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Role of the steroid receptor coactivator SRC-3 in cell growth

Ge Zhou1, Yoshihiro Hashimoto, Inseok Kwak

  • 1Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.

Molecular and Cellular Biology
|October 16, 2003
PubMed

Insights

Steroid receptor coactivator 3 (SRC-3) promotes mammalian cell growth by activating AKT/mTOR signaling. Reducing SRC-3 levels decreases cell size, highlighting its role in growth regulation.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • Steroid receptor coactivator 3 (SRC-3) is a p160 family member implicated in normal animal growth.
  • SRC-3 is frequently amplified or overexpressed in various cancers, including breast and prostate cancers.
  • The precise mechanisms underlying SRC-3's role in growth regulation are not fully understood.

Purpose of the Study:

  • To investigate the role of SRC-3 in regulating cell growth and size.
  • To elucidate the signaling pathways modulated by SRC-3 during cell growth.
  • To determine the impact of SRC-3 modulation on AKT signaling.

Main Methods:

  • Overexpression of SRC-3 in prostate cancer cell lines.
  • Down-regulation of SRC-3 using small interfering RNA (siRNA).
  • Analysis of AKT signaling pathway activation.
  • Examination of SRC-3 null mutant mice.

Main Results:

  • SRC-3 overexpression significantly increased cell size in prostate cancer cells.
  • SRC-3 modulated the AKT signaling pathway independently of steroids, activating AKT/mTOR signaling.
  • SRC-3 down-regulation led to decreased cell growth and smaller cell size.
  • AKT signaling was reduced in SRC-3 null mutant mice tissues.

Conclusions:

  • SRC-3 is a critical regulator of mammalian cell growth.
  • SRC-3 influences cell size through modulation of the AKT/mTOR signaling pathway.
  • These findings provide insights into SRC-3's function in both normal growth and cancer development.

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