Alteration of the methylation status of tumor-promoting genes decreases prostate cancer cell invasiveness and tumorigenesis in vitro and in vivo

Cancer Res. 2006 Sep 15;66(18):9202-10. doi: 10.1158/0008-5472.CAN-06-1954.


We tested the hypothesis that cell invasiveness and tumorigenesis are driven by hypomethylation of genes involved in tumor progression. Highly invasive human prostate cancer cells PC-3 were treated with either the methyl donor S-adenosylmethionine (SAM) or methyl DNA-binding domain protein 2 antisense oligonucleotide (MBD2-AS). Both treatments resulted in a dose- and time-dependent inhibition of key genes, such as urokinase-type plasminogen activator (uPA), matrix metalloproteinase-2 (MMP-2), and vascular endothelial growth factor expression to decrease tumor cell invasion in vitro. No change in the levels of expression of genes already known to be methylated in late-stage prostate cancer cells, such as glutathione S-transferase P1 and androgen receptor, was seen. Inoculation of PC-3 cells pretreated with SAM and MBD2-AS into the flank of male BALB/c nu/nu mice resulted in the development of tumors of significantly smaller volume compared with animals inoculated with PC-3 cells treated with vehicle alone or MBD2 scrambled oligonucleotide. Immunohistochemical analysis of tumors showed the ability of SAM and MBD2-AS to significantly decrease tumoral uPA and MMP-2 expression along with levels of angiogenesis and survival pathway signaling molecules. Bisulfite sequencing analysis of tumoral genomic DNA showed that inhibition of both uPA and MMP-2 expression was due to methylation of their 5' regulatory region. These studies support the hypothesis that DNA hypomethylation controls the activation of multiple tumor-promoting genes and provide valuable insight into developing novel therapeutic strategies against this common disease, which target the demethylation machinery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Transformation, Neoplastic / genetics*
  • Cell Transformation, Neoplastic / pathology
  • DNA Methylation*
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / deficiency
  • DNA-Binding Proteins / genetics
  • Down-Regulation
  • Genetic Therapy / methods
  • Humans
  • Male
  • Matrix Metalloproteinase 2 / biosynthesis
  • Matrix Metalloproteinase 2 / genetics
  • Mice
  • Mice, Inbred BALB C
  • Neoplasm Invasiveness
  • Neovascularization, Pathologic / genetics
  • Neovascularization, Pathologic / therapy
  • Oligonucleotides, Antisense / genetics
  • Plasminogen Activators / biosynthesis
  • Plasminogen Activators / deficiency
  • Plasminogen Activators / genetics
  • Prostatic Neoplasms / blood supply
  • Prostatic Neoplasms / genetics*
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / therapy*
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • S-Adenosylmethionine / pharmacology
  • Transfection
  • Vascular Endothelial Growth Factor A / biosynthesis
  • Vascular Endothelial Growth Factor A / deficiency
  • Vascular Endothelial Growth Factor A / genetics
  • Xenograft Model Antitumor Assays


  • DNA-Binding Proteins
  • MBD2 protein, human
  • Oligonucleotides, Antisense
  • RNA, Messenger
  • Vascular Endothelial Growth Factor A
  • S-Adenosylmethionine
  • Plasminogen Activators
  • Matrix Metalloproteinase 2