Figure 3

Effects of EGCG on tumor spheroids and cell viability of prostate cancer stem cells (CSCs). (A), Prostate CSCs were seeded in suspension and treated with EGCG (0-60 μM) for 7 days. Pictures of spheroids formed in suspension were taken by a microscope. (B), Prostate CSCs were seeded in suspension and treated with EGCG (0-60 μM) for 7 days. At the end of incubation period, all the spheroids were collected and resuspended. Cell viability was measured by trypan blue assay. Data represent mean ± SD. *, #, % or ## = significantly different from control, P < 0.05. (c), EGCG inhibits colony formation by prostate CSCs. Prostate CSCs were seeded in soft agar and treated with various doses of EGCG and incubated at 4°C for 21 days. At the end of incubation period, colonies were counted. Data represent mean ± SD. * or # = significantly different from respective controls, P < 0.05. (D), Transwell migration assay. Prostate CSCs were plated in the top chamber of the transwell and treated with EGCG (0-60 μM) for 24 h. Cells migrated to the lower chambered were fixed with methanol, stained with crystal violet and counted. Data represent mean ± SD. * or # = significantly different from respective controls, P < 0.05. (E) Matrigel invasion assay. Prostate CSCs were plated onto the Matrigel-coated membrane in the top chamber of the transwell and treated with EGCG (0-60 μM) for 48 h. Cells invaded to the lower chambered were fixed with methanol, stained with crystal violet and counted. Data represent mean ± SD. * or # = significantly different from respective controls, P < 0.05.