Detecting microRNA (miRNA) using nanopore single molecule detector

Abstract

MicroRNAs (miRNAs) are a class of short (~18-24-nt) non-coding RNAs molecules that regulate gene expression at the post- transcriptional level. Aberrant expression of miRNAs has been found in all types of tumors. Most notably, specific miRNAs are released from the primary tumor into blood circulation, making the detection of circulating miRNAs a powerful tool for noninvasive cancer detection, diagnosis, staging, and monitoring. We developed a robust nanopore sensor that selectively detects single molecules of circulating miRNAs derived from primary cancer. The nanopore is a fabricated 2-nm molecular pore. Such a tiny pore can generate a signature current signal when a miRNA molecule is specifically captured in it. These signals function as fingerprints that enable us to identify a specific miRNA and quantify its concentration. The prototype has demonstrated the capability to discriminate single nucleotide difference between miRNAs. In clinical tests, we have differentiated miRNA levels in blood between lung cancer patients and healthy people. Due to the label-free single molecule detection without nucleic acids amplification, the nanopore sensor is higher selective, precise and accurate over the gold standard RT-PCR and microarray. The nanopore array in development would achieve high throughput capability for detecting miRNA profile. Potential Areas of Applications: Detection of any nucleic acids fragments, including all microRNAs and pathogenic DNAs or RNAs, Study of nucleic acid folding/unfolding reactions, Study of miRNA mechanism and principle of regulation Study single nucleotide polymorphisms (SNPs), Study of oligonucleotide-protein and oligonucleotide-drug interactions for drug discovery and development, Biomarker characterization, Diagnostics, prognostics and theranostics. Patent Status: Patent pending. Inventor(s): Li-Qun Gu, Yong Wang.