Background/aim: The cancer stem cell model suggests that only a rare subpopulation, known as cancer stem cells (CSC) are responsible for tumor initiation. CSC from several human carcinomas are characterized by specific cell surface markers, such as CD133. The CD133 role in colon tumorigenesis remains controversial.
Materials and methods: CD133 was evaluated by immunohistochemistry in a mouse model of colitis-related colon tumorigenesis induced by a combined treatment with azoxymethane (AOM) and dextran sodium sulphate (DSS).
Results: In normal tissue rare scattered positive cells were detectable at the bottom of the crypts. The percentage of positive cells significantly increased in dysplastic lesions and appeared to progressively decrease in the passage from dysplasia to adenoma and then to cancer, although always remaining greater in number than in the normal tissue.
Conclusion: An increased CD133 expression occurs at early stages of colon tumorigenesis in the mouse. CD133-expressing cells might play an important role from the earlier phase and throughout the entire process of colon cancer development.