# MicroRNAs in circulating extracellular vesicles as biomarkers of early colorectal cancer captured using high mannose N-glycan-specific lectin from Oscillatoria Agardhii

## TL;DR

A new method using a cyanobacterium-derived lectin captures extracellular vesicles in blood, revealing microRNA biomarkers for early colorectal cancer detection.

## Contribution

Demonstrates that OAA1-captured EVs contain miRNAs with high accuracy in distinguishing early-stage CRC from healthy individuals.

## Key findings

- OAA1 effectively captures HM N-glycans and EVs from plasma samples.
- Five miRNAs and three internal controls showed high potential for CRC detection (AUC = 0.948).
- OAA1-based method could serve as a liquid biopsy tool for early CRC surveillance.

## Abstract

Lectin (OAA), isolated from the filamentous cyanobacterium Oscillatoria agardhii, exhibits high specificity and strong binding affinity for high-mannose (HM) N-glycans. Previous studies have demonstrated that OAA captured extracellular vesicles (EVs) derived from cancer cell lines. This study aimed to confirm the effectiveness of OAA in capturing HM N-glycans in blood and explore its potential in capturing circulating EVs derived from early-stage colorectal cancer (CRC) tumors.

OAA1 (a recombinant OAA variant) was used to capture HM N-glycans from blood samples. The ability of OAA1 to capture circulating EVs in patients with stage I CRC was assessed. The miRNA profiles of the OAA1-captured EVs were analyzed and compared between 60 patients with stage I CRC and 60 healthy controls. Statistical analyses were performed to evaluate the potential of the specific miRNAs as CRC biomarkers.

OAA1 effectively captured HM N-glycans in the plasma. Nanoparticle and immunoblot analyses confirmed the presence of EVs in the OAA1-captured from plasma. The miRNA profile of OAA1-captured EVs exhibited characteristics of patients with CRC. Statistical analysis identified five miRNAs (miR-122-5p, miR-130a-3p, miR-146a-5p, miR-15b-5p, and miR-126) and three internal control miRNAs (miR-93-5p, miR-192-5p, and miR-502-5p) with a high potential for cancer separation (area under the curve (AUC) = 0.948; sensitivity = 0.883; specificity = 0.933).

These results suggest that circulating miRNAs in OAA1-captured EVs could serve as biomarkers for the surveillance of early stage CRC using liquid biopsy. The OAA1-immobilized column device facilitates easier and quicker inspection processes and accentuates differences in circulating miRNAs associated with the disease.

OAA1-column showed potential clinical application to analyze circulating EVs and miRNAs associated with CRC, serving as a relevant liquid biopsy for early cancer detection.