2-Methoxyestradiol--biology and mechanism of action.

In the last decade the endogenous estradiol metabolite, 2-methoxyestradiol (2ME), has gained more and more interest due to its marked anticancerogenic properties and possible cardiovascular benefits, as shown in numerous animal and experimental investigations. Some promising results in terms of the usage of 2ME as a therapeutic agent were obtained by various clinical studies in patients with breast cancer and prostate cancer. However, one main problem appears to be the bioavailability of 2ME, therefore new formulations are now in the test phase. In this review, the most important aspects of the biology and molecular mechanisms of 2ME are summarized.