Lost inHELLS: disentangling the mystery ofSALNRexistence in senescence cellular models

Abstract

AbstractLong non-coding RNAs (lncRNAs) have emerged as key regulators of cellular senescence by transcriptionally and post-transcriptionally modulating the expression of many important genes involved in senescence-associated pathways and processes. Among the different lncRNAs associated to senescence,Senescence Associated Long Non-coding RNA(SALNR) was found to be down-regulated in different cellular models of senescence. Since its release in 2015,SALNRhas not been annotated in any database or public repository, and no other experimental data have been published. TheSALNRsequence is located on the long arm of chromosome 10, at band 10q23.33, and it overlaps the 3’ end of theHELLSgene. This investigation helped to unravel the mystery of the existence ofSALNRby analyzing publicly available short- and long-read RNA sequencing data sets and RT-PCR analysis in human tissues and cell lines. Additionally, the expression ofHELLShas been studied in cellular models of replicative senescence, bothin silicoandin vitro. Our findings, while strongly questioning the actual existence ofSALNRas an independent transcript, support the expression of a predictedHELLSisoform entirely covering theSALNRgenomic region. Furthermore, we observed a strong down-regulation ofHELLSin senescent cells versus proliferating cells, supporting its role in the senescence and aging process.Graphical abstract