Control of specific gene expression in mammalian cells by co-expression of long complementary RNAs.

The use of long double-stranded RNA (dsRNA) for gene silencing in mammalian cells has generally been restricted to embryonic cell types and proposed to induce non-specific effects on gene expression in differentiated cells. In this study, we report that foreign and endogenous gene expression can be regulated in immortalised human cell lines by co-expression of long complementary RNAs with the potential to form dsRNA. The observed gene silencing effect was transferable to recipient control cells, occurred independently of cytoplasmic Dicer and produced an epi-allelic series of clones suitable for gene function studies. This complementary RNA co-expression approach permits the use of long complementary RNAs for regulating specific gene expression in mammalian cells.