These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Mechanism of action of a tyrphostin, 3,4-dihydroxy-alpha-cyanothiocinnamamide, in breast cancer cell growth inhibition involves the suppression of cyclin B1 and the functional activity of cyclin B1/p34cdc2 complex.
    Author: Faaland CA, Adhikarakunnathu S, Thomas T, Thomas TJ.
    Journal: Breast Cancer Res Treat; 1997 May; 44(1):47-56. PubMed ID: 9164677.
    Abstract:
    Tyrphostins are a group of compounds specifically targeted for the inhibition of tyrosine phosphorylation in signal transduction pathways. We studied the effects of a tyrphostin, 3,4-dihydroxy-alpha-cyanothiocinnamamide (tyrphostin-47), on hormone-responsive MCF-7 and hormone-unresponsive MCF-7-5C cell growth by DNA analysis for a period of 10 days. The growth of both cell lines was inhibited by this drug at 50 and 100 microM concentrations. Flow cytometric analysis showed that tyrphostin treatment caused a significant delay in the progression of MCF-7 cells through G1 and S phases of the cell cycle. The level of cyclin B1, a component of the mitosis promoting factor (MPF), was reduced by 90% in the presence of 100 microM tyrphostin. The other component of MPF, p34cdc2 kinase, was not affected; however, its functional activity was dramatically reduced, as determined by histone H1 phosphorylation assay. In contrast, G1 cyclins (D1 and E) and tyrosine kinase activity were not markedly affected by tyrphostin-47, as determined by Western immunoblot detection with specific antibodies. Our results suggest that a possible mechanism of tyrphostin action in breast cancer cells might involve the suppression of cyclin B1 and inhibition of the functional activity of cyclin B1/p34cdc2 complex. Our data indicate that the cell cycle machinery might be a target for developing novel drugs for breast cancer.
    [Abstract] [Full Text] [Related] [New Search]