Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.1.1.37 (
DNA methyltransferase
)
4,983
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
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.
...
PMID:Promoter methylation and silencing of the tissue factor pathway inhibitor-2 (TFPI-2), a gene encoding an inhibitor of matrix metalloproteinases in human glioma cells. 1288 7