Human blood serum is cellular buffet of different biological molecules sampled continuously from every tissue of the body. So it’s not surprising that many researchers have attempted to identify biomarkers in serum that reflect a particular physiological or disease state. Most of these potential biomarkers are proteins (important-yes, exciting-not really), but Zvi Bentwich, Ayelet Chajut, and colleagues at Rosetta Genomics Ltd. (Israel) recently identified promising miRNA biomarkers in serum. Now that’s exciting, especially if you consider the attributes that make miRNAs ideal biomarkers.
miRNAs are remarkably stable in body fluids and show tissue- and disease-specific expression profiles. Bentwich, Chajut, and co-workers developed protocols to extract and quantitate the low levels of miRNAs in serum and urine. To investigate whether the serum miRNA profile can reflect physiological conditions, the researchers quantified serum levels of 28 placenta-specific miRNAs in pregnant and non-pregnant women. The levels of placental miRNAs were higher in pregnant women than in non-pregnant women and correlated with gestational stage. The technique might be used to monitor pregnancy complications such as pre-eclampsia, a condition in which a distinct placenta-specific miRNA expression profile has been detected. PLoS One, September 2008