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Updated: Oct 4, 2026

Analysis of Cell Cycle Position in Mammalian Cells
12:19

Analysis of Cell Cycle Position in Mammalian Cells

Published on: January 21, 2012

ErbB2/neu kinase modulates cellular p27(Kip1) and cyclin D1 through multiple signaling pathways

A E Lenferink1, D Busse, W M Flanagan

  • 1Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.

Cancer Research
|August 28, 2001
PubMed

Insights

Blocking ErbB2 kinase with AG1478 halts breast cancer cell growth by inhibiting mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling, affecting cyclin D1 and p27 protein levels.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cell Signaling

Background:

  • ErbB1 and ErbB2 signaling pathways are implicated in mammary epithelial cell transformation.
  • ErbB2 overexpression is common in certain breast cancers, driving proliferation.
  • Understanding ErbB1/ErbB2 cooperation is crucial for targeted cancer therapies.

Purpose of the Study:

  • To investigate the role of ErbB1/ErbB2 signaling in breast cancer cell transformation.
  • To elucidate the downstream signaling events affected by ErbB2 kinase inhibition.
  • To identify key cell cycle regulators modulated by ErbB2 signaling.

Main Methods:

  • Utilized the ErbB kinase inhibitor AG1478 in ErbB2-overexpressing breast cancer cell lines (BT-474 and SKBR-3).
  • Assessed effects on ErbB2 dephosphorylation, cell cycle progression (G1 arrest), and key signaling pathways (MAPK, PI3K/Akt).
  • Investigated the modulation of cell cycle proteins cyclin D1 and p27, employing antisense oligonucleotides and adenovirus-mediated gene expression.

Main Results:

  • AG1478 treatment led to rapid ErbB2 dephosphorylation and G1 cell cycle arrest.
  • Inhibition of MAPK and PI3K/Akt signaling pathways was observed.
  • Modulation of cyclin D1 and p27 stability and activity was critical for the observed G1 arrest.

Conclusions:

  • ErbB2 kinase blockade necessitates the modulation of both p27 and cyclin D1 for growth arrest.
  • ErbB2-overexpressing cells utilize MAPK and PI3K/Akt pathways to regulate p27 and cyclin D1, thereby controlling the G1-to-S phase transition.

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