Roger Feakins

Tumour-infiltrating lymphocytes in colorectal cancer with microsatellite instability are activated and cytotoxic

Patients with colorectal cancer that display high‐level microsatellite instability (MSI‐H) appear to have a better prognosis. This may be explained by the pronounced T cell infiltrate seen in MSI‐H tumours that is related to a specific antigen‐driven immune response. The nature of tumour‐infiltrating lymphocytes in colorectal cancers was investigated using quantitative real‐time polymerase chain reaction (PCR) and immunohistochemistry.

Analysis of colorectal cancers in British Bangladeshi identifies early onset, frequent mucinous histotype and a high prevalence of RBFOX1 deletion.

BackgroundPrevalence of colorectal cancer (CRC) in the British Bangladeshi population (BAN) is low compared to British Caucasians (CAU). Genetic background may influence mutations and disease features.MethodsWe characterized the clinicopathological features of BAN CRCs and interrogated their genomes using mutation profiling and high-density single nucleotide polymorphism (SNP) arrays and compared findings to CAU CRCs.ResultsAge of onset of BAN CRC was significantly lower than for CAU patients (p=3.0 x 10-5) and this difference was not due to Lynch syndrome or the polyposis syndromes. KRAS mutations in BAN microsatellite stable (MSS) CRCs were comparatively rare (5.4%) compared to CAU MSS CRCs (25%; p=0.04), which correlates with the high percentage of mucinous histotype observed (31%) in the BAN samples. No BRAF mutations was seen in our BAN MSS CRCs (CAU CRCs, 12%; p=0.08). Array data revealed similar patterns of gains (chromosome 7 and 8q), losses (8p, 17p and 18q) and LOH (4q, 17p and 18q) in BAN and CAU CRCs. A small deletion on chromosome 16p13.2 involving the alternative splicing factor RBFOX1 only was found in significantly more BAN (50%) than CAU CRCs (15%) cases (p=0.04). Focal deletions targeting the 5’ end of the gene were also identified. Novel RBFOX1 mutations were found in CRC cell lines and tumours; mRNA and protein expression was reduced in tumours.ConclusionsKRAS mutations were rare in BAN MSS CRC and a mucinous histotype common. Loss of RBFOX1 may explain the anomalous splicing activity associated with CRC.

Colorectal cancers with microsatellite instability display mRNA expression signatures characteristic of increased immunogenicity

BackgroundColorectal cancers displaying high-degree microsatellite instability (MSI-H) have an improved prognosis compared to microsatellite stable (MSS) cancers. The observation of pronounced lymphocytic infiltrates suggests that MSI-H cancers are inherently more immunogenic. We aimed to compare the gene expression profiles of MSI-H and MSS cancers to provide evidence for an activated immune response in the former.ResultsWe analysed tissue from 133 colorectal cancer patients with full consent and Local Ethics Committee approval. Genomic DNA was analysed for microsatellite instability in BAT-26. High-quality RNA was used for microarray analysis on the Affymetrix® HG-U133A chip. Data was analysed on GeneSpring software version 6.0. Confirmatory real-time RT-PCR was performed on 28 MSI-H and 26 MSS cancers. A comparison of 29 MSI-H and 104 MSS cancers identified 2070 genes that were differentially expressed between the two groups [P < 0.005]. Significantly, many key immunomodulatory genes were up-regulated in MSI-H cancers. These included antigen chaperone molecules (HSP-70, HSP-110, Calreticulin, gp96), pro-inflammatory cytokines (Interleukin (IL)-18, IL-15, IL-8, IL-24, IL-7) and cytotoxic mediators (Granulysin, Granzyme A). Quantitative RT-PCR confirmed up-regulation of HSP-70 [P = 0.016], HSP-110 [P = 0.002], IL-18 [P = 0.004], IL-8 [0.002] and Granulysin [P < 0.0001].ConclusionsThe upregulation of a large number of genes implicated in immune response supports the theory that MSI-H cancers are immunogenic. The novel observation of Heat Shock Protein up-regulation in MSI-H cancer is highly significant in light of the recognised roles of these proteins in innate and antigen-specific immunogenicity. Increased mRNA levels of pro-inflammatory cytokines and cytotoxic mediators also indicate an activated anti-tumour immune response.

