The Wnt target LGR5 has been recently identified as a murine intestinal stem cell marker. Its role during each stage of human colorectal tumorigenesis remains to be determined.

LGR5 expression was investigated by immunohistochemical analysis in 17 low-grade and 13 high-grade intraepithelial neoplasias and 30 adenocarcinomas.

The number of LGR5-positive cells increased tumor, with clustering of the cells to form patches. An apparent difference in their distribution among the tumorigenesis stages was observed. LGR5 expression in luminal surface showed a negative association with the progressive grade of tumors, while that in lower crypt exhibited a positive association with grade. In adenocarcinomas, LGR5 expression in luminal surface was negatively associated with pStage, while it was almost invariably high in lower crypt during advanced pStage disease.

These results suggest that the shifts in the distribution of LGR5-positive cells towards the lower crypt play a role in the development and progression of colorectal cancer.

PMID: 21273608 [PubMed - indexed for MEDLINE] Source: National Library of Medicine.