Tissue Factor promotes breast cancer stem cell activity in vitro

Area of Science:

• Oncology
• Cell Biology
• Biochemistry

Background:

• Cancer stem cells (CSCs) drive tumor initiation and metastasis.
• Tissue Factor (TF), a clotting protein, is implicated in cancer progression and metastasis.
• Potential link between TF expression and CSC activity requires investigation.

Purpose of the Study:

• To determine if Tissue Factor (TF) enhances breast cancer stem cell (CSC) activity in vitro.
• To investigate the role of TF in CSC self-renewal and tumor-initiating properties.

Main Methods:

• Compared TF expression in CSC-enriched vs. unselected human breast cancer cell lines.
• Assessed CSC activity via mammosphere formation, holoclone formation, and ALDH1 activity.
• Utilized FACS sorting, TF knockdown (siRNA), and TF overexpression (cDNA) models.
• Examined the effect of FVIIa (TF pathway activator) on CSC markers.

Main Results:

• Increased TF expression observed in anoikis-resistant and high ALDH1-activity cells.
• TF-expressing and TF-overexpressing cells exhibited enhanced CSC activity.
• TF knockdown significantly reduced CSC activity.
• FVIIa stimulation dose-dependently increased CSC activity, an effect blocked by TF siRNA.

Conclusions:

• Breast CSCs exhibit increased activity correlated with higher TF expression.
• TF signaling pathways are critical for maintaining breast CSC activity in vitro.
• Targeting the TF pathway presents a potential therapeutic strategy against CSCs.