Honokiol Eliminates Human Oral Cancer Stem-Like Cells Accompanied with Suppression of Wnt/β-Catenin Signaling and Apoptosis Induction
Figure 1
SAS SP cells possessed the properties of stem cells. (a) Spheroidal morphology of SP cells and fibroblast-like shape of Non-SP cells after 7 days of culture. The SP and Non-SP cells were sorted by Hoechst 33342 staining as indicated in the flow cytometry histogram and the gated region for dye excluding SP cells was identified by verapamil as described in Section 2. (b) SP cells had markedly higher clonogenicity than the Non-SP cells. The colonies formed were counted as described in materials and methods. (c) The mRNA expressions of multiple drug resistance genes (ABCG2, ABCC5) and epithelial cell adhesion molecule (EpCAM) in SP cells were much higher than those in Non-SP cells (GAPDH expression used as loading control). (d) The SP cells expressed much higher mRNA levels of stemness markers Oct-4, CD133, CD44, and β-catenin than the Non-SP cells (GAPDH expression used as loading control). (e) Flow cytometric analysis of stem cell markers expression in SP and Non-SP cells. The histograms display the expression of Oct-4, CD133, and CD44 in SP and Non-SP cells (I-SP, I-Non-SP: isotype control of SP and Non-SP cells, resp.; N: Non-SP cells; S: SP cells; the I-SP and I-Non-SP in the histograms of Oct-4 and CD44 are almost overlapped.).
