Fig. 2.

p53 status and the rate of tumor cell elimination upon MYC inactivation. (A) Measurement of tumor cell elimination upon MYC inactivation. p53 wild-type (p53⁺), p53 negative (p53⁻), and p53 restored (p53⁻ to ⁺) tumor cells were retrovirally labeled with luciferase before s.c. injection into syngeneic mice. Mice were serially imaged by bioluminescence imaging at the indicated times, before and after MYC inactivation, to monitor transplanted tumor growth (MYC On) and tumor regression upon doxycycline treatment (100 μg/ml) (MYC Off). A summary of changes in luciferase activity is shown. Each cohort consisted of at least 5 mice. Representative data from one of three experiments is shown. (B) Representative images of bioluminescence imaging.