A functional variant in NKX3.1 associated with prostate cancer susceptibility down-regulates NKX3.1 expression
A functional variant in NKX3.1 associated with prostate cancer susceptibility down-regulates NKX3.1 expression
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DOI：
10.1093/hmg/ddq350
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发表时间：
2010-11-01
影响因子：
3.5
通讯作者：
Nakagawa, Hidewaki
中科院分区：
文献类型：
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作者：
Akamatsu, Shusuke;Takata, Ryo;Nakagawa, Hidewaki
全基因组关联研究（GWAS）发现了前列腺癌（PC）的多个易感基因座，最近的GWAS暗示染色体8 p21上的常见变异rs 1512268与PC易感性相关，该变异位于前列腺肿瘤抑制基因NKX3.1下游14 kb处。为了阐明该位点的易感基因和功能变体，我们对该区域进行了重新测序和精细定位，并确定了12个彼此绝对连锁的功能性单核苷酸多态性候选者。通过RNA稳定性测定、电泳迁移率变动测定（EMSA）和报告基因测定对这些变体进行筛选，表明NKX3.1 5 '-UTR中的rs 11781886对等位基因之间的核蛋白表现出不同的结合亲和力，并且NKX3.1启动子的转录活性在该变体的易感等位基因中显着降低。Sp1被确定为与易感G等位基因结合的转录因子，但不与非易感A等位基因结合。等位基因特异性转录定量（ASTQ）和定量PCR分析显示，携带易感等位基因的单倍型受试者前列腺中NKX3.1的表达显著降低。这些结果表明，NKX3.1的5 '-UTR中的功能变体rs 11781886可以通过改变转录因子Sp1的结合亲和力来影响其转录，并且可能通过降低NKX3.1在前列腺中的表达而导致PC易感性。
Genome-wide association studies (GWAS) identified multiple susceptible loci for prostate cancer (PC), and recent GWAS implicated that a common variant rs1512268 on chromosome 8p21 is associated with PC susceptibility, which is located at 14 kb downstream of a prostate tumor suppressor gene NKX3.1. To clarify a susceptibility gene and functional variants in this locus, we performed re-sequencing and fine mapping of this region and identified 12 candidates of functional single nucleotide polymorphisms that were absolutely linked with each other. Screening of these variants by RNA stability assay, electrophoretic mobility shift assay (EMSA) and reporter assay indicated that rs11781886 in the 5'-UTR of NKX3.1 displayed different binding affinity to nuclear proteins between the alleles, and that the transcriptional activity of the NKX3.1 promoter was significantly lower in the susceptible allele of this variant. Sp1 was determined to be the transcription factor that binds to the susceptible G allele, but not to the non-susceptible A allele. Allele-specific transcript quantification (ASTQ) and quantitative PCR analyses showed that the expression of NKX3.1 in the prostate was significantly lower in the subjects with the haplotype carrying the susceptible allele. These results suggest that the functional variant rs11781886 in the 5'-UTR of NKX3.1 can affect its transcription by altering the binding affinity of a transcriptional factor Sp1, and might result in PC susceptibility by lowering expression of NKX3.1 in the prostate.