Cis-platin responsive sequences in the human c-myc promoter.

We have transfected recombinant plasmids carrying 5' c-myc sequences linked to the reporter gene chloramphenicol acetyl-transferase (cat) and to the selectable marker aminoglycoside phosphotransferase (aph) into rat fibroblasts and obtained stable transfectants. The response to cis-platin of these cell lines was studied. At 5 X 10(-5) M concentration cis-platin stimulates cat gene expression 9 and 11 fold respectively in cell lines containing constructs with c-myc promoter sequences truncated at -2319 and -350 relative to c-myc RNA start site P1. A third cell line expressing a myc/cat recombinant truncated at -290 shows no response to cis-platin, thus defining a cis-platin responsive element between coordinates -290 and -350 on the myc promoter region.