# Addressing cancer disparity through defining the molecular link between breast feeding and triple negative breast cancer

> **NIH NIH R01** · OHIO STATE UNIVERSITY · 2022 · $434,990

## Abstract

PROJECT SUMMARY
The long-term objective of this proposal is to reduce the risk of developing aggressive triple negative breast
cancer (TNBC), especially for African-American women (AAW), by discovering how prolonged breastfeeding
protects the breast from this risk. AAW have lower breastfeeding rates that likely contribute to the higher
incidence of TNBC and higher mortality. Therefore, our work will specifically address this disparity in breast
cancer outcomes faced by AAW. We developed unique mouse models for studying gradually involuting (GI-
prolonged breastfeeding) vs abruptly involuting (AI-short breastfeeding) mammary glands. We have shown
dramatic shifts in cellular composition of the mammary epithelial cell compartment and global changes in
inflammatory markers and importantly have observed precancerous hyperplastic lesions within 120 days
postpartum in the AI glands. These precancerous glands highly expressed the transcription factor Elf5, a key
gene expressed by luminal progenitor cells, the cell-of-origin for TNBC. Based on these studies, we hypothesize
that lack of breastfeeding not only alters the cellular composition and increases inflammation but leads to a
higher risk of developing TNBC through Elf5 mediated aberrant differentiation: In this proposal, we will use
innovative approaches including novel mouse models and patient samples to delineate the link between
breastfeeding and TNBC. Aim 1A: Delineate the protective effects of GI vs. AI in mouse models of human breast
cancer. 1B. determine if blocking estrogen signaling will abrogate the hyperplastic changes induced by AI. We
will use MMTV-Cre;Brca1fl/fl;p53fl/fl mice and a chemical-carcinogen induced model to assess if AI accelerates
tumor incidence and progression of TNBC. We will treat AI mice with tamoxifen to assess if progression to
hyperplasia is mitigated. Aim 2: Elucidate the role of Elf5 and alterations in the microenvironment (ME) that led
to the precancerous changes seen in the AI mammary glands. We will use mammary-specific Elf5 conditional
knock-out mouse models and in vitro methods for this aim. Gene expression and CHIP-Seq will be utilized to
identify the downstream effectors of Elf5. We will determine the differences in the ME between AI versus GI
glands, especially the recruitment of different types of macrophages. Aim 3: Validate the histological and
molecular changes observed in mice using human mammary tissue obtained from parous women who breastfed
0-3 (AI) vs. > 6 months (GI). We will obtain FFPE breast tissue from the Susan G. Komen for the Cure® Tissue
Bank to study the differences in collagen deposition and other inflammatory markers in the two cohorts. Racial
differences will also be evaluated. Our work has a high translational significance in reducing the disparity in
breast cancer related mortality among AAW by identifying novel preventive strategies for TNBC. Furthermore,
these studies will lead to discovery of novel agents that could help women who...

## Key facts

- **NIH application ID:** 10372950
- **Project number:** 5R01CA231857-04
- **Recipient organization:** OHIO STATE UNIVERSITY
- **Principal Investigator:** Ramesh K. Ganju
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $434,990
- **Award type:** 5
- **Project period:** 2019-03-06 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10372950

## Citation

> US National Institutes of Health, RePORTER application 10372950, Addressing cancer disparity through defining the molecular link between breast feeding and triple negative breast cancer (5R01CA231857-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10372950. Licensed CC0.

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