Altered phenotypic characteristics of T47d human breast cancer cells after prolonged growth in estrogen-deficient medium.
T47D human breast cancer cells were cultured in estrogen-deficient media for up to 32 months and the resulting cell line (L(hE(-))) exhibited unique phenotypic and genotypic characteristics. Compared to low passage (L) cells, the L(hE(-)) cells exhibited a significantly higher rate of proliferation, unique morphological features, advanced ploidy status and 5- to 10-fold higher levels of the estrogen receptor (ER) as determined by ligand binding and Western blot analysis. Sequence analysis of the DNA binding domain of the ER revealed a C-->A transversion which resulted in a H513N amino acid change. Treatment of L cells with 10 n m 17beta-estradiol (E2) resulted in a greater than two-fold increase in cell proliferation which was inhibited by tamoxifen, 4'-hydroxytamoxifen, ICI 164,384 and ICI 182,780. In contrast, 10 n m E2 caused a 70% decrease in growth of L(hE(-)) cells and this antimitogenic activity was blocked by ICI 164,384 and ICI 182,780 but not by tamoxifen or 4'-hydroxytamoxifen. L(hE(-)) cells were E2-responsive in transient transfection studies using a plasmid containing an estrogen-responsive element derived from the vitellogenin A2 gene promoter. These data show that the phenotypic and genotypic characteristics of L(hE(-)) T47D cells resemble those described for ER-negative cell lines stably transfected with the ER.
Fernandez
P
P
Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA.
Wilson
C
C
Hoivik
D
D
Safe
S H
SH
D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects; D003470:Culture Media; D004958:Estradiol / Q000008:administration & dosage; D004965:Estrogen Antagonists / Q000494:pharmacology; D005260:Female; D005838:Genotype; D006801:Humans; D009376:Neoplasms, Hormone-Dependent / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D010641:Phenotype; D011003:Ploidies; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism; D013629:Tamoxifen / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D003470:Culture Media; D004965:Estrogen Antagonists; D011960:Receptors, Estrogen; D013629:Tamoxifen; D004958:Estradiol