Conor O'Keane

Fibrogenesis in Crohn's Disease

INTRODUCTION:Over one-third of patients with Crohns disease (CD) will develop an intestinal stricture and the great majority of these will require at least one surgical procedure. While the pathogenesis of inflammation in CD has been extensively investigated, knowledge of stricture pathogenesis remains limited. The aim of this review is to discuss the current understanding of fibrogenesis in CD and to outline potential directions in research and therapeutics.METHODS:The electronic literature (January 1966 to May 2006) on CD-associated fibrosis was reviewed. Further references were obtained by cross-referencing from key articles.RESULTS:CD-associated fibrosis results from chronic transmural inflammation and a complex interplay among intestinal mesenchymal cells, cytokines, and local inflammatory cells. The fibroblast is the key cell type mediating stricture formation. The cytoarchitecure of the bowel wall is altered with disruption of the muscularis mucosa, thickening of the muscularis propria, and deposition of collagen throughout. The cytokine TGF-β appears critical in this process, acting to increase growth factor and extracellular matrix (ECM) production and dysregulate ECM turnover. Potential therapeutic interventions are likely to concentrate on modulating down-stream targets of TGF-β.CONCLUSIONS:Greater understanding of the biology of fibrostenosis is likely to yield significant advances in our ability to care for patients with stricturing CD. Potential dividends of this approach include identification of novel therapeutic targets and biomarkers useful for prognostication and therapeutic monitoring.

2D-DIGE as a Strategy To Identify Serum Markers for the Progression of Prostate Cancer

Prostate cancer is the most common solid organ malignancy affecting men in the United States and Western Europe. Currently, the main diagnostic tools used to look for evidence of prostate cancer include physical examination using digital rectal exam (DRE), serum concentrations of prostate specific antigen (PSA) and biopsy. However, due to the low specificity of PSA in differentiating prostate cancer from other benign conditions, many patients undergo overtreatment for their disease. There is an urgent need for additional markers to improve the diagnostic accuracy for early stages of prostate cancer. Proteomic analysis of serum has the potential to identify such markers. An initial discovery study has been completed using 12 serum samples from patients with different grades of prostate cancer (Gleason score 5 and 7) undergoing radical prostatectomy. Serum samples were subjected to immunoaffinity depletion and protein expression analysis using 2D-DIGE. Image analysis isolated 63 spots that displayed differential expression between the Gleason score 5 and 7 cohorts (p < 0.05), 13 of which were identified as statistically significant using two independent image analysis packages. Identification of differentially expressed spots was carried out using LC-MS/MS. Because of their functional relevance and potential significance with regards to prostate cancer progression, two of these proteins, pigment epithelium-derived factor (PEDF) and zinc-alpha2-glycoprotein (ZAG), have undergone extensive validation in serum and tissue samples from the original cohort and also from a larger independent cohort of patients. These results have indicated that PEDF is a more accurate predictor of early stage prostate cancer. We are confident that proteomics-based approaches have the potential to provide more insight into the underlying molecular mechanisms of the disease and also hold great promise for biomarker discovery in prostate cancer.

Net1 and Myeov: computationally identified mediators of gastric cancer

Gastric adenocarcinoma (GA) is a significant cause of mortality worldwide. The molecular mechanisms of GA remain poorly characterised. Our aim was to characterise the functional activity of the computationally identified genes, NET 1 and MYEOV in GA. Digital Differential Display was used to identify genes altered expression in GA-derived EST libraries. mRNA levels of a subset of genes were quantitated by qPCR in a panel of cell lines and tumour tissue. The effect of pro- and anti-inflammatory stimuli on gene expression was investigated. Cell proliferation and invasion were measured using in an in-vitro GA model following inhibition of expression using siRNA. In all, 23 genes not previously reported in association with GA were identified. Two genes, Net1 and Myeov, were selected for further analysis and increased expression was detected in GA tissue compared to paired normal tissue using quantitative PCR. siRNA-mediated downregulation of Net1 and Myeov resulted in decreased proliferation and invasion of gastric cancer cells in vitro. These functional studies highlight a putative role for NET1 and Myeov in the development and progression of gastric cancer. These genes may provide important targets for intervention in GA, evidenced by their role in promoting invasion and proliferation, key phenotypic hallmarks of cancer cells.

Priming prostate carcinoma cells for increased apoptosis is associated with up-regulation of the caspases.

The potential to prime prostatic carcinoma cell lines for apoptosis represents an exciting strategy for the treatment of patients with this disease. The ability and the underlying molecular mechanisms involved in sensitizing both androgen‐sensitive and androgen‐insensitive cell types to a range of apoptotic‐inducing agents are investigated by the authors.

