Single‐Molecule Co‐Immunoprecipitation Reveals Functional Inheritance of EGFRs in Extracellular Vesicles

Abstract

Cancer cells actively release extracellular vesicles (EVs) as important carriers of cellular information to tumor microenvironments. Although the composition and quantity of the proteins contained in EVs are characterized, it remains unknown how these proteins in EVs are related to those in the original cells at the functional level. With epidermal growth factor receptor (EGFR) in lung adenocarcinoma cells as a model oncoprotein, it is studied how distinct types of EVs, microvesicles and exosomes, represent their original cells at the protein and protein–protein interaction (PPI) level. Using the recently developed single‐molecule immunolabeling and co‐immunoprecipitation schemes, the quantity and PPI strengths of EGFRs derived from EVs and the original lung adenocarcinoma cells are determined. It is found that the microvesicles exhibit higher correlations with the original cells than the exosomes in terms of the EGFR levels and their PPI patterns. In spite of these detailed differences between the microvesicles and exosomes, the EGFR PPI strengths measured for EVs generally show a tight correlation with those determined for the original cells. The results suggest that EGFRs contained in EVs closely reflect the cellular EGFR in terms of their downstream signaling capacity.

Dual-Aptamer Modified Graphene Field-Effect Transistor Nanosensor for Label-Free and Specific Detection of Hepatocellular Carcinoma-Derived Microvesicles

“…TEM was used to reflect the morphology of HepG2-MVs, while NTA was employed to analyze the concentration, zeta potential, and particle size distribution of HepG2-MVs. As represented in Figure S1A, it can be clearly known from the TEM image that the HepG2-MVs had irregular circular shapes with a diameter of about 300 nm and a complete membrane structure, which is similar to the morphology and particle size of MVs reported in other works. , The NTA analysis result in Figure S1B shows that the as-purified HepG2-MVs had a mean diameter of ∼300 nm and the size distribution ranged from 100 to 800 nm, which indicates that MVs are larger and more heterogeneous in size than exosomes. This particle size distribution is consistent with the corresponding research results that have been reported in other works. , Moreover, it can also be known from the NTA analysis that the original concentration of HepG2-MVs was 6 × 10 9 particles/mL and the average zeta potential of HepG2-MVs was −24.3 mV (Figure S1C), implying that the concentration of as-obtained HepG2-MVs is quite high and HepG2-MVs are negatively charged.…”

“…Cancerous microvesicles (MVs) are nanosized (100–1000 nm) membranous vesicles that directly germinate from maternal cells to the extracellular environment and have been widely recognized as new indicators for a noninvasive liquid biopsy of the next generation of cancer. − As reported, cancerous MVs are of higher maternal cell homology than exosomes, so the specific detection of cancerous MVs can more accurately reflect the expression level of disease-related molecules on maternal cancer cells and be used to diagnose and monitor the corresponding cancers. More importantly, the high homology of cancerous MVs with their maternal cancer cells enables the simultaneous detection of cancerous MVs after screening specific antibodies or aptamers against maternal cancer cells, thus making the detection of cancerous MVs more specific to the corresponding cancers.…”

Employing Macrophage-Derived Microvesicle for Kidney-Targeted Delivery of Dexamethasone: An Efficient Therapeutic Strategy against Renal Inflammation and Fibrosis

“…Cells release heterogeneous vesicles of different sizes and intracellular origins, including exosomes and microvesicles. Recent study finds that the epidermal growth factor receptors in microvesicles exhibit a higher level of functional similarity with the originating cells than those in exosomes 31. This indicates that the function of membrane proteins on microvesicles is not affected when budding from the plasma membrane.…”

Tumoral microvesicle–activated glycometabolic reprogramming in fibroblasts promotes the progression of oral squamous cell carcinoma

“…EVs, including MVs and exosomes, are small vesicles secreted by nearly all types of cells under physiologic or pathologic conditions. Compared with exosomes, MVs exhibit higher correlations with the original cells in terms of protein level, thereby reflecting down‐stream signaling capacity (33). Tumor and stromal cells interplay and continually undergo signal and energy exchanges, creating an environment conducive to tumor growth.…”