TITLE

ADHERENT E COLI FROM COLON CANCER TISSUE INCLUDE ISOLATES CAPABLE OF INDUCING IL-8 RELEASE AND COX2 EXPRESSION

AUTHOR(S)
Martin, H.M.; Campbell, B.J.; Nayar, M.; Williams, H.; Hart, C.A.; Rhodes, J.M.
PUB. DATE
April 2003
SOURCE
Gut;Apr2003 Supplement 1, Vol. 52, pA30
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Introduction: A previous study by Swidsinski et al demonstrated the presence of intracellular E coli in both the carcinoma and in the macroscopically normal tissue of colon cancer patients. It is our hypothesis that the altered mucosal glycoconjugates seen in colon cancer and pre-cancerous polyps may function as receptors for adhesions of otherwise non-pathogenic bacteria, promoting mucosal recruitment and intestinal inflammation. Methods: Mucosally associated and intraepithelial bacteria from both malignant and mocroscopically normal colonic mucosa of patients with colon cancer (n = 21) were isolated after removal of surface mucus followed by the gentamicin protection assay. Bacteria identified as E coil were screened for agglutination of human red blood cells and characterised for genotype/phenotype using PCR. E coil were also assessed for attachment/invasion to intestinal cells and for their ability to induce release pro-inflammatory cytokines. Results: 71% (15/21) of tumour tissue specimens were positive for mucosa associated bacteria compared with 57% (12/21) of macroscopically normal tissue. However, we were unable to confirm previous reports of intra-epithelial E coli in the unaffected mucosa of colon cancer patients. 38% (8/21) of tumour specimens were positive for agglutinating E coli compared to 24% (5/21) of distant normal specimens. Using a panel of glycoconjugates, all agglutinating E coli were inhibited by soluble plantain fibre and bovine submaxillary mucin. PCR showed that all agglutinating E coli possessed at least one adhesin gene but no known virulence genes. E coli isolated from 3/8 cancer patients possessed the cytotoxic necrotising factor 1 gene, encoding a toxin known to induce COX2 expression in fibroblasts. All agglutinating E coil attached to both HT29 and 1407 cell lines, with invasion only in 1407 cells. All agglutinating E coli induced IL-8 release, up to 5 times above basal levels (p < 0.01). Conclusions: These results support the...
ACCESSION #
9747459

 

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