Table 1.
Effect of 4 Gy Irradiation on Mean Maximal Increase in p53 and Related Protein Expression and Time after Irradiation, Clonogenic Survival, and Apoptosis Relative to Untreated Controls in Cell Lines Studied
| Cell line | p53 status | p53* | Hours | MDM2 | Hours | WAF1 | Hours | Clonogenic survival† (%) | Apoptosis‡ (%) maximum (hours) |
|---|---|---|---|---|---|---|---|---|---|
| Neuroblastoma | |||||||||
| SHSY5Y | WT | 11.5 (0.1) | 4–6 | 13.8 (7.9) | 6 | 19.1 (13.9) | 6 | 5.05 (3.64–7.02) | 14.46 (96) |
| SHEP | WT | 2.1 (0.4) | 2 | 4.4 (0.1) | 4–6 | 2.1 (0.9) | 6 | 19.28 (14.00–26.54) | 2.3 (108) |
| SKNSH | WT | 18.6 (10.7) | 4–6 | 15.4 (11.2) | 4–6 | 6.1 (2.4) | 6–24 | 0.66 (0.22–1.97) | 35.31 (24) |
| IMR32 | WT | 24.7 (10.1) | 2 | 4.4 (1.3) | 4–6 | 11.4 (8.6) | 6–24 | 0.10 (0.02–0.41) | 5.64 (48) |
| NGP | WT | 3.4 (2.2) | 2 | 2.0 (1.0) | 4–6 | 8.2 (2.1) | 6–24 | 2.24 (1.62–3.10) | 32.03 (96) |
| SKNBE(2c) | Mut | N/C | N/C | N/D | 16.33 (11.36–23.48) | 7.02 (108) | |||
| Controls | |||||||||
| NB100 | Mut | N/D | N/C | N/D | 8.78 (5.41–14.25) | 13.03 (108) | |||
| MCF7 | WT | 4.9 (1.6) | 4 | 6.4 | 6 | 5.5 (1.6) | 6–24 | 2.15 (1.64–2.81) | 5.55 (108) |
| SAOS2 | Null | N/D | N/C | N/D | 4.28 (3.16–5.80) | 10.93 (108) |
*Mean maximal protein induction (±SD of at least two independent experiments) measured by densitometry relative to control and loading control actin. If <2-fold change = N/C. 50 μg total protein on Western blots.
†Mean (95% confidence interval) of three independent experiments set up in quadruplicate.
‡Apoptosis assessed by nuclear staining with Hoechst 33258. Maximum recorded value of three experiments.
WT, wild-type; Mut, mutant; N/C, no change; N/D, not detectable.