p53 and DNA concentration in the fibroblast-populated collagen matrix. (A) Immunoblot of p53 in attached vs. released matrices at indicated time post-release in two strains (F1 & F2; loaded with equal cell number; F1 data reproduced from previous work ). (B) Immunoblot of p53 and GAPDH in attached vs. released matrices for strain F3 (loaded with equal cell number). (C) Immunoblot of p53 in attached matrices for strains F4 vs. F5 over 2 weeks (loaded with equal cell number). (D) Densitometry of p53 bands in panel C (mean ± sd of 3 experiments). (E) Lysate [DNA] of attached matrices from responder (R; n = 6) vs. nonresponder (NR; n = 9) strains, with sample p53 immunoblot under each plot. Correlation coefficient shown is from nonparametric Wilcoxon testing. (F) Lysate [DNA] for data in panel D (upper), and p53 signal normalized to lysate [DNA] (lower); mean ± sd of 3 experiments. *p < 0.05, ANOVA.