Methylation of the androgen receptor promoter CpG island is associated with loss of androgen receptor expression in prostate cancer cells.
Methylation of the androgen receptor promoter CpG island is associated with loss of androgen receptor expression in prostate cancer cells.
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DOI：
10.1097/00005392-199904010-00253
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发表时间：
1998-12
期刊：
影响因子：
11.2
通讯作者：
D. Jarrard;H. Kinoshita;Yan Shi;C. Sandefur;Douglas G Hoff;L. Meisner;Chawnshang Chang;J. Herman;W. Isaacs;N. Nassif
中科院分区：
文献类型：
--
作者：
D. Jarrard;H. Kinoshita;Yan Shi;C. Sandefur;Douglas G Hoff;L. Meisner;Chawnshang Chang;J. Herman;W. Isaacs;N. Nassif
雄激素非依赖性转移性前列腺癌的特征在于肿瘤细胞中雄激素受体（AR）表达的异质性缺失。在这项研究中，我们评估DNA超甲基化作为一个潜在的转录调控机制在AR阴性前列腺癌细胞系。核苷酸序列分析表明，AR基因中约15 kb的CpG岛，包括转录起始位点和外显子1。使用Southern印迹与甲基化敏感的限制性内切酶和甲基化特异性PCR，我们发现异常甲基化的AR表达阴性细胞系Du 145，DuPro，TSU-PR 1，和PPC 1。AR CpG岛的不完全甲基化也见于正常女性乳腺和卵巢组织，这与一条X染色体因超甲基化而失活一致。相比之下，前列腺癌细胞系LNCaP和PC 3表达AR并且是未甲基化的。正常前列腺上皮细胞株显示无甲基化。AR阴性前列腺癌细胞系暴露于5-氮杂-2 '脱氧胞苷（一种去甲基化剂）诱导DuPro和TSU-PR 1中AR RNA的再表达。这种重新表达与该区域的去甲基化有关。前列腺特异性抗原，雄激素反应基因，也特别是在这些线后，AR再表达诱导。因此，5' CpG AR岛的体外DNA甲基化可能与AR表达的丧失相关。此外，我们的研究结果表明，治疗与去甲基化剂可能会导致再表达和AR阴性细胞系中的雄激素受体的功能。
Androgen-independent metastatic prostate cancer is characterized by a heterogeneous loss of androgen receptor (AR) expression among tumor cells. In this study, we evaluate DNA hypermethylation as a potential transcriptional regulatory mechanism in AR-negative prostate cancer cell lines. Nucleotide sequence analysis demonstrates an approximately 15-kb CpG island in the AR gene that encompasses the transcription start site and exon 1. Using Southern blotting with methylation-sensitive restriction enzymes and methylation-specific PCR, we find aberrant methylation in the AR expression-negative cell lines Du145, DuPro, TSU-PR1, and PPC1. Incomplete methylation in the AR CpG island is also seen in normal female breast and ovarian tissues consistent with the inactivation of one X chromosome by hypermethylation. In contrast, prostate cancer cell lines LNCaP and PC3 express AR and are unmethylated. Normal prostate epithelial cell strains demonstrate no methylation. Exposure of AR-negative prostate cancer cell lines to 5-aza-2' deoxycytidine, a demethylating agent, induces the reexpression of AR RNA in DuPro and TSU-PR1. This reexpression is associated with a demethylation of this region. Prostate-specific antigen, an androgen-responsive gene, is also specifically induced in these lines after AR reexpression. Therefore, in vitro DNA methylation of the 5' CpG AR island may be associated with the loss of AR expression. Furthermore, our results demonstrate that treatment with demethylating agents may engender the reexpression and function of the androgen receptor in AR-negative cell lines.