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Updated: Oct 17, 2026

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

Expression levels of estrogen receptor-alpha, estrogen receptor-beta, coactivators, and corepressors in breast cancer

J Kurebayashi1, T Otsuki, H Kunisue

  • 1Department of Breast and Thyroid Surgery, Kawasaki Medical School, Okayama, Japan. kure@med.kawasaki-m.ac.jp

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research
|February 26, 2000
PubMed

Insights

Estrogen receptor (ER)-alpha and cofactors are upregulated during early breast cancer development. Their expression decreases as breast cancer progresses, suggesting roles in tumor development and progression.

Area of Science:

  • Molecular Biology
  • Oncology
  • Gene Expression Analysis

Background:

  • Estrogen receptor (ER) signaling is crucial in breast cancer, involving complex interactions with coactivators and corepressors.
  • The specific roles of ER-beta, coactivators, and corepressors in breast cancer development and progression require further elucidation.

Purpose of the Study:

  • To investigate the expression levels of ER-alpha, ER-beta, coactivators, and corepressors in normal mammary glands, intraductal carcinomas, invasive ductal carcinomas, and breast cancer cell lines.
  • To explore potential correlations between ERs, coactivators, and corepressors in breast cancer tissues and cell lines.

Main Methods:

  • Multiplex reverse transcription-PCR was used to screen expression levels of ER-alpha, ER-beta, coactivators (SRC-1, TIF2, AIB1, CBP, P/CAF), and corepressors (N-CoR, SMRT).
  • Enzyme immunoassay was employed to measure ER-alpha protein levels for correlation analysis with mRNA expression.

Main Results:

  • ER-alpha mRNA expression strongly correlated with ER-alpha protein levels.
  • Significant correlations were found between ER-alpha and cofactors (TIF2, AIB1, P/CAF, N-CoR), and between ER-beta and cofactors (AIB1, CBP).
  • ER-alpha, TIF2, and CBP were upregulated in intraductal carcinomas compared to normal glands, while ER-alpha and N-CoR were higher in intraductal than invasive carcinomas.

Conclusions:

  • Findings suggest a positive correlation between ERs and cofactors, with ER-alpha and cofactors upregulated during early breast cancer development (intraductal carcinoma).
  • A decrease in ER-alpha and cofactor expression levels during breast cancer progression from intraductal to invasive stages was observed.
  • These cofactors may play significant roles in breast cancer development and progression, warranting further investigation.

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