Long noncoding RNAs: biogenesis, regulation, function, and their emerging significance in toxicology

The repertoire of regulatory noncoding RNAs (ncRNAs) has been enriched by the inclusion of long noncoding RNA (lncRNA) that are longer than 200 nt. Some of the currently known lncRNAs, were reported in the 1990s before the term lncRNA was introduced. These lncRNAs have diverse regulatory functions including regulation of transcription via interactions with proteins and RNAs, chromatin remodeling, translation, posttranslational protein modification, protein trafficking and cell signaling. Predictably, the dysregulation of lncRNA expression due to exposure to toxicants may precipitate adverse health consequences. Dysregulation of lncRNAs has also been implicated in various adverse human health outcomes. There is an increasing agreement that lncRNA expression profiling data needs to be closely examined to determine whether their altered expression can be used as biomarkers of toxicity as well as adverse human health outcomes. This review summarizes the biogenesis, regulation, function of lncRNA and their emerging significance in toxicology and disease conditions. Because our understanding of the lncRNA-toxicity relationship is still evolving, this review discusses this developing field using some examples.