The MUC13 cell surface mucin is highly expressed by human colorectal carcinomas

Walsh MD, Young JP, Leggett BA, Williams SH, Jass JR, McGuckin MA (2007) The MUC13 cell surface mucin is highly expressed by human colorectal carcinomas. Human pathology 38:883-892

Mucins are complex mucosal glycoproteins that can be highly expressed by adenocarcinomas, having diagnostic, therapeutic, and biological significance. MUC13 encodes a cell surface membrane-anchored mucin expressed in the normal gastrointestinal tract, trachea, and kidney as well as colorectal, esophageal, gastric, pancreatic, and lung cancers. MUC13 protein expression was determined immunohistochemically in 99 sporadic colorectal cancers, assessing proportion of tumor cells stained, stain intensity, and localization. In normal colon, intense apical membrane and variable cytoplasmic MUC13 staining was present in both goblet and columnar cells, with strongest reactivity in the upper crypts and surface epithelium. All cancers showed staining of most tumor cells, being most conspicuous in the apical membranes of gland spaces. Left-sided tumors had a higher overall proportion of MUC13-positive tumor cells than right-sided tumors (P < .05),="" and="" high="" staining="" intensity="" was="" more="" frequent="" in="" adenocarcinomas="" (81%)="" than="" mucinous="" tumors="" (50%)="" (p="">< .05).="" poorly="" differentiated="" and="" late-stage="" tumors="" were="" more="" likely="" to="" have="" high-intensity="" cytoplasmic="" staining="" (p="">< or=".025)." basolateral="" cell="" membranes="" were="" stained="" in="" 24%="" of="" cases,="" being="" more="" common="" in="" poorly="" differentiated="" tumors="" (55%)="" than="" well="" or="" moderately="" differentiated="" tumors="" (16%)="" (p="">< or=".001)." partial="" or="" full="" circumferential="" muc13="" staining="" was="" frequently="" observed="" in="" areas="" of="" tumor="" budding.="" although="" muc13="" immunoreactivity="" was="" not="" predictive="" of="" patient="" outcome,="" there="" was="" a="" trend="" toward="" poorer="" outcome="" in="" patients="" with="" tumors="" showing="" basolateral="" muc13.="" in="" summary,="" muc13="" was="" expressed="" abundantly="" by="" all="" colorectal="" cancers,="" with="" the="" highest="" expression="" in="" more="" poorly="" differentiated="">