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Updated: Aug 12, 2026

Profiling of Estrogen-regulated MicroRNAs in Breast Cancer Cells
Published on: February 21, 2014
17beta-Estradiol metabolites affect some regulators of the MCF-7 cell cycle
M L Lottering1, M de Kock, T C Viljoen
1Department of Physiology, Faculty of Medicine, University of Pretoria, South Africa.
Abstract:
The activity of p34(cdc2) plays a key role in the regulation of the eukaryotic cell cycle. Another cell cycle associated molecule is PCNA. We investigated the effects of 2-hydroxy-17beta-estradiol, a cell proliferator, and 2-methoxy-17beta-estradiol, a potent inhibitor of cell growth, on the levels and activity of p34(cdc2) and on the levels of PCNA, as well as on protein phosphorylation in MCF-7 cells. 2-Hydroxyestradiol increased p34(cdc2) activity at G1/S and elevated PCNA levels during S-phase. 2-Methoxyestradiol caused unscheduled activation of p34(cdc2) in S-phase and decreased levels of p34(cdc2) and PCNA during G2/M. We conclude that 2-hydroxy- and 2-methoxyestradiol have definite, though different regulatory functions during the cell cycle.
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