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Updated: Mar 22, 2026

An Orthotopic Murine Model of Human Prostate Cancer Metastasis
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Published on: September 18, 2013

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Progesterone receptor antagonism inhibits progestogen-related carcinogenesis and suppresses tumor cell proliferation

Oukseub Lee1, Mi-Ran Choi1, Konstantin Christov2

  • 1Department of Surgery, Northwestern University, Chicago, IL, USA.

Cancer Letters
|April 16, 2016
PubMed
Abstract

Insights

Telapristone acetate (TPA) shows consistent anti-tumorigenic effects in preclinical models for breast cancer prevention. This strategy targets the progestogen-progesterone receptor (PR) axis, reducing cell proliferation and angiogenesis.

Area of Science:

  • Oncology
  • Endocrinology
  • Pharmacology

Background:

  • The progestogen-progesterone receptor (PR) axis is a potential target for breast cancer prevention.
  • Preclinical evaluation of PR antagonists is crucial for developing novel preventive strategies.

Purpose of the Study:

  • To evaluate the preclinical efficacy of telapristone acetate (TPA), ulipristal acetate (UPA), and mifepristone in blocking the PR axis for breast cancer prevention.

Main Methods:

  • Tumor induction in mice and rats using specific hormonal and chemical agents.
  • Assessment of mammary gland histology, tumor characteristics, and immunohistochemical markers (proliferation, angiogenesis, ER, PR).
  • In vitro testing of TPA, UPA, and mifepristone for spheroid growth inhibition.

Main Results:

  • TPA demonstrated anti-tumorigenic effects in rat models, reducing tumor incidence and burden.
  • Significant decreases in cell proliferation (pHH3) and angiogenesis (CD34) markers were observed with TPA treatment.
  • TPA and UPA exhibited superior inhibition of T47D spheroid growth compared to mifepristone.

Conclusions:

  • Telapristone acetate exhibits consistent anti-tumorigenic effects across multiple preclinical models.
  • These effects are associated with reduced cell proliferation, angiogenesis, and hormone receptor expression.
  • PR axis blockade represents a promising avenue for breast cancer prevention.
Keywords:
Mammary carcinogenesisPreventionProgesterone receptorProgestogenRatsTelapristone acetate

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