Inhibition of RAD51 by siRNA and Resveratrol Sensitizes Cancer Stem Cells Derived from HeLa Cell Cultures to Apoptosis

Figure 5

Resveratrol decreases viability and increases apoptosis of sphere cultures. (a and b) RESveratrol (RES) induces higher apoptosis levels of HeLa SPhere (SP) cultures compared to controls. Ethanol was used as vehicle. Apoptosis was evaluated by Annexin-V assay. (c) RES induced cell cycle arrest at S phase in both HeLa ML and SP cultures. HeLa cells under both conditions were treated with 137 μM of RES for 72 h, and then, cells were harvested and stained with propidium iodide (PI) for 30 min at 37°C. Cells were then subjected to flow cytometric analysis to determine the cell distribution at each phase of the cell cycle. (d) Graphics show fluorescence distribution for antibody isotype (control) and CD49f-PE antibody. Histogram graphs show that CD49f-positive subpopulation decreases significantly when HeLa SP enriched in CSC are treated with resveratrol for 72 h (from 84% to 16%). The detection of CD49f cells involves the fixation and stain with CD49f-PE antibody for 45 min or isotype (see Materials and Methods). .

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