Microarray profiling defines circulating microRNAs associated with myelodysplastic syndromes.

Circulating microRNAs (miRNAs) are non-coding RNAs secreted into body fluids, and aberrant levels of these miRNAs correlate with diseases of various origins, making them highly potential clinical biomarkers. We investigated the spectrum of circulating miRNAs in the plasma of myelodysplastic syndrome (MDS) patients to identify miRNAs showing discriminatory levels in the patients with different prognosis. Plasma samples were analyzed with microarrays to define miRNA profiles, and the deregulated miRNAs were further studied using droplet digital PCR. With regard to the prognosis, the levels of miR-27a-3p, miR-150-5p, miR-199a-5p, miR-223-3p and miR-451a were reduced in higher-risk MDS. Multivariate analysis indicated miR-451a level as an independent predictor of progression-free survival (HR = 0.072, P = 0.006) and revealed a significant association of miR-223-3p level with overall survival (HR = 0.039, P = .032). Our data demonstrate that plasma levels of specific miRNAs are associated with MDS patient outcome and may add information beyond the currently used scoring systems.

Circulating MicroRNAs: Methodological Aspects in Detection of These Biomarkers.

MicroRNAs (miRNAs) are evolutionarily conserved small non-coding RNAs that regulate expression of protein-coding genes involved in important biological processes and (patho)physiological states. Circulating miRNAs are protected against degradation, indicating their relevant biological functions. Many studies have demonstrated an association of the specific profile of circulating miRNAs with a wide range of cancers as well as non-malignant diseases. These findings demonstrate the implication of circulating miRNAs in the pathogenesis of diseases and their potential as non-invasive disease biomarkers. However, methods for measurement of circulating miRNAs have critical technical hotspots, resulting in a discrepancy of the reported results and difficult definition of consensus disease biomarkers that may be implicated in clinical use. Here, we review functions of circulating miRNAs and their aberrant expression in particular diseases. Further, we discuss methodological aspects of their detection and quantification as well as our experience with the methods.

Transcriptome alterations in maternal and fetal cells induced by tobacco smoke.

OBJECTIVES: Maternal smoking has a negative effect on all stages of pregnancy. Tobacco smoke-related defects are well established at the clinical level; however, less is known about molecular mechanisms underlying these pathologic conditions. We thus performed a comprehensive analysis of transcriptome alterations induced by smoking in maternal and fetal cells. STUDY DESIGN: Samples of peripheral blood (PB), placenta (PL), and cord blood (UCB) were obtained from pregnant smokers (n = 20) and gravidas without significant exposure to tobacco smoke (n = 52). Gene expression profiles were assayed by Illumina Expression Beadchip v3 for analysis of 24,526 transcripts. The quantile method was used for normalization. Differentially expressed genes were analyzed in the Limma package and the P-values were corrected for multiple testing. Unsupervised hierarchical clustering was performed using average linkage and Euclidean distance. The enrichment of deregulated genes in biological processes was analyzed in DAVID database. RESULTS: Comparative analyses defined significant deregulation of 193 genes in PB, 329 genes in PL, and 49 genes in UCB of smokers. The deregulated genes were mainly related to xenobiotic metabolism, oxidative stress, inflammation, immunity, hematopoiesis, and vascularization. Notably, functional annotation of the affected genes identified several deregulated pathways associated with autoimmune diseases in the newborns of smokers. CONCLUSIONS: The study demonstrated maternal smoking causes significant changes in transcriptome of placental and fetal cells that deregulate numerous biological processes important for growth and development of the fetus. An activation of fetal CYP genes showed a limited ability of the placenta to modulate toxic effects of maternal tobacco use.