Resveratrol Impedes the Stemness, Epithelial-Mesenchymal Transition, and Metabolic Reprogramming of Cancer Stem Cells in Nasopharyngeal Carcinoma through p53 Activation
Figure 1
The concept and process validation of NPC CSC isolation achieved by behavior selection. (a) The concept of behavior selection is based on CSC properties, which are resistance to irradiation and drugs, long-term self-renewal, and antianoikis. Through the behavior selection platform, abundant and high-purity CSCs could be obtained. (b) After four rounds of 11 Gy irradiation selection, radioresistant clones (RR) of TW01, TW06, and HONE-1 were established. Further colony formation assays of these radioresistant cells and parental cells (PT) were performed with seeding 5 × 103 cells after 10 Gy irradiation. Representative images are macroscopically visible survival colonies after fixation and crystal violet staining. Radioresistant cells show distinct radioresistant phenotype. (c) After irradiation selection, tumor sphere selection was performed. Compared with parental cells, radioresistant clones could generate more and larger spheres. Scale bars indicate 100 μm. (d) Side population assay shows that TW01 parental cells (left panel) contained less side population cells compared with tumor sphere cells (right panel). The top panel represents the cells incubated with Hoechst 33342. A subset of side population cells pumped out of the Hoechst dye by ABC transporters and demonstrated low fluorescence expression. The bottom panel shows that the gating proportion is reduced from 0.15% to 0.11% in parental cells and from 31.59% to 0.28% in tumor sphere cells after fumitremorgin C (FTC) treatment. FTC can block the ABC transporters and result in full side population efflux inhibition.
