Antisense non-coding RNAs and regulation of gene transcription.

Transcriptome analyses have revealed the existence of a large variety of non-coding RNAs (ncRNAs) that, although specifically expressed, are largely unknown in function. The best-studied role of ncRNAs is the regulation of gene expression, mostly participating in transcription. We report here the role of an antisense ncRNA that represses transcription of LEF1 by recruiting Polycomb repressive complex 2 (PRC2), which trimethylates H3K27. This antisense LEF1 transcript undergoes splicing losing its inhibitory function. We also discuss the possible general relevance of this finding.