Junctional adhesion molecule C (JAM-C) dimerization aids cancer cell migration and metastasis

Area of Science:

• Cell Biology
• Molecular Oncology
• Cancer Research

Background:

• Metastasis, the spread of cancer cells, is a major cause of cancer mortality.
• Tumor cell adhesion molecules, like Junctional Adhesion Molecule C (JAM-C), play a critical role in this process.
• JAM-C interacts with JAM-B and influences cell adhesion and tumor progression.

Purpose of the Study:

• To investigate the role of JAM-C dimerization sites in cancer cell adhesion and metastasis.
• To identify specific structural sites within JAM-C critical for JAM-B interaction and their impact on tumor cell behavior.

Main Methods:

• Neoexpression of JAM-C in JAM-C-negative carcinoma cells.
• Directed mutagenesis of JAM-C at critical sites (E66 and K68) to disrupt JAM-C/JAM-B interaction.
• Assays for cell adhesion, proliferation, migration, and in vivo metastasis in mouse models.

Main Results:

• Neoexpression of JAM-C led to reduced adhesion and increased pro-metastatic capacity.
• Mutagenesis of JAM-C at E66 and K68 sites abolished JAM-B binding and correct junctional localization.
• Mutant JAM-C proteins enhanced cell adhesion while reducing proliferation and migration of lung carcinoma cells.
• Carcinoma cells expressing mutant JAM-C showed impaired metastatic colonization in mice.

Conclusions:

• The E66-K68 dimerization sites of JAM-C are essential for its interaction with JAM-B.
• These JAM-C dimerization sites regulate cell adhesion, polarization, and migration.
• Disruption of JAM-C dimerization significantly impairs tumor cell metastasis, highlighting its potential as a therapeutic target.