@article{c0141731486142d9a4365aaa3c0e14cf,
title = "The DNA binding and accumulation of p53 from breast cancer cell lines and the link with serine 15 phosphorylation",
abstract = "Stress treatment generally causes the post-translational modification and accumulation of the p53 protein, although the role of these aspects has not been always understood in relation to this protein's tumor suppressor activity. We analyzed these attributes of p53 in eight different breast cancer cell lines, with either wild-type or mutant p53 protein, in response to oxidative stress. We found that the wild-type p53 protein from MCF-7 and ZR-75-1 cells binds with different affinity to 12 gene sequences covering several pathways regulated by p53. Treatment of MCF-7 cells with H2O2 caused an increase in this binding affinity while this same treatment of ZR-75-1 cells caused the p53 protein to lose binding affinity to several genes. The mutant p53 proteins from all cell lines had minimal to weak binding to these sequences even after treatment with H2O2. The p53 protein from the ZR-75-1 cells and three cell lines with mutant p53 showed serine 15 phosphorylated protein, but we found no correlation between that modification and the levels or localization of this protein although DNA binding affinity of wild-type protein might be affected by this modification. From this and other work, it appears that the mutation status of the TP53 gene alone cannot predict the activity of this tumor suppressor since cell lines with the same genetic information do not show the same properties of this protein.",
author = "Debolina Ray and Murphy, {Keith R.} and Susannah Gal",
note = "Funding Information: p53 was quantitated in the same way and compared with the The authors would like to thank Dr Dennis McGee (Binghamton density of the total p53 detected on a blot using the DO-7 University) for the use of his tissue culture facilities for part of the antibody. work, Dr Gokul Das (Roswell Park Cancer Institute) for provid-Electrophoretic mobility shift assay. An aliquot of nuclear ing some of the cells, Nancy Monteith for assistance with some p53 (50 pg, as estimated from ELISA) was allowed to react with of the tissue culture, and Matthew T. Balmer and Rebecca S. 20 pmol of biotinylated double stranded DNA sequence (custom Young for helpful discussions. The work was supported by grants synthesis by Integrated DNA Technologies) as described.13 The from the Upstate New York Translational Research Network reaction mixture was separated on a 5% TBE (Tris borate EDTA) and the Bella Fund, both to S.G., a grant from the NIH (R15 polyacrylamide gel (BioRad; 456-5013) and transferred to a nylon GM-093941) to support D.R., and a grant to the State University membrane. The membrane was subsequently blocked in 5% BSA of New York at Binghamton from the Howard Hughes Medical in 1x PBST. The membrane was incubated with alkaline phos-Institute through the Precollege and Undergraduate Science phatase conjugated streptavidin at a dilution of 1:10,000 (Cell Education Program to support K.R.M. Signaling; 7055). The membrane was subsequently developed colorimetrically with the BCIP (5-bromo-4-chloro-3-indolyl-SupplementalMaterial phosphate)/NBT (nitro blue tetrazolium) substrate (Kirkegaard Supplemental materials may be found here: and Perry Laboratories, Inc., 50-81-18). www.landesbioscience.com/journals/cbt/article/20835",
year = "2012",
month = aug,
doi = "10.4161/cbt.20835",
language = "English (US)",
volume = "13",
pages = "848--857",
journal = "Cancer Biology and Therapy",
issn = "1538-4047",
publisher = "Taylor and Francis Ltd.",
number = "10",
}