Expression of intestinal MUC17 membrane-bound mucin in inflammatory and neoplastic diseases of the colon.
OBJECTIVE
To determine the cellular location and expression of MUC17 mucin in specimens of normal, inflamed and neoplastic colon.


METHODS
Immunohistochemical analysis of human surgical resection specimens (n=106) was performed with a specific antibody to the MUC17 apomucin protein. A semi-quantitative scoring system was used to measure MUC17 expression. In various colon cancer cell lines, the MUC17 expression was examined by immunoblot analysis and normal RT-PCR.


RESULTS
MUC17 was highly expressed on the surface epithelium and crypts of colonic mucosa. In contrast, the expression of MUC17 was significantly decreased in colonic mucosa of chronic ulcerative colitis (p<0.0001) and ischaemic colitis (p=0.003). Similarly, MUC17 expression was decreased in hyperplastic polyps (p=0.0003), tubular and tubulovillous adenomas (p<0.0001) and colon cancers (p<0.0001). Furthermore, of eight different colon cancer cell lines, MUC17 expression was only detected in LS174T and LS180 cells.


CONCLUSIONS
Results indicate that the potential protective effects of this membrane-bound mucin are primarily or secondarily diminished in inflammatory and neoplastic conditions. Further research is needed to determine the specific role of MUC17 in the pathogenesis of these conditions.
Senapati
Shantibhusan
S
Department of Biochemistry and Molecular Biology, University of Nebraska, Omaha, Nebraska, USA.
Ho
Samuel B
SB
Sharma
Poonam
P
Das
Srustidhar
S
Chakraborty
Subhankar
S
Kaur
Sukhwinder
S
Niehans
Gloria
G
Batra
Surinder K
SK
D000230:Adenocarcinoma / Q000378:metabolism; D000236:Adenoma / Q000378:metabolism; D003092:Colitis / Q000378:metabolism*; D017091:Colitis, Ischemic / Q000378:metabolism; D003093:Colitis, Ulcerative / Q000378:metabolism; D003106:Colon / Q000378:metabolism / Q000473:pathology; D003110:Colonic Neoplasms / Q000378:metabolism*; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D009077:Mucins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014407:Tumor Cells, Cultured
C450720:MUC17 protein, human; D009077:Mucins