Abstract 1331: Ethnic-specific polymorphisms in CHRNA3 and CHRNA9 genes.

Abstract Several recent studies demonstrated significant association of numerous common polymorphisms in the CHRNA5-CHRNA3-CHRNB4 gene cluster encoding the α5, α3 and β4 nicotinic acetylcholine receptor (nAChR) subunits with the risk of lung cancer. However, due to high linkage disequilibrium, role of each protein in the tumorigenesis remains unclear. Large number of the single nucleotide polymorphisms (SNPs) including a majority of amino acid substitutions escaped the focus of previous research. Although some ethnic variations in this cluster are known, previous research was focused on the SNPs common for various ethnic groups. Little is currently known about epidemiological role of haplotypes specific for ethnical groups. We have assessed the global frequency distributions of coding and some non-coding nAChR SNPs by direct sequencing of 3 regions of CHRNA3 and 5 regions of CHRNA9 genes in 330 individuals from anthropologically defined human populations. The results revealed statistically significant ethnic-specific differences. In CHRNA3, for 8 SNPs, including one non-synonymous amino acid substitution, and in CHRNA9 for 7, including 2 non-synonymous SNPs. Among these SNPs, some were unique to one or two ethnical groups. For example, Arg110His in CHRNA3 (rs77574318) was seen only in Russians with heterozygosity 0.06. Thus, analysis of any amino acid substitution uniquely present in a particular ethnic group may guide further studies of the role of nAChRs gene polymorphism in various types of cancer Citation Format: Anna Chikova, Sergei Grando. Ethnic-specific polymorphisms in CHRNA3 and CHRNA9 genes. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1331. doi:10.1158/1538-7445.AM2013-1331 Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.