HOUSE OF TOEHOLDSAll toeholds must bind. miRNAs are coming.
Cervical cancer is the second most common cancer globally as well as among Indian women with 500 million people at risk, and an unforgiving 50% mortality rate. Poor awareness and access to effective screening have caused enormous disease burden. We are developing a biosensor comprising nucleic-acid toehold switches designed to bind to certain identified differentially expressed circulating miRNA biomarkers of early-stage cervical cancer, namely miRNA-20a, miRNA-21, miRNA-29a and miRNA-200a. Each toehold switch is a second-generation design, requiring a biomarker-antimiR complex to release the expression of GFP, whose fluorescence intensity is measured. We have modelled and calibrated the performance of our toehold switches, and produced software for the integrated design and predicted modelling of these switches. Our parts characterization was performed cell-free. The developed switches may be embedded in a composite biosensor to yield a paper-based device for detecting cervical cancer.