Small-molecule Wnt inhibitors are a potential novel therapy for intestinal fibrosis in Crohns disease.

Intestinal fibrosis and stricture formation is an aggressive complication of Crohns disease (CD), linked to increased morbidity and costs. The present study investigates the contribution of Wingless-Int-1 (Wnt) signalling to intestinal fibrogenesis, considers potential cross-talk between Wnt and transforming growth factor ß1 (TGFß) signalling pathways, and assesses the therapeutic potential of small-molecule Wnt inhibitors. ß-catenin expression was explored by immunohistochemistry (IHC) in formalin-fixed paraffin embedded (FFPE) tissue from patient-matched nonstrictured (NSCD) and strictured (SCD) intestine (n=6 pairs). Functional interactions between Wnt activation, TGFß signalling, and type I collagen (Collagen-I) expression were explored in CCD-18Co cells and primary CD myofibroblast cultures established from surgical resection specimens (n=16) using small-molecule Wnt inhibitors and molecular techniques, including siRNA-mediated gene knockdown, immunofluorescence (IF), Wnt gene expression arrays, and western blotting. Fibrotic SCD tissue was marked by an increase in ß-catenin-positive cells. In vitro, activation of Wnt-ß-catenin signalling increased Collagen-I expression in CCD-18Co cells. Conversely, ICG-001, an inhibitor of ß-catenin signalling, reduced Collagen-I expression in cell lines and primary CD myofibroblasts. TGFß increased ß-catenin protein levels but did not activate canonical Wnt signalling. Rather, TGFß up-regulated WNT5B, a noncanonical Wnt ligand, and the Wnt receptor FZD8, which contributed directly to the up-regulation of Collagen-I through a ß-catenin-independent mechanism. Treatment of CCD-18Co fibroblasts and patient-derived myofibroblasts with the FZD8 inhibitor 3235-0367 reduced extracellular matrix (ECM) expression. Our data highlight small-molecule Wnt inhibitors of both canonical and noncanonical Wnt signalling, as potential antifibrotic drugs to treat SCD intestinal fibrosis. They also highlight the importance of the cross-talk between Wnt and TGFß signalling pathways in CD intestinal fibrosis.

Changes in neuromuscular structure and functions of human colon during ageing are region-dependent.

OBJECTIVE: To determine if human colonic neuromuscular functions decline with increasing age. DESIGN: Looking for non-specific changes in neuromuscular function, a standard burst of electrical field stimulation (EFS) was used to evoke neuronally mediated (cholinergic/nitrergic) contractions/relaxations in ex vivomuscle strips of human ascending and descending colon, aged 35-91 years (macroscopically normal tissue; 239 patients undergoing cancer resection). Then, to understand mechanisms of change, numbers and phenotype of myenteric neurons (30 306 neurons stained with different markers), densities of intramuscular nerve fibres (51 patients in total) and pathways involved in functional changes were systematically investigated (by immunohistochemistry and use of pharmacological tools) in elderly (≥70 years) and adult (35-60 years) groups. RESULTS: With increasing age, EFS was more likely to evoke muscle relaxation in ascending colon instead of contraction (linear regression: n=109, slope 0.49%±0.21%/year, 95% CI), generally uninfluenced by comorbidity or use of medications. Similar changes were absent in descending colon. In the elderly, overall numbers of myenteric and neuronal nitric oxide synthase-immunoreactive neurons and intramuscular nerve densities were unchanged in ascending and descending colon, compared with adults. In elderly ascending, not descending, colon numbers of cell bodies exhibiting choline acetyltransferase immunoreactivity increased compared with adults (5.0±0.6 vs 2.4±0.3 neurons/mm myenteric plexus, p=0.04). Cholinergically mediated contractions were smaller in elderly ascending colon compared with adults (2.1±0.4 and 4.1±1.1 g-tension/g-tissue during EFS; n=25/14; p=0.04); there were no changes in nitrergic function or in ability of the muscle to contract/relax. Similar changes were absent in descending colon. CONCLUSION: In ascending not descending colon, ageing impairs cholinergic function.

Expression of polymeric immunoglobulin receptor and stromal activity in pancreatic ductal adenocarcinoma.