Predictors of Survival in Early Oral Cancer

OBJECTIVE Despite the substantial rate of neck conversion reported among patients with early oral cancer, a policy of routine elective neck dissection has been criticized on the grounds that it confers little survival advantage while subjecting many to potentially avoidable morbidity. However, the identification of factors predictive of survival may allow for the identification of those patients who are more likely to benefit from elective neck treatment. STUDY DESIGN AND SETTING The clinical and histologic material of 71 patients with stage I or II squamous carcinoma of the oral cavity were reviewed. Patients were followed up for a minimum of 3 years after their surgery, and the impact of these variables on 3-year survival was assessed. RESULTS Increased tumor thickness was significantly predictive of decreased survival (P = 0.030). Although having no prognostic value alone, when combined with thickness, both pattern of invasion and gender increased the significance of the latter in predicting outcome. Conclusion and significance Measuring tumor thickness and pattern of invasion in patients with early oral cancer may allow for the identification of those patients with more aggressive disease who are more likely to benefit from elective neck treatment.

Mucosal metabolism in ulcerative colitis and Crohn's disease.

PURPOSE: Colonic mucosal metabolism of butyrate may be impaired in ulcerative colitis. In this study we sought to confirm this observation, to determine if a similar change occurs in Crohns colitis, and to establish whether a panenteric disorder of butyrate metabolism exists in either condition. METHODS: With use of a microculture technique, mucosal metabolic fluxes of14[C]-labeled butyrate and14[C]-labeled glutamine were measured as14[C] carbon dioxide production in mucosal biopsy specimens from the colon and ileum in patients with ulcerative colitis, Crohns colitis, and healthy bowel. Results were expressed as pmol/µg biopsy DNA/hour. RESULTS: In the colon the mucosal metabolic fluxes of both butyrate and glutamine are reduced in both ulcerative colitis and Crohns colitis compared with healthy controls. These changes were most marked in the presence of moderate to severe mucosal inflammation, there being no significant difference in mucosal metabolic flux between mildly inflamed mucosa and healthy controls. In the ileum the mucosal metabolic fluxes of butyrate and glutamine did not differ between healthy controls and those with either ulcerative colitis or Crohns colitis. CONCLUSIONS: Changes in colonic mucosal metabolism of butyrate and glutamine in inflammatory bowel disease occur as a consequence of the inflammatory process and are not peculiar to ulcerative colitis. Ileal mucosal metabolism is unchanged in ulcerative colitis and Crohns colitis, indicating the absence of a panenteric abnormality of mucosal metabolism in these two conditions.

Mycosis fungoides - : a review of the management of 28 patients and of the recent literature

Background  Mycosis fungoides is an uncommon cutaneous T‐cell lymphoma characterized by malignant monoclonal proliferation of T‐helper lymphocytes. Its course is variable with a potential for lymphatic and hematogenous involvement. We report the investigations, staging, treatment, follow‐up, and outcome of 28 patients. This is the first such study reported from Ireland.

Sentinel lymph node mapping in colorectal cancer (Br J Surg 2003; 90: 659‐667)

Sir Potential advantages of sentinel lymph node (SLN) mapping include identification of aberrant drainage, as well as upstaging. While we agree that a multi-centre trial employing a standard technique of SLN mapping in colorectal cancer is timely, there are some caveats. The inherent challenges of this technique may result in variability of the results. Therefore, mapping technique (e.g. in-vivo colonic and ex-vivo rectal mapping; and lymphoscintigraphy and/or blue dye in all), degree of nodal sectioning (e.g. 4 sections), and method of ultrastaging (e.g. immunohistochemistry if negative on H & E staining) should be standardised between institutions. Furthermore, strict criteria for trial entry should be established in advance and data recording standardised (e.g. pre-operative radiotherapy, type of operation, aberrant drainage, tumour stage, etc.). Finally, power calculation (as alluded to in the letter of Smith et al.1) and the trial end-points (e.g. success of mapping, accuracy of sentinel node in predicting nodal status, survival of those patients who are sentinel node positive only etc.) would have to be determined clearly in advance. In order to overcome some of these biases, surgeons considering joining such a trial should perform a local audit of 100 procedures. A success rate > 90 per cent should indicate proficiency with sentinel lymph node mapping in colorectal cancer that would be sufficient to begin entering patients into the trial. J. Mulsow, D. C. Winter, C. O’Keane and P. R. O’Connell Mater Misericordiae Hospital, Dublin 7, Ireland DOI: 10.1002/bjs.4444

Bioinformatic analysis of the colonic polyp-cancer pathway

Background: The pathways implicated in progression from normal colonic mucosa to polyps to cancer are not fully elucidated. Examination of transcribed genes at each step of progression may identify markers of disease progression. Methods: Samples of colonic adenomas and carcinomas and matched normals were obtained at colonoscopy. RNA was extracted and DNA hybridised to the Affymetrix U133 microarray. Expression data was analysed using hierarchial clustering and principal component analysis. Results: Representative samples from normal, simple adenomas, advanced adenomas and carcinomas were analysed. Unsupervised hierarchial clustering demonstrated differentiation between the expression patterns of normal tissue, adenomas and carcinomas. Principal component analysis confirmed this differentiation. Ontological classification of genes highly expressed in adenomas revealed 764 genes significantly altered between histological subtypes; including genes associated with cellular proliferation, oncogenesis and cell cycle regulation. Conclusion: The expression profile of adenomas reveals a discrete differentiation pattern to normal tissue. Examination of the secreted proteins of this profile may highlight novel biomarkers for colorectal polyps.