Chemoresistance of CD133+ cancer stem cells in laryngeal carcinoma.

BACKGROUND: Mounting evidence suggests that tumors are histologically heterogeneous and are maintained by a small population of tumor cells termed cancer stem cells. CD133 has been identified as a candidate marker of cancer stem cells in laryngeal carcinoma. This study aimed to analyze the chemoresistance of CD133(+) cancer stem cells.

METHODS: The response of Hep-2 cells to different chemotherapeutic agents was investigated and the expression of CD133 was studied. Fluorescence-activated cell sorting analysis was used to identify CD133, and the CD133(+) subset of cells was separated and analyzed in colony formation assays, cell invasion assays, chemotherapy resistance studies, and analyzed for the expression of the drug resistance gene ABCG2.

RESULTS: About 1% - 2% of Hep-2 cells were CD133(+) cells, and the CD133(+) proportion was enriched by chemotherapy. CD133(+) cancer stem cells exhibited higher potential for clonogenicity and invasion, and were more resistant to chemotherapy. This resistance was correlated with higher expression of ABCG2.

CONCLUSIONS: This study suggested that CD133(+) cancer stem cells are more resistant to chemotherapy. The expression of ABCG2 could be partially responsible for this. Targeting this small population of CD133(+) cancer stem cells could be a strategy to develop more effective treatments for laryngeal carcinoma.