Alu expression profiles as a novel RNA signature in biology and disease

SINE retrotransposons of the Alu subfamily are the most numerous active mobile DNA elements in the human genome. Alu transcription by RNA polymerase III is subjected to tight epigenetic silencing, but activated in response to viral infection, genotoxic anticancer agents and other stimuli, through uncharacterized epigenetic switches interspersed throughout the genome. The elucidation of Alu RNA roles in cell biology and pathology has long been hampered by difficulties in their profiling at single-locus resolution, due to their repetitive nature. We recently found how to overcome this limitation by computational screening of RNA-seq data, thus opening the way to Alu transcriptome profiling as a novel tool to explore disease-related epigenome alterations.