Fig. 5.

In vivo activity of LET +/− MK-8669 +/− MK-0646 in MCF-7/AC-1 xenografts. a As previously described, 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 ≥ 9 mice/cohort) and the appropriate treatments initiated (Control, LET, MK-8669, MK-0646, MK-8669 + MK-0646, LET + MK-0646, LET + MK-8669 or LET + MK-0646 + MK-8669) for a total of 28 days. Tumor volumes were measured weekly and depicted as percent change relative to day 0. Error bars represent SEM and results are representative of two independent experiments. b Tumors from treatment groups were collected 28 days post treatment initiation, immediately snap frozen and lysates pooled (n ≥ 3 samples/treatment cohort) for Western Blot analysis