Handheld ISFET Lab-on-Chip detection of YAP1 nucleic acid and AR-FL and AR-V7 mRNA from liquid biopsies for prostate cancer prognosis

Prostate cancer (PCa) is a highly prevalent disease, causing the second largest amount of male cancer deaths worldwide. Currently, the prostate specific antigen (PSA) test remains the standard serum prognostic and diagnostic monitoring biomarker but it lacks specificity and sensitivity. PSA testing can lead to invasive biopsies which can result in under detection of clinically significant disease and potential overtreatment of indolent disease. Promising circulating biomarkers could facilitate less invasive and more accurate tests, but present challenges in robust quantitation and deployment in clinical settings. This work presents the detection of circulating YAP1 nucleic acid, androgen receptor (AR-FL) and AR-V7 mRNA for PCa prognostics in blood plasma from PCa patients. Sensitive detection of circulating YAP1 nucleic acid, AR-FL and AR-V7 mRNA extracted from PCa clinical samples was achieved with a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay. Optimisation of mRNA extraction methodologies for reliable detection of circulating mRNA for RT-LAMP and RT-qPCR detection took place. Multiplex testing of circulating AR-FL mRNA and YAP1 nucleic acid on an ISFET Lab-on-Chip platform was readily achieved with bio-electronic signal detection taking place within 15 min. Detection of AR-V7 and AR-FL mRNA could also be achieved simultaneously with the handheld device. Evaluation of clinical data indicated that circulating YAP1 nucleic acid presence in extracted RNA from the blood plasma of patients correlated with more advanced clinical cancer staging (p = 0.043) and PSA at diagnosis (p = 0.035). The work presents potential for Point-of-Care detection of circulating mRNA from clinical samples for PCa prognostics.