2007 Winter Meeting - London - The Pathological Society of Great ...

P5The Actin-Bundling Protein Fascin is Overexpressed inInflammatory Bowel Disease{P} D Qualtrough, D Littlejohns, M PignatelliUniversity of Bristol, Bristol, United KingdomFascin, an actin-bundling protein, is not expressed by normal colonic epithelialcells but is upregulated in colorectal tumours where it promotes cell motilityand invasion. Analysis of the fascin promoter suggests that its expression maybe induced by inflammatory mediators.Immunohistochemical analysis of inflammatory bowel disease(IBD) specimens showed fascin expression in both ulcerative colitis (34/34) andCrohn’s colitis (7/7). Its expression correlated with the degree of inflammatoryactivity. Highly expressing foci were observed at the edges of ulcers whereflattened, motile epithelial cells are actively involved in epithelial restitution.We studied the effect of therapeutic modalities used in the treatmentof IBD on the expression of fascin in SW480 and HT29 colon carcinoma cellsby western blotting. Non-steroidal anti-inflammatory drugs (NSAIDs) reducedfascin expression (60%) in both cell lines, whereas butyrate (a fermentationproduct of resistant starch and potential treatment for IBD) increased itsexpression 2-7 fold.These data suggest that Fascin expression could be of importance inIBD and that its regulation by NSAIDs and butyrate may affect motility and theepithelial restitution of colonic mucosa.P6Expression of Transporter Proteins in Rat PlacentationR Stratton, T Aldridge, J Noakes, D Moore, C Sadler,A Hargreaves, {P} J WrightSyngenta, CTL, Cheshire, United KingdomATP-binding cassette (ABC) transporters are a large super family oftransmembrane proteins, which mediate trafficking of a wide variety ofsubstrates in an ATP dependant manner across membranes and are fundamentalto protecting the foetus from xenobiotics exposure. We investigated theexpression profiles of 3 ABC transporters; p-Glycoprotein (p-Gp), Multidrugresistance associated protein 2 (MRP2) and Breast cancer resistance protein(BCRP) in rat placenta.Han Wister rats were time mated and foetal gestational days 6 -21 wereinvestigated by IHC, Immunoblotting and genomics.p-Gp protein and mRNA were found to be expressed in rat placenta from day13 increasing up to day 20. MRP2 and BCRP proteins were found to beexpressed from day 14 and day 12 respectively, increasing up to day 20.Human placental expression of p-Gp is reported to be greatest within the firsttrimester and decreasing over time, in contrast to the rat. Human placentalexpression of BCRP is reported to remain constant throughout pregnancy againin contrast to the rat.These species differences need to be considered when choosing an animalmodel to investigate foetal exposure to xenobiotics in relation to human riskassessment.P7Inhibition of COX-2 with NS-398 decreases colon cancer cellmotility through blocking epidermal growth factor receptortransactivation: possibilities for combination therapy{P} M Pignatelli, N Banu, A Buda, S Chell, D Elder,M Moorghen, C Paraskeva, D QualtroughUniversity of Bristol, Bristol, United KingdomThe use of NSAIDs has proved of great interest in the prevention and treatmentof colorectal cancer. Overexpression of COX-2 and prostaglandin productionpromote metastasis and have been shown to increase cell motility in vitro. Weinvestigated whether specific inhibition of COX-2 with NS-398 inhibited themotility of colorectal cancer cells and whether this was modulated throughEGFR transactivation. A trans-well filter assay was used to study cell motility.Expression of COX-2, EGFR phosphorylation and PGE 2 receptors was assessedby Western blot and RT-PCR. NS-398 significantly reduced PGE 2 levels andreduced cell migration in HT29 and HCA7 colorectal cancer cells and thiseffect was rescued by addition of PGE 2. Specific inhibition of COX-2 with NS-398 reduces EGFR phosphorylation. Inhibition of EGFR activity with AG1478reduced PGE 2-stimulated motility, demonstrating that PGE 2 acts via the EGFRsignalling pathway. The novel combination of NS-398 and AG1478dramatically reduced migration of colorectal cancer cells. The data presentedhere indicate that use of NS-398 in chemoprevention and adjuvant therapy forcolorectal cancer may work in part, through the inhibition of cell motility. Ourdata suggests that the combined use of NSAIDs with EGFR antagonists couldbe explored further for future use in the clinic.P8Notch Signalling is Altered in Colorectal Tumours and CanInfluence Malignant Progression{P} P Rees, M Pignatelli, D QualtroughUniversity of Bristol, Bristol, United KingdomNotch is a highly conserved developmental signalling pathway expressed inadult intestinal epithelium. Aberrant Notch activation is oncogenic in a numberof tissues but its role in intestinal tumourigenesis is undefined. A commonfeature of Notch in embryogenesis is participation in processes that involveselective changes in adhesion including the epithelial to mesenchymal transition(EMT), a process thought to be important in colorectal tumour invasion.In this study we analysed Notch1 (N1) and E-cadherin (as a marker of EMT) in9 colorectal carcinoma (CaCo2, HCA7/C29, HCT15, HCT116, HT29, JW2,LS174T, SW480, SW620) and in 4 adenoma-derived cell lines (RG/C2,AN/C1, AA/C1, BH/C1) by western blotting. N1 expression was increased inthe carcinoma cell lines (especially SW480 and SW620) compared with theadenomas, which were either negative (RG/C2, BH/C1) or low expressors(AA/C1, AN/C1). A hallmark of EMT and tumour invasion is a decrease in theepithelial marker E-cadherin. There was an inverse relationship between E-cadherin and N1 expression in all adenoma and carcinoma derived cell linesexamined. In vivo, 5/10 adenocarcinoma tissue samples showed N1immunoreactivity compared to 2/8 adenomas. These findings highlight Notchas a regulator on EMT in colonic tumours and its possible role in colorectaltumour progression.Winter Meeting (191 st ) 3–5 January 2007 Scientific Programme29