Advances in Targeting Neutrophil Extracellular Traps as a Promising Approach for Breast Cancer Treatment

Neutrophils release neutrophil extracellular traps (NETs), a reticular structure mainly composed of antimicrobial peptides, DNA, and histones. Neutrophil elastase (NE), matrix metalloproteinase-9, and histone G are the key components of NETs critically involved in breast cancer invasion and migration, which suggests an important role of NETs in tumorigenesis and metastasis. Studies have reported that NETs significantly promote breast cancer invasion, intravascular infiltration, and distant metastasis by inducing epithelial-mesenchymal transition (EMT), remodeling the extracellular matrix, and modulating the immune microenvironment. Meanwhile, NETs also function crucially in capturing circulating tumor cells, forming a pre-metastatic microenvironment, and awakening dormant cancer cells. Notably, NETs are also closely associated with chemotherapy and immunotherapy resistance in breast cancer. Therapeutic strategies targeting NETs, including DNase I, PAD4 inhibitors, elastase inhibitors, and histone C inhibitors, have been widely studied. These targeted therapies can effectively suppress the generation of NETs, improve drug efficacy, and delay tumor metastasis. This review aimed to systematically elucidate the mechanism of action of NETs in the progression and drug resistance of breast cancer and explore potential targeted therapeutic strategies against NETs. These strategies could effectively inhibit the generation of NETs, delay the progression of breast cancer, and improve therapeutic efficacy. An in-depth study of the mechanism of action of NETs and the clinical significance of their targeted interventions is expected to provide a new direction for breast cancer treatment.