Reproduction Abstracts

Introduction: 2-Methoxyestradiol (2-ME) is an endogenous metabolite of 17-estradiol (E₂) that interacts with estrogen receptors (ERs) and microtubules, and it has a low affinity for ERs. It has been identified as a potential novel antitumor agent combining anti-proliferative activity on a wide range of tumor cell types with anti-angiogenic actions. Also, 2-ME attracted considerable interest as a potential anti-cancer therapeutic.

Materials and methods: To performed in vitro experiment to evaluate estrogenic effect of 2-ME using GH3 cells, we measured mRNA expression of CaBP-9k and progesterone receptor (PR), the indicators of estrogenic effects using real-time PCR. In vivo experiment also investigated how 2-ME has an estrogenic effect on immature mice uterus by measured mRNA expression of lactoferrin and ER, the indicators of estrogenic effects using real-time PCR.

Results and discussion: In vitro CaBP-9k mRNA expression was increased in 2-ME (10⁻⁷ M) treatment group in parallel with response to E2 (10⁻⁹ M). In vivo lactoferrin mRNA expression was also increased in 2-ME (40 mg/kg BW) group to similar response with E₂ (40 μg/kg BW). As a blocker for ER activity, ICI 182 780 reversed the both E2-mediated and 2-ME-mediated increase of CaBP-9k and lactoferrin mRNA. We also investigated how 2-ME is associated with ERs and PR. In vitro, 2-ME did not significantly induce ER transcripts but PR transcripts. In vivo, 2-ME did not significantly induce PR transcripts unlike ER. Based on the study, we demonstrated that 2-ME has an estrogenic effect on in vitro and in vivo condition.