Biological characteristics of CD133(+) cells in nasopharyngeal carcinoma.

Cancer stem cells are regarded as the cause of tumour formation and recurrence in nasopharyngeal carcinoma (NPC). However, ideal surface markers for stem cells in NPC remain unidentified. In the present study, we investigated the expression of CD133, Nanog and Sox2 in the nasopharyngeal carcinoma cell line CNE2 and primarily cultured NPC cells using immunofluorescence or flow cytometry. A cell population with a CD133(+) phenotype was enriched using magnetic-activated cell sorting technology. We demonstrated that CD133(+) cells exhibited a strong potential for self-renewal, proliferation and differentiation and a greater potential for in vivo tumour formation in nude mice compared to CD133(-) cells, although the percentage of CD133(+) cells was small. However, the specific marker antigens Nanog and Sox2 were simultaneously expressed in normal cancer stem cells. Our results showed that CD133 can serve as a specific surface marker for nasopharyngeal cancer stem cells.