Inhibition of Epidermal Growth Factor Receptor-Mediated Signaling by “Combi-Triazene” BJ2000, a New Probe for Combi-Targeting Postulates

  1. Fouad Brahimi1,
  2. Stephanie L. Matheson1,
  3. Fabienne Dudouit1,
  4. James P. Mcnamee2,
  5. Ana M. Tari3 and
  6. Bertrand J. Jean-Claude
  1. 1Cancer Drug Research Laboratory, Department of Medicine, Division of Medical Oncology, McGill University Health Center/Royal Victoria Hospital, Montreal, Quebec, Canada (F.B., S.L.M., F.D.); 2Consumer and Clinical Radiation Protection Bureau, Health Canada, Ottawa, Ontario, Canada (J.P.M.); and 3Department of Bioimmunotherapy, Section of Immunobiology and Drug Carriers, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (A.M.T.)
  1. Dr. Bertrand J. Jean-Claude, Cancer Drug Research Laboratory/Royal Victoria Hospital, 687 Pine Ave. West, Room 7.19, Montreal, Quebec H3A1A1, Canada. E-mail:bertrand{at}med.mcgill.ca

Abstract

The Combi-Targeting concept postulates that a molecule termed combi-molecule (C-molecule) with binary epidermal growth factor receptor (EGFR) targeting/DNA-damaging properties and with the ability to be hydrolyzed to another EGFR inhibitor should induce sustained antiproliferative activity in cells overexpressing EGFR. Because we postulate that the EGFR affinity of the C-molecule and that of its hydrolytic metabolites are critical parameters for sustained potency against EGFR-overexpressing cells, we synthesized BJ2000 (IC50 = 0.1 μM, competitive binding at ATP site), a novel C-molecule that can decompose into a 6-amino-4-anilinoquinazoline FD105 (IC50 = 0.2 μM). Studies using the EGFR-overexpressing A431 cells revealed that BJ2000 could damage DNA and block epidermal growth factor-stimulated EGFR autophosphorylation by a partially irreversible mechanism. Blockade of EGFR autophosphorylation subsequently induced inhibition of mitogen-activated protein kinase activation and c-fos gene expression. Enzyme-linked immunosorbent assay and growth factor-mediated stimulation of proliferation assays in the EGFR-expressing NIH3T3HER14 demonstrated the preferential EGFR-targeting properties of BJ2000, and more importantly suggest that blockade of EGFR phosphorylation by this drug translate into significant growth inhibitory effects. These properties culminated into irreversible antiproliferative effects as confirmed by a sulforhodamine B assay. Five days after a 2-h treatment, BJ2000 retained significant antiproliferative effect in A431 cells, whereas its reversible metabolite FD105 almost completely lost its activity. This result in toto lend support to the Combi-Targeting concept according to which a molecular conjugate kept small enough to interact with EGFR and designed to degrade into another inhibitor of the same target plus a DNA-damaging species may induce sustained growth inhibitory effect in EGFR-overexpressing cells.

Footnotes

  • This study was supported by Cancer Research Society Inc. (to C.R.S.). This work was presented as an abstract at the AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics Meeting. Proc. of 2001 AACR-NCI-EORTC Please spell out AACR-NCI-EORTC in funding footnote. International Conference, Abstract 594, p 121.

  • DOI: 10.1124/jpet.102.039099

  • Abbreviations:
    EGFR
    epidermal growth factor receptor
    TK
    tyrosine kinase
    EGF
    epidermal growth factor
    C-molecule
    combi-molecule
    TEM
    temozolomide
    MTIC
    monoalkyltriazene 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide
    DMSO
    dimethyl sulfoxide
    FBS
    fetal bovine serum
    HPLC
    high-pressure liquid chromatography
    PGT
    poly(l-glutamic acid-l-tyrosine, 4:1)
    PBS
    phosphate-buffered saline
    ELISA
    enzyme-linked immunosorbent assay
    PDGF
    platelet-derived growth factor
    MAPK
    mitogen-activated protein kinase
    Erk2
    extracellular signal-regulated kinase 2
    RT-PCR
    reverse transcription-polymerase chain reaction
    TGFα
    transforming growth factor-α
    SRB
    sulforhodamine B
    AGT
    O6-alkylguanine DNA transferase
    GAPDH
    glyceraldehyde-3-phosphate dehydrogenase
    • Received May 15, 2002.
    • Accepted June 12, 2002.
« Previous | Next Article »Table of Contents

This Article

  1. doi: 10.1124/jpet.102.039099 JPET October 1, 2002 vol. 303 no. 1 238-246
  1. » Abstract
  2. Full Text
  3. Full Text (PDF)

Responses

  1. Submit a response
  2. No responses published

Current Issue

  1. November 2009, 331 (2)
  1. Current Issue
  1. Alert me to new issues of JPET