title: Protein electrocatalysis for direct sensing of circulating microRNAs.
abstract: MicroRNAs (miRNAs) are potentially useful biomarkers for diagnosis, classification, and prognosis of many diseases, including cancer. Herein, we developed a protein-facilitated electrocatalytic quadroprobe sensor (Sens(PEQ)) for detection of miRNA signature of chronic lymphocytic leukemia (CLL) in human serum. The developed signal-ON sensor provides a compatible combination of two DNA adaptor strands modified with four methylene blue molecules and electrocatalysis using glucose oxidase in order to enhance the overall signal gain. This enhanced sensitivity provided the response necessary to detect the low-abundant serum miRNAs without preamplification. The developed Sens(PEQ) is exquisitely sensitive to subtle π-stack perturbations and capable of distinguishing single base mismatches in the target miRNA. Furthermore, the developed sensor was employed for profiling of three endogenous miRNAs characteristic to CLL, including hsa-miR-16-5p, hsa-miR-21-5p, and hsa-miR-150-5p in normal healthy serum, chronic lymphocytic leukemia Rai stage 1 (CLL-1), and stage 3 (CLL-3) sera, using a non-human cel-miR-39-3p as an internal standard. The sensor results were verified by conventional SYBR green-based quantitative reverse-transcription polymerase chain reaction (RT-qPCR) analysis.
authors.affiliation: Department of Chemistry, University of Ottawa , 10 Marie Curie, Ottawa, Ontario K1N 6N5, Canada.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Labib
authors.forename: Nasrin
authors.initials: N
authors.lastname: Khan
authors.forename: Maxim V
authors.initials: MV
authors.lastname: Berezovski
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation*; D017173:Caenorhabditis elegans; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004867:Equipment Design; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D005949:Glucose Oxidase / Q000378:metabolism; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000097:blood* / Q000175:diagnosis / Q000235:genetics; D035683:MicroRNAs / Q000097:blood* / Q000235:genetics; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor; D005949:Glucose Oxidase; D035683:MicroRNAs; C533097:MIR150, human; C505362:MIRN16 microRNA, human; C524940:MIRN21 microRNA, human