A DNA-binding peptide comprising three zinc-fingers has been engineere
d to bind specifically to a unique nine-base-pair region of a BCR-ABL
fusion oncogene in preference to the parent genomic sequences. Binding
to the target oncogene in chromosomal DNA is possible In transformed
cells in culture, and results in blockage of transcription. Consequent
ly, murine cells rendered independent of growth factors by the action
of the oncogene revert to factor dependence upon transient transfectio
n with a vector expressing the peptide.