Differential inhibition of the DNA binding of transcription factors NF kappa B and OTF-1 by nitrogen mustard and quinacrine mustard: transcriptional implications.
Nitrogen mustard (HN2) and quinacrine mustard (QM) both inhibited the binding of NF kappa B to the GC-rich consensus sequence in the HIV long terminal repeat (LTR), as assessed by gel-shift assays. QM also inhibited the binding of OTF-1 to the AT-rich octamer present in the H2B promoter whereas HN2 was inactive. Inhibition of the binding of transcription factors was due to the drug interaction with DNA, since it also occurred when transcription factors were added to DNA after removal of free drug. In Jurkat cells transfected with pI3CAT, where the chloramphenicol acetyltransferase (CAT) gene is under the control of the HIV LTR, both HN2 and QM inhibited CAT gene expression. However, in Jurkat cells transfected with plasmid -147, where the CAT gene is under the control of the H2B promoter, QM inhibited CAT expression but HN2 did not. These results were obtained at concentrations of HN2 or QM that inhibited total DNA and RNA synthesis to a similar extent. The present results suggest that the more selective pharmacological activity of HN2 (HN2 is an active antineoplastic agent whereas QM is inactive and very toxic) might be related to its preferential functional inhibition of GC-rich consensus sequence, possibly important in the regulation of genes involved in the malignant proliferation and behavior of some tumors.
Fabbri
S
S
Laboratory of Cancer Chemotherapy, Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
Prontera
C
C
Broggini
M
M
D'Incalci
M
M
D001482:Base Composition; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D016325:HIV Long Terminal Repeat; D051863:Host Cell Factor C1; D006801:Humans; D007938:Leukemia / Q000235:genetics; D008466:Mechlorethamine / Q000494:pharmacology*; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D050811:Octamer Transcription Factor-1; D015345:Oligonucleotide Probes / Q000737:chemistry; D010835:Phytohemagglutinins / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D011797:Quinacrine Mustard / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; C497692:HCFC1 protein, human; D051863:Host Cell Factor C1; D016328:NF-kappa B; D050811:Octamer Transcription Factor-1; D015345:Oligonucleotide Probes; C494165:POU2F1 protein, human; D010835:Phytohemagglutinins; D014157:Transcription Factors; D011797:Quinacrine Mustard; D008466:Mechlorethamine; D015500:Chloramphenicol O-Acetyltransferase; D013755:Tetradecanoylphorbol Acetate