DNA TRIPLEX FORMATION ON THE GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR GENE PROXIMAL PROMOTER

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hemapoi etic cytokine that has been implicated in certain pathological conditi ons. We have previously demonstrated that an intermolecular DNA triple r formation on a target overlapping the NF-kappa B binding site on the GM-SCF proximal promoter inhibited gene transcription. A substitution of guanine (G) for thymine (T) in the tripler forming oligonucleotide (TFO) opposite a C:G inversion in the underlying duplex led to a sign ificant increase in the TFO binding affinity and its ability to block NF-kappa B protein binding to the DNA. However, the substitution did n ot significantly affect the inhibition of GM-CSF promoter reporter gen e activity by the TFO in Jurkat T cells.