Role of matrix metalloproteinase,tissue inhibitor of metalloproteinase and tumor necrosis factor-α single nucleotide gene polymorphisms in inflammatory bowel disease

AIM:To study the (functional) relevance of single nucleotide polymorphisms (SNPs) in genes encoding matrix metalloproteinases (MMP)-1,-2,-3,-9,tissue inhibitors of metalloproteinases (TIMP)-1,-2 and tumor necrosis factor (TNF)-α in the etiopathogenesis of inflammatory bowel diseases (IBD),that may enhance susceptibility and/or disease severity. METHODS:Genomic DNA from 134 Crohn's disease (CD),111 ulcerative colitis (UC) patients and 248 control subjects was isolated from resected intestinal tissue or blood. Allelic composition at SNP loci was determined by PCR-RFLP or tetra primer ARMS PCR. RESULTS:The TIMP-1 genotype TT in women and T in men at SNP +372 T/C was found to increase CD susceptibility (39% vs 23.8%,P=0.018 and 67.9% vs 51.6%,P=0.055,respectively),while women with this genotype were less prone to development of fistulae during follow-up (41.4% vs 68.3%,P=0.025). Male IBD or CD patients carrying the TIMP-1 +372 T-allele expressed lower levels of TIMP-1 in surgically resected macroscopically inflamed tissue (0.065 < P < 0.01). The 5T5T genotype at MMP-3 SNP -1613 5T/6T increased the chance of stenotic complications in CD during follow-up (91.2% vs 71.8%,P = 0.022) but seemed to protect against colonic involvement of this disease at first endoscopic/radiologic examination (35.3% vs 59.5%,P=0.017). CONCLUSION:Allelic composition at the examinedSNPs in genes coding for TIMP-1 and MMP-3 affect CD susceptibility and/or phenotype,i.e.,fistulizing disease,stricture pathogenesis and first disease localisation. These findings reinforce the important role of these proteins in IBD.

Angiogenic markers endoglin and vascular endothelial growth factor in gastroenteropancreatic neuroendocrine tumors

AIM:To investigate the expression and potential prognostic role of vascular endothelial growth factor(VEGF) and endoglin in gastroenteropancreatic neuroendocrine tumors(GEP-NETs) . METHODS:Microvessel density(MVD) in GEP-NETs was evaluated using endoglin and CD31 immunohistochemistry.In addition,tissue levels of endoglin and VEGF were determined in homogenates by ELISA. RESULTS:Endoglin was highly expressed on tumor endothelial cells.CD31 MVD in GEP-NETs was significantly higher compared to endoglin MVD(P<0.01) .Two-tofour-fold higher tissue levels of endoglin and VEGF were seen in tumors compared to associated normal tissue. This increased endoglin tissue expression in tumors was significantly related to tumor size(P<0.01) ,presence of metastases(P=0.04) ,and a more advanced tumor stage(P=0.02) ,whereas expression of VEGF was not. CONCLUSION:We suggest that endoglin is a potential marker to indicate and predict metastases,which might be useful in the post-resection therapeutic approach of patients with GEP-NETs.

THE EXPRESSION OF RECEPTORS FOR VASOACTIVE INTESTINAL PEPTIDE AND SECRETIN IN COLON NEOPLASMS

Objective: To investigate the expression of the receptors for vasoactive intestinal peptide (VIP) and secretin in colon cancer. Methods: This study visualized and characterized the receptors for VIP and secretin in the sequence of human tumor-free colon, adenoma, carcinoma, liver metastasis using storage phosphor autoradiography. Results: Receptors for VIP and secretin were demonstrated in tumor-free colon and colon tumors. A decrease in affinity of VIP receptors was shown in the colonic liver metastasis (Kd = 3.30 nmol) when compared with tumor-free colon (Kd = 0.82 nmol). An up-regulation of receptors for secretin was found in colonic liver metastases. Conclusions: VIP and secretin were both expressed on normal colon tissues. Binding of VIP decreased while secretin increased in colonic liver metastasis. A down-regulation of receptors for VIP in colonic liver metastases may helpful to understand the migration of colon cancer.