Characterizing the Inflammatory Profile of Neutrophil-Rich Triple-Negative Breast Cancer

Area of Science:

• Oncology
• Immunology
• Cell Biology

Background:

• Triple-negative breast cancer (TNBC) is linked to increased neutrophil infiltration, poor prognosis, and reduced immunotherapy effectiveness.
• Understanding the interaction between neutrophils and breast cancer cells is crucial for developing new treatments.

Purpose of the Study:

• To investigate the in vitro bidirectional effects of neutrophils on metastatic TNBC (MDA-MB-231) versus less-metastatic MCF-7 breast cancer cell lines.
• To explore how breast cancer cells influence neutrophil behavior, including viability, NETosis, and inflammatory marker expression.

Main Methods:

• Utilized neutrophil-like HL60 cells and breast cancer cell lines (MDA-MB-231, MCF-7).
• Assessed neutrophil viability, NETosis (nucleic acid staining), inflammatory marker expression (flow cytometry), and migratory capacity (transwell assay).
• Analyzed conditioned media (CM) from breast cancer cells to evaluate their impact on neutrophils.

Main Results:

• Breast cancer cells and their CM reduced neutrophil viability.
• MDA-MB-231 CM induced higher levels of cellular stress and NETosis in differentiated HL60 cells compared to MCF-7 CM.
• MDA-MB-231 CM promoted neutrophil inflammatory phenotypes, including increased adhesion, degranulation, CD54 expression, and migratory capacity.

Conclusions:

• Breast cancer, particularly TNBC, may exploit neutrophils via NETosis and complement activation.
• The crosstalk between breast cancer cells and neutrophils represents a potential mechanism driving tumor progression.
• Targeting this neutrophil-breast cancer interaction could offer novel therapeutic strategies.