Figure 2. Phenotypic analysis of tumor cells.

(a) CD117 and CD133 staining of tumor cells. Mice salivary gland tumor cells were divided into CD44^neg, CD44^int, and CD44^hi subpopulations via FACS; each subpopulation was analyzed for CD117 and CD133 expression. (b) BrdU incorporation. BrdU was injected into tumor-bearing mice at 50 mg/kg twice daily for 5 days, then half of the mice were sacrificed and half were rested for 4 weeks before CD44 and BrdU analysis. (n = 5 each group, * p<0.05 t-test). (c) Comparison of transcript levels for stem cell related genes in CD44^neg and CD44^hi tumor cells. Transcripts levels for all four genes were higher in CD44^hi cells than in CD44^neg cells (p<0.05, t-test).