Better understanding and management of lung cancer are needed. Although much has been learned from known protein coding genes, long noncoding RNAs (lncRNAs), a relatively new and fast evolving large family of transcripts, have recently generated much attention for new discoveries. LncRNAs play critical regulatory functions and are emerging as new players in tumorigenesis and phenotypic determinators of lung cancer. Here, the authors highlight the latest development of lncRNAs, including circular RNAs in lung cancer. They start with well-characterized lncRNAs and circular RNAs as an oncogene or tumor suppressor and then extend our discussion on the impact of SNPs in lncRNA on its functions and lung cancer risk and the clinical applications of lncRNAs as biomarkers and therapeutic targets.
Long noncoding RNA categories based on genomic locations and biological functions
(A) LncRNAs categorized based on their genomic locations: lncRNAs (red arrows) and their genomic positions are shown relative to the protein-coding genes (blue arrows) on a chromosome (black line). The exons of lncRNAs are represented by solid red boxes. The exons of protein-coding genes are represented by solid blue boxes (for each gene, only two exons are shown for simplicity of the illustration). The arrowheads point to the direction of transcription. The percentage of each category of lncRNAs are shown in brackets (based on Derrien et al. ). (B) LncRNAs categorized based on their biological functions. LncRNA (red hairpin) can function as a (I) signal; (II) decoy; (III) guide or (IV) scaffold to participate in the regulatory mechanisms. The gene names of lung cancer-related lncRNAs are given as examples for each category.