Regulation of Collective Metastasis by Nanolumenal Signaling

Area of Science:

• Oncology
• Cell Biology
• Cancer Metastasis

Background:

• Collective metastasis involves the cohesive migration of tumor cell clusters.
• The downstream signaling pathways of tumor cell clustering are not well understood.
• Cell adhesion is crucial for cluster formation and metastatic colonization.

Purpose of the Study:

• To identify collective signals generated by tumor cell clusters that support metastatic colonization.
• To investigate the role of the growth factor epigen in collective metastasis.
• To explore nanolumenal signaling as a potential therapeutic target in breast cancer.

Main Methods:

• Utilized mouse and human breast cancer models.
• Investigated the role of epigen in tumor cell clusters.
• Analyzed nanolumina-intercellular compartments and cell-cell junctions.
• Performed epigen knockdown experiments.
• Compared basal-like 2 and mesenchymal-like triple-negative breast cancer cell lines.

Main Results:

• Tumor cell clusters produce and concentrate the growth factor epigen within nanolumina.
• Nanolumina are intercellular compartments sealed by cell-cell junctions and lined with microvilli-like protrusions.
• Epigen knockdown significantly reduced metastatic outgrowth and shifted clusters from proliferation to collective migration.
• Basal-like 2 triple-negative breast cancer cells showed higher epigen expression and impaired outgrowth upon nanolumenal junction disruption compared to mesenchymal-like cells.

Conclusions:

• Nanolumenal signaling, mediated by epigen concentration within intercellular compartments, plays a critical role in supporting metastatic colonization.
• Targeting nanolumenal signaling presents a potential therapeutic strategy for aggressive metastatic breast cancers, particularly basal-like 2 triple-negative subtypes.