Aberrant promoter methylation in human DAB2 interactive protein (hDAB2IP) gene in breast cancer
Aberrant promoter methylation in human DAB2 interactive protein (hDAB2IP) gene in breast cancer
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DOI：
10.1158/1078-0432.ccr-03-0236
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发表时间：
2004-03-15
影响因子：
11.5
通讯作者：
Shimizu, N
中科院分区：
文献类型：
--
作者：
Dote, H;Toyooka, S;Shimizu, N
目的：人DOC-2/DAB2相互作用蛋白(HDAB21P)基因是Ras GTP酶激活家族的新成员，已被证明是前列腺癌甲基化失活的抑癌基因。我们分析了hDAB21P在乳腺癌中的甲基化和表达状态。实验设计：根据我们之前关于前列腺癌的报道，将hDAB21P的启动子区分为两个区域(M2a和M2b)，并用亚硫酸氢盐DNA测序法确定乳腺癌细胞系中的甲基化状态。用实时荧光定量逆转录-聚合酶链式反应对其进行半定量检测，发现甲基化异常与表达呈负相关。结果：25株乳腺癌细胞株中有11株(44%)和39株原发肿瘤中有15株(38%)在M2a区出现异常甲基化，在M2b区有12株(48%)和13例(33%)出现异常甲基化。此外，用5-氮杂2‘-脱氧胞苷甲基化的细胞系恢复了基因表达，证实了甲基化导致了基因下调。我们还研究了hDAB21P甲基化与原发肿瘤临床病理特征的关系，发现M2B区域的甲基化与肿瘤的进展淋巴结状态有关。结论：我们建立了hDAB21P甲基化特异的聚合酶链式反应，并检测了其在乳腺癌中的甲基化状态。我们的结果表明，hDAB2IP甲基化在乳腺癌中频繁存在，并在hDAB21P失活中起关键作用，提示hDAB2IP甲基化与乳腺癌的淋巴转移有关。
Purpose: Human DOC-2/DAB2 interactive protein (hDAB21P) gene is a novel member of the Ras GTPaseactivating family and has been demonstrated to be a tumor suppressor gene inactivated by methylation in prostate cancer. We analyzed methylation and expression status of hDAB21P in breast cancer.Experimental Design: The promoter region of hDAB21P was divided into two regions (m2a and m2b) following our previous report on prostate cancer, and methylation status was determined in breast cancer cell lines with bisulfited DNA sequencing. Expression was semiquantified with real-time reverse transcription-PCR to rind that aberrant methylation showed the inverse relationship with expression. On the basis of sequence data, we developed methylation-specific PCR for m2a and m2b regions and applied to samples.Results: Aberrant methylation was detected in 11 of 25 breast cancer cell lines (44%) and 15 of 39 primary tumors (38%) at the m2a region and in 12 of 25 cell lines (48%) and 13 of 39 tumors (33%) at the m2b region. In addition, gene expression was restored in methylated cell lines with 5-aza2'-deoxycytidine, confirming that methylation caused gene down-regulation. We also examined the relationship between hDAB21P methylation and clinicopathologic features in primary tumors and found that methylation in the m2b region was associated with progressive nodal status of tumors.Conclusions: We developed methylation-specific PCR for hDAB21P and examined its methylation status in breast cancer. Our results demonstrate that hDAB2IP methylation frequently is present in breast cancer and plays a key role in hDAB21P inactivation, suggesting the relationship between hDAB2IP methylation and lymph node metastasis of breast cancer.