BackgroundMicroRNAs have been identified as potential cancer biomarkers due to their presence and stability in many body fluids including urine and plasma, but the relationship of the pattern of expression of these messengers across various biological media has not been addressed and could provide important information in order to translate these biomarkers for epidemiologic or clinical use.MethodsWe analyzed microRNA of matched FFPE-tumor tissue, plasma, urine exosomes (n = 16) and WBCs (n = 11) from patients with bladder cancer, using Nanostring miRNA assays and droplet digital PCR for validation. Pearson correlations were used to compare expression between media.ResultsNumerous microRNAs were detected and overlapping from specific bio-specimen sources. MiR-4454 and miR-21 overexpression was found in three sources: tumor, WBCs and urine. Additionally, miR-15b-5p, miR-126-3p, miR-93-5p, and miR-150-5p were common to tumor/WBCs, while miR-720/3007a, miR-205, miR-200c-3p and miR-29b-3p common to tumor/urine. Significant associations were noted between the log-adjusted average miRNA counts in tumor vs. WBCs (r = 0.418 p < 0.001), and tumor vs. urine (r = 0.38 p < 0.001). No association was seen tumor vs. plasma exosome miRs (r = 0.07 p = 0.06).ConclusionsMicroRNA profiling from matched samples in patients shows a significant number of microRNAs up regulated in bladder tumors are identifiable in urine exosomes and WBCs of the same patient, but not in blood plasma. This study demonstrated varying relationships between miRNA detected in biological media from the same patient, and serves to inform the potential of urine-based microRNAs as biomarkers for bladder cancer and potentially other malignancies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-015-0466-2) contains supplementary material, which is available to authorized users.

The importance of imprinted genes in regulating feto-placental development has been long established. However, a comprehensive assessment of the role of placental imprinted gene expression on fetal growth has yet to be conducted. In this study, we examined the association between the placental expression of 108 established and putative imprinted genes and birth weight in 677 term pregnancies, oversampled for small for gestational age (SGA) and large for gestational age (LGA) infants. Using adjusted multinomial regression analyses, a 2-fold increase in the expression of 9 imprinted genes was positively associated with

Background:Arsenic is one of the most commonly encountered environmental toxicants, and research from model systems has suggested that one mode of its toxic activity may be through alterations in DNA methylation. In utero exposure to arsenic can affect fetal, newborn, and infant health, resulting in a range of phenotypic outcomes.Objectives:This study examined variation in placental DNA methylation and its relationship to arsenic exposure in 343 individuals enrolled in the New Hampshire Birth Cohort Study.Methods:Linear regression models using a reference-free correction to account for cellular composition were employed to determine CpG loci affected by arsenic levels.Results:Total arsenic measured in maternal urine during the second trimester was not associated with methylation in the placenta, whereas arsenic levels quantified through maternal toenail collected at birth were associated with methylation at a single CpG locus (p = 4.1 × 10–8). Placenta arsenic levels were associated with 163 differentially methylated loci (false discovery rate < 0.05), with 11 probes within the LYRM2 gene reaching genome-wide significance (p < 10–8). Measurement of LYRM2 mRNA levels indicated that methylation was weakly to moderately correlated with expression (r = 0.15, p < 0.06). In addition, we identified pathways suggesting changes in placental cell subpopulation proportions associated with arsenic exposure.Conclusions:These data demonstrate the potential for arsenic, even at levels commonly experienced in a U.S. population, to have effects on the DNA methylation status of specific genes in the placenta and thus supports a potentially novel mechanism for arsenic to affect long-term children’s health.Citation:Green BB, Karagas MR, Punshon T, Jackson BP, Robbins DJ, Houseman EA, Marsit CJ. 2016. Epigenome-wide assessment of DNA methylation in the placenta and arsenic exposure in the New Hampshire Birth Cohort Study (USA). Environ Health Perspect 124:1253–1260; http://dx.doi.org/10.1289/ehp.1510437

(2016) Regions of variable DNA methylation in human placenta associated with newborn neurobehavior, Epigenetics, 11:8, 603-613, DOI: 10.1080/15592294.2016 ABSTRACTThe placenta regulates the in utero environment and functionally impacts fetal development. Candidate gene studies identified variation in placental DNA methylation is associated with newborn neurologic and behavioral outcomes including movement quality, lethargic behavior, attention, and arousal. We sought to identify novel regions of variable DNA methylation associated with newborn attention, lethargy, quality of movement, and arousal by performing an epigenome-wide association study in 335 infants from a US birth cohort. Methylation status was quantified using the Illumina HumanMethylation450 BeadChip array and associations to newborn outcomes assessed by the NICU Network Neurobehavioral Scales (NNNS) were identified while incorporating established bioinformatics algorithms to control for confounding by cell type composition. Methylation of CpGs within FHIT (cg15970800) and ANKRD11 (cg16710656) demonstrated genome-wide significance (P < 1.8 £ 10 ¡7 ) in specific associations with infant attention. CpGs whose differential methylation was associated with all 4 neurobehavioral outcomes were common to 50 genes involved in biological processes relating to cellular adhesion and nervous system development. Comprehensive methylation profiling identified relationships between methylation of FHIT and ANKRD11, which have been previously linked to neurodevelopment and behavioral outcomes in genetic association studies. Subtle changes in DNA methylation of these genes within the placenta may impact normal variation of a newborn's ability to alter and track visual and auditory stimuli. Gene ontology analysis suggested that those genes with variable methylation related to these outcomes are overrepresented in biological pathways involved in brain development and placental physiology, supportive of our hypothesis for a key role of the placenta in neurobehavioral outcomes.