Studies On Estrogen-like Activities Of Arsenic Trioxide(As₂O₃)

To determine whether Arsenic trioxide has estrogen-like activities, the cell proliferation and the estrogen receptor and progesterone receptor expressions were measured in human cervical cancer line in vitro. The Hela cells were grown in improved RPMI-1640 supplemented respectively withβ-estradiol (1nM), Arsenic trioxide (0.5μM, 1μM, 5μM), fulvestrant (500nM),β-estradiol (1nM) and fulvestrant (500nM), Arsenic trioxide (1μM) and fulvestrant(500nM).The technique of cell culture was used to culture Hela cells. The method of MTT was used to study the cell proliferation. The technique of flow cytometry was used to measure DNA content. The method of RT-PCR was used to measure the estrogen receptor and progesterone receptor expressions.The results proved that the activities of arsenite (0.5μM) were similar with the activities of theβ-estradiol (1nM). They significantly stimulated the proliferation of Hela cells. They stimulated the proliferation of Hela cells at S phases. They also decreased the expressions of ER mRNA and increased PR mRNA. The result of DNA sequence assay proved that the sequences were some part of human ER and PR. But in another groups, the proliferation of Hela cells were suppressed, and the expressions of ER and PR were changed relevantly. The results also proved that the estrogen-like activities of Arsenic trioxide could be inhibited by the antiestrogen fulvestrant (500nM). This phenomenon deeply proved that Arsenic trioxide (<0.5μM) has estrogen-like activities. Although whether the Arsenic trioxide is Environmental Endocrine Disruptor (EEDs) has not been determined, this study can prove Arsenic trioxide (<0.5μM) has estrogen-like activities. This result can also help the study of cancer.