Figure 1.

Biogenesis and function of lncRNAs. Classification of lncRNAs into five classes: sense lncRNAs, intronic lncRNAs, lincRNAs, antisense lncRNAs and bidirectional lncRNAs, based upon their genomic locations and transcription. LncRNAs regulate the expression of genes in the cytoplasm by interacting directly with microRNAs (miRNAs) or proteins, and stabilizing mRNA transcripts. Noncoding transcripts in the nucleus are known to regulate gene expression at the level of chromatin modification, transcription and post-transcriptional processing. In addition, lncRNAs are considered as biomarkers or participant in tissue crosstalk by entering the bloodstream directly, or bound to carrier proteins, even incorporated into extracellular vesicles which can be further released into bloodstream.