Dose-dependent effect of 17 beta-estradiol determined by growth curves and flow cytometric DNA analysis of a human breast carcinoma (T61) grown in nude mice

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N Brünner, M Spang-Thomsen, L Vindeløv, A Nielsen, S A Engelholm, B Svenstrup

An estrogen and progesterone receptor-positive human breast carcinoma (T61) grown in nude mice was exposed to 1.0, 0.1, 0.01, and 0.001 mg 17 beta-estradiol. These doses resulted in serum peak concentrations (day 1) of estradiol ranging from 3.5 X 10(-8) to 6.9 X 10(-10) M. The effect of the treatment was evaluated using growth curves and flow cytometric DNA analysis. The treatment induced a dose-dependent growth delay and dose-dependent changes in the cell cycle distribution. The cell cycle changes comprised a decrease in the G1 phase, an accumulation of cells in the S phase, and an increasing fraction of polyploid cells. The results suggest that estradiol induces a dose-dependent cell killing effect in the T61 human breast carcinoma. The correlation between the treatment-induced growth delay and the effect on the cell cycle distribution indicates that the changes in the cell cycle are a reflection of the estradiol-induced cell destruction. Since no tumor growth stimulation could be observed even at very low serum estradiol concentrations, the T61 human breast carcinoma may represent a new aspect in the study of human breast cancer.
Original languageEnglish
JournalExperimental Cell Biology
Issue number4
Pages (from-to)220-32
Number of pages12
Publication statusPublished - 1985

Bibliographical note

Keywords: Animals; Cell Cycle; DNA; Dose-Response Relationship, Drug; Estradiol; Female; Flow Cytometry; Humans; Male; Mammary Neoplasms, Experimental; Mice; Mice, Nude; Middle Aged

ID: 12871205