# Functional genomics approach to evaluate mechanisms of mutant p53 gain-of-function phenotypes

> **NIH NIH F31** · VANDERBILT UNIVERSITY · 2021 · $10,276

## Abstract

Project Summary/Abstract
Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that lacks traditional clinical
targets; as a result, cytotoxic chemotherapy is the current standard of care. Development of targeted therapies
for TNBC is challenging due to molecular heterogeneity and a lack of therapeutically targetable, high-frequency
“driver” alterations. The most unifying feature across TNBC cases is that ~80% harbor a mutation in the tumor
suppressor gene TP53. Mutations in p53 are commonly missense and have been proposed to result in gain-of-
function (GOF) activity leading to novel oncogenic phenotypes. Although the mechanistic underpinnings of this
GOF activity are not understood, alterations in TP53 are highly correlated with increased chromosomal
instability (CIN) and the development of aneuploidy, and have been associated with dysregulated metabolism.
To study p53 GOF mutant proteins, our lab developed two isogenic cell line models (non-transformed
mammary epithelial and TNBC cell lines) using CRISPR/Cas-mediated genome editing. The models include
clonal cell lines expressing two common “hotspot mutant” p53 proteins (R175H and R273H), wild-type (WT)
protein, or no p53 protein (Null). This panel of cell lines allows for the study of various forms of p53, all
expressed and regulated by the endogenous gene promoter and without the confounding effects caused by
ectopic and unregulated overexpression. Additionally, these models afford a unique opportunity to both dissect
novel and evaluate proposed GOF mechanisms and phenotypes that stem from loss of functional (LOF) p53
and/or concomitant gain of mutant p53 protein expression. We have shown that our isogenic cell lines with
mutant p53 have higher levels of CIN, development of aneuploidy and dysregulated metabolism. Additionally,
we have found that stabilization of mutant protein significantly correlates with the development of aneuploidy.
In Aim 1 I will deploy biochemical techniques and analysis of an array of genomics data sets generated from
our cell line models to evaluate the relationship between mutant p53 and p73 interactions and CIN. In Aim 2 I
will use biochemical techniques and targeted metabolomics to study how development of aneuploidy underlies
the GOF phenotypes of mutant p53 stabilization and altered metabolism. Through these aims I will test the
hypothesis that discovery and dissection of mutant p53 LOF and/or GOF mechanisms, which generate
cellular states associated with aneuploidy in tumor cells, will lead to the identification of novel pre-
clinical targets for TNBC. I anticipate that the dissection of novel mechanisms as well as the evaluation of the
reproducibility of proposed mechanisms for mutant p53 GOF phenotypes will improve the current
understanding of the role mutant p53 in tumorigenesis. The results generated from our studies have the
potential for clinical translation, not only in TNBC (for which the need for a targeted therapy is critical...

## Key facts

- **NIH application ID:** 10240594
- **Project number:** 5F31CA247356-03
- **Recipient organization:** VANDERBILT UNIVERSITY
- **Principal Investigator:** Lindsay Redman
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $10,276
- **Award type:** 5
- **Project period:** 2019-09-09 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10240594

## Citation

> US National Institutes of Health, RePORTER application 10240594, Functional genomics approach to evaluate mechanisms of mutant p53 gain-of-function phenotypes (5F31CA247356-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10240594. Licensed CC0.

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