Project 1: Roles and Regulation of Mutant p53 and ANp63 in Breast Cancer Cells Carol Prives, Ph.D. Increasing evidence supports the likelihood that, in stark contrast to wild-type p53, tumor-derived mutant forms of p53 play roles in fostering tumor development, invasion and metastasis. To gain insight into the mechanism by which mutant p53 may play a role in breast cancer we adopted the """"""""3D"""""""" protocol in which placing normal mammary epithelial cells (such as MCF10A cells) into an extracellular matrix-rich environment leads to their assembling into acinar structures with hollow lumens that resemble the terminal ducts of the mammary gland. We discovered that expression of mutant p53 in MCF10A cells leads to acini with filled rather than hollow lumens, while shRNA mediated down-regulation of mutant p53 in 2 breast cancer cell lines leads to reduced invasive behavior in one case (MDA-231 cells) and conversion of disordered structures into proper hollow acini in the other case (MDA-468 cells). To understand how mutant p53 prevents mammary cells from forming proper acini we will pursue the observation that mutant p53 up-regulates integrin ?4 in 3D culture conditions and integrin ?4 regulates invasive behavior in MD-231 cells. In collaboration with Scott Lowe and Arnold Levine we will pursue another discovery that mutant p53 increases levels of several enzymes involved in sterol biosynthesis when cell are plated in 3D culture conditions, and that treatment of such cells with statins leads to reduced invasive behavior and cell death. In each case we will seek the mechanism by which mutant p53 regulates these pathways. Another potential regulator of cell proliferation is the ?Np63a isoform of p63. We previously discovered that levels of ?Np63a are maintained by a novel protein (Stxbp4) and reduced by another protein (Rack 1) whose ability to induce degradation of ?Np63a is repressed by Stxbp4. We have now identified the APC/C E3 ubiquitin ligase complex as another regulator of ?Np63a turnover and have shown that it's degradation of ?Np63a is blocked by Stxbp4. Since our data and that of our co-program member Carlos Cordon-Cardo indicate that ?Np63 likely plays pro-proliferative and tumorigenic roles (including prevention of acinar luminal clearing in 3D cultures) we will elucidate the role of Stxbp4 in stabilizing ?Np63 and seek ways to prevent their interaction. Finally we will investigate the roles of p63 and p73 in regulation of formation of acinar like structures in the 3D culture setting and will determine whether the abilities of ?Np63a and mutant p53 to prevent luminal hollowing work by similar or different mechanisms.

Public Health Relevance

Both mutant forms of p53 and the AN forms of p63 have been implicated in breast and bladder cancer; two of the major forms of human cancer. The goal of this program is to determine the mechanisms by which mutant p53 and DeltaNp63 regulate novel pathways discovered under the auspices of this program that are involved in these and other forms of cancer. The experiments we propose in many cases are derived from and dependent on inter-program collaborations.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Program Projects (P01)
Project #
5P01CA087497-14
Application #
8706066
Study Section
Special Emphasis Panel (ZCA1-RPRB-O)
Project Start
Project End
Budget Start
2014-08-01
Budget End
2015-07-31
Support Year
14
Fiscal Year
2014
Total Cost
$437,376
Indirect Cost
$82,598
Name
Columbia University (N.Y.)
Department
Type
DUNS #
049179401
City
New York
State
NY
Country
United States
Zip Code
10027
Otaka, Yukihiro; Rokudai, Susumu; Kaira, Kyoichi et al. (2017) STXBP4 Drives Tumor Growth and Is Associated with Poor Prognosis through PDGF Receptor Signaling in Lung Squamous Cell Carcinoma. Clin Cancer Res 23:3442-3452
Zabala-Letona, Amaia; Arruabarrena-Aristorena, Amaia; Martín-Martín, Natalia et al. (2017) mTORC1-dependent AMD1 regulation sustains polyamine metabolism in prostate cancer. Nature 547:109-113
Agmon, Eran; Stockwell, Brent R (2017) Lipid homeostasis and regulated cell death. Curr Opin Chem Biol 39:83-89
Kastenhuber, Edward R; Lowe, Scott W (2017) Putting p53 in Context. Cell 170:1062-1078
Levine, Arnold J; Berger, Shelley L (2017) The interplay between epigenetic changes and the p53 protein in stem cells. Genes Dev 31:1195-1201
Stockwell, Brent R; Friedmann Angeli, José Pedro; Bayir, Hülya et al. (2017) Ferroptosis: A Regulated Cell Death Nexus Linking Metabolism, Redox Biology, and Disease. Cell 171:273-285
Kribelbauer, Judith F; Laptenko, Oleg; Chen, Siying et al. (2017) Quantitative Analysis of the DNA Methylation Sensitivity of Transcription Factor Complexes. Cell Rep 19:2383-2395
Vabret, Nicolas; Bhardwaj, Nina; Greenbaum, Benjamin D (2017) Sequence-Specific Sensing of Nucleic Acids. Trends Immunol 38:53-65
Badal, Brateil; Solovyov, Alexander; Di Cecilia, Serena et al. (2017) Transcriptional dissection of melanoma identifies a high-risk subtype underlying TP53 family genes and epigenome deregulation. JCI Insight 2:
Hayano, M; Yang, W S; Corn, C K et al. (2016) Loss of cysteinyl-tRNA synthetase (CARS) induces the transsulfuration pathway and inhibits ferroptosis induced by cystine deprivation. Cell Death Differ 23:270-8

Showing the most recent 10 out of 133 publications