Figure 5

EGCG increases the stress sensitivity of MCF-7 cells. The cells were treated with EGCG for 24 h and then heat shocked (44°C for 1 h) or treated with H₂O₂ (500 μM, 37°C for 24 h). (A), (B) Cell viability was measured by MTT assay. Asterisk, P < 0.005, significantly different from the cells treated with heat shock or H₂O₂ alone. (C), (D) The levels of HSP70 and HSP90 were monitored by Western blot analysis.