[Carcinogenicity study of CD133(+)CD44(+) laryngeal cancer stem cells and identification of related microRNAs].

ABSTRACT

Objective: To compare the carcinogenic abilities of CD133(+)CD44(+) laryngeal cancer stem cells and general laryngeal cancer stem cells and to identify the mechanism underlying the action of miRNAs. Methods: Solid tumor-derived laryngeal carcinoma stem cells and Hep-2-derived laryngeal carcinoma stem cells were cultured, and CD133(+)CD44(+) laryngeal cancer stem cells were sorted by flow cytometry. Boden chamber invasion assay, cell migration assay and tumor formation assay were then performed to compare the invasion, migration and tumorigenic abilities of CD133(+)CD44(+) laryngeal cancer stem cells and general laryngeal cancer stem cells. And then, miRNAs isolated from two laryngeal cancer stem cells were detected and analysed with miRNA chip. Results: (1)In Boyden chamber invasion assay, the cell invasion rate of CD133(+)CD44(+) laryngeal cancer stem cells was obviously higher (80.2%±2.3% vs. 63.9%±3.2%, t=5.011, P=0.027); (2)CD133(+)CD44(+) laryngeal cancer stem cells also had higher mobility in cell migration assay (82.9%±1.1% vs. 70.9%±0.6%, t=4.514, P=0.031); (3)In tumor formation assay, the tumor formation rate of CD133(+)CD44(+) laryngeal cancer stem cells was also higher (80% vs. 50%). What's more, we identified 15 miRNAs that were significantly upregulated in CD133(+)CD44(+) laryngeal cancer stem cells and 3 miRNAs that were significantly downregulated in CD133(+)CD44(+) laryngeal cancer stem cells, compared with normal laryngeal cancer stem cells. Conclusions: CD133(+)CD44(+) laryngeal cancer stem cells have stronger invasion, migration and tumorigenic abilities compared with normal laryngeal cancer stem cells, and the difference of miRNAs' expression is one of the possible causes.