ALTERED PHENOTYPIC CHARACTERISTICS OF T47D HUMAN BREAST CANCER CELLS AFTER PROLONGED GROWTH IN ESTROGEN-DEFICIENT MEDIUM

✍ Scribed by Pat Fernandez; Cody Wilson; Debie Hoivik; Stephen H. Safe

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 314 KB
• Volume: 22
• Category: Article
• ISSN: 1065-6995
• DOI: 10.1006/cbir.1998.0303

✦ Synopsis

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.