Recently, scientists from the University of Pittsburgh Schools
of the Health Sciences (UPMC), Helicos Biosciences Corp.,
Integromics Inc., and the University of Geneva Medical School
published an article in Nature showing that mammalian cells are
capable of synthesizing RNA by copying RNA molecules directly.
Contrary to the widely held belief that small RNA molecules
(sRNA) of under 200 nucleotides are simply degradation products,
previous studies have shown that sRNAs may have both a
functional role and predict the existence of novel biochemical
cellular pathways. In this recent study, researchers profiled
small RNAs from human cells and tissues, uncovering several new
classes of RNAs, including antisense termini-associated short
RNAs, which are likely derived from messenger RNAs of protein-
coding genes by yet uncharacterized, pervasive RNA-copying
mechanisms in human cancer cell lines. According to co-author
Bino John, Ph.D., assistant professor, Department of
Computational and Systems Biology, Pitt School