The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Effects of 17 beta-estradiol metabolites on cell cycle events in MCF-7 cells.

Different cell growth effects were observed in MCF-7 cells after six daily exposures to either 17 beta-estradiol (E2), 2-hydroxyestradiol (2-OHE2), or 2-methoxyestradiol (2-MeOE2) at 10 nM levels. 2-OHE2 enhanced cell growth significantly (P < 0.05) more than did the parent compound, whereas 2-MeOE2 inhibited cell growth. To identify the estrogen-affected cellular processes involved in cell cycle progression, hydroxy urea-synchronized MCF-7 cells were studied. No effects on DNA synthesis in mid-S-phase or on mitotic indices were observed after E2 or 2-OHE2 treatment. 2-MeOE2, however, significantly (P < 0.05) inhibited DNA synthesis and mitosis. Synchronized cells were exposed for 1 h to E2, 2-OHE2, or 2-MeOE2 before cAMP levels were determined in early S-phase and mid-S-phase, as well as during mitosis. E2 and 2-OHE2 had no effect, but 2-MeOE2 caused a significant (P < 0.05) increase in cAMP concentration in early S-phase and a decrease during mitosis. Phosphorylation of S-phase proteins was also studied. [32P]Pi incorporation was significantly (P < 0.05) enhanced in many proteins in 2-MeOE2-exposed cells. Small proteins (M(r) < 25,000), as well as large proteins (M(r) > 220,000), were most prominently affected. In comparison, E2 and 2-OHE2 had little effect. We suggest that the enhanced 2-MeOE2-induced protein phosphorylation during S-phase may affect S-phase events, which subsequently causes inhibition of mitosis. Protein synthesis during G2/M transition was unexpectedly enhanced by 2-OHE2 and was not enhanced by E2. [35S]Methionine incorporation into proteins in the order of M(r) 32,000-46,000, 47,000-50,000, 58,000-67,000, and 83,000-89,000 was significantly (P < 0.05) increased. 2-MeOE2 had no effect. The results of this study indicate that 2-OHE2 may be the more potent mitogen, whereas 2-MeOE2 acts as a cytostatin.[1]


  1. Effects of 17 beta-estradiol metabolites on cell cycle events in MCF-7 cells. Lottering, M.L., Haag, M., Seegers, J.C. Cancer Res. (1992) [Pubmed]
WikiGenes - Universities