Androgen receptor expression in androgen-independent prostate cancer cell lines

Prostate. 2001 Apr;47(1):66-75. doi: 10.1002/pros.1048.

Abstract

Background: Almost all attempts at establishing prostate carcinoma cell lines have resulted in generation of cells that are androgen-independent, including commonly used LNCaP which expresses androgen receptor (AR) and AR-negative Du145 and PC-3. We attempted to clarify the mechanism(s) responsible for the failure to respond to androgen.

Methods: Cell lines LNCaP, CWR22R, PC-3, Du145, and CA7T2CL were used to examine the AR promoter function with a reporter gene assay and its methylation status by Southern blot, PCR of bisulfite-converted DNA, and 5-aza-2'-deoxycytidine treatment. Structural abnormalities of the AR were identified by sequencing of reverse-transcribed mRNA.

Results: All tested AR-positive prostate carcinoma cells were capable of AR transcription at a significantly higher level than PC-3 and Du145, thus suggesting relative deficiency of the transcription factors in the AR-negative cells, further associated with methylation. Examination of CWR22R cells, which express the AR but are androgen-independent, identified an in-frame duplication of exon 3, which resulted in insertion of 39 amino acids in the DNA-binding domain.

Conclusions: Relative deficiency of transcription factors associated with methylation is responsible for the lack of AR promoter function in most of AR-negative cell lines. Mutations in the AR gene are present in the cells that express the AR but are androgen-independent.

Publication types

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

MeSH terms

  • Adenocarcinoma*
  • Androgens / pharmacology
  • Animals
  • DNA Methylation
  • DNA Mutational Analysis
  • DNA, Neoplasm / metabolism
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Male
  • Mice
  • Mice, Nude
  • Promoter Regions, Genetic
  • Prostatic Neoplasms*
  • Receptors, Androgen / genetics*
  • Transcription, Genetic
  • Tumor Cells, Cultured

Substances

  • Androgens
  • DNA, Neoplasm
  • Receptors, Androgen