μMap-FFPE: A High-Resolution Protein Proximity Labeling Platform for Formalin-Fixed Paraffin-Embedded Tissue Samples.

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Understanding disease states requires elucidating small-scale biomolecular protein interaction networks (microenvironments).
• Photoproximity labeling, such as μMap, offers high-resolution mapping of spatial relationships within subcellular architectures.
• Existing in vitro models lack the cell-type heterogeneity and 3D structure crucial for clinical relevance.

Purpose of the Study:

• To develop a photoproximity labeling method compatible with formalin-fixed paraffin-embedded (FFPE) tissues.
• To enable the study of protein interactions within the native cellular environment of FFPE samples.
• To compare the CD20 interactome across healthy, cancerous, and patient-derived tissues.

Main Methods:

• Introduction of μMap-FFPE, a novel labeling system.
• Adaptation of photoproximity labeling techniques for FFPE tissues, overcoming chemical modification incompatibilities.
• Application of μMap-FFPE to analyze the CD20 interactome.

Main Results:

• Successfully adapted photoproximity labeling for FFPE tissues.
• Enabled comparison of the CD20 interactome in diverse cellular contexts.
• Demonstrated the utility of μMap-FFPE for studying protein interactions in preserved patient samples.

Conclusions:

• μMap-FFPE is a valuable tool for mapping protein interactions in FFPE tissues.
• This method facilitates the study of cellular microenvironments in native tissue architectures.
• Findings from μMap-FFPE can provide critical clinical insights into disease states.