Two Single Nucleotide Polymorphisms of the ETS2 Transcriptional Factor Gene Predispose Individuals to High-Risk Acute Myelogenous Leukemia (AML).

ETS2 (v-ets avian erythroblastosis virus E2 oncogene homolog 2) is a transcription factor located in the human chromosomal region 1q22.3 encoding a 56-kDa protein. In this study we carefully selected a set of haplotype-tagging SNPs (htSNP) and genotyped their frequencies in order to identify polymorphic variants that contributes to the inter-individual differences in susceptibility to disease phenotypes. Here we report polymorphisms of ETS2, a hematopoietic transcription factor gene is associated with increased risk to AML. Seven SNPs derived from genomic region of the ETS2 gene, rs1209953, rs3746882, rs2298560, rs457705, rs2070531, rs711 and rs5307 were genotyped to estimate allele frequency, haplotype block and linkage disequilibrium (LD) map. Among those rs711 and rs530 were shown to be associated with increased risk to AML with statistical significance. The odds ratio (OR) for rs711 and rs530 relative to wild type genotypes are 1.76 (95% C.I. 1.2–2.5, p=0.0019) and 1.67 (95% C.I. 1.3–2.2, p=0.0003) respectively. Cumulative frequencies of four common haplotypes are 72%, among which T-T-G-T-C-G-T was the most ancestral haplotype comprising 36% of total haplotypes. We also examined the possibility of haplotype association, but no association was found. When we compared LD map with LDs constructed from the International HapMap project, Korean LD map was similar to Japanese LD, but least similarity was shown with LDs from African(Yoruba in Ibadan, Nigeria). Since these two SNPs are located in the 3′ UTR region we simulated the change in secondary structure in silico of the 3′ UTR region with two variants sequence. Severe change in the secondary structure was observed in the rs530 containing domain suggesting this change might affects stability of mRNA. Real time Q-PCR and western blot revealed that expression of ETS2 decreased in a dosage-dependant manner, showing most abundant expression when homozygously T/T at rs530, least expression with the homozygous A/A and intermediate level of expression when the heterozygous genotype. Our results suggest that polymorphic variants in the 3′ UTR region predispose individual to high-risk AML by altering the secondary structure of mRNA.