Characterization of colon cancer cells: a functional approach characterizing CD133 as a potential stem cell marker

Background: Isolation and characterization of tumourigenic colon cancer initiating cells may help to develop novel diagnostic and therapeutic procedures. Methods: We characterized a panel of fourteen human colon carcinoma cell lines and their corresponding xenografts for the surface expression of different potential stem cell markers: CD133, CD24, CD44, CDCP1 and CXCR4. In five cell lines and nine xenografts mRNA expression of the investigated markers was determined. Tumour growth behaviour of CD133+, CD133- and unsorted SW620 cells was evaluated in vivo. Results: All surface markers showed distinct expression patterns in the examined tumours. Analyses of the corresponding xenografts revealed a significant reduction of cell numbers expressing the investigated markers. CD44 and CXCR4 mRNA expression correlated within the cell line panel and CD44 and CDCP1 within the xenograft panel, respectively. Small subpopulations of double and triple positive cells could be described. SW620 showed significantly higher take rates and shorter doubling times in vivo when sorted for CD133 positivity. Conclusion: Our data support the hypothesis of a small subset of cells with stem cell-like properties characterized by a distinct surface marker profile. In vivo growth kinetics give strong relevance for an important role of CD133 within the mentioned surface marker profile.

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Schneider M, Huber J, Hadaschik B, Siegers GM, Fiebig HH, Schüler J