A detailed characterization of stepwise activation of the androgen receptor variant 7 in prostate cancer cells

Oncogene. 2021 Feb;40(6):1106-1117. doi: 10.1038/s41388-020-01585-5. Epub 2020 Dec 15.

Abstract

Expression of the androgen receptor splice variant 7 (AR-V7) is frequently detected in castrate resistant prostate cancer and associated with resistance to AR-targeted therapies. While we have previously noted that homodimerization is required for the transcriptional activity of AR-V7 and that AR-V7 can also form heterodimers with the full-length AR (AR-FL), there are still many gaps of knowledge in AR-V7 stepwise activation. In the present study, we show that neither AR-V7 homodimerization nor AR-V7/AR-FL heterodimerization requires cofactors or DNA binding. AR-V7 can enter the nucleus as a monomer and drive a transcriptional program and DNA-damage repair as a homodimer. While forming a heterodimer with AR-FL to induce nuclear localization of unliganded AR-FL, AR-V7 does not need to interact with AR-FL to drive gene transcription or DNA-damage repair in prostate cancer cells that co-express AR-V7 and AR-FL. These data indicate that AR-V7 can function independently of its interaction with AR-FL in the true castrate state or "absence of ligand", providing support for the utility of targeting AR-V7 in improving outcomes of patients with castrate resistant prostate cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alternative Splicing / genetics*
  • Cell Line, Tumor
  • Cell Nucleus / genetics
  • DNA Damage / genetics
  • DNA Repair / genetics
  • DNA-Binding Proteins / genetics
  • Gene Expression Regulation, Neoplastic / genetics
  • Humans
  • Male
  • Prostate / pathology
  • Prostatic Neoplasms / genetics*
  • Prostatic Neoplasms / pathology
  • Protein Isoforms / genetics*
  • Receptors, Androgen / genetics*

Substances

  • AR protein, human
  • DNA-Binding Proteins
  • Protein Isoforms
  • Receptors, Androgen