Extracellular vesicle (EV)-polyphenol nanoaggregates for microRNA-based cancer diagnosis

Abstract

Small extracellular vesicles (EVs), including exosomes, in body fluids have important applications in the noninvasive liquid biopsy-based diagnosis of cancer. Current EV-based diagnostic techniques still face practical challenges, such as inefficient EV isolation. Here, we report an efficient, resource-free pre-enrichment approach using (-)-epigallocatechin-3-gallate (EGCG), a polyphenolic biomolecule, to isolate and detect exosomal microRNAs (miRNAs) in human blood plasma samples. Our system comprises three steps: (1) EGCG-mediated EV aggregation, (2) filter-based EV isolation, and (3) molecular beacon-based detection of target miRNA in EVs. Using blood samples from cancer patients with gastric cancer or hepatocellular carcinoma, we constructed an EGCG-assisted miRNA diagnostic system. For both cancers, the levels of target miRNAs (miR-21, -27a, and -375) in EVs were strongly correlated with those in the publicly available GEO database. Our approach, an easy-to-use method for efficient EV isolation and the detection of miRNA in clinical samples, is applicable for molecular diagnostics in precision medicine.

Advances in Analytical Technologies for Extracellular Vesicles

“…EVs adhered to EGCG to form EV aggregate bundles which were collected by filtration using a much lower pressure and shear force. They demonstrated that the EGCG-assisted filtration method isolated EVs more efficiently with higher purity compared with commercial EV isolation kits-ExoQuick Exosome Precipitation Solution (System Biosciences) and Total Exosome Isolation Reagent (Invitrogen) …”

Extracellular vesicle isolation, purification and evaluation in cancer diagnosis

“…46), can give us information about genetic changes and gene expression profile of this cancer type (Ref. 45). EV signature is able to distinguish metastatic or non-metastatic breast cancer with high accuracy (~ 91%) (Ref.…”

“…Second, very low concentration of exosomes in serum samples (<10 9 vesicles/ml) is another issue (Ref. 45). Third, low levels of expressions for EV-related RNAs at early-stage cancer, detection of which at this stage is highly valuable (Ref.…”

“…Evaluation of body fluids is a non-invasive way for cancer diagnosis (Ref. 45), enabling detection of tumour risk in cancers hardly detected by routine methods. EV isolation from tumours like pancreatic cancer, which show cold immunity and represent poor prognosis (Ref.…”

“…Polyphenol has potent adhesive tendency to biological molecules, which allows exosome collection within biofluids, such as whole blood, serum, plasma and urine (Ref. 45). Circulating EVs can be captured using nanoparticle biochips.…”