title: A methodological procedure for evaluating the impact of hemolysis on circulating microRNAs.
abstract: Circulating microRNAs (miRNAs) are promising non-invasive biomarkers whose expression may be affected by confounding factors, including hemolysis, that should be considered in studies of miRNA discovery. The present study proposes a methodology for evaluating the impact of hemolysis on the expression of miRNAs. An experiment ofin vitrocontrolled hemolysis was designed for assessing if changes in the expression of eight miRNAs observed to be circulating in plasma may be associated with hemolysis, and also to estimate the level of red blood cell (RBC) contamination in plasma samples where the expression of these miRNAs will be measured. It was confirmed that four miRNAs, miR-16, miR-92a, miR-451 and miR-486, known to be present in blood cells, were influenced by contamination of RBCs. Furthermore, it was demonstrated that miR-378 and miR-30c are hemolysis-independent and that the expression of miR-320 and miR-324-3p was associated with the level of RBC contamination. This procedure is proposed as a tool for the evaluation of the influence of hemolysis on candidate circulating miRNA biomarkers prior to their analysis in plasma samples.
authors.affiliation: Unit of Medical Statistics, Biometry and Bioinformatics, Scientific Institutes for Research and Treatment Foundation 'National Cancer Institute', I-20133 Milan, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Pizzamiglio
authors.affiliation: Department of Experimental Oncology and Molecular Medicine, Scientific Institutes for Research and Treatment Foundation 'National Cancer Institute', I-20133 Milan, Italy; Molecular Genetics of Cancer Group, FIRC Institute of Molecular Oncology Foundation, I-20139 Milan, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Zanutto
authors.affiliation: Unit of Medical Statistics, Biometry and Bioinformatics, Scientific Institutes for Research and Treatment Foundation 'National Cancer Institute', I-20133 Milan, Italy; Department of Clinical Sciences and Community Health, University of Milan, I-20133 Milan, Italy.
authors.forename: Chiara M
authors.initials: CM
authors.lastname: Ciniselli
authors.affiliation: Laboratory of Experimental Molecular Pathology, Department of Pathology, Scientific Institutes for Research and Treatment Foundation 'National Cancer Institute', I-20133 Milan, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Belfiore
authors.affiliation: Unit of Medical Statistics, Biometry and Bioinformatics, Scientific Institutes for Research and Treatment Foundation 'National Cancer Institute', I-20133 Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bottelli
authors.affiliation: Department of Experimental Oncology and Molecular Medicine, Scientific Institutes for Research and Treatment Foundation 'National Cancer Institute', I-20133 Milan, Italy; Molecular Genetics of Cancer Group, FIRC Institute of Molecular Oncology Foundation, I-20139 Milan, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Gariboldi
authors.affiliation: Unit of Medical Statistics, Biometry and Bioinformatics, Scientific Institutes for Research and Treatment Foundation 'National Cancer Institute', I-20133 Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Verderio
keywords: circulating microRNA; hemolysis; plasma