Seeger Harald, Wallwiener Diethelm, Kraemer Elizabeth, Mueck Alfred O
Section of Endocrinology and Menopause, University Women's Hospital, Calwerstrasse 7, 72076 Tuebingen, Germany.
Maturitas. 2006 Apr 20;54(1):72-7. doi: 10.1016/j.maturitas.2005.08.010. Epub 2005 Oct 4.
Certain estradiol metabolites may play a pivotal role in breast carcinogenesis. Of special interest are the metabolites 2-hydroxyestradiol (2-OHE2), which can react anti-carcinogenically, and 4-hydroxyestradiol (4-OHE1) and 16a-hydroxyestrone (16-OHE1), which may have procarcinogenic potential. In the present study, we have compared for the first time the effect of these metabolites and their parent substance 17beta-estradiol (E2) on proliferation, apoptosis, apoptosis markers and markers of metastatic property of human breast cancer cells.
MCF-7 cells (human estrogen-receptor positive metastatic breast cancer cell line) were incubated with the estrogens at concentrations of 0.1-100 nM. Cell proliferation rate was measured by the ATP-assay. Apoptosis was measured by cell death assay and the apoptosis markers cytochrome C, Bcl-2, Fasl and p53 were determined in cell lysates by ELISAs. The markers of metastatic property of the cell line, VEGF and MCP-1 were measured in the cell supernatant by ELISAs.
The estrogens E2, 4-OHE2 and 16-OHE1 display a proliferative effect on MCF-7 cells which is accompanied by a down-regulation of apoptosis. Various markers of apoptosis such as Bcl-2, cytochrome C and p53 appear to be involved. No significant effect was found for the metabolite 2-OHE2. VEGF and MCP-1 were up-regulated by E2 and 16-OHE1, whereas 2-OHE2 and 4-OHE2 did not show any effect.
The most potent estrogen regarding proliferation, apoptosis and metastasis of breast cancer cells seems to be estradiol. However, the estradiol metabolites 4-OHE2 and 16-OHE1 elicit similar properties on cell proliferation, apoptosis and metastasis as compared to estradiol but only at higher concentrations. In contrast 2-OHE2 did not show any significant effect on these parameters. Thus, intracellular estradiol metabolism may determine an individual's risk for breast carcinogenesis.
某些雌二醇代谢物可能在乳腺癌发生过程中起关键作用。特别值得关注的是具有抗癌作用的2-羟基雌二醇（2-OHE2）代谢物，以及可能具有致癌潜力的4-羟基雌二醇（4-OHE1）和16α-羟基雌酮（16-OHE1）。在本研究中，我们首次比较了这些代谢物及其母体物质17β-雌二醇（E2）对人乳腺癌细胞增殖、凋亡、凋亡标志物和转移特性标志物的影响。
将MCF-7细胞（人雌激素受体阳性转移性乳腺癌细胞系）与浓度为0.1-100 nM的雌激素孵育。通过ATP检测法测量细胞增殖率。通过细胞死亡检测法测量凋亡，并通过酶联免疫吸附测定法（ELISA）在细胞裂解物中测定凋亡标志物细胞色素C、Bcl-2、Fasl和p53。通过ELISA在细胞上清液中测量细胞系转移特性的标志物VEGF和MCP-1。
雌激素E2、4-OHE2和16-OHE1对MCF-7细胞具有增殖作用，并伴随着凋亡的下调。各种凋亡标志物如Bcl-2、细胞色素C和p53似乎都参与其中。未发现代谢物2-OHE2有显著影响。VEGF和MCP-1被E2和16-OHE1上调，而2-OHE2和4-OHE2未显示任何影响。
关于乳腺癌细胞的增殖、凋亡和转移，最有效的雌激素似乎是雌二醇。然而，与雌二醇相比，雌二醇代谢物4-OHE2和16-OHE1仅在较高浓度下对细胞增殖、凋亡和转移产生类似特性。相比之下，2-OHE2对这些参数未显示任何显著影响。因此，细胞内雌二醇代谢可能决定个体患乳腺癌的风险。
