Figure 3.

Leptin inhibition of the antiestrogenic effect of tamoxifen under estradiol stimulated conditions in MCF-7 and T-47D cells. In MCF-7 cells with estradiol 10 nM stimulation, leptin had no effect on the activity of tamoxifen for each combination treatment (A). At estradiol 20 nM stimulation, when leptin 50 ng/mL was added to tamoxifen treatment, leptin significantly inhibited the 10 and 20 µM tamoxifen responses (B). In T-47D cells, leptin 50 ng/mL had an inhibitory effect on tamoxifen 10 µM with estradiol 10 and 20 nM (C and D, respectively). There was no significant difference between leptin 100 ng/mL treatment and no leptin treatment. With tamoxifen 20 µM, cell viability was notably decreased compared to tamoxifen 10 µM treatment, and there was no difference between each combination. All cell viability results are expressed by the ratio of comparison to control (no treatment) group.