[Revision of Functionally Relevant and Widely Expressed Long Non-Coding RNAs]

Long non-coding RNAs (lncRNAs) are involved in many cellular processes while displaying high tissue specificity. In contrast, protein-coding genes, including the category of housekeeping ones, exhibit broad expression patterns. The aim of this study was to highlight the functional importance of widely expressed lncRNAs. We analyzed experimental data from cell-growth screen of lncRNA loci in human cells, which allowed us to identify 18 lncRNA hits. Notably, these lncRNAs were not only widely expressed in most human tissues, but also played functional roles within them. Detail investigation revealed them encompass a variety of molecular functions, from cardiomyocyte damage controlling to macrophage class switching. Interestingly, experimental data highlighted the fact that a significant part of these lncRNAs encoded small but functional polypeptides. A set of lncRNAs, NEAT1, SNHG1, SNHG7, SNHG12, SNHG15, SNHG16, MIR17HG, LINC00680, LINC00263 and LINC00339, that were highly likely to be translated into small polypeptides was identified. Additionally, for EPB41L4A-AS1, CRNDE, SNHG6, LINC00493, and LINC01420, a dual function associated with both the RNA sequences and small proteins they encoded was established.