The p53 signaling pathway is the most commonly subverted pathway identified in human tumors. In normal cells, p53 plays a critical role in maintaining normal physiology by coordinating the response of cells to a diverse range of environmental and endogenous stress. There is extensive evidence indicating that the ability of p53 to function as a sequence-specific transactivator is central to its role as a tumor suppressor. Recent results show that p53 is able to discriminate between consensus binding sites in downstream genes in vivo, presumably activating gene transcription that mediates the appropriate response in a given cellular environment and physiological situation. The overall goal of this proposal is to characterize the factors which dictate p53 DNA binding properties in vivo and the physiological relevance of select downstream target genes. To accomplish this goal, the following interrelated hypotheses are proposed: 1. The selectivity of transcriptional regulation by p53 is achieved by multiple factors working in concert, including: (a) the overall level of p53 in the cell, (b) the post-translational modification of p53 that may regulate stability or association with co-activators, and (c) the sequence heterogeneity of p53 binding sites in target genes that dictates p53 affinity for a site. 2. Cell fate after p53 activation is dependent on the differential, cell type-dependent transactivation of select genes, whose protein products regulate pathways of cell cycle arrest and survival. New technologies and reagents will be exploited, as well as classic molecular biology, genetic, and biochemical methods to test these hypotheses through the following Specific Aims: 1. To characterize p53 binding to target genes promoters in vivo in primary, normal human cell cultures. 2. To """"""""trap"""""""" p53 in vivo at consensus DNA binding sites in normal ceIIs after various forms of cell stress and create libraries of p53 DNA binding sites. These sites will be analyzed to determine: (a) the sequence of the sites to which p53 is bound and the extent of heterogeneity, (b) the affinity of p53 For a select number of the DNA sites to which it is bound under a given condition, and (c) the genetic loci for novel sites and adjacent coding regions. 3. To determine the role of select p53 target gene products in dictating cellular outcome after stress induction, with primary focus on p53-inducible gene 3 PIG3), a putative NAD(P)H oxidoreductase. The importance of understanding p53 signaling is underscored by the frequency of p53 mutations in tumors and the findings that modulating this pathway in cancer cells can induce cell cycle arrest, apoptosis, or chemosensitization depending upon cell type, mutations, and environment. Understanding how p53 mediates these outcomes is expected to translate into therapeutic benefit in the treatment of tumors, and thus would have major impact on human health.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA070856-08
Application #
6690034
Study Section
Chemical Pathology Study Section (CPA)
Program Officer
Blair, Donald G
Project Start
1997-01-01
Project End
2005-12-31
Budget Start
2004-01-01
Budget End
2004-12-31
Support Year
8
Fiscal Year
2004
Total Cost
$332,134
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Biochemistry
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Jovanovi?, Bojana; Mayer, Ingrid A; Mayer, Erica L et al. (2017) A Randomized Phase II Neoadjuvant Study of Cisplatin, Paclitaxel With or Without Everolimus in Patients with Stage II/III Triple-Negative Breast Cancer (TNBC): Responses and Long-term Outcome Correlated with Increased Frequency of DNA Damage Response Gene Clin Cancer Res 23:4035-4045
Marshall, Clayton B; Mays, Deborah J; Beeler, J Scott et al. (2016) p73 Is Required for Multiciliogenesis and Regulates the Foxj1-Associated Gene Network. Cell Rep 14:2289-300
Lehmann, Brian D; Bauer, Joshua A; Schafer, Johanna M et al. (2014) PIK3CA mutations in androgen receptor-positive triple negative breast cancer confer sensitivity to the combination of PI3K and androgen receptor inhibitors. Breast Cancer Res 16:406
Chen, Xi; Li, Jiang; Gray, William H et al. (2012) TNBCtype: A Subtyping Tool for Triple-Negative Breast Cancer. Cancer Inform 11:147-56
Lehmann, Brian D; Bauer, Joshua A; Chen, Xi et al. (2011) Identification of human triple-negative breast cancer subtypes and preclinical models for selection of targeted therapies. J Clin Invest 121:2750-67
Rosenbluth, Jennifer M; Mays, Deborah J; Jiang, Aixiang et al. (2011) Differential regulation of the p73 cistrome by mammalian target of rapamycin reveals transcriptional programs of mesenchymal differentiation and tumorigenesis. Proc Natl Acad Sci U S A 108:2076-81
Eby, Kathryn G; Rosenbluth, Jennifer M; Mays, Deborah J et al. (2010) ISG20L1 is a p53 family target gene that modulates genotoxic stress-induced autophagy. Mol Cancer 9:95
Bauer, Joshua A; Chakravarthy, A Bapsi; Rosenbluth, Jennifer M et al. (2010) Identification of markers of taxane sensitivity using proteomic and genomic analyses of breast tumors from patients receiving neoadjuvant paclitaxel and radiation. Clin Cancer Res 16:681-90
Bauer, Joshua A; Ye, Fei; Marshall, Clayton B et al. (2010) RNA interference (RNAi) screening approach identifies agents that enhance paclitaxel activity in breast cancer cells. Breast Cancer Res 12:R41
Adams, Sylvia; Chakravarthy, A Bapsi; Donach, Martin et al. (2010) Preoperative concurrent paclitaxel-radiation in locally advanced breast cancer: pathologic response correlates with five-year overall survival. Breast Cancer Res Treat 124:723-32

Showing the most recent 10 out of 51 publications