QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: jpet.104.069872v1 311/1/373    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Zhang, X. Articles by Ding, X. Search for Related Content PubMed PubMed Citation Articles by Zhang, X. Articles by Ding, X.

TOXICOLOGY

Development of a Real-Time Polymerase Chain Reaction-Based Method for the Measurement of Relative Allelic Expression and Identification of CYP2A13 Alleles with Decreased Expression in Human Lung

Wadsworth Center, New York State Department of Health, and School of Public Health, State University of New York at Albany, Albany, New York

CYP2A13 is a human cytochrome P450 monooxygenase that is efficient in the metabolic activation of tobacco-specific nitrosamines. Sequence variations that affect CYP2A13 expression may contribute to interindividual differences in susceptibility to tobacco-related tumorigenesis. The aim of this study was to identify any impact of CYP2A13 single-nucleotide polymorphisms (SNPs) on CYP2A13 expression in human lung. Expression levels of CYP2A13 mRNA in normal lung displayed significant interindividual variation (>50-fold). Preliminary sequence analysis of CYP2A13 RNA-polymerase chain reaction (PCR) products suggested that a 7520C > G variation, located in the 3'-untranslated region, could be associated with low transcript abundance. Subsequently, we developed a method for the measurement of relative allelic expression, by taking advantage of the capability for melting-curve analysis in real-time PCR. Quantitative analyses using this method indicated that transcripts from the 7520G-containing alleles were >10-fold less abundant than those from the 7520C-containing alleles in 14 of 16 samples examined. The frequencies of the 7520C > G variation in anonymous White, African American, Hispanic, and Asian newborns from New York State were found to be 5.2, 26.8, 17.7, and 4.3%, respectively. The 7520C > G SNP was previously known to be present in both CYP2A13^*1H and ^*3 alleles. However, analyses of SNP distribution indicated that, in 15 of the 16 heterozygous DNA samples, the 7520C > G SNP belonged to new CYP2A13^*1 haplotypes. These findings provide a basis for further studies that associate CYP2A13 haplotypes with incidences of smoking-related lung tumors and for studies on the mechanisms of the low-expression phenotype of the 7520G-containing allele.

Address correspondence to: Dr. Xinxin Ding, Wadsworth Center, New York State Department of Health, Empire State Plaza, Box 509, Albany, NY 12201-0509. E-mail: xding{at}wadsworth.org

This article has been cited by other articles:

				J. D'Agostino, X. Zhang, H. Wu, G. Ling, S. Wang, Q.-Y. Zhang, F. Liu, and X. Ding Characterization of CYP2A13*2, a Variant Cytochrome P450 Allele Previously Found to Be Associated with Decreased Incidences of Lung Adenocarcinoma in Smokers Drug Metab. Dispos., November 1, 2008; 36(11): 2316 - 2323. [Abstract] [Full Text] [PDF]

				X. Zhang, J. D'Agostino, H. Wu, Q.-Y. Zhang, L. von Weymarn, S. E. Murphy, and X. Ding CYP2A13: Variable Expression and Role in Human Lung Microsomal Metabolic Activation of the Tobacco-Specific Carcinogen 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone J. Pharmacol. Exp. Ther., November 1, 2007; 323(2): 570 - 578. [Abstract] [Full Text] [PDF]

				G. Ling, Y. Wei, and X. Ding Transcriptional Regulation of Human CYP2A13 Expression in the Respiratory Tract by CCAAT/Enhancer Binding Protein and Epigenetic Modulation Mol. Pharmacol., March 1, 2007; 71(3): 807 - 816. [Abstract] [Full Text] [PDF]