Table 1.

Quantitation of p53 abundance by flow cytometry

Cell line–gated on p53%Low p53%High p53Median lowMedian highMedian overall
1975-no caffeine15.616.713,17356,23628,386
1975-caffeine22.111.413,87856,52323,752
MDA-MB231-no caffeine15.51624,18599,97848,545
MDA-MB231-caffeine22.310.523,62297,28343,054
U20S-no caffeine1615.84,81029,95117,454
U20S-caffeine3.445.63,18032,15225,935
H1048-no caffeine15.715.928,84895,28556,699
H1048-caffeine33.56.227,44491,85544,920
H1048-MG13219.38.528,82290,10850,980
H1048-MG132 + caffeine19.410.328,18190,68752,022
WI38-no caffeine15.715.814,10559,95239,757
WI38-caffeine8.822.98,99860,33444,033
ABC1 shGFP-0h1615.32,0756,9534,349
ABC1 shGFP-3h caffeine28.372,2146,8773,637
ABC1-shMdm2-0h1616.49262,6321,723
ABC1 shMdm2-3h caffeine15.617.19552,6711,742
Cell line–gated on H2AX% Low p53% High p53Median lowMedian highMedian overall
H1048 γH2AX-Pi non-dox15.114.81,1874,0912,233
H1048 γH2AX-Pi dox8.820.71,2424,1322,506
Cell line–gated on ATM% Low p53% High p53Median lowMedian highMedian overall
H1048 control si15.915.211,64134,36720,973
H1048 ATM si42.57.516,17942,76220,466
Cell line–gated on p-ATM% Low p53% High p53Median lowMedian highMedian overall
H1048 p-ATM15.514.518,86245,85234,385
  • NOTE: The median level of mutant p53 as measured by flow cytometry using indicated antibodies (see Materials and Methods) in each overall cell population, and in the low and high p53, γH2AX-Pi, ATM, or p-ATM abundance gates, is shown in the last three columns, along with the percentage of cells in the low and high p53, γH2AX-Pi, ATM, or p-ATM abundance gates in the first two columns. All differences (increase or decrease) in median overall intensity for pairwise combinations of control and treatment (±caffeine, ± doxorubicin, or siControl vs. siATM) for each cell line were P < 0.05.

  • Abbreviation: dox, doxorubicin.