Validation of Miniaturized One-Step Reverse Transcription qPCR Assays for High-Throughput Screening and Comparison to a Reporter Gene Methodology

Integration of Acoustic Liquid Handling into Quantitative Analysis of Biological Matrix Samples

Acoustic liquid handlers deliver small volumes (nL-µL) of multiple fluid types with accuracy and dynamic viscosity profiling. They are widely used in the pharmaceutical industry with applications extending from high-throughput screening in compound management to gene expression sequencing, genomic and epigenetic assays, and cell-based assays. The capability of the Echo to transfer small volumes of multiple types of fluids could benefit bioanalysis assays by minimization of sample volume and by simplifying dilution procedures by direct dilution. In this study, we evaluated the Labcyte Echo 525 liquid handler for its ability to deliver small volumes of sample preparations in biological matrix (plasma and serum) and to assess the feasibility of integration of the Echo with three types of bioanalytical assay platforms: microplate enzyme-linked immunosorbent assay, Gyrolab immunoassay, and liquid chromatography with tandem mass spectrometry. The results demonstrated acceptable consistency of dispensed plasma samples from multiple lots and species by the Echo. Equivalent assay performance demonstrated between the Echo and manual liquid procedures indicated great potential for the integration of the Echo with the bioanalytical assay, which allows the successful implementation of microsampling strategies in drug discovery and development.

Follow-up of gestational trophoblastic disease/neoplasia via quantification of circulating nucleic acids of placental origin using C19MC microRNAs, hypermethylated RASSF1A, and SRY sequences

The aim of the study was to evaluate the effectiveness of placental-specific markers, extracellular fetal DNA (sex-determining region Y and hypermethylated RASSF1A sequences) and circulating C19MC microRNAs (miR-516-5p, miR-517-5p, miR-518b, miR-520a-5p, miR-520h, miR-525, and miR-526a) for the diagnosis and consecutive follow-up of gestational trophoblastic disease/neoplasia. Increased levels of extracellular fetal DNA and C19MC microRNAs were detected in patients with active disease when compared with the period when the patients reached remission of the disease. The positive correlation between plasma levels of hypermethylated RASSF1A sequence, C19MC microRNAs, and human chorionic gonadotropin serum levels was found. MiR-520a-5p had the best performance to detect patients with active disease (a positive predictive value of 100% at a null false positive ratio (FPR)). MiR-516-5p and miR-525 were able to diagnose 100% of women with active disease at the FPR 3.9%/7.7%. The overall predictive capacity of single miR-526a (81.8% at null FPR), miR-517-5p (90.9% at 15.4% FPR), miR-518b (100% at 38.5% FPR), and miR-520h (90.9% at 26.9% FPR) biomarkers to detect active disease cases was slightly lower. Transient increase in C19MC microRNA plasma levels after the first cycle of chemotherapy indicated the decay of placental trophoblast residual tissue. The increased levels of extracellular fetal DNA and placental-specific C19MC microRNAs are associated with gestational trophoblastic disease/neoplasia. Screening of extracellular placental-specific biomarkers may represent an additional option to identify a significant proportion of women with active disease and to monitor the therapy response. Non-invasive follow-up of the decomposing residual tissue in the form of extracellular nucleic acids of placental origin packed into apoptotic bodies derived from placental trophoblasts is available.

Reproducibility of quantitative real-time PCR assay in microRNA expression profiling and comparison with microarray analysis in narcolepsy

MicroRNAs (miRNAs) have been shown in the pathogenesis of human neurological disorders. The study aims to identify the involvement of miRNAs in the pathophysiology of narcolepsy. Here, we conducted three independent high-throughput analysis of miRNA (miRNA microarray) in peripheral blood from 20 narcolepsy patients who fulfilled the criteria compared to 20 healthy controls with validation experiment using quantitative real-time polymerase chain reaction (real-time PCR) panels. By analyzing 2805 miRNAs in peripheral blood with microarray we identified 128 miRNAs (105 high expression and 23 low expression) that were different in patients with narcolepsy in comparison with healthy control. Then we chose six high expression candidates and six low expression candidates of at least twofold difference and p value < 0.05 to validate the changes in three independent experiments in vitro using real-time PCR. The validation test showed that levels of hsa-mir-1267, hsa-miR-4309, hsa-miR-554, hsa-miR-1272, hsa-miR-4501, hsa-miR-182-3p were higher, whereas the level of hsa-miR-625-5p, hsa-miR-100-5p, hsa-miR-125b-5p, hsa-miR-197-3p, hsa-miR-4522, hsa-miR-493-5p was lower in narcolepsy patients than healthy controls. The levels of 12 miRNAs differed significantly in peripheral blood from narcolepsy patients which suggested that alterations of miRNAs expression may be involved in the pathophysiology of narcolepsy.