Oestetrol stimulates proliferation and oestrogen receptor expression in breast cancer cell lines: Comparison of four oestrogens. (February 2015)

• Record Type: Journal Article
• Authors: Liu, Shunyu; Ruan, Xiangyan; Schultz, Silke; Neubauer, Hans; Fehm, Tanja; Seeger, Harald; Mueck, Alfred O.
• Is Part Of: European journal of contraception & reproductive health care. Volume 20:Number 1(2015:Feb.)
• Page Start: 29
• Page End: 35
• Publication Date: 2015-02
• Subjects: Contraception -- Periodicals; Reproductive health -- Periodicals; Generative organs, Female -- Periodicals; Contraception -- Periodicals; Reproductive Medicine -- Periodicals; 613.9
• DOI: 10.3109/13625187.2014.951997
• Languages: English
• ISSNs: 1362-5187

Abstract

<abstract> <title>Abstract</title> <p> <bold>Objectives</bold> Oestetrol (15-alpha-hydroxyoestriol, E<sub>4</sub>) is an endogenous oestradiol metabolite mainly produced at high concentrations in the fetal liver. In earlier studies E<sub>4</sub> was investigated for its use as marker for pregnancies at risk, especially with vascular problems. Some current investigations suggest that the use of E<sub>4</sub> in hormone therapy or contraception may have advantages in terms of breast cancer risk when compared to other oestrogens.</p> <p> <bold>Methods</bold> Proliferation of two oestrogen receptor-positive breast cancer cell lines (ZR 75-1 and HCC 1500) was investigated after incubation with oestrone (E<sub>1</sub>), oestradiol (E<sub>2</sub>), oestriol (E<sub>3</sub>), and oestetrol (E<sub>4</sub>). Receptor expression of oestrogen receptor-alpha (ERα) and -beta (ERβ) was determined by Western-Blot.</p> <p> <bold>Results</bold> All four oestrogens elicited a significant proliferative stimulation at concentrations of 10<sup>−10</sup> und 10<sup>−9</sup> M as compared to controls. Oestrone displayed a significantly weaker effect than E<sub>2</sub>. Oestetrol was significantly less effective than E<sub>2</sub> at the lower concentration. Expression of ERα and ERβ was significantly upregulated by all oestrogens tested, without differences between the latter.</p> <p> <bold>Conclusions</bold> Our results indicate a slightly lower proliferative effect of E<sub>4</sub>, but only at low concentrations. However, no difference was found regarding receptor expression. Breast cancer risk associated with use of oestetrol should be tested in clinical trials.</p> </abstract>