Improved RNA-DNA interaction calling suggests RNA-based gene regulation of phenotypic transitions.

Chromatin-localized RNAs play diverse roles in gene regulation and nuclear architecture. Mapping genome-wide RNA-DNA interactions is possible using a variety of molecular methods, including using bridging oligonucleotides to ligate RNA and DNA in proximity. While molecular methods have progressed, a robust computational method for calling biologically meaningful RNA-DNA interactions from these data is lacking. Herein, we present RADIAnT, a reads-to-interactions pipeline for analyzing RNA-DNA ligation data. RADIAnT calls interactions against a dataset-specific, unified background, which considers RNA binding site-TSS distance and genomic region bias, and outperforms previously proposed methods in the accurate recall of genome-wide RNA-DNA interactions. Accurate RNA-DNA interaction calling enables the analysis of gene regulatory RNAs in dynamic biological contexts. Here, dynamically chromatin-associated RNAs were identified in the physiologically- and pathologically relevant process of endothelial-to-mesenchymal transition. By depleting candidate chromatin-associated lncRNAs, their gene regulatory behavior at bound target genes important to endothelial phenotype maintenance could be validated. These data demonstrate how effective RNA-DNA interaction calling can help to place RNAs at key points in gene regulatory networks governing cellular behavior.