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Updated: Apr 4, 2026
Using Nanoplasmon-Enhanced Scattering and Low-Magnification Microscope Imaging to Quantify Tumor-Derived Exosomes
Published on: May 24, 2019
A Comprehensive Proteomics Analysis Reveals a Secretory Path- and Status-Dependent Signature of Exosomes Released
Yinghui Zhu1,2, Xianwei Chen1,2, Qingfei Pan1,2
1CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences , Beijing 100101, China.
Abstract:
Exosomes are 30-120 nm-sized membrane vesicles of endocytic origin that are released into the extracellular environment and play roles in cell-cell communication. Tumor-associated macrophages (TAMs) are important constituents of the tumor microenvironment; thus, it is critical to study the features and complex biological functions of TAM-derived exosomes. Here, we constructed a TAM cell model from a mouse macrophage cell line, Ana-1, and performed comparative proteomics on exosomes, exosome-free media, and cells between TAMs and Ana-1. Proteomic analysis between exosome and exosome-free fractions indicated that the functions of exosome dominant proteins were mainly enriched in RNA processing and proteolysis. TAM status dramatically affected the abundances of 20S proteasome subunits and ribosomal proteins in their exosomes. The 20S proteasome activity assay strongly indicated that TAM exosomes possessed higher proteolytic activity. In addition, Ana-1- and TAM-derived exosomes have different RNA profiles, which may result from differential RNA processing proteins. Taken together, our comprehensive proteomics study provides novel views for understanding the complicated roles of macrophage-derived exosomes in the tumor microenvironment.
Insights
Tumor-associated macrophage (TAM) exosomes show higher proteolytic activity and distinct RNA profiles compared to exosomes from normal macrophages. This proteomic study reveals new insights into macrophage-derived exosomes in the tumor microenvironment.
Area of Science:
- Cell Biology
- Proteomics
- Cancer Biology
Background:
- Exosomes mediate cell-cell communication.
- Tumor-associated macrophages (TAMs) are key components of the tumor microenvironment.
- Understanding TAM-derived exosomes is crucial for cancer research.
Purpose of the Study:
- To compare the proteomic and RNA profiles of exosomes derived from TAMs and normal macrophages (Ana-1).
- To investigate the functional differences, particularly proteolytic activity, between TAM-derived and Ana-1-derived exosomes.
Main Methods:
- Comparative proteomics analysis of exosomes, exosome-free media, and cells from TAMs and Ana-1.
- Exosome isolation and characterization.
- 20S proteasome activity assays.
- RNA profiling of exosomes.
Main Results:
- Proteomic analysis revealed enrichment of RNA processing and proteolysis functions in exosome-dominant proteins.
- TAM exosomes exhibited significantly altered abundances of 20S proteasome subunits and ribosomal proteins compared to Ana-1 exosomes.
- TAM exosomes demonstrated higher proteolytic activity.
- Distinct RNA profiles were observed between TAM-derived and Ana-1-derived exosomes, potentially due to differential RNA processing.
Conclusions:
- TAM-derived exosomes possess unique proteomic and RNA signatures.
- The increased proteolytic activity of TAM exosomes may play a role in the tumor microenvironment.
- This study provides novel insights into the complex functions of macrophage-derived exosomes in cancer.
