Small but mighty: harnessing microRNAs for lung cancer diagnosis
Over the last two decades, microRNAs have emerged as biomarkers for tumour diagnosis, prognosis and prediction of response to treatment. Their presence in biological fluids has also spurred great interest in their use as non-invasive biomarkers for the early detection of cancer. Several techniques have been reported for measuring microRNA expression in biological fluids. However, despite technological advances all these methods require several and laborious steps in sample preparation and amplification, thereby introducing variability and error. This has hampered the clinical utility of microRNAs as clinically valuable biomarkers.
Proprietary technology for microRNA detection
Undertaken with the support of the Marie Skłodowska-Curie programme, the miRNA-DisEASY project developed an innovative approach that successfully merges two technologies in one assay. Detection of microRNAs in biological fluids takes place through a highly sensitive photonics reader (from Optoi) that uses Chem-NAT, a unique chemical method for nucleic acid testing. “Our goal was to develop a sensitive and low-cost assay for detecting lung cancer biomarkers in biological fluids,” explains project coordinator Cristina Ress. The miRNA-DisEASY assay exploits the proprietary technology of DestiNA Genomica to detect microRNAs with a single-base resolution accuracy. The technology relies on peptide nucleic acid (PNA) probes that perfectly hybridise to target microRNA strands. These PNA probes have been synthesised with a blank position where a complementary labelled SMART nucleobase will sit and emit light. This approach offers single base specificity and can accurately identify microRNAs that differ by just one base.
Platform validation
Researchers validated the miRNA-DisEASY platform by testing the detection of miR-21, one of the most frequently deregulated miRNAs in non-small cell lung cancer (NSCLC) patients. Results demonstrated the potential of profiling microRNAs directly from a liquid biopsy without RNA extraction, pre-amplification or pre-labelling. Emphasis was placed on microRNAs that exhibit a differential expression profile in lung adenocarcinoma and squamous cell carcinoma. A particular miRNA expression (miR-375) has shown the potential to distinguish neuroendocrine from non-neuroendocrine lung tumours while two additional miRNAs could serve as biomarkers for the auxiliary diagnosis of NSCLC.
Project significance and future prospects
Lung cancer is usually diagnosed at advanced stages with a 5-year survival rate of less than 20 %. To limit unnecessary computed tomography scanning, there is a need for a non-invasive screening approach. “The miRNA-DisEASY platform has the capacity to transform and expand routine testing and screening of circulating miRNAs in clinical diagnostic practice,” emphasises Ress. The miRNA-DisEASY approach offers both qualitative and quantitative analysis of microRNA biomarkers in biological fluids, advancing the field of diagnostics. It can be customised to analyse microRNA biomarkers of diagnostic and prognostic clinical relevance in other diseases apart from cancer as well as for toxicology testing. Moreover, the platform may be tailored to profile miRNAs in carrier vessels, such as exosomes, whose interest in the diagnostic field is expanding. Ress foresees “a smooth yet fast integration of the technology in routine clinical practice given the rapid analysis, reliability and cost-effectiveness of the method.” However, she notes that future endeavours for development finalisation will require additional funding or joint ventures to commercially exploit the platform.
Keywords
miRNA-DisEASY, biomarkers, microRNA, lung cancer, assay, Chem-NAT, liquid biopsy, optical sensor
