Inhibition of NF-kappa B specific transcriptional activation by PNA strand invasion.

Peptide nucleic acid (PNA) strand invasion offers an attractive alternative to DNA oligonucleotide directed triplex formation as a potential tool for gene inhibition. Peptide nucleic acid has been shown to interact with duplex DNA in a process which involves strand invasion of the duplex and binding of one of the DNA strands with two PNA oligomers. By blocking the interaction of a transcription factor with 5' regulatory sequences, PNA might specifically down-regulate gene activity. Here we demonstrate that PNA is capable of specifically blocking interaction of the transcription factor NF-kappa B with the IL2-R alpha NF kappa-B binding site in vitro. We further demonstrate that this interaction is sufficient to prevent transcriptional transactivation both in vitro and when transfected into cells in culture.