Inhibition of DNA binding of the NF-Y transcription factor by the pyrrolobenzodiazepine-polyamide conjugate GWL-78

• Published in: Molecular cancer therapeutics Vol. 7; no. 5; pp. 1319 - 1328
• Main Authors: Kotecha, Minal, Kluza, Jerome, Wells, Geoff, O'Hare, C Caroline, Forni, Claudia, Mantovani, Roberto, Howard, Philip W, Morris, Peter, Thurston, David E, Hartley, John A, Hochhauser, Daniel
• Format: Journal Article
• Language: English
• Published: United States American Association for Cancer Research 01-05-2008
• Subjects: Amino Acid Motifs; Animals; Antigens, Neoplasm - drug effects; Antigens, Neoplasm - genetics; Antineoplastic Agents - pharmacology; Base Sequence; Benzodiazepines - pharmacology; Binding Sites; CCAAT-Binding Factor - antagonists & inhibitors; CCAAT-Binding Factor - genetics; CCAAT-Binding Factor - metabolism; Cell Cycle; Dipeptides - pharmacology; DNA - metabolism; DNA Topoisomerases, Type II - drug effects; DNA Topoisomerases, Type II - genetics; DNA-Binding Proteins - drug effects; DNA-Binding Proteins - genetics; Electrophoretic Mobility Shift Assay; Mice; Molecular Sequence Data; NF-Y; NIH 3T3 Cells; pyrrolobenzodiazepine; transcription factor
• ISSN: 1535-7163; 1538-8514
• DOI: 10.1158/1535-7163.MCT-07-0475

Many genes involved in cell cycle control have promoters that bind the heterotrimeric transcription factor NF-Y. Several minor-groove
binding drugs have been shown to block interactions of transcription factors with cognate DNA-binding sequences. We showed
previously that noncovalent minor-groove binding agents block interactions of NF-Y with the promoter of topoisomerase IIα
(topo IIα). In this study, we investigated the ability of GWL-78, a pyrrolobenzodiazepine-poly( N -methylpyrrole) conjugate, to inhibit the binding of NF-Y to DNA. Electrophoretic mobility shift assays showed that GWL-78
could displace NF-Y bound to several CCAAT motifs within promoters of genes involved in cell cycle progression. DNase I footprinting
of the topo IIα promoter confirmed binding of GWL-78 to AT-rich sequences corresponding to the preferred binding site of NF-Y.
Incubation with GWL-78 resulted in displacement of NF-Y binding to DNA. Chromatin immunoprecipitation assays on the topo IIα
promoter showed that GWL-78 was able to enter the nucleus and interact with specific DNA sequences. Treatment of NIH3T3 cells
with GWL-78 resulted in a block of cell cycle progression, which did not involve activation of p53. Thus, agents such as GWL-78
may be useful in modulating transcription and blocking cellular proliferation. [Mol Cancer Ther 2008;7(5):1319–28]