Tumor cell adhesion and migration supported by interaction of a receptor-protease complex with its inhibitor

Area of Science:

• Oncology
• Cell Biology
• Biochemistry

Background:

• Tissue factor (TF) is a cell-surface receptor crucial for coagulation factor VIIa (TF-VIIa) binding.
• TF signaling, particularly through its cytoplasmic domain interactions and TF-VIIa complex formation, is implicated in cancer metastasis.
• TF pathway inhibitor (TFPI-1) is a key inhibitor of the TF-VIIa complex's protease activity.

Purpose of the Study:

• To investigate the role of the TF-VIIa complex and its interaction with TFPI-1 in cancer cell migration and adhesion.
• To elucidate the mechanism by which TFPI-1 influences TF-mediated cellular processes at the tumor invasive edge.
• To explore the cooperative function of TF and integrin-mediated adhesion in complex extracellular matrices.

Main Methods:

• Localization studies of the TF-VIIa complex at the invasive edge of primary bladder carcinoma cells.
• In vitro cell culture experiments assessing adhesion, migration, and intracellular signaling of TF-expressing tumor cells on immobilized TFPI-1.
• Analysis of TF-VIIa-dependent cell adhesion on immobilized heparin mimicking extracellular matrix proteoglycans.
• Investigation of TF's role in cell migration on composite matrices containing integrin and TF-VIIa ligands.

Main Results:

• The TF-VIIa complex localizes to the invasive edge of bladder carcinoma cells, near TFPI-1-rich vessels.
• Binding of TF-VIIa to TF-expressing tumor cells facilitates cell adhesion, migration, and signaling on immobilized TFPI-1.
• Immobilized heparin enhances TF-VIIa-dependent cell adhesion by binding TFPI-1.
• TF collaborates with integrin-mediated adhesion and migration on complex extracellular matrices.

Conclusions:

• A novel mechanism of protease-supported cell migration exists, independent of matrix degradation.
• This mechanism involves protease-dependent bridging between TF's extracellular domain and ECM-associated TFPI-1.
• TF-TFPI-1 interactions play a significant role in tumor cell invasion and metastasis.