Drastically improving the prognosis of cancer patients requires diagnosis to be made early, before the appearance of the first physiological symptoms. Widespread screening programmes would help address this issue but require test that are minimally invasive, low-cost and based on the detection of biomarkers that are both highly sensitive and highly specific. Molecular profiling of liquid biopsies has the potential to satisfy all criteria. Circulating, cell-free, nucleic acids have recently emerged as novel blood-based fingerprints for cancer diagnosis, even at an early stage. Among them microRNAs (or miRs) hold the greatest promise as either individual biomarkers or in combinations.
Surprisingly, only few miRs have been clinically validated so far. This is mainly due to the lack of standardised protocols for extracting and quantitatively analysing miRs from whole blood. Moreover, most currently available technologies for miR detection use complex, multi- step procedures that (i) rely on enzyme-catalysed amplification step(s) to increase signal intensity (with associated risks of contamination, bias and error) and (ii) require heavy blood processing prior to analysis which, in the absence of standardised procedures, is a major source of error and variation between analyses.
In this project, we are developing two new technological platforms for (1) automated release and isolation of miRs from whole blood and (2) amplification-free, isothermal, quantitative detection of endogenous miRs. Once technically validated individually, these two modular platforms will be miniaturised and combined on a low-cost, single-use and portable microchip for miR sensing and profiling from whole blood.