Effect of EGCG on cell survival. MM cells were cultured in the medium containing no EGCG or various concentrations of EGCG ranging from 0.1 to 10 μM. Cells were harvested at different time points as indicated and proliferative potential was assessed by trypan blue exclusion or ³H-thymidine labeling. The growth curves show the mean of 3 independent experiments, with SEM. (A) IL-6-dependent INA6 myeloma cells. (B) ARP myeloma cells. (C) OPM1 myeloma cells. (D) Myeloma cell lines MM1S, INA6, OPM1, 8226, and Waldenstrom cells (BCWM) were treated with 10 and 20 μM EGCG for 72 hours and proliferative potential was assessed by ³H-thymidine incorporation. (E) Three samples of CD138⁺ purified myeloma cells derived from patient bone marrow were treated with 10 and 20 μM EGCG for 72 hours and cell proliferation was evaluated by ³H-thymidine incorporation. (F) Effect of EGCG treatment in normal diploid fibroblasts and PBMCs from a healthy donor at days 1, 3, and 5. (G) Effect of EGCG on proliferation of PBMC from healthy donors is shown by trypan blue exclusion and ³H-thymidine incorporation, following 72 h treatment with 10 and 20 μM drug. (H) PBMCs from healthy donors (donors 4 and 5) were activated with anti-CD3 antibody, treated with 10 μM EGCG for 72 hours, and cell proliferation was evaluated by ³H-thymidine incorporation.