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. Author manuscript; available in PMC: 2016 May 5.
Published in final edited form as: JAMA. 2015 Nov 3;314(17):1850–1860. doi: 10.1001/jama.2015.13134

Figure 4. Apoptosis Response Relative to Number of Copies of TP53.

Figure 4

Percentage of apoptosis is shown for peripheral blood lymphocytes treated with 2 Gy of ionizing radiation from 10 individuals with Li-Fraumeni syndrome (with 1 functioning TP53 allele), 10 healthy controls (with 2 TP53 alleles), and 1 African elephant tested in 3 independent experiments (with 40 TP53 alleles). Ionizing radiation–induced apoptosis increased proportionally with additional copies of TP53 and inversely correlated with cancer risk. Experiments performed in quadruplicate for each individual and each colored box represents the mean percentage of cells in late apoptosis as measured by flow cytometry (percentage of annexin V–positive [AV+] and propidium iodide–positive [PI+] treated cells minus AV+PI+ untreated cells). The healthy control lymphocytes underwent more apoptosis than those from LFS patients (P < .001), and elephant lymphocytes underwent more apoptosis than those from healthy controls (P < .001 by 2-sided t test). Horizontal lines indicate the combined mean for all data points in each group with error bars indicating 95%CIs.