Crohn's disease (CD), hierarchical architecture of the inflammatory network, including subordination of IL-18, an IFN-γ-inducing cytokine, to the inflammasome, have remained undeciphered. Heterogeneity among patients of such a subordination cannot be evaluated by animal models, monofactorial in their etiology and homogenous in disease progression. To address these issues, we set up an ex vivo model of inflamed mucosa explant cultures from patients with active long-standing CD.

Hierarchical clustering identifies a subgroup of colonic adenocarcinomas expressing crypt-like differentiation markers, associated with MSS status and better prognosis.

The aim of this study was to identify in the group of colonic adenocarcinomas, not otherwise specified (NOS), subgroups of oncogenetic and prognostic significance based on the expression of immunohistochemical markers of epithelial cell differentiation of the gastrointestinal tract. Hierarchical clustering analysis of 122 adenocarcinomas (NOS) identified four clusters based on how closely their profile of immunohistochemical expression of differentiation markers was related: (i) a major cluster of 83 adenocarcinomas (68%) called crypt-like carcinoma (CLA) with a immunohistochemically expressing colonic crypt differentiation markers (cytokeratin 20+, CDX2+, MUC2+ or MUC2-) and (ii) three minor clusters, characterized by the loss of colonic crypt differentiation markers and/or the acquisition of expression of markers of metaplastic foveolar gastric differentiation (MUC5AC+) and/or aberrant cytokeratin 7 expression. CLAs were invariably MSS (χ (2) test: p < 0.

Acute cytotoxicity of MIRA-1/NSC19630, a mutant p53-reactivating small molecule, against human normal and cancer cells via a caspase-9-dependent apoptosis.

Although numerous studies have focused on the mechanisms of action of the candidate chemotherapeutic drug MIRA-1/NSC19630, initially described as a mutant p53-reactivating small molecule, the issue of its toxicological evaluation remains open. Here, we devised a strategy to examine the effects of MIRA-1 on a variety of human normal cells and cancer cell lines. First, we demonstrated a massive and rapid (within 2 hours) MIRA-1 apoptotic effect on human normal primary epithelial cells as shown using an intestinal mucosa explant assay.

Reappraisal of the so-called 'villous tumours' of the rectosigmoid, based on histological, immunohistochemical and genotypic features.

Background: Villous tumours of the rectosigmoid are historically defined as broad-based lesions associated with secretory diarrhoea.

Objective: This study aimed to perform a reappraisal of these tumours, on the basis of newly introduced histological, immunohistochemical and molecular parameters.

Methods: For this study, 22 villous tumours, diagnosed by endoscopic criteria (19 Paris 0-IIa, three Paris 0-Is), were evaluated according to WHO classification.

Association of HER1 amplification with poor prognosis in well differentiated gastric carcinomas.

Aims: The pattern of E-cadherin expression and the HER1/HER2 status were studied in European patients with gastric carcinomas in relation with their differentiation and prognosis.

Methods: 82 gastric carcinomas (five papillary, 52 tubular, 19 poorly cohesive and six mixed according to WHO classification) were investigated for E-cadherin distribution (normal: restricted to the membrane; abnormal: absent or cytoplasmic expression), HER1 and HER2 expression using HercepTest and amplification using fluorescent in situ hybridisation. Statistical analysis assessed the association between the markers and their correlation with clinicopathological parameters and follow-up information.

Differential roles of Hath1, MUC2 and P27Kip1 in relation with gamma-secretase inhibition in human colonic carcinomas: a translational study.

Hath1, a bHLH transcription factor negatively regulated by the γ-secretase-dependent Notch pathway, is required for intestinal secretory cell differentiation. Our aim was fourfold: 1) determine whether Hath1 is able to alter the phenotype of colon cancer cells that are committed to a differentiated phenotype, 2) determine whether the Hath1-dependent alteration of differentiation is coupled to a restriction of anchorage-dependent growth, 3) decipher the respective roles of three putative tumor suppressor genes Hath1, MUC2 and P27kip1 in this coupling and, 4) examine how our findings translate to primary tumors. Human colon carcinoma cell lines that differentiate along a mucin secreting (MUC2/MUC5AC) and/or enterocytic (DPPIV) lineages were maintained on inserts with or without a γ-secretase inhibitor (DBZ).

Delineation of the infrequent mosaicism of KRAS mutational status in metastatic colorectal adenocarcinomas.