BACKGROUND/OBJECTIVES: Polymeric immunoglobulin receptor (pIgR) traffics Immunoglobulins (IgA and IgM) through epithelial cells in normal mucosae but neither are expressed in the normal pancreas. Recent work from our laboratory suggested pIgR may be upregulated in pancreatic ductal adenocarcinoma (PDAC). Our aim was to assess the role of pIgR in human PDAC. METHODS: pIgR expression was manipulated (siRNA and shRNA) in cell lines to evaluate its subsequent effect on cell behaviour in 2D assays as well as 3D organotypics models. Tissue Microarrays of 88 patients with PDAC were analysed after pIgR, αSMA, E-Cadherin and Picrosirius Red staining to assess their role as a combined bio-marker panel. RESULTS: Cytokines such as interleukin 4 (IL4) and Tumour Necrosis Factor (TNFα) could not modulate pIgR expression in PDAC cell lines despite this effect being seen in other studies. Down-regulation in pIgR expression in Capan1 cancer cell line resulted in reduction of cellular proliferation, adhesion and migration in 2D assays. In 3D physiomimetic organotypic models, pIgR downregulation resulted in reduced cancer cell invasion, alteration of apico-basal polarity and diminished stromal activity. In human PDAC, decreased E-cadherin expression correlates with increased pIgR expression through pancreatic intra-epithelial neoplasia (PanIN) progression. In combination with enhanced stromal indices (α-smooth muscle action (SMA) and Picrosirius red), low pIgR scores had a trend towards better survival. CONCLUSION: pIgR may be involved in PDAC progression and may be linked stromal activity. Further work on its precise role is mandated in in vivo models, to understand its influence on cancer progression.

Activated pancreatic stellate cells sequester CD8+ T cells to reduce their infiltration of the juxtatumoral compartment of pancreatic ductal adenocarcinoma.

BACKGROUND & AIMS: Pancreatic ductal adenocarcinoma (PDAC) is characterized by a prominent desmoplastic microenvironment that contains many different immune cells. Activated pancreatic stellate cells (PSCs) contribute to the desmoplasia. We investigated whether distinct stromal compartments are differentially infiltrated by different types of immune cells. METHODS: We used tissue microarray analysis to compare immune cell infiltration of different pancreaticobiliary diseased tissues (PDAC, ampullary carcinoma, cholangiocarcinoma, mucinous cystic neoplasm, chronic inflammation, and chronic pancreatitis) and juxtatumoral stromal (<100 µm from tumor) and panstromal compartments. We investigated the association between immune infiltrate and patient survival times. We also analyzed T-cell migration and tumor infiltration in LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre (KPC) mice and the effects of all-trans retinoic acid (ATRA) on these processes. RESULTS: Juxtatumoral compartments in PDAC samples from 2 independent groups of patients contained increased numbers of myeloperoxidase(+) and CD68(+) cells compared with panstromal compartments. However, juxtatumoral compartments of PDACs contained fewer CD8(+), FoxP3(+), CD56(+), or CD20(+) cells than panstromal compartments, a distinction absent in ampullary carcinomas and cholangiocarcinomas. Patients with PDACs that had high densities of CD8(+) T cells in the juxtatumoral compartment had longer survival times than patients with lower densities. In KPC mice, administration of ATRA, which renders PSCs quiescent, increased numbers of CD8(+) T cells in juxtatumoral compartments. We found that activated PSCs express cytokines, chemokines, and adhesion molecules that regulate T-cell migration. In vitro migration assays showed that CD8(+) T cells, from patients with PDAC, had increased chemotaxis toward activated PSCs, which secrete CXCL12, compared with quiescent PSCs or tumor cells. These effects could be reversed by knockdown of CXCL12 or treatment of PSCs with ATRA. CONCLUSIONS: Based on studies of human PDAC samples and KPC mice, activated PSCs appear to reduce migration of CD8(+) T cells to juxtatumoral stromal compartments, preventing their access to cancer cells. Deregulated signaling by activated PSCs could prevent an effective antitumor immune response.

Predictive factors for incidental gallbladder dysplasia and carcinoma.