Deranged smooth muscle alpha-actin as a biomarker of intestinal pseudo-obstruction: a controlled multinational case series.

Background and aims: Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a severe motility disorder associated with significant morbidity. Several histopathological (neuropathic and myopathic) phenotypes have been described but only a single adult with jejunal smooth (circular) muscle α-actin deficiency. We present a prospective multinational case series investigating smooth muscle α-actin deficiency as a biomarker of this disease. Methods: A total of 115 fully clinically and physiologically (including prolonged (24 hour) ambulatory jejunal manometry) characterised CIIP patients from three European centres were studied. Immunohistochemical localisation of actins and other cytoskeletal proteins were performed on laparoscopic full thickness jejunal biopsies and compared with adult controls. Distribution of α-actin was also characterised in other gut regions and in the developing human alimentary tract. Results: Twenty eight of 115 (24%) CIIP patient biopsies had absent (n = 22) or partial (n = 6) jejunal smooth muscle α-actin immunostaining in the circular muscle layer. In contrast, smooth muscle α-actin staining was preserved in the longitudinal muscle and in adult jejunal controls (n = 20). Comparative study of other adult alimentary tract regions and fetal small intestine, suggested significant spatial and temporal variations in smooth muscle α-actin expression. Conclusions: The ability to modulate α-smooth muscle actin expression, evident in development, is maintained in adult life and may be influenced by disease, rendering it a valuable biomarker even in the absence of other structural abnormalities.

Incidence of Inflammatory Bowel Disease is Rising and Abdominal Tuberculosis is Falling in Bangladeshis in East London, United Kingdom

OBJECTIVES:Ulcerative colitis (UC) and Crohns disease (CD) were previously thought to be uncommon and abdominal tuberculosis (TB) common in patients from Bangladesh. We have reevaluated their incidence in Bangladeshis resident in East London.METHODS:Bangladeshis resident in Tower Hamlets presenting between 1997 and 2001 were identified from pathology, endoscopy, and medical records. Demographic, clinical, and management details were recorded. Incidences were calculated and compared with those from 1981 to 1989.RESULTS:Sixteen Bangladeshi patients with UC, 19 with CD, and 5 with abdominal TB were identified. Between 1997 and 2001, the age-standardized incidence of UC was 8.2/105/yr (95% CI 2.5–13.9) compared with 2.4 (95% CI 0.8–3.8) in 1981–1989, and that of CD was 7.3/105/yr (95% CI 2.0–12.6) (2.3, 95% CI 0.7–3.7 in 1981–1989). The standardized ratios for the incidences of UC and CD in recent periods compared with previous periods were 2.1 (95% CI 0.9–3.9) and 2.5 (1.2–4.6), respectively. There was a significant increase in the number of Bangladeshis developing CD by age <20 yr between the earlier and more recent periods (p < 0.02). The standardized incidence of abdominal TB was 2.5/105/yr (95% CI 0.2–4.8) in 1997–2001, and 7.4 (95% CI 2.1–12.7) in 1985–1989 (p < 0.05). The standardized ratio for the incidence of TB in the two periods was 0.22 (95% CI 0.07–0.53).CONCLUSIONS:In Bangladeshis in East London, the incidence of IBD has increased and of abdominal TB has fallen over the last decade; CD has become a more likely diagnosis than abdominal TB. Clinicians in the Western world need to be aware of the changing incidences of IBD and abdominal TB in South Asians.

Efficacy and tolerability of oral iron therapy in inflammatory bowel disease: a prospective, comparative trial

Background : In patients with inflammatory bowel disease, oral iron is anecdotally reported to be less effective and less well tolerated than in those without inflammatory bowel disease, and to increase disease activity.

