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Updated: Aug 9, 2026

Detecting the Ligand-binding Domain Dimerization Activity of Estrogen Receptor Alpha Using the Mammalian Two-Hybrid Assay
09:07

Detecting the Ligand-binding Domain Dimerization Activity of Estrogen Receptor Alpha Using the Mammalian Two-Hybrid Assay

Published on: December 19, 2018

Akt-mediated phosphorylation and activation of estrogen receptor alpha is required for endometrial neoplastic

Anna Vilgelm1, Zenglin Lian, Hong Wang

  • 1Human Genetics Program and Department of Pathology, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA.

Cancer Research
|April 6, 2006
PubMed

Insights

Loss of the PTEN tumor suppressor gene in the endometrium activates Akt, leading to estrogen receptor alpha (ERalpha) phosphorylation and activation. This ERalpha activation drives endometrial cancer development, highlighting a key pathway in neoplastic progression.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • PTEN is a crucial tumor suppressor gene frequently altered in human cancers, regulating cell death and proliferation.
  • Loss of PTEN is an early event in endometrioid endometrial cancer, and Pten(+/-) mice model this progression.
  • The specific in vivo downstream pathways critical for PTEN's tumor suppressive function in different tissues remain largely undefined.

Purpose of the Study:

  • To investigate the in vivo downstream molecular events following PTEN loss in the mouse endometrium.
  • To determine the role of Akt and estrogen receptor alpha (ERalpha) in Pten-deficient endometrial tumorigenesis.
  • To elucidate the mechanism by which PTEN loss contributes to endometrial neoplastic progression.

Main Methods:

  • Utilized Pten(+/-) mice as a model for endometrial cancer.
  • Analyzed Akt activation and ERalpha phosphorylation at Ser(167) in mouse endometrial tissue.
  • Assessed the transcriptional activity of ERalpha target genes.
  • Investigated the effect of reducing ERalpha levels and activity on Pten loss-induced neoplasia.

Main Results:

  • Loss of Pten in the mouse endometrium leads to Akt activation.
  • Akt activation results in increased phosphorylation of ERalpha on Ser(167).
  • Phosphorylated ERalpha exhibits ligand-independent activation and enhanced target gene transcription.
  • Reducing ERalpha levels significantly mitigates the neoplastic effects of Pten loss in the endometrium.

Conclusions:

  • PTEN loss in the endometrium activates the Akt pathway, which subsequently activates ERalpha.
  • ERalpha activation, even without ligand, plays a pivotal role in Pten loss-driven endometrial neoplasia.
  • These findings provide in vivo evidence for ERalpha-dependent pathways being critical in PTEN-deficient endometrial cancer development.

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