BACKGROUND: This study aims to analyze clinical characteristics and demographics of all patients admitted for cholecystectomy in a tertiary referral center to determine predictors of incidental gallbladder dysplasia (IGBD) and incidental gallbladder carcinoma (IGBC). METHODS: A retrospective analyses of clinical, demographic, and histologic features of patients undergoing cholecystectomy in a single tertiary institution from 2005-2012 were performed using a logistic regression model to determine the predictors of IGBD and IGBC. RESULTS: Some 771 (28 conversions to open surgery [3.6%]) and 93 patients (10.7%) underwent laparoscopic and open cholecystectomies for gallstone disease, respectively. At final pathology, IGBD (low-grade [n = 10], high-grade [n = 2], mixed-grade [n = 1], and adenoma-associated [n = 5] dysplasia) was found in 18 patients (2%; median age, 45 y; interquartile range, 42.5-63.5; male-to-female ratio, 1:2; six Caucasian; and 12 Asian). IGBC was found in seven patients (0.8%; median age, 69 y; interquartile range, 69-72; one Afro-Caribbean; four Caucasian; and two Asian). Logistic regression analysis revealed Asian patients to be at a higher risk of IGBD (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.1-8.0; P = 0.02). Only age (OR, 1.12; 95% CI, 1.04-1.2; P < 0.01) and polypoid lesions (OR, 37.4; 95% CI, 2.97-470.6; P = 0.01) were significantly associated with IGBC. Receiver operating characteristic curve analysis demonstrated that age >68 y correlated positively to IGBC. CONCLUSIONS: IGBD and IGBC are fairly common incidental histologic finding after cholecystectomy for gallstone disease. When considering cholecystectomy, patients' demographics, in particular age and race, should always be considered as this might help the surgeon and the pathologist to institute the appropriate treatment.

The impact of long-course chemoradiotherapy on the myenteric plexus, neuromuscular functions and responses to prokinetic drugs in the human rectum.

BACKGROUND & AIMS: The long-term effects of chemoradiotherapy on human rectum are poorly understood. The aims were to investigate changes in inflammatory status, myenteric neuron numbers/phenotype, neuromuscular functions and prokinetic drug efficacy. METHODS: Macroscopically normal proximal-to-mid rectum was obtained from 21 patients undergoing surgery for bowel cancer, 98 days (range: 63-350) after concurrent capecitabine and pelvic radiotherapy, and 19 patients without chemoradiotherapy. Inflammatory status was measured by H&E, CD45 staining and qPCR. Myenteric neurons were examined by immunohistochemistry. Neuromuscular functions and drug efficacy were studied using exogenous agents and electrical field stimulation (EFS) to activate intrinsic nerves. RESULTS: Inflammation was not detected. Numbers of myenteric ganglia/neurons were unchanged (11.7 ± 2.4 vs. 10.3 ± 2.2 neurons/mm myenteric plexus with/without chemoradiotherapy) as were the numbers of cholinergic/nitrergic neurons. EFS stimulated cholinergic and nitrergic neurons so the contractile response of the muscle was the sum of both but dominated by cholinergic (causing contraction) or less often, nitrergic activity (relaxation), followed, after termination of EFS, by neuronally mediated contraction. Inhibition of nitric oxide synthase (by L-NAME 300 µM) more clearly defined EFS-evoked contractions. The 5-HT4 agonist prucalopride 10 µM and the cholinesterase inhibitor donepezil 1 µM, respectively increased and greatly increased the composite contractile response to EFS (measured as 'area-under-the curve') and the contractions isolated by L-NAME (respectively, by 22 ± 14% and 334 ± 87%; n = 11/8). After chemoradiotherapy, nitrergic-mediated muscle relaxations occurred more often during EFS (in 29.8 ± 6.1% preparations vs. 12.6 ± 5.1% without chemoradiotherapy, n = 21/18). With L-NAME, the ability of prucalopride to facilitate EFS-evoked contraction was lost and that of donepezil approximately halved (contractions increased by 132 ± 36%; n = 8). CONCLUSIONS: Several months after chemoradiotherapy, the rectum was not inflamed and myenteric neuron numbers/phenotype unchanged. However, nitrergic activity was increased relative to cholinergic activity, and prokinetic-like drug activity was lost or greatly reduced. Thus, chemoradiotherapy causes long-term changes in neuromuscular functions and markedly reduces the efficacy of drugs for treating constipation.

Clonality assessment and clonal ordering of individual neoplastic crypts shows polyclonality of colorectal adenomas.

