March 2025: Merav Cohen: New breast cancer study published in Nature Cancer

A new study, published in the prestigious journal Nature Cancer, and featured on their monthly cover, was led by Dr. Merav Cohen, Edmond J. Safra affiliate (Medicine), her lab members, Dr. Sandra Camargo and the MD-PhD student Ori Moskowitz, and colleagues from TAU, Weizmann Institute, Tel Aviv Sourasky Medical Center, and Hubrecht Institute in the Netherlands.

The researchers applied advanced single-cell based technologies, focusing on the tumor microenvironment in advanced stages of breast cancer. They discovered that immune cells called neutrophils are recruited by the tumor microenvironment and actually support it during advanced stages of the disease.  In light of this, the researchers believe that neutrophils, which are unique to the tumor environment, could serve as a target for new drug development, as well as a biological marker for advanced-stage breast cancer.

The researchers used a mouse model and took mammary gland samples from four stages: at 10 days old, 3 weeks old (corresponding to adolescent breast development), healthy adult mice, and adult mice with breast cancer. All samples underwent single-cell RNA sequencing, and the data was analyzed using advanced bioinformatics methods. This revealed two cell types predominantly found in late-stage cancer tissues: neutrophils that were located in proximity to cancer cells, and endothelial cells that construct the blood vessels.

The researchers concluded that neutrophils play a role in breast cancer. To examine this more deeply, they analyzed their molecular communication – the signals they send and receive. This helped uncover a complex process that supports tumor growth: Cancer cells stimulate macrophages (immune cells in the milk ducts) to recruit neutrophils to the tumor microenvironment. Once there, the neutrophils physically interact with the cancer cells, causing the release of substances that enhance the cancer’s ability to spread and invade additional tissues, and stimulate the formation of new blood vessels to nourish the tumor.

Dr. Cohen concluded: "In this study, we uncovered a key mechanism in breast cancer progression. We found that neutrophils – immune cells recruited to the tumor microenvironment, actually support cancer development. These findings have significance for both diagnosis and treatment – neutrophils and the signals they send may serve as targets for new drug development, as well as biomarkers for advanced stages of the disease."