This study addresses the extent of the heterogeneity of KRAS status, present in a minority of metastatic colorectal carcinomas (mCRCs), on the basis of a thorough analysis of surgical resection specimens. Eighteen patients with mCRC were included. KRAS mutations (exon 2, codons 12 and 13) were determined using PCR and subsequent direct sequencing.

HLA-E/β2 microglobulin overexpression in colorectal cancer is associated with recruitment of inhibitory immune cells and tumor progression.

The host immune response plays a major role in colorectal carcinoma (CRC) progression. A mechanism of tumor immune escape might involve expression of the human leucocyte antigen (HLA)-E/β2m on tumor cells. The inhibitory effect of HLA-E/β2m on CD8+ cytotoxic T lymphocytes and natural killer (NK) cells is mediated by the main HLA-E receptor CD94/NKG2A.

A multiparametric approach to monitor the effects of γ-secretase inhibition along the whole intestinal tract.

γ-secretase inhibitors (GSIs) have been recently proposed as chemopreventive agents in gastrointestinal neoplasia, because they lead, through inhibition of the Notch signaling pathway, to goblet cell conversion in some intestinal adenomas of the Apc(Min) mice, and halt epithelial cell proliferation. In this study, we examine in depth, in normal mice, the effects of a GSI, dibenzazepine (DBZ), intraperitoneally administered for 8 days at a non toxic dose, on the gene expression pattern of secretory mucin (MUC), goblet cell conversion, organization of the crypt structural-proliferative units, stem cell niche and apoptotic compartments, along the entire length of the small intestine and colon. We demonstrate that DBZ elicits a homogeneous goblet cell conversion all along the mouse intestinal tract, associated with an overexpression of the gene Muc2 without ectopic expression of the gastric genes Muc5ac and Muc6, and with the emergence of lysozyme-positive 'intermediate cells' in the colon.

Loss of interleukin-10 or transforming growth factor β signaling in the human colon initiates a T-helper 1 response via distinct pathways.

Background & Aims: Signaling via interleukin (IL)-10 or transforming growth factor (TGF)-β is disrupted in subpopulations of patients with inflammatory bowel disease, but it is not clear how a T-helper (Th) 1 cell response is induced. We studied conversion of human mucosal innate immune cells into inflammatory cells and the initiation of a Th1 cell response following loss of IL-10 or TGF-β signaling.

Methods: We depleted IL-10 or TGF-β from explant cultures of human normal colonic mucosa using immunoneutralization.

ADAM15 to α5β1 integrin switch in colon carcinoma cells: a late event in cancer progression associated with tumor dedifferentiation and poor prognosis.

ADAM15, a member of the A Disintegrin And Metalloproteinase (ADAM) family, is a membrane protein containing an adhesion domain that binds to α5β1 integrin through a unique RGD domain. ADAM15, expressed by human normal colonocytes, is involved in epithelial wound healing and tissue remodeling in inflammatory bowel disease. The aims of our study were (i) to analyze ADAM15 expression in a series of colon carcinomas and paired normal mucosa and (ii) to integrate the spatial relationship of ADAM15 with its binding partners α5β1 integrin, a mesenchymal marker, as well as with other adhesion molecules, α3β1 integrin and E-cadherin.

KLF4-dependent, PPARgamma-induced expression of GPA33 in colon cancer cell lines.

The glycoprotein A33 (GPA33) is a colon cancer antigen. Phase I trials with 131I and 125I monoclonal antibody A33 in colon carcinoma patients showed excellent localization to colorectal cancer and some evidence of tumor response. Using DNA microarrays, we have identified the GPA33 gene as a target of PPARgamma in HT29-Cl.

In situ evidence of involvement of Schwann cells in ulcerative colitis: autocrine and paracrine signaling by A disintegrin and metalloprotease-17-mediated tumor necrosis factor alpha production.

An increase in S100 protein-positive cells has been reported in inflammatory bowel diseases, mainly Crohn disease. These cells were interpreted as myeloid-derived dendritic cells, chiefly in follicular areas. We were prompted to assess the nature of these cells in interfollicular areas of inflamed colonic mucosa in ulcerative colitis and study their involvement in tumor necrosis factor alpha production, the main inflammatory cytokine in ulcerative colitis.

TACE inhibition amplifies TNF-alpha-mediated colonic epithelial barrier disruption.

