Effects of long dsRNA expression in HeLa and HEK293 cells

Double-stranded RNA (dsRNA) can enter different pathways in mammalian cells, including sequence-specific RNA interference, sequence-independent interferon response and editing by adenosine deaminases. To assess the potential of expressed dsRNA to induce interferon stimulated genes in somatic cells, we performed microarray analysis of HEK293 and HeLa cells transfected with a MosIR plasmid expressing an mRNA with a long inverted repeat structure in its 3’UTR (MosIR) or with a parental MosIR plasmid (without inverted repeat) as a control. Clustering analysis based on differentially expressed genes suggested that there was no common transcriptome signature in cells expressing dsRNA. Overall, the number of genes with altered expression upon transfection of the MosIR plasmid was rather small and only 19 probe sets, corresponding to 17 genes, were changed more than two-fold in both cell lines. Total RNA from cultured HEK293 or HeLa cells was used in each sample. Two independent biological replicates were analyzed for each condition.