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Profiling of Estrogen-regulated MicroRNAs in Breast Cancer Cells
16:24

Profiling of Estrogen-regulated MicroRNAs in Breast Cancer Cells

Published on: February 21, 2014

Why are estrogen-receptor-negative breast cancers more aggressive than the estrogen-receptor-positive breast cancers?

M S Sheikh1, M Garcia, P Pujol

  • 1Université de Montpellier 1, Faculté de Médecine, Institut National de la Santé et de la Recherche Médicale, Hormones et Cancer (U 148), France.

Invasion & Metastasis
|January 1, 1994
PubMed

Insights

Estrogen receptor (ER) status impacts breast cancer aggressiveness. While ER-positive cancers can be driven by estrogen, introducing ER into ER-negative cells may reduce their aggressive nature, suggesting complex protective mechanisms.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • Hormone-resistant breast cancers often lack functional estrogen receptor (ER), correlating with a more aggressive metastatic phenotype.
  • Estrogen activation of ER in ER-positive breast cancers increases aggressiveness.
  • Conversely, introducing ER into aggressive ER-negative cells can diminish their aggressiveness, indicating a complex protective role.

Purpose of the Study:

  • To review and propose mechanisms underlying the higher aggressiveness observed in most ER-negative breast cancers.
  • To explore the complex protective effects of the estrogen receptor (ER) in breast cancer.
  • To investigate the altered gene expression potentially mediating ER's influence on proliferation, differentiation, and invasiveness.

Main Methods:

  • Literature review focusing on estrogen receptor (ER) function in breast cancer.
  • Analysis of studies investigating ER-positive and ER-negative breast cancer phenotypes.
  • Synthesis of proposed mechanisms for ER's role in cancer aggressiveness and metastasis.

Main Results:

  • ER-negative breast cancers frequently exhibit a more aggressive metastatic phenotype.
  • The protective effect of ER is complex and may involve altered expression of genes related to cell proliferation, differentiation, and invasiveness.
  • Estrogen activation of ER can enhance aggressiveness in ER-positive cancers, but exogenous ER can reduce aggressiveness in ER-negative cells.

Conclusions:

  • The absence of functional estrogen receptor (ER) is a key factor in the heightened aggressiveness of many breast cancers.
  • Altered gene expression profiles likely mediate the influence of ER on critical cellular processes like proliferation and invasion.
  • Understanding these mechanisms is crucial for developing targeted therapies for aggressive ER-negative breast cancers.

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