Fig. 1.

IGF-1R inhibition (MK-0646) does not enhance hormonal therapy (letrozole or tamoxifen) in MCF-7/AC-1 xenografts. Ovariectomized female nu/nu mice between the ages of 7–8 weeks old were inoculated with MCF-7/AC-1 tumor cells in each flank and immediately supplemented with androstenedione (100 μg/day). Once bilateral flank tumors (both left and right) reached the appropriate size (250–300 mm³), mice were randomized (n ≥ 8 mice/cohort) and the appropriate treatments initiated (control, MK-0646, letrozole (LET), LET + MK-0646, tamoxifen (TAM), TAM + MK-0646) for a total of 28 days. Tumor volumes were measured twice weekly and depicted as percent change relative to day 0. Error bars represent SEM and results are representative of three independent experiments