Highly Sensitive Multiplexed Sensing of miRNAs in\na Gastric Cancer Patient’s Liquid Biopsy

Gastric\ncancer (GC) is one of the leading causes of cancer mortality\nin the world. Most patients are in the advanced stage of the disease\nat the time of diagnosis because the symptoms of early gastric cancer\npatients are not obvious. Early diagnosis of gastric cancer is still\nchallenging due to the high cost, invasiveness, and low accuracy of\ntraditional diagnostic methods such as endoscopy and biopsy. Herein,\nwe develop clinically accurate and highly sensitive detection of multiple\nGC miRNA biomarkers in human serum using an isothermal nucleic acid\nprimer exchange reaction (PER). The isothermal nucleic acid primer\nexchange reaction demonstrates high sensitivity and robustness, exemplified\nby a one-pot reaction achieving a detection limit of 28.71 fM. By\nquantifying the levels of three miRNA biomarkers selected through\nbioinformatics analysis in gastric cancer serum samples, the diagnostic\napproach effectively distinguished between clinical gastric cancer\npatients (<i>n</i> = 25) and noncancer controls (<i>n</i> = 10). The performance of our three-miRNA signature in\ndiscriminating between GC and controls was as follows: area under\nthe curve (AUC): 0.808, sensitivity: 89%, specificity: 88%, positive\npredictive value (PPV): 96%, and negative predictive value (NPV):\n70%.