The hidden power of antisense long non-coding RNAs: a dive into a novel regulatory layer mediated by double-stranded RNA formation.

Over the past decade, non-coding RNAs (ncRNAs) have gained prominence in research due to their widespread presence in cells, yet their functions remain increasingly complex and less understood. Despite being initially deemed 'junk', many lncRNAs are now recognized as key regulators in cells and are often affected in disease contexts. Notably, numerous mRNAs have annotated antisense RNAs (asRNAs). Because asRNAs resemble the largest group of lncRNAs and were identified to serve a general function in Saccharomyces cerevisiae, they are the focus of this review. In S. cerevisiae, the absence of RNA interference (RNAi) enables unbiased study and allowed researchers to investigate their roles in gene regulation more directly with intriguing results, summarized here. Expression of asRNA leads to the formation of double-stranded RNAs (dsRNAs) with the regarding sense counterpart, resulting in enhanced gene expression through preferential nuclear export. Thus, these hidden leaders can boost gene expression and require future attention pivotal for elucidating their influence on biological processes and revealing disease mechanisms.