Haplotype-environment interactions that regulate the human glutathione S-transferase P1 promoter
Haplotype-environment interactions that regulate the human glutathione S-transferase P1 promoter
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DOI：
10.1158/0008-5472.can-05-4457
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发表时间：
2006-06-15
期刊：
影响因子：
11.2
通讯作者：
Spivack, Simon D.
中科院分区：
文献类型：
--
作者：
Cauchi, Stephane;Han, Weiguo;Spivack, Simon D.
据报道，致癌物的 II 期解毒可介导候选化学预防剂的一些抗癌作用。我们探讨了 GSTP1 基因启动子序列变异与候选化学预防暴露在调节人类 GSTP1 表达方面的相互作用。在 40 名白人受试者的白细胞 [外周血单核细胞 (PBMC)] 中鉴定出沿 1.8 kb 的 GSTP1 启动子的多态性。 10 个启动子多态性（9 个之前未报告）表现出强烈的连锁不平衡，从而鉴定出三种常见的单倍型 [HAP 1 (43%)、RAP2 (36%) 和 HAP3 (8%)]。每个单元型被克隆到荧光素酶报告构建体中并转染到正常人支气管上皮细胞中。随着萝卜硫素、异硫氰酸苄酯 (BITC) 和表没食子儿茶素没食子酸酯 (EGCG) 浓度的增加，基础 HAP3 报告基因活性显着升高（1.8 倍），但降低至与 HAP2 和 HAP1 相同的水平。为了确认天然 HAP3 功能，我们定量了来自同一患者的未培养的 PBMC 和激光显微切割的正常肺上皮细胞 (MNLEC) 中的 mRNA 表达。 HAP3个体中的基础mRNA表达高于其他基因型[HAP3杂合子为1.8倍(PBMC)和4倍(MNLEC)，HAP3纯合子为2.3倍(PBMC)和15倍(MNLEC)]。 PBMC GSTP1 mRNA 表达与 MNLEC 表达相关 (R-2 = 0.77)。经过培养并体外暴露于萝卜硫素、BITC 或 EGCG 后，HAP3 个体的 PBMC 升高的 GSTP-1 mRNA 表达降低至常见表达水平。 HAP3 功能的升高在 PBMC 的蛋白质水平上得到证实（HAP3 杂合子高 5 倍，HAP3 纯合子高 7.6 倍）。这些数据表明潜在的保护性 GSTP1 启动子单倍型和不可预测的抑制性化学预防剂-单倍型相互作用。
Phase II detoxification of carcinogens is reported to mediate some of the anticarcinogenesis effects of candidate chemopreventive agents. We explored the interaction between sequence variation in the GSTP1 gene promoter and candidate chemopreventive exposure in regulating human GSTP1 expression. Polymorphisms along 1.8 kb of the GSTP1 promoter were identified in leukocytes [peripheral blood mononuclear cells (PBMC)] from 40 Caucasian subjects. Ten promoter polymorphisms (9 previously unreported) displayed strong linkage disequilibrium, yielding identification of three frequently observed haplotypes [HAP 1 (43%), RAP2 (36%), and HAP3 (8%)]. Each haplotype was cloned into luciferase reporter constructs and transfected into normal human bronchial epithelial cells. Basal HAP3 reporter activity was significantly elevated (1.8-fold) but decreased to the same levels as HAP2 and HAP1 with increasing concentrations of sufforaphane, benzyl isothiocyanate (BITC), and epigallocatechin gallate (EGCG). To confirm native HAP3 functionality, we quantitated mRNA expression in uncultured PBMCs and in laser microdissected normal lung epithelial cells (MNLEC) from the same patients. Basal mRNA expression was higher in HAP3 individuals [1.8-fold (PBMC) and 4-fold (MNLEC) for HAP3 heterozygotes and 2.3-fold (PBMC), and 15-fold (MNLEC) for the HAP3 homozygote] than in the other genotypes. PBMC GSTP1 mRNA expression correlated to MNLEC expression (R-2 = 0.77). After culture and in vitro exposure to sulforaphane, BITC, or EGCG, the elevated GSTP-1 mRNA expression of PBMCs from HAP3 individuals decreased to common expression levels. Elevated HAP3 function was confirmed at the protein level in PBMCs (5-fold higher for HAP3 heterozygotes and 7.6-fold for the HAP3 homozygote). These data suggest a potentially protective GSTP1 promoter haplotype and unpredicted inhibitory chemopreventive agent-haplotype interactions.