MicroRNAs and prognosis of lung cancer

MicroRNAs have recently emerged as important regulatory molecules of normal and abnormal cellular behavior. They are small (18-22 nucleotides) noncoding RNA that control translation by sequence complementarity of their "seed" sequence to the 3' untranslated regions (UTR) of their target mRNAs, which are RNA species that code for proteins. Apart from their biological importance, these small molecules have received attention as biomarkers because of their remarkable stability in tissues and body fluids and the ease of their measurement. A recent article in Cancer Research by Voortman et al has failed to validate the hypothesis that tumor microRNA expression is associated with prognosis. In light of this significant finding, this article summarizes the current state of the art of microRNA biomarkers for the prognostication of lung cancer.