Fig. 7.

Cooperative effects of 1-benzyl-I3C and I3C with tamoxifen on the inhibition of DNA synthesis and stimulation in G1 phase arrested cells in MCF-7 cells. MCF-7 cells were treated with the indicated combinations of 100 μM I3C, 0.5 μM 1-benzyl-I3C (1-B-I3C) and/or 1 μM tamoxifen for 72 hours. The effects on DNA synthesis was monitored by pulsed labeling with 3 μCi [³H]thymidine during the last three hours of incubation (upper panel). The effects on the number of cells arrested in the G1 phase of the cell cycle was monitored by flow cytometry for DNA content of propidium iodide stained nuclei (lower panel). The reported data represent the mean of three independent experiments.