Kai Wang, Ph.D., senior research scientist at the Institute for Systems Biology, discussed extracellular miRNA as a new source of biomarkers. Dr. Wang and colleagues in David Galas’ lab are studying many aspects of miRNA, both functional and disease-correlative. By profiling both miRNA and mRNA expression levels in numerous body fluids, including breast milk, urine, and plasma, they determined various miRNA signatures (profiles) discretely associated with various biological states (e.g., pregnancy, presence of disease, stage of disease).
The identification of stable miRNAs in extracellular environments suggests a biological function that may relate to cell-cell communication. Dr. Wang’s research aims to understand the potential of miRNAs as biomarkers, as well as their mechanisms of function, intra- and extracellularly, through study of human samples and animal models.
The challenges, as he acknowledged in his presentation, are current limitations in miRNA measurement and assessment. “When we evaluate miRNA measurement data, we need to be extremely judicious.” Using different platforms may yield significantly different results, which can complicate data verification and validation.
It is commonly acknowledged, for instance, that fluorescence- or other colorimetric-based microarray data can vary from that obtained with the same samples using qPCR, Dr. Wang noted. The imperative is, then, as much as possible, to use the same platform within a study and to be aware of possible differences between measurement methods, he advised.