Could urine samples be used for early cancer screening?
In a new study, Professor Yoon-Kyoung Cho and her team from Ulsan National Institute of Science and Technology (UNIST; South Korea) have developed a technique to assess urine-based biomarkers for early detection of cancer, using an integrated centrifugal microfluidic system called ‘Exodisc.’
Extracellular vesicles (EVs) are cell-derived nanoscale vesicles carrying nucleic acids and proteins from their cells of origin. Despite the clinical importance of EVs as potential biomarkers in the diagnosis of various diseases including cancer, current methods of EV separation and analysis have several limitations.
To overcome these limitations, the team developed a rapid, label-free and sensitive method for EV isolation and quantification using a lab-on-a-disc integrated with two nanofilters which they called the Exodisc. Using a tabletop-sized centrifugal microfluidic system, automated enrichment of EVs (sized between 20–600 nm) from raw biological samples, such as cell culture supernatant or cancer patient urine, was achieved within 30 minutes.
Above 95% recovery of EVs from cell culture supernatant was enabled by the Exodisc, confirmed by quantitative tests using nanoparticle-tracking analysis. Additionally, on analysis of mRNA retrieved from EVs, it was revealed that compared with the perceived gold standard method of ultracentrifugation, the Exodisc provided over a 100-fold increase in the concentration of mRNA.
Furthermore, on-disc ELISA using urinary EVs isolated from bladder cancer patients demonstrated high levels of CD9 and CD81 expression, suggesting that this technique may potentially be useful to for cancer diagnosis by testing urinary EV-based biomarkers.
The study was conducted in collaboration with Professor Yoon-Keun Kim of the Institute of MD Healthcare (South Korea). It has been supported by the Korean Ministry of Health & Welfare, the Institute for Basic Science and SRC.
Source: Woo H-K, Sunkara V, Park J et al. Exodisc for rapid, size-selective, and efficient isolation and analysis of nanoscale extracellular vesicles from biological samples. ACS Nano. 11(2), 1360–1370 (2017); www.digitaljournal.com/tech-and-science/science/urine-samples-can-be-used-for-early-cancer-screening/article/487655
