DNA methylation and soy phytoestrogens: quantitative study in DU-145 and PC-3 human prostate cancer cell lines
DNA methylation and soy phytoestrogens: quantitative study in DU-145 and PC-3 human prostate cancer cell lines
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DOI：
10.2217/epi.11.103
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发表时间：
2011-12-01
期刊：
影响因子：
3.8
通讯作者：
Bernard-Gallon, Dominique
中科院分区：
文献类型：
--
作者：
Adjakly, Mawussi;Bosviel, Remy;Bernard-Gallon, Dominique
目的：DNA 高甲基化是一种表观遗传机制，可诱导前列腺癌中肿瘤抑制基因的沉默。许多研究报告称，大豆植物雌激素等食用植物的特定成分可能对前列腺癌的发生或进展具有保护作用。据报道，金雀异黄酮和大豆黄酮是主要的植物雌激素，能够逆转癌细胞系中的 DNA 高甲基化。本研究的目的是研究这两种大豆化合物对 BRCA1、GSTP1、EPHB2 和 BRCA2 启动子基因的潜在去甲基化作用。方法和材料：前列腺细胞系 DU-145 和 PC-3 用金雀异黄素 40 μM、大豆黄酮 110 μM、布地奈德（甲基化剂）2 μM 和 5-氮杂胞苷（去甲基化剂）2 μM 处理。在这两种人类前列腺癌细胞系中，我们使用 Mmethyl Profiler DNA 甲基化分析进行甲基化定量。该技术基于甲基化特异性消化，然后进行定量 PCR。我们通过蛋白质印迹分析了相应蛋白的表达。结果：大豆植物雌激素诱导了所研究的所有启动子区域的去甲基化，但 BRCA2 除外，BRCA2 在对照细胞系中未甲基化。蛋白质印迹分析也证明了它们的蛋白质表达增加，并证实了大豆植物雌激素的潜在去甲基化作用。结论：本研究表明，大豆植物雌激素、染料木黄酮和大豆黄酮可诱导 BRCA1、GSTP1 和 EPHB2 启动子甲基化降低。因此，大豆植物雌激素可能对前列腺癌有保护作用。然而，需要更多的研究来了解金雀异黄酮和大豆黄酮对 DNA 甲基化具有抑制作用的机制。
Aim: DNA hypermethylation is an epigenetic mechanism which induces silencing of tumor-suppressor genes in prostate cancer. Many studies have reported that specific components of food plants like soy phytoestrogens may have protective effects against prostate carcinogenesis or progression. Genistein and daidzein, the major phytoestrogens, have been reported to have the ability to reverse DNA hypermethylation in cancer cell lines. The aim of this study was to investigate the potential demethylating effects of these two soy compounds on BRCA1, GSTP1, EPHB2 and BRCA2 promoter genes. Methods & materials: Prostate cell lines DU-145 and PC-3 were treated with genistein 40 mu M, daidzein 110 mu M, budesonide (methylating agent) 2 mu M and 5-azacytidine (demethylating agent) 2 mu M. In these two human prostate cancer cell lines we performed methylation quantification by using Methyl Profiler DNA methylation ana-lysis. This technique is based on a methylation-specific digestion followed by quantitative PCR. We analyzed the corresponding protein expression by western blotting. Results: Soy phytoestrogens induced a demethylation of all promoter regions studied except for BRCA2, which is not methylated in control cell lines. An increase in their protein expression was also demonstrated by western blot ana-lysis and corroborated the potential demethylating effect of soy phytoestrogens. Conclusion: This study showed that the soy phytoestrogens, genistein and daidzein, induce a decrease of methylation of BRCA1, GSTP1 and EPHB2 promoters. Therefore, soy phytoestrogens may have a protective effect on prostate cancer. However, more studies are needed in order to understand the mechanism by which genistein and daidzein have an inhibiting action on DNA methylation.