Promoter methylation and silencing of the tissue factor pathway inhibitor-2 (TFPI-2), in human glioma cells

Santhi D. Konduri, Kalkunte S. Srivenugopal, Niranjan Yanamandra, Dzung H. Dinh, William C. Olivero, Meena Gujrati, Donald C. Foster, Walter Kisiel, Francis Ali-Osman, Shakuntala Kondraganti, Sajani S. Lakka, Jasti S. Rao

Research output: Contribution to journalArticle

Abstract

We have shown previously that the tissue factor pathway inhibitor-2 (TFPI-2), a broad range proteinase inhibitor, is highly expressed in low-grade gliomas, but, minimally expressed or undetectable in glioblastomas, and that enforced expression of this gene reduces the invasive properties of brain tumor cells. Here, we examined the role of promoter methylation as a mechanism of TFPI-2 gene silencing. In SNB19 glioblastoma cells, which have no detectable TFPI-2 expression, 5-aza-2′-deoxycytidine (5aC), an inhibitor of DNA methyltransferase, induced TFPI-2 mRNA in a dose-dependent manner. Trichostatin A (TSA), the histone deacetylase (HDAC) inhibitor, by itself, was more efficient than 5aC in inducing TFPI-2 transcripts, and the 5aC + TSA combination resulted in highly synergistic reactivation of the gene, both at the transcript and protein levels. In Hs683 glioma cells, which express the TFPI-2 gene at high levels, transfection of the in vitro methylated TFPI-2 promoter constructs resulted in a drastic decrease of promoter activity compared to the unmethylated promoter. Further, the methylation-specific PCR in SNB19 and Hs683 cells showed that TFPI-2 gene repression was closely linked with methylation of the CpG islands in the promoter. Finally, the chromatin immunoprecipitation assays in SNB19 cells showed that the methylated and repressed TFPI-2 promoter was associated with the methyl-CpG binding protein 2 (MeCP2), and that gene reactivation resulted in the loss of MeCP2 from this site. These studies establish that TFPI-2 is transcriptionally silenced through promoter methylation in SNB19 cells.

Original languageEnglish (US)
Pages (from-to)4509-4516
Number of pages8
JournalOncogene
Volume22
Issue number29
DOIs
StatePublished - Jul 17 2003

Keywords

  • 5′-CpG methylation
  • Epigenetic mechanisms
  • Gene silencing
  • Gliomas
  • Histone deacetylation
  • Methyl CpG-group binding protein
  • Proteinase inhibitor
  • TFPI-2

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cancer Research

Fingerprint Dive into the research topics of 'Promoter methylation and silencing of the tissue factor pathway inhibitor-2 (TFPI-2), in human glioma cells'. Together they form a unique fingerprint.

  • Cite this

    Konduri, S. D., Srivenugopal, K. S., Yanamandra, N., Dinh, D. H., Olivero, W. C., Gujrati, M., Foster, D. C., Kisiel, W., Ali-Osman, F., Kondraganti, S., Lakka, S. S., & Rao, J. S. (2003). Promoter methylation and silencing of the tissue factor pathway inhibitor-2 (TFPI-2), in human glioma cells. Oncogene, 22(29), 4509-4516. https://doi.org/10.1038/sj.onc.1206695