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Updated: Nov 25, 2025

Sequencing Small Non-coding RNA from Formalin-fixed Tissues and Serum-derived Exosomes from Castration-resistant Prostate Cancer Patients
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Regulation and targeting of androgen receptor nuclear localization in castration-resistant prostate cancer

Shidong Lv1,2,3, Qiong Song3,4, Guang Chen3,5

  • 1Department of Urology, Nanfang Hospital, Southern Medical University, and.

The Journal of Clinical Investigation
|December 17, 2020
PubMed

Insights

Androgen receptor (AR) can enter the nucleus without androgens, leading to degradation. A new drug, CPPI, blocks this androgen-independent AR import and promotes degradation in castration-resistant prostate cancer.

Area of Science:

  • Molecular Biology
  • Cancer Research
  • Cellular Signaling

Background:

  • Nuclear localization of the androgen receptor (AR) is crucial for its function.
  • Understanding AR regulation in prostate cancer, especially castration-resistant prostate cancer (CRPC), is clinically significant.
  • The classical model of AR trafficking (androgen-induced import, withdrawal-induced export) is being updated.

Purpose of the Study:

  • To investigate the mechanisms of AR nuclear import and degradation in CRPC.
  • To explore the role of androgen-independent AR nuclear localization in CRPC progression.
  • To evaluate the therapeutic potential of targeting AR nuclear import and stabilization in CRPC.

Main Methods:

  • Comparative analysis of AR localization and ubiquitination in androgen-sensitive (LNCaP) and castration-resistant (C4-2) prostate cancer cells.
  • Utilizing a small molecule inhibitor, 3-(4-chlorophenyl)-6,7-dihydro-5H-pyrrolo[1,2-a]imidazole (CPPI), identified in a high-throughput screen.
  • Assessing CPPI's effects on AR nuclear import, polyubiquitination, MDM2 interaction, and degradation in CRPC cells.

Main Results:

  • AR can be imported into the nucleus in the absence of androgens, followed by ubiquitination and degradation.
  • Androgen withdrawal leads to nuclear AR degradation, not export.
  • CRPC cells exhibit reduced nuclear AR polyubiquitination and higher nuclear AR levels compared to androgen-sensitive cells.
  • CPPI acts as a competitive AR antagonist, enhancing AR-MDM2 interaction and promoting nuclear AR degradation.
  • CPPI effectively blocks androgen-independent AR nuclear import in CRPC cells.

Conclusions:

  • AR nuclear import and stabilization can occur independently of androgens in CRPC.
  • Targeting androgen-independent AR nuclear import and stabilization presents a viable therapeutic strategy for CRPC.
  • Small molecule inhibitors like CPPI show promise in disrupting AR signaling in CRPC.
Keywords:
Drug therapyOncologyProstate cancerTherapeutics

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