* To whom correspondence should be addressed.
Received December 9, 2003; Revision received February 10, 2004
Triplex-forming oligonucleotides (TFOs) are a challenging and very promising subject in modern biochemistry and molecular genetics. Over the last decade, several studies have stated that TFOs: a) can bind to DNA in a sequence-specific manner; b) can provoke DNA repair and recombination in mammalian cells, and c) can be a very effective biological tool in embryonic and oncogenic research on gene expression pathways. Herein we review the basic modes in which TFOs exist, their gene-regulation properties, as well as the obstacles that should be overcome before they become useful in clinical practice (chemotherapy and/or gene therapy).
KEY WORDS: triplex DNA, gene regulation, antisense and antigene drugs, chemotherapy