Identification of Complete Hydatidiform Mole Pregnancy–Associated MicroRNAs in Plasma

Abstract

To the Editor: The presence of pregnancy-associated, placenta-specific microRNAs (miRNAs)1 in the plasma of pregnant women has recently been reported (1). Such miRNAs have potential as molecular markers for complete hydatidiform mole (CHM), which is usually diploid and androgenetic in origin. We aimed to identify CHM pregnancy–associated miRNAs in plasma. All participants gave written informed consent, and the Research Ethics Committee of Nagasaki University approved the study. First, we obtained a set of CHM tissues and blood samples from a CHM pregnant woman at 10 weeks' gestation and normal villous tissue from a woman with an uncomplicated singleton pregnancy who underwent artificial abortion at 10 weeks' gestation. Both the androgenetic origin of the CHM (46,XX) and the biparental origin of normal villous tissue (46,XX) were confirmed by DNA genotyping analysis. Isolation of total RNA (including small RNAs), assessment of their quality, concentration measurements, construction of a small-RNA library, next-generation sequencing (NGS), miRNA mapping, and NGS analysis of the differential expression of miRNA-encoding genes were performed as described previously (2). NGS analysis of the sample set yielded 16 920 412 reads from CHM tissue, 17 462 519 reads from the patient's blood cells, and 30 447 835 reads from normal villous tissue. All of these sequence data were deposited in the DNA Data Bank of Japan (DDBJ) Sequence Read Archive (http://www.ddbj.nig.ac.jp/index-e.html). The accession ID is DRA001009 (http://trace.ddbj.nig.ac.jp/DRASearch/). …