BACKGROUND & AIMS: According to the somatic mutation theory, monoclonal colorectal lesions arise from sequential mutations in the progeny of a single stem cell. However, studies in a sex chromosome mixoploid mosaic (XO/XY) patient indicated that colorectal adenomas were polyclonal. We assessed adenoma clonality on an individual crypt basis and completed a genetic dependency analysis in carcinomas-in-adenomas to assess mutation order and timing. METHODS: Polyp samples were analyzed from the XO/XY individual, patients with familial adenomatous polyposis and attenuated familial adenomatous polyposis, patients with small sporadic adenomas, and patients with sporadic carcinoma-in-adenomas. Clonality was analyzed using X/Y chromosome fluorescence in situ hybridization, analysis of 5q loss of heterozygosity in XO/XY tissue, and sequencing of adenomatous polyposis coli. Individual crypts and different phenotypic areas of carcinoma-in-adenoma lesions were analyzed for mutations in adenomatous polyposis coli, p53, and K-RAS; loss of heterozygosity at 5q, 17p, and 18q; and aneuploidy. Phylogenetic trees were constructed. RESULTS: All familial adenomatous polyposis-associated adenomas and some sporadic lesions had polyclonal genetic defects. Some independent clones appeared to be maintained in advanced adenomas. No clear obligate order of genetic events was established. Top-down growth of dysplastic tissue into neighboring crypts was a possible mechanism of clonal competition. CONCLUSIONS: Human colorectal microadenomas are polyclonal and may arise from a combination of host genetic features, mucosal exposures, and active crypt interactions. Analyses of tumor phylogenies show that most lesions undergo intermittent genetic homogenization, but heterotypic mutation patterns indicate that independent clonal evolution can occur throughout adenoma development. Based on observations of clonal ordering the requirement and timing of genetic events during neoplastic progression may be more variable than previously thought.

Expression of p16 Within Myenteric Neurons of the Aged Colon: A Potential Marker of Declining Function.

Human colonic neuromuscular functions decline among the elderly. The aim was to explore the involvement of senescence. A preliminary PCR study looked for age-dependent differences in expression of CDKN1A (encoding the senescence-related p21 protein) and CDKN2A (encoding p16 and p14) in human ascending and descending colon (without mucosa) from 39 (approximately 50: 50 male: female) adult (aged 27-60 years) and elderly donors (70-89 years). Other genes from different aging pathways (e.g., inflammation, oxidative stress, autophagy) and cell-types (e.g., neurons, neuron axonal transport) were also examined. Unlike CDKN1A, CDKN2A (using primers for p16 and p14 but not when using p14-specific primers) was upregulated in both regions of colon. Compared with the number of genes appearing to upregulate in association with temporal age, more genes positively associated with increased CDKN2A expression (respectively, 16 and five of 44 genes studied for ascending and descending colon). Confirmation of increased expression of CDKN2A was sought by immunostaining for p16 in the myenteric plexus of colon from 52 patients, using a semi-automated software protocol. The results showed increased staining not within the glial cells (S100 stained), but in the cytoplasm of myenteric nerve cell bodies (MAP2 stained, with identified nucleus) of ascending, but not descending colon of the elderly, and not in the cell nucleus of either region or age group (5,710 neurons analyzed: n = 12-14 for each group). It was concluded that increased p16 staining within the cytoplasm of myenteric nerve cell bodies of elderly ascending (but not descending) colon, suggests a region-dependent, post-mitotic cellular senescence-like activity, perhaps involved with aging of enteric neurons within the colon.

Non-invasive markers of liver fibrosis in fatty liver disease are unreliable in people of South Asian descent.

OBJECTIVE: Liver biopsy is the most accurate method for determining stage and grade of injury in non-alcoholic fatty liver disease (NAFLD). Given risks and limitations of biopsy, non-invasive tests such as NAFLD fibrosis score, aspartate transaminase (AST) to platelet ratio index, Fib-4, AST/alanine transaminase ratio and BARD are used. Prevalence and severity of NAFLD and metabolic syndrome vary by ethnicity, yet tests have been developed in largely white populations. We tested our hypothesis that non-invasive tests that include metabolic parameters are less accurate in South Asian compared with white patients. DESIGN: Retrospective cross-sectional. SETTING: Specialist liver centre. PATIENTS: Patients with histologically confirmed NAFLD. INTERVENTIONS: Scores calculated using clinical data taken within 1 week and compared with histology (Kleiner). MAIN OUTCOME MEASURES: Diagnostic test characteristics. RESULTS: 175 patients were identified. South Asians (n=90) were younger, had lower body mass index and lower proportion of obesity compared with white patients (n=79), with comparable rates of diabetes and liver injury. Tests are less sensitive at detecting advanced fibrosis in South Asian compared with white patients. Relative risk of correct diagnosis in white patients compared with South Asians is 1.86 (95% CI 1.4 to 2.6). In binary logistic regression models, ethnicity and platelet count predicted accuracy. Transient elastography was equally and highly accurate in both ethnicities. CONCLUSIONS: Blood test-based non-invasive scores are less accurate in South Asian patients, irrespective of metabolic parameters. Ethnicity should be considered when devising risk-stratification algorithms for NAFLD.

