Selective binding to human genomic sequences of two synthetic analogues structurally related to U-71184 and adozelesin

In this paper, we analyse the in vitro sequence-selectivity of two syntheti c analogues of U-71184 and adozelesin by polymerase chain reaction (PCR) pe rformed on human genomic DNA. In addition, DNase footprinting and nucleotid e sequence analysis on arrested-PCR products were performed to confirm sequ ence-selective binding. Finally, the antitumor effects were studied in vitr o on human leukemic L1210 cells. The binding activity of the two newly synt hesized compounds to human gene sequences was compared with the CC-1065 ana logue U-71184, the A+T sequence-selective drug distamycin and the GI-C sequ ence-selective drugs mithramycin and chromomycin. As molecular model system s for in vitro DNA-binding studies we used the human estrogen receptor gene and the Ha-ras oncogene. In some experiments the PCR approach was performe d using as target DNA a portion of the long terminal repeat (LTR) of the hu man immunodeficiency type 1 virus (HIV-1). These genomic regions contain se quences that are different with respect to A+T/G+C ratios, being the upstre am sequence of the human estrogen receptor gene A+T rich, while the Ha-ras and HIV-1 LTR sequences contain G+C-rich regions. The first conclusion that can be drawn from the experiments reported in our paper is that the two ne wly synthetized analogues of U-71184 and adozelesin inhibit PCR-mediated am plification of genomic regions in a sequence-dependent manner. A second con clusion of our experiments is that these compounds are active inhibitors of tumor cell growth in vitro. (C) 1999 Wiley-Liss, Inc.