The urotensin-II receptor: A marker for staging and steroid outcome prediction in ulcerative colitis

BACKGROUND

Urotensin-II receptor- (UTR) related pathway exerts a key-role in promoting inflammation. The aim was to assess the relationship between UTR expression and clinical, endoscopic and biochemical severity of ulcerative colitis (UC), exploring its predictivity of intravenous (iv) steroid administration therapeutic outcome.

METHODS

One-hundred patients with first diagnosis of UC and 44 healthy subjects were enrolled. UTR expression was assessed by qPCR, Western Blot (WB) and immunohistochemistry (IHC). Clinical, endoscopic and histological activity of UC were evaluated by using Truelove and Witts (T&W) severity index, Mayo Endoscopic Score (MES), and Truelove and Richards Index (TRI). The partial and full Mayo scores (PMS and FMS) were assessed to stage the disease.

RESULTS

The UTR expression, resulted higher in the lesioned mucosa of UC patients in comparison to healthy subjects (p < .0001 all). Direct relationship between UTR (mRNA and protein) expression and disease severity assessment (T&W, PMS, MES and TRI) was highlighted (p < .0001 all). UTR expression resulted also higher in the 72 patients requiring iv steroids administration compared to those who underwent alternative medications, (p < .0001). The 32 steroid-non-responders showed an increased UTR expression (WB, IHC and qPCR from lesioned mucosa), compared to 40 steroid-responders (p: .0002, .0001, p < .0001 respectively). The predictive role of UTR expression (p < .05) on the negative iv steroids administration therapeutic outcome was highlighted and ROC curves identified the thresholds expressing the better predictive performance.

CONCLUSIONS

UTR represents a promising inflammatory marker related to clinical, endoscopic, and histological disease activity as well as a predictive marker of steroid administration therapeutic outcome in the UC context.

Urotensin-II receptor is over-expressed in colon cancer cell lines and in colon carcinoma in humans

BACKGROUND

Urotensin (U)-II receptor (UTR) has been previously reported to be over-expressed in a number of tumours. Whether UTR-related pathway plays a role in colon carcinogenesis is unknown.

METHODS

We evaluated UTR protein and mRNA expression in human epithelial colon cancer cell lines and in normal colon tissue, adenomatous polyps and colon cancer. U-II protein expression was assessed in cancer cell lines. Moreover, we evaluated the effects of U-II(4-11) (an UTR agonist), antagonists and knockdown of UTR protein expression through a specific shRNA, on proliferation, invasion and motility of human colon cancer cells.

RESULTS

Cancer cell lines expressed U-II protein and UTR protein and mRNA. By immunohistochemistry, UTR was expressed in 5-30% of epithelial cells in 45 normal controls, in 30-48% in 21 adenomatous polyps and in 65-90% in 48 colon adenocarcinomas. UTR mRNA expression was increased by threefold in adenomatous polyps and eightfold in colon cancer, compared with normal colon. U-II(4-11) induced a 20-40% increase in cell growth while the blockade of the receptor with specific antagonists caused growth inhibition of 20-40%. Moreover, the knock down of UTR with a shRNA or the inhibition of UTR with the antagonist urantide induced an approximately 50% inhibition of both motility and invasion.

CONCLUSIONS

UTR appears to be involved in the regulation of colon cancer cell invasion and motility. These data suggest that UTR-related pathway may play a role in colon carcinogenesis and that UTR may function as a target for therapeutic intervention in colon cancer.