AGR2 Is a Novel Surface Antigen That Promotes the Dissemination of Pancreatic Cancer Cells through Regulation of Cathepsins B and D

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal cancers largely due to disseminated disease at the time of presentation. Here, we investigated the role and mechanism of action of the metastasis-associated protein anterior gradient 2 (AGR2) in the pathogenesis of pancreatic cancer. AGR2 was induced in all sporadic and familial pancreatic intraepithelial precursor lesions (PanIN), PDACs, circulating tumor cells, and metastases studied. Confocal microscopy and flow cytometric analyses indicated that AGR2 localized to the endoplasmic reticulum (ER) and the external surface of tumor cells. Furthermore, induction of AGR2 in tumor cells regulated the expression of several ER chaperones (PDI, CALU, RCN1), proteins of the ubiquitin-proteasome degradation pathway (HIP2, PSMB2, PSMA3, PSMC3, and PSMB4), and lysosomal proteases [cathepsin B (CTSB) and cathepsin D (CTSD)], in addition to promoting the secretion of the precursor form pro-CTSD. Importantly, the invasiveness of pancreatic cancer cells was proportional to the level of AGR2 expression. Functional downstream targets of the proinvasive activity of AGR2 included CTSB and CTSD in vitro, and AGR2, CTSB, and CTSD were essential for the dissemination of pancreatic cancer cells in vivo. Taken together, the results suggest that AGR2 promotes dissemination of pancreatic cancer and that its cell surface targeting may permit new strategies for early detection as well as therapeutic management.

Paneth cell granule depletion in the human small intestine under infective and nutritional stress

Paneth cells are important contributors to the intestinal antimicrobial barrier through synthesis and release of antimicrobial peptides and proteins. Animal studies indicate that Paneth cell numbers, location and granule morphology are altered by infection and zinc status. We examined human tissue to determine whether Paneth cell numbers, distribution or granule morphology are altered in infective, inflammatory and nutritional disorders. Archival sections from infective disorders (giardiasis, cryptosporidiosis, HIV, helminth infection) were compared with active inflammatory conditions (coeliac, Crohns and graft‐versus‐host diseases) and histologically normal tissues. A subset of tissues was studied by electron microscopy and TUNEL staining for apoptosis. Human defensin‐5 (HD5) peptide and mRNA was analysed by immunohistochemistry, in situ hybridization and quantitative reverse transcription polymerase chain reaction. Sections from a tropical population cohort study were then analysed to determine the relationship of granule depletion to infection, nutritional status and plasma zinc concentration. In HIV‐related cryptosporidiosis, but not other disorders, Paneth cells were reduced in number and markedly depleted of granules. Paneth cell granule depletion was associated with reduced HD5 immunoreactivity, but this was not due to apoptosis and there was no reduction in mRNA transcripts. In the tropical population studied, depletion of granules was associated with reduced body mass index, reduced plasma zinc levels and HIV infection. Paneth cell granules in human small intestine may be depleted in response to infective and nutritional stress. We postulate that this is one mechanism through which zinc status influences host susceptibility to intestinal infection.

Appendiceal inflammation in ulcerative colitis

Previous uncontrolled reports have suggested that appendiceal inflammation may occur as a discontinuous lesion in ulcerative colitis. This study aims semiquantitatively to compare the prevalence and histological features of appendiceal inflammation in patients with ulcerative colitis and Crohns disease, using colonic carcinoma and acute appendicitis specimens as controls.

The expression of p53 and bcl-2 in gastrointestinal stromal tumours is associated with anatomical site, and p53 expression is associated with grade and clinical outcome

Aims : To compare the expression of p53 and bcl‐2 in gastrointestinal stromal tumours (GISTs) with anatomical site, National Institutes of Health (NIH) risk category (grade), pathological features, and clinical outcome.