Neurotensin receptor 1 overexpression in inflammatory bowel diseases and colitis-associated neoplasia

AIM: To explore the association of neurotensin receptor 1 (NTSR1) with inflammatory bowel diseases (IBD) and colitis-associated neoplasia. METHODS: NTSR1 was detected by immunohistochemistry in clinical samples of colonic mucosa with IBD colitis, colitis-associated raised low-grade dysplasia (LGD) including dysplasia-associated lesions or masses (DALMs, n = 18) and adenoma-like dysplastic polyps (ALDPs, n = 4), colitis-associated high-grade dysplasia (HGD, n = 11) and colitis-associated colorectal carcinoma (CACRC, n = 13), sporadic colorectal adenomatous polyp (SAP, n = 17), and sporadic colorectal carcinoma (SCRC, n = 12). The immunoreactivity of NTSR1 was semiquantitated (as negative, 1+, 2+, and 3+) and compared among different conditions. RESULTS: NTSR1 was not detected in normal mucosa but was expressed similarly in both active and inactive colitis. LGD showed a significantly stronger expression as compared with non-dysplastic colitic mucosa, with significantly more cases showing > 2+ intensity (68.75% in LGD vs 32.26% in nondysplastic mucosa, P = 0.001). However, no significant difference existed between DALMs and ALDPs. CACRC and HGD showed a further stronger expression, with significantly more cases showing 3+ intensity than that in LGD (61.54% vs 12.50% for CACRC vs LGD, P = 0.022; 58.33% vs 12.50% for CACRC/HGD vs LGD, P = 0.015). No significant difference existed between colitis-associated and non-colitic sporadic neoplasia. CONCLUSION: NTSR1 in colonic epithelial cells is overexpressed in IBD, in a stepwise fashion with sequential progress from inflammation to dysplasia and carcinoma.