Reference SummaryLu C, J Natl Cancer Inst 2003 Dec 17;95(24):1825-33


Effect of epidermal growth factor receptor inhibitor on development of estrogen receptor-negative mammary tumors.


Lu C; Speers C; Zhang Y; Xu X; Hill J; Steinbis E; Celestino J; Shen Q; Kim H; Hilsenbeck S; Mohsin SK; Wakeling A; Osborne CK; Brown PH


J Natl Cancer Inst










BACKGROUND: Although antiestrogens have been effective in preventing estrogen receptor (ER)-positive breast cancer, chemopreventive agents are still needed to prevent ER-negative breast cancer. Tyrosine kinase inhibitors are promising agents for the treatment and prevention of human cancers. ZD1839 (gefitinib or Iressa) is an orally active epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that blocks signal transduction pathways in epithelial cells. We examined whether ZD1839 blocks signal transduction and prevents the development of ER-negative breast cancer. METHODS: The ability of ZD1839 to block signal transduction in normal, immortalized, and malignant breast cells was assessed by western blotting with specific antibodies to detect phosphorylation of cytoplasmic signaling molecules. The effect of ZD1839 on growth of these breast cells was assessed with anchorage-dependent and anchorage-independent growth assays. Its effect on ER-negative mammary tumorigenesis was assessed in MMTV-erbB2 transgenic mice. All statistical tests were two-sided. RESULTS: ZD1839 suppressed the phosphorylation of EGFR and mitogen-activated protein kinase in normal and malignant breast cells. ZD1839 treatment statistically significantly suppressed mammary tumorigenesis in MMTV-erbB2 transgenic mice; median time to tumor development was approximately 230 days in vehicle-treated mice and more than 310 days in mice treated with ZD1839 at 100 mg/kg (P<.001). ZD1839 reduced proliferation of normal breast cells by 20.3% (95% confidence interval [CI] = -13.7% to 44.2%) and of tumor cells by 42.0% (95% CI = 20.2% to 58.2%). ZD1839 also increased expression of the cell cycle regulator p27 in normal mammary tissue by 48.7% (95% CI = 27.0% to 74.2%) and in tumor tissue by 50.3% (95% CI = 35.8% to 66.7%). CONCLUSION: This study appears to provide the preclinical rationale for the development of these EGFR tyrosine kinase inhibitors for the prevention of human breast cancer.


J:87515 – MGI References
14679152 – National Library of Medicine/PubMed

Strain Notes

Strain Note
FVB/N-Tg(MMTVneu)202Mul/J Mice were obtained from The Jackson Laboratory at 10-12 weeks of age.


Strain Model Name Treatment Agent(s) Organ Affected Frequency Model Details
FVB/N-Tg(MMTVneu)202Mul/J Mammary gland tumor
  • pituitary isograft
Mammary gland


FVB/N-Tg(MMTVneu)202Mul/J Mammary gland tumor
  • pituitary isograft
  • gefitinib
Mammary gland

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