Potential and Limitations of the MinION Nanopore array for miRNA-Enabled Early Cancer Detection

The 2024 Nobel Prize in Physiology or Medicine was awarded to the pioneers who reported that microRNAs (miRNAs) regulate and direct the switch between physiological and pathological pathways via their over- or under-expression. The discovery has not yielded any health benefit primarily due to raw data with no clear distinction between healthy and diseased blood samples. MiRNAs exist at femtomolar level in biological fluids, and typically quantified using amplification-based techniques. Experimental nanopores have illustrated potential for trace analysis including amplification-free miRNA quantification. We repurposed the MinION, the only commercially available nanopore-array device, and developed unique probes and protocols to quantify microRNAs in blood and urine. Our 2024 report revealed (i) miRNA copies are proportional to the total RNA isolated from the biospecimen, and (ii) several known miRNA cancer biomarkers were 1.8-fold overexpressed in blood samples from breast, prostate and pancreatic cancer patients compared to healthy. In contrast to literature reports sample variability was undetectable after normalization to the same RNA content. Here the earlier data were confirmed, and the conclusions extended to ovarian, lung, and colorectal cancer. The potential of the ready-to-use MinION/Yenos platform for multiple cancer early detection (MCED) using blood or urine is discussed.