Genistein reverses hypermethylation and induces active histone modifications in tumor suppressor gene B-Cell translocation gene 3 in prostate cancer

Cancer. 2010 Jan 1;116(1):66-76. doi: 10.1002/cncr.24662.


Background: : B-cell translocation gene 3 (BTG3/ANA/APRO4) is a candidate tumor suppressor gene in some malignancies. We report here that B-cell translocation gene 3 (BTG3) is transcriptionally down-regulated in prostate cancer and the mechanism of inactivation is through promoter hypermethylation.

Methods: : Prostate cancer and normal cell lines were treated with different doses of genistein and 5-aza-2'-deoxycytidine (5Aza-C). BTG3 messenger ribonucleic acid (mRNA) expression was determined by quantitative real-time polymerase chain reaction in tissues and cell lines. Bisulfate-modified polymerase chain reaction, cloning and sequencing were used to examine promoter methylation in tumor samples and cell lines. Enzyme activity/inhibition assays were done to check the effect of genistein and 5Aza-C on DNA methyltransferases. ChIP assay was performed to analyze chromatin modifications caused by genistein treatment.

Results: : BTG3 mRNA expression was down-regulated in cancer tissues and cells. Genistein and 5Aza-C induced BTG3 mRNA expression in all PC cell lines. Complete methylation of BTG3 promoter in tumor samples and cancer cell lines was observed. Genistein and 5Aza-C treatment significantly decreased promoter methylation, reactivating BTG3 expression. Genistein and 5Aza-C increased levels of acetylated histones 3, 4, histone 3 dimethylated at lysine 4, histone 3 trimethylated at lysine 4, and RNA polymerase II, decreased DNA methyl transferase and methyl-binding domain protein 2 activity, and increased histone acetyl transferase (HAT) activity.

Conclusions: : This is the first report to show that BTG3 is silenced in prostate cancer and can be reactivated by genistein-induced promoter demethylation and active histone modification. Genistein showed similar effects to that of 5Aza-C, which is currently undergoing phase 2 clinical trials as a treatment for prostate cancer. Because genistein is a natural, nontoxic, and dietary isoflavone, these results indicate that genistein is a novel, advantageous therapeutic agent for treating prostate cancer.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Base Sequence
  • Cell Cycle Proteins
  • Cell Line, Tumor
  • Chromatin Assembly and Disassembly / drug effects
  • DNA Methylation / drug effects*
  • Genes, Tumor Suppressor
  • Genistein / pharmacology*
  • Histones / metabolism*
  • Humans
  • Male
  • Molecular Sequence Data
  • Prostatic Neoplasms / genetics*
  • Proteins / genetics*


  • BTG3 protein, human
  • Cell Cycle Proteins
  • Histones
  • Proteins
  • Genistein