Fig. 9.

Combination therapy with gemcitabine and digoxin prevents tumor relapse. MDA-MB-231 cells were implanted into the mammary fat pad of female Scid mice. When a tumor was palpable (day 1), the mice were randomized to three groups, which were treated with i.p. injections of: saline, gemcitabine [20 mg/kg on days 5, 10, 15, 20, and 25 (arrows)], or gemcitabine and digoxin (2 mg/kg on days 1–25). Tumor volumes were determined every 2–3 d and mean ± SEM (n = 3) are shown. The saline-treated mice were euthanized (E) on day 24 when tumor volume exceeded 1,000 mm³. The experiment was terminated on day 32, 7 d after treatment was discontinued. *P < 0.001 by Student's t test.