Serum MicroRNAs Are Promising Novel Biomarkers

TLDR

Circulating nucleic acids offer unique opportunities for early diagnosis of clinical conditions. Serum microRNA levels were compared between pregnant and non‑pregnant women to assess changes during physiological or pathological states. We demonstrate that microRNAs are stable, detectable in serum, show elevated placenta‑associated levels during pregnancy that correlate with gestational stage, and overall represent promising, clinically useful circulating nucleic acid biomarkers.

Abstract

Circulating nucleic acids (CNAs) offer unique opportunities for early diagnosis of clinical conditions. Here we show that microRNAs, a family of small non-coding regulatory RNAs involved in human development and pathology, are present in bodily fluids and represent new effective biomarkers.After developing protocols for extracting and quantifying microRNAs in serum and other body fluids, the serum microRNA profiles of several healthy individuals were determined and found to be similar, validating the robustness of our methods. To address the possibility that the abundance of specific microRNAs might change during physiological or pathological conditions, serum microRNA levels in pregnant and non pregnant women were compared. In sera from pregnant women, microRNAs associated with human placenta were significantly elevated and their levels correlated with pregnancy stage.Considering the central role of microRNAs in development and disease, our results highlight the medically relevant potential of determining microRNA levels in serum and other body fluids. Thus, microRNAs are a new class of CNAs that promise to serve as useful clinical biomarkers.