Proximity Labeling and SILAC-Based Proteomic Approach Identifies Proteins at the Interface of Homotypic and...

Area of Science:

• Cell Biology
• Proteomics
• Cancer Research

Background:

• Cell-cell interactions are fundamental for organismal growth and homeostasis.
• These interactions are crucial in the tumor microenvironment, driving cancer progression.

Purpose of the Study:

• To develop and validate a novel method for analyzing the cell-to-cell interactome.
• To identify proteins and pathways involved in cancer cell-cell interactions.

Main Methods:

• Enzyme-catalyzed proximity labeling coupled with Stable Isotope Labeling by Amino acids in Cell culture (SILAC)-based proteomics.
• Targeting horseradish peroxidase (HRP) to the plasma membrane of 'bait' cells to label adjacent 'prey' cells.
• Distinguishing and analyzing proteomes of bait and prey cells in co-culture systems.

Main Results:

• Successfully mapped homotypic and heterotypic interactomes of epithelial and mesenchymal breast cancer cells.
• Confirmed specificity through enrichment of cell surface and extracellular proteins.
• Identified prominent signaling pathways and highlighted the role of exosomes in mediating cell-cell interactions.

Conclusions:

• The developed methodology accurately identifies proteins mediating cell-cell interactions.
• This approach provides insights into signaling pathways governing cancer cell communication.
• The method is versatile and applicable to various cell-cell interaction studies in 2D and 3D models.