# Identification and diagnostic evaluation of an aptamer targeting prostate-cancer-derived small extracellular vesicles

## TL;DR

This study developed a new aptamer that can detect prostate cancer by targeting specific small extracellular vesicles in urine, offering a non-invasive diagnostic tool.

## Contribution

The paper introduces a novel aptamer (seq25) that specifically targets prostate cancer-derived extracellular vesicles with high affinity and diagnostic potential.

## Key findings

- The aptamer seq25 showed strong binding affinity with a KD of 24.02 nM for prostate cancer-derived small extracellular vesicles.
- Seq25 could distinguish prostate cancer-derived sEVs from normal prostate cell lines using nanoflow cytometry.
- Urine samples from prostate cancer patients had significantly higher seq25-positive sEVs compared to those with benign prostatic hyperplasia.

## Abstract

Prostate cancer (PCa) lacks convenient, non-invasive, and highly specific diagnostic markers. Aptamers have emerged as preferred probes for biosensors that target extracellular vesicles (EVs). This study aimed to explore the diagnostic value of PCa-specific EVs aptamer probes. We used EV-SELEX to identify aptamers that selectively target PCa small EVs (sEVs). Surface plasmon resonance (SPR) and nanoflow cytometry were used to verify aptamer affinity. The diagnostic value of PCa was evaluated using clinical samples from patients. We screened and validated an aptamer, seq25, which exhibited high specificity for PCa-derived sEVs. The SPR assay revealed a strong binding affinity, with a KD of 24.02 nM and a dose-dependent binding response. Nanoflow cytometry demonstrated that seq25 could distinguish sEVs from PCa and normal prostate cell lines. In clinical specimens, the proportion of seq25-positive sEVs isolated from urine samples was significantly higher in patients with PCa than in those with benign prostatic hyperplasia. Our study integrated the diagnostic advantages of EVs with the technical benefits of aptamers to develop a PCa-specific sEVs aptamer probe that offers a promising non-invasive approach for PCa diagnosis.

This paper identified a high-affinity aptamer (seq25) specifically targeting prostate cancer (PCa)-derived small extracellular vesicles (EVs). Seq25 effectively distinguished PCa-derived sEVs from benign sources in cell lines and, critically, in patient urine samples. This aptamer probe offers a promising non-invasive diagnostic approach for PCa.