Neutrophil extracellular traps sequester circulating tumor cells via β1-integrin mediated interactions

Area of Science:

• Oncology
• Immunology
• Cell Biology

Background:

• Metastasis is the primary cause of cancer mortality, and surgical interventions, while crucial for local control, can paradoxically increase metastasis rates.
• Neutrophil extracellular traps (NETs) are released by neutrophils during inflammation and have been implicated in capturing circulating tumor cells (CTCs), potentially promoting metastatic disease.
• Understanding the molecular mechanisms underlying NET-CTC interactions is critical for developing strategies to prevent metastasis.

Purpose of the Study:

• To investigate the role of β1-integrin in mediating the adhesion of circulating tumor cells (CTCs) to neutrophil extracellular traps (NETs).
• To elucidate the molecular mechanisms by which NETs contribute to cancer metastasis in a postoperative inflammatory setting.

Main Methods:

• In vitro and in vivo experiments were conducted to assess the role of β1-integrin in CTC adhesion to NETs.
• A murine model of intra-abdominal sepsis was used to simulate the postoperative inflammatory environment.
• The effect of DNAse 1 administration on NET-CTC interactions was evaluated.

Main Results:

• β1-integrin expression on both cancer cells and NETs was found to be crucial for the adhesion of CTCs to NETs.
• β1-integrin expression was upregulated in the context of inflammation in vivo.
• Administration of DNAse 1 abrogated the increased early cancer cell adhesion to NETs in vivo.

Conclusions:

• This study identifies β1-integrin as a key molecular mediator of CTC adhesion to NETs.
• The findings provide the first molecular mechanism explaining how NETs trap CTCs, particularly in an inflammatory context.
• Targeting β1-integrin interactions with NETs may offer a novel therapeutic strategy to reduce cancer metastasis after surgery.