Solid pseudopapillary tumour of the pancreas: clinicopathological analysis.

BACKGROUND: We report on our experience of the surgical management and outcomes of 11 patients with solid pseudopapillary tumour of the pancreas (SPT). We sought to correlate the immunohistochemical staining of these tumours with that previously reported in the literature. METHODS: A retrospective analysis of the clinical presentation, radiological findings, surgical treatment, histopathological characteristics and outcomes for patients surgically managed with SPT at The Royal London Hospital. A literature search was performed to analyse the immunohistochemical stains commonly used to diagnose SPT. RESULTS: Between August 2006 and April 2016, 10 females and one male patient underwent surgery for SPT. The localization of the tumour was in the pancreatic head in two patients, one in the neck, three in the body and five in the tail. All 11 patients had localised disease. Six patients suffered post-surgical complications. Histopathology shows immunoreactivity for: ß-catenin, vimentin, CD-10, CD-56, α1-antitrypsin and negative staining for synaptophysin and chromogranin. At a median of 24 months of follow-up, the disease-free survival rate was 100% and no recurrence was noted. A literature review generated 38 suitable articles with 116 individual cases of SPT, with high expression of vimentin and neuron specific enolase throughout, and low rates of chromogranin and synatophysin positivity. CONCLUSION: SPT is rare and affects mostly young women. An accurate diagnosis is important as the relative indolent behaviour can be managed with surgical resection even when large in size, bringing excellent long-term outcomes.

Intussuscepting Ampullary Adenoma: An Unusual Cause of Gastric Outlet Obstruction Leading to Cavitating Lung Lesions.

Ampullary adenomas are a rare clinical entity, occurring at a rate of 0.04-0.12% in the general population. They are premalignant lesions which have the capability to progress to malignancy, and they should be excised if they are causing immediate symptoms and/or are likely to degenerate to carcinoma. Intestinal intussusception in adults is rare and, unlike in children, is often due to a structural pathology. Intussuscepting duodenal/ampullary adenomas have been reported in the literature on 13 previous occasions, however never before with this presentation. We report the case of a woman who presented with a 1-year history of recurrent chest infections. She was treated with numerous antibiotics, whilst intermittent symptoms of recurrent vomiting and weight loss were initially attributed to her lung infections. A chest CT demonstrated multiple cavitating lung lesions, whilst an obstructing polypoid mass was noted at D2 on dedicated abdominal imaging. Due to ongoing nutritional problems, she had a semi-urgent pancreaticoduodenectomy. Intraoperative findings demonstrated a large mass at D2 with a duodeno-duodenal intussusception. Histological analysis reported a duodenal, ampullary, low-grade tubular adenoma, 75 × 28 × 30 mm in size, with intussusception and complete resection margins. The patient recovered well and was discharged on postoperative day 10, with no complications to date. Ampullary adenomas may present with obstruction of the main gastrointestinal tract and/or biliary/pancreatic ducts. Common presentations include gastric outlet obstruction, gastrointestinal bleeding or acute pancreatitis. This unique presentation should remind clinicians of the need to investigate recurrent chest infections for a possible gastrointestinal cause.

The attitudes of relatives to autopsy: a misconception.

AIM: Hospital autopsy rates have been falling steadily over recent decades. One factor that has been implicated in this decline is the perception that the general public views postmortem examinations unfavourably and that this often makes clinicians reluctant to discuss autopsy with families and seek their consent. The aim of this study was to test this assumption. OBJECTIVES/METHODS: In the division of lymphoid malignancies at St Bartholomew's Hospital, we suggested autopsy and discussed it in depth with the families of all the patients who died in hospital in an 8-month period in order to assess whether the autopsy rate could be increased by improving the approach to the relatives. RESULTS: Consent for a postmortem examination was requested in 18 of 23 cases and granted in 16 cases, giving a consent rate of 89%, and an overall rate of autopsy of 69.5%. CONCLUSION: The attitude of the general public is positive overall, and translates into high autopsy rates when the value of the examination is presented honestly and the details of the procedure are adequately explained.

Biliary Cystadenoma Causing Obstructive Jaundice: Case Report and Literature Review.

Biliary cystadenomas are rare, potentially malignant neoplasms of biliary origin. Presentation is usually with vague and non-specific symptoms. Here, we describe an unusual case of biliary cystadenoma in a woman presenting with acute onset obstructive jaundice and review the relevant literature of 26 such cases reported over the last two decades.