Characterization of novel LncRNA P14AS as a protector of ANRIL through AUF1 binding in human cells

• Main Authors: Wanru Ma, Juanli Qiao, Jing Zhou, Liankun Gu, Dajun Deng
• Format: Article
• Language: English
• Published: BMC 2020-02-01
• Series: Molecular Cancer
• Subjects: lncRNA; CDKN2A; P14AS; ANRIL; P16; AUF1
• Online Access: http://link.springer.com/article/10.1186/s12943-020-01150-4

Abstract Background The CDKN2A/B locus contains crucial tumor suppressors and a lncRNA gene ANRIL. However, the mechanisms that coordinately regulate their expression levels are not clear. Methods Novel RNAs transcribed from the CDKN2A gene were screened by CDKN2A-specific RNA capture deep-sequencing and confirmed by Northern blotting and clone-sequencing. Long non-coding RNA (lncRNA) binding proteins were characterized by RNA pull-down combined with mass spectrometry and RNA immunoprecipitation. LncRNA functions in human cells were studied using a set of biological assays in vitro and in vivo. Results We characterized a novel lncRNA, P14AS with its promoter in the antisense strand of the fragment near CDKN2A exon 1b in human cells. The mature P14AS is a three-exon linear cytoplasmic lncRNA (1043-nt), including an AU-rich element (ARE) in exon 1. P14AS decreases AUF1-ANRIL/P16 RNA interaction and then increases ANRIL/P16 expression by competitively binding to AUF1 P37 and P40 isoforms. Interestingly, P14AS significantly promoted the proliferation of cancer cells and tumor formation in NOD-SCID mice in a P16-independent pattern. Moreover, in human colon cancer tissues, the expression levels of P14AS and ANRIL lncRNAs were significantly upregulated compared with the paired normal tissues. Conclusion A novel lncRNA, P14AS, transcribed from the antisense strand of the CDKN2A/P14 gene, promotes colon cancer development by cis upregulating the expression of oncogenic ANRIL.