Supplemental Data p53 and p21 Regulate Error-Prone DNA Repair to Yield a Lower Mutation Load

Cell cultures. The H1299 cell line derived from a human large cell lung carcinoma (Brower et al., 1986), and Hep3B hepatoma cells do not express p53 (Bressac et al., 1990). H1299Val135 and 4BV cells were derived by stable transfection of H1299 and Hep 3B, respectively, with DNA encoding the temperature-sensitive mouse p53 mutant, p53Val135 (Michalovitz et al., 1990). Cells from p53-deficient, p21-deficient, and wild-type mouse embryonic fibroblasts were previously described (de Rozieres et al., 2000). H1299 and H1299Val135 cells were cultured in RPMI 1640 medium. Cells from the other cell lines and the MEF cells were maintained in Dulbeco’s Modified Engle’s Medium (DMEM). Each medium was supplemented with 10 % fetal bovine serum, 100 units/ml of penicillin and 100 µg/ml of streptomycin. The cells were incubated at 37oC in a 5% CO2 atmosphere. Construction of a gapped plasmid with a site-specific cisplatin-GG adduct. A gapped plasmid carrying a site-specific cisplatin-GG adduct (GP-cisPtGG1) was prepared using a procedure similar to the preparation of the gap-plasmid with a site-specific BP-G adduct (Avkin et al., 2004). A site-specifically modified 12-mer oligonucleotid