CD133 Expression Pattern Distinguishes Intraductal Papillary Mucinous Neoplasms From Ductal Adenocarcinomas of the Pancreas

OBJECTIVES: The rate of intraductal papillary mucinous neoplasm (IPMN) progression is much slower than that of invasive ductal adenocarcinomas. The identification of a clinicopathological marker to distinguish IPMNs from ductal adenocarcinomas is important for understanding the molecular mechanisms of pancreatic cancer. METHODS: We examined the expression pattern of the cell surface marker CD133, which has been used to identify putative cancer stem cells from solid tumors, in adult pancreatic ductal adenocarcinomas (n = 10) and IPMNs (n = 34). RESULTS: CD133 expression was detected in the centroacinar region and intralobular ductal cells of normal pancreas. CD133 expression was also observed in ductal adenocarcinomas. In contrast, CD133 expression was not observed in the mucin-producing epithelial cells and carcinoma cells on IPMNs. CONCLUSIONS: These results demonstrate that the expression of CD133 is down-regulated in IPMNs, suggesting that loss of CD133 expression might be a useful clinicopathological marker distinguishing IPMNs from ductal adenocarcinomas.