Inflammatory bowel diseases (IBD) are characterized by tumor necrosis factor alpha (TNF-alpha)-mediated epithelial barrier disruption. TNF-alpha production and the bioavailability of its receptors on the cell surface are regulated by TACE (TNF-alpha converting enzyme), a pleiotropic metalloprotease also known as ADAM17, and its specific inhibitor TIMP3. We therefore examined ADAM17 and TIMP3 expression in human intestinal epithelial cells (IEC) using immunohistochemistry on tissue microarrays and real-time PCR on preparations of IEC isolated from human normal and IBD colon.

N-cadherin serves as diagnostic biomarker in intrahepatic and perihilar cholangiocarcinomas.

As a definite immunoprofile of this tumor is missing, the histopathologic diagnosis of intrahepatic cholangiocarcinoma is difficult. The aim of this study was to explore E- and N-cadherin expressions in intrahepatic bile duct tumors, and to determine their potential interest in differential diagnosis. Normal liver tissue, 5 cirrhosis with ductular reaction, 5 focal nodular hyperplasia, 5 bile duct hamartomas, 5 bile duct adenomas, and 45 intrahepatic cholangiocarcinomas from Caucasian patients were studied.

Mucosal IL-10 and TGF-beta play crucial roles in preventing LPS-driven, IFN-gamma-mediated epithelial damage in human colon explants.

IL-10 is an immunomodulatory cytokine that plays an obligate role in preventing spontaneous enterocolitis in mice. However, little is known about IL-10 function in the human intestinal mucosa. We showed here that IL-10 was constitutively expressed and secreted by the human normal colonic mucosa, including epithelial cells.

PAR-2 activation increases human intestinal mucin secretion through EGFR transactivation.

PAR-2 (protease-activated receptors-2) are G protein-coupled receptors whose action on mucin secretion by intestinal epithelial cells is still unknown. The aim of this study was to examine the effect of PAR-2 activation on mucin secretion in the human colonic goblet cell line HT29-Cl.16E and the intracellular pathways involved.

Time resolved secretion of chloride from a monolayer of mucin-secreting epithelial cells.

Short-circuit current (Isc) measurement is used to quantify transepithelial ion flux. This technique provides a direct measure of net charge transport across a cell monolayer. Isc however, lacks chemical selectivity.

Involvement of the serrated neoplasia pathway in inflammatory bowel disease-related colorectal oncogenesis.

The purpose of this study is to identify colorectal serrated lesions in the inflammatory mucosa of inflammatory bowel disease (IBD), to characterize their molecular status based on BRAF and KRAS mutations, mismatch-repair (MMR) deficiency and microsatellite instability (MSI), and to verify that these molecular alterations are specific to the 'serrated neoplasia pathway' in IBD. Neoplastic lesions from 36 patients with IBD were reviewed retrospectively, including 13 adenocarcinomas (1 mucinous and 12 conventional), 28 dysplasias [1 traditional serrated adenoma (TSA) and 27 conventional adenomas] and 1 hyperplastic polyp (HP). Both the HP and TSA exhibited the V600E BRAF mutation without MSI or MMR deficiency.

ADAM-15: a metalloprotease that mediates inflammation.

Cell-cell and cell-matrix interactions are of utmost importance in the pathogenesis of inflammatory diseases. For example, cell-cell and cell-matrix interactions are crucial for leukocyte homing and recruitment to inflammatory sites. The discovery of the disintegrin and metalloprotease (ADAM) proteins, which have both adhesive and proteolytic activities, raised the question of their involvement in inflammatory processes.

Over-expression of neurotensin high-affinity receptor 1 (NTS1) in relation with its ligand neurotensin (NT) and nuclear beta-catenin in inflammatory bowel disease-related oncogenesis.

We investigated the expression of the neurotensin high-affinity receptor 1 (NTS1) during inflammatory bowel disease (IBD)-related colorectal oncogenesis, in colonic samples from 30 patients with IBD-related adenocarcinomas, dysplasias, and inflammatory mucosa (IM). The percentage of NTS1-positive epithelial cells progressively increased from the inflammatory condition to adenocarcinoma and was significantly higher in adenocarcinomas than in IM (p=0.0169).

Low expression of ORF4, a dominant negative variant of peroxisome proliferator-activated receptor gamma, in colorectal adenocarcinoma.

Peroxisome proliferator-activated receptor gamma (PPARgamma) agonists have been demonstrated to exert an inhibitory effect on cell growth, and to induce the cell differentiation and apoptosis of colorectal cancer cells. PPARgamma was therefore proposed as a therapeutic target. Recently, a variant of PPARgamma which functions as a dominant negative (ORF4) was described.