2-methoxyestradiol-induced growth suppression and lethality in estrogen-responsive MCF-7 cells may be mediated by down regulation of p34cdc2 and cyclin B1 expression.

  • Authors:
    • M N Zoubine
    • A P Weston
    • D C Johnson
    • D R Campbell
    • S K Banerjee
  • View Affiliations

  • Published online on: October 1, 1999     https://doi.org/10.3892/ijo.15.4.639
  • Pages: 639-685
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Abstract

MCF-7 breast cancer cells increase their rate of proliferation, as indicated by incorporation of tritiated thymidine into DNA, when exposed to estrogen. In confirmation of other studies, 10 nM 17beta-estradiol (E2) increased proliferation by 2.8-fold after 6 days of exposure. As indicated by trypan blue exclusion and TUNEL assays, cell survival was increased and apoptosis decreased by the presence of E2. The estradiol metabolite 2-methoxyestradiol (2-ME) when present in the culture medium in concentrations greater than 1 microM for three days, dose-dependently reduced the effectiveness of E2 on cell proliferation by increasing the rate of apoptosis. To examine a mechanism for the increase in apoptosis, expression of p34cdc2 and cyclin B1 protein levels were monitored by examination of immunoblots of their proteins. E2 increased p34cdc2 and cyclin B1 protein levels significantly after 6 days of exposure. This effect was inhibited significantly by the presence of 2-ME. The results indicate that up-regulation of p34cdc2 and cyclin B1 is closely associated with increased survivability and lack of apoptosis in estrogen-induced proliferation of MCF-7 cells. Further, anti-estrogenic effects of 2-ME in these cells can be accounted for by its activation of apoptotic functions, which are correlated with reductions in expression of p34cdc2 and cyclin B1 genes.

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Oct 1999
Volume 15 Issue 4

Print ISSN: 1019-6439
Online ISSN:1791-2423

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Spandidos Publications style
Zoubine M, Weston A, Johnson D, Campbell D and Banerjee S: 2-methoxyestradiol-induced growth suppression and lethality in estrogen-responsive MCF-7 cells may be mediated by down regulation of p34cdc2 and cyclin B1 expression.. Int J Oncol 15: 639-685, 1999
APA
Zoubine, M., Weston, A., Johnson, D., Campbell, D., & Banerjee, S. (1999). 2-methoxyestradiol-induced growth suppression and lethality in estrogen-responsive MCF-7 cells may be mediated by down regulation of p34cdc2 and cyclin B1 expression.. International Journal of Oncology, 15, 639-685. https://doi.org/10.3892/ijo.15.4.639
MLA
Zoubine, M., Weston, A., Johnson, D., Campbell, D., Banerjee, S."2-methoxyestradiol-induced growth suppression and lethality in estrogen-responsive MCF-7 cells may be mediated by down regulation of p34cdc2 and cyclin B1 expression.". International Journal of Oncology 15.4 (1999): 639-685.
Chicago
Zoubine, M., Weston, A., Johnson, D., Campbell, D., Banerjee, S."2-methoxyestradiol-induced growth suppression and lethality in estrogen-responsive MCF-7 cells may be mediated by down regulation of p34cdc2 and cyclin B1 expression.". International Journal of Oncology 15, no. 4 (1999): 639-685. https://doi.org/10.3892/ijo.15.4.639