Targeting Long NonCoding RNA splicing by novel candidate drug Many nascent long noncoding RNAs have received considerable attention in recent years because of their major regulatory roles in gene expression and signaling pathways at various levels. Indeed long noncoding RNAs undergo the same maturation steps as premRNAs of proteincoding genes, but they are less efficiently spliced and polyadenylated in comparison to them. Here we focus on a specific human long noncoding RNA and we show the activity of a new candidate drug that potentially affect his splicing and generate an antiHIV and antiinflammatory effects driven by upregulation of microRNA biogenesis. To investigate this activity we combine the use of capture sequencing technology and an ab initio transcript assembly on cells from six healthy individuals. The sequencing depth of capture sequencing permitted us to assemble transcripts exhibiting a complex array of splicing patterns. In essence, we revealed that splicing of the long noncoding RNA is activated by the drug whereas this splicing was not present in untreated samples.

Ribosomal inframe mistranslation of stop codons in multiple open reading frames of specific human long noncoding RNAs. One of the major discoveries of the early postgenomic era, as embodied by the gene catalogs of the FANTOM and ENCODE (Encyclopedia of DNA Elements) consortia, is that twothirds of human genes do not encode known proteins. Those 40,000 nonproteincoding (noncoding RNA) human genes (www.gencodegenes.org) remain poorly understood. Long noncoding RNA (lncRNA) genes are the most numerous category of human ncRNA genes. Hundreds of lncRNAs have recentlydiscovered functions and are now understood to be fundamental nuclear and cytoplasmic, epigenetic and posttranscriptional, positive and negative regulators of gene expression in normal cellular functions and in a wide range of human diseases. However, the functions, if any, of the vast majority of lncRNAs remain obscure. Significantly, an unconventional role for their transcripts as unexpected defacto messenger RNAs has not been formally excluded. Ribosome profiling (Riboseq) predicts translational potential; nonetheless, without independent evidence of proteins matching lncRNA open reading frames (ORFs), ribosome binding does not prove translation. We were the first to massspectrometrically document translation of specific lncRNAs in human cells (https:genome.cshlp.orgcontent2291646.long). We have now performed a global search for lncRNA translation in human MCF7 breast cancer cells, integrating strandspecific RNAseq, Riboseq, and deep mass spectrometry of trypsindigested u003c15kDa fractions postUHPLC (Orbitrap MSMS) in biological quadruplicates by two independent core facilities. We excluded knownprotein matches. UCSC Genome Browserassisted manual annotation of imperfect (trypticdigestpeptides)to(lncRNAthreeframe translations) alignments initially revealed three peptides hypothetically explicable by xe2x80x9cstoptononstopxe2x80x9d in frame replacement of stop codons by amino acids in two ORFs of the lncRNA MMP24AS1. To search for this phenomenon genomewide, we designed and implemented an unprecedented computational pipeline, matching trypticdigest spectra to wildcardinsteadofstop versions of repeatmasked, sixframe, wholegenome translations. Along with singleton stoptononstop events affecting four other lncRNAs, we identified 24 additional peptides with stoptononstop inframe substitutions from multiple MMP24AS1 lncRNA ORFs. Only UAG and UGA, but not UAA, stop codons were affected. All MMP24AS1matching spectra met the same significance thresholds as highconfidence knownprotein signatures. Targeted resequencing of MMP24AS1 genomic DNA and cDNA from the same samples did not reveal any mutations, polymorphisms, or sequencingdetectable RNA editing. We have therefore discovered an apparent genespecific violation of the genetic code. It highlights the importance of matching peptides to wholegenome, not knowngenesonly, ORFs in massspectrometry workflows, and suggests a new mechanism enhancing the combinatorial complexity of the proteome.