Abstract
Arylamine N-acetyltransferase-1 (NAT1) has been associated with disorders involving folate metabolism, such as spina bifida, as well as numerous human cancers. As a result, the transcriptional and post-transcriptional regulation of NAT1 activity has been extensively studied. However, little work has been reported on the epigenetic control of NAT1 expression. Here, we demonstrate that the histone deacetylase inhibitor trichostatin A (TSA) increases NAT1 activity in human cancer cells by increasing transcription from the proximal promoter NATb. A specific Sp1 binding site was identified as essential for optimal induction of NAT1 by TSA. However, TSA did not increase the expression of Sp1 in HeLa cells. Instead, TSA increased the acetylation of histones associated with the NATb promoter. This allowed recruitment of Sp1 to the promoter along with acetylated histones. We propose that NAT1 transcription is partially repressed by the local chromatin condensation in the vicinity of NATb and that histone deacetylase inhibition leads to up-regulation of NAT1 expression via a direct change in chromatin conformation.
Footnotes
- Received September 2, 2010.
- Accepted September 23, 2010.
Article, publication date, and citation information can be found at http://dmd.aspetjournals.org.
doi:10.1124/dmd.110.036202.
ABBREVIATIONS:
- NAT1
- arylamine N-acetyltransferase-1
- bp
- base pairs
- TSA
- trichostatin A
- HDAC
- histone deacetylase
- DMSO
- dimethyl sulfoxide
- PBS
- phosphate-buffered saline
- PCR
- polymerase chain reaction
- qPCR
- quantitative real-time polymerase chain reaction
- DTT
- dithiothreitol
- PMSF
- phenylmethylsulfonyl fluoride
- EMSA
- electromobility shift assay
- GAPDH
- glyceraldehyde-3-phosphate dehydrogenase
- ChiP
- chromatin immunoprecipitation.
- Copyright © 2011 by The American Society for Pharmacology and Experimental Therapeutics
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