RNA stability defines the identity of long noncoding RNA in mammals

There is growing recognition that mammalian genomes produce huge number of long noncoding RNAs (ncRNAs). However, the biological functions of most long ncRNAs are still unclear. Here we report a new approach to uncover the discriminative property of the functional long ncRNAs by combination of comprehensively measuring the half-lives and functional analysis. Our approach reveals hundreds of short-lived ncRNAs in which many well-known functional long ncRNAs are sorted. Moreover, we provide strong evidence that modulation of half-lives of relatively short-lived functional long ncRNAs, viz. NEAT1/MEN ? and GAS5, alters functional consequence, and identified novel short-lived intergenic noncoding transcripts (SLITs), those degradations are regulated by stimuli, involving in cell proliferation. Together, these results propose that short-lived property of ncRNA will be key parameter for identifying the uncharacterized long ncRNAs.