# Exosomal CD44 in the metastasis of triple negative breast cancer

> **NIH NIH F32** · NORTHWESTERN UNIVERSITY · 2022 · $78,550

## Abstract

Abstract
The objective of this proposal is to determine the functions of breast cancer cell-secreted exosomes
in regulating tumor motility, stemness, and immune evasion. Our preliminary results demonstrate
that circulating tumor cells (CTCs) aggregate to form clusters and promote stemness for polyclonal
metastases in triple negative breast cancer (TNBC) (Cancer Discovery, 2019). We also found that
cancer exosomes induce the clustering and migration of tumor recipient cells. Educating human
leucocytes with cancer exosomes inhibit immune cells, and suppress its tumor-killing effects. A
growing body of evidence highlights the role of exosomes in cellular communications, and
regulatory effects of exosomal proteins on metastatic niche and tumor immune
microenvironment; however, the role of cancer exosomes in cancer stemness and immune
regulation is not elucidated. We hypothesize that cancer exosomes promote metastasis of
breast tumor cells and suppress neutrophil-mediated anti-tumor immunity in TNBC. In order
to test our hypothesis we will: 1) examine the role of tumor exosomes in the stemness of tumor
recipient cells and 2) determine the role of cancer exosomes in neutrophil suppression. We
have optimized protocols to isolate exosomes, characterize them, and perform functional
studies. Human patient-derived xenograft (PDX) models, MDA-MB-231 cells, and mouse
breast tumor models E0771 and 4T1 will be used to examine the functions of cancer exosomes.
Human and mouse immune cells will be isolated from the blood for exosome education and
tumor-immune cell interaction analyses. Taken together, this study aims to determine if cancer
exosomes serve as a new therapeutic target for both stemness and immunosuppression in TNBC.

## Key facts

- **NIH application ID:** 10364638
- **Project number:** 5F32CA257345-02
- **Recipient organization:** NORTHWESTERN UNIVERSITY
- **Principal Investigator:** Lamiaa El-Shennawy
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $78,550
- **Award type:** 5
- **Project period:** 2021-03-02 → 2023-03-01

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10364638

## Citation

> US National Institutes of Health, RePORTER application 10364638, Exosomal CD44 in the metastasis of triple negative breast cancer (5F32CA257345-02). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10364638. Licensed CC0.

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