ORIGINAL ARTICLESFunctional properties of an alternative, tissue-specific promoter for human arylamine N-acetyltransferase 1Barker, David F.; Husain, Anwar; Neale, Jason R.; Martini, Benjamin D.; Zhang, Xiaoyan; Doll, Mark A.; Christopher States, J.; Hein, David W.Author Information Department of Pharmacology and Toxicology and James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, Kentucky, USA Correspondence and requests for reprints to David W. Hein, Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40292, USA Tel: +1 502 852 5141; fax: +1 502 852 7868; e-mail: [email protected] Sponsorship: This work was partially supported by USPHS grants CA34627 (D.W.H.) and ES12557 (A.H.) and a grant from the University of Louisville Center for Genetics and Molecular Medicine (D.W.H.). Received 8 December 2005 Accepted 31 January 2006 Pharmacogenetics and Genomics: July 2006 - Volume 16 - Issue 7 - p 515-525 doi: 10.1097/01.fpc.0000215066.29342.26 Buy Metrics Abstract Variable expression of human arylamine N-acetyltransferase 1 (NAT1) due to genetic polymorphism, gene regulation or environmental influences is associated with individual susceptibility to various cancers. Recent studies of NAT1 transcription showed that most mRNAs originate at a promoter, P1, located 11.8 kb upstream of the single open reading frame (ORF) exon. We have now characterized an alternative NAT1 promoter lying 51.5 kb upstream of the NAT1 ORF. In the present study, analysis of human RNAs representing 27 tissue types by reverse transcriptase-polymerase chain reaction (RT-PCR) and quantitative RT-PCR showed the upstream 51.5 kb promoter, designated P3, to be most active in specific tissues, including kidney, liver, lung, and trachea. All NAT1 P3 mRNAs included 5′-untranslated region (5′-UTR) internal exons of 61 and 175 nucleotides in addition to the 79 nucleotide 5′-UTR exon present in P1 mRNA. CAP-dependent amplification of 5′-P3 mRNA termini defined an 84 bp transcription start region in which most start sites are centrally clustered. The hepatoma-derived HepG2 cell line expressed a high level of P3 mRNA with the same spliced structure and start site pattern as found in normal tissues. A 435-bp minimal promoter was defined by transfection of HepG2 with luciferase expression constructs containing genomic fragments from the P3 start region. These findings imply a fundamental role for P3 in NAT1 regulation and define additional regions for genetic polymorphisms associated with enhanced cancer risk. © 2006 Lippincott Williams & Wilkins, Inc.