CD133(+) CD44(+) Cells Mediate in the Lung Metastasis of Osteosarcoma.

CD133 and CD44 are commonly used markers of cancer stem cells (CSCs), which are characterized by their ability for self-renewal and tumorigenicity. However, the clinical value and significance of CD133 and CD44 in lung metastasis of osteosarcoma (OS) remains controversial. The purpose of this study was to investigate whether CD133(+) CD44(+) cells mediates the metastasis of OS. We identified the CD133(+) CD44(+) cells in lung metastatic lesions and OS cell lines, and next demonstrated CD133(+) CD44(+) cells were more aggressive in sphere formation, migration and invasiveness compared with CD133(+) CD44(-) , CD133(-) CD44(+) , or CD133(-) CD44(-) cells. We finally sorted the CD133(+) CD44(+) and CD133(-) CD44(-) cells from Saos-2 cell lines, after intratibial xenograft in nude mice, these cells developed primary tumors, and CD133(+) CD44(+) cells are more potential to form lung metastatic tumors. Thus we concluded that CD133(+) CD44(+) cells may mediate in the lung metastasis of OS.