Up-regulation of DNA methyltransferase 3B expression in endometrial cancers
Up-regulation of DNA methyltransferase 3B expression in endometrial cancers
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DOI：
10.1016/j.ygyno.2004.10.039
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发表时间：
2005-02-01
影响因子：
4.7
通讯作者：
Jiang, SN
中科院分区：
文献类型：
--
作者：
Jin, F;Dowdy, SC;Jiang, SN
客观的。了解表观遗传调控在子宫内膜癌发病机制中的作用。我们研究了正常、I 级和 III 级子宫内膜样癌中 DNA 甲基转移酶 3B (DNMT3B) 基因表达的特征。并检查了子宫内膜癌细胞系中 DNMT3B 启动子的活性。方法。在正常、I 级和 III 级子宫内膜样癌样本中测量了 DNMT3B 表达。进行实时 PCR 和蛋白质印迹分析来比较 DNNT3B mRNA 和蛋白质水平。还比较了子宫内膜细胞系（包括 Ishikawa、KLE、AN3、RL-95）之间的 DNMT3B 水平。 HEC-1A 和 HEC-1B。构建了 DNMT3B 启动子报告质粒。通过体外报告基因转染比较分化良好和分化不良的细胞系中的启动子活性。结果。与正常对照相比，DNMT3B 在 I 级和 III 级癌症中均显着上调。 Western blot 分析证实癌组织中 DNMT3B 蛋白表达增加。还发现高分化子宫内膜细胞系Ishikawa比低分化KLE细胞表达更低水平的DNMT3B，其表达模式与肿瘤标本中观察到的相似。结论。结果表明 DNMT3B 过度表达可能在子宫内膜癌的发展中发挥重要作用。此外，转染实验表明DNMT3B启动子在低分化子宫内膜癌细胞系中更加活跃，这表明体外实验为研究与肿瘤转化相关的DNMT3B反式激活机制提供了有用的模型。 (C) 2004 Elsevier Inc. 保留所有权利。
Objective. To understand the role of epigenetic regulation in the pathogenesis of endometrial cancer. we have characterized DNA methyltransferase 3B (DNMT3B) gene expression in normal, Grade I and Grade III endometrioid cancers. and examined DNMT3B promoter activities in endometrial cancer cell lines.Methods. DNMT3B expression was measured in normal, Grade I. and Grade III endometrioid cancer samples. Real-time PCR and Western blot analysis were performed to compare DNNT3B mRNA and protein levels. DNMT3B levels were also compared among endometrial cell lines including those for Ishikawa, KLE, AN3, RL-95. HEC-1A, and HEC-1B. DNMT3B promoter reporter plasmids were constructed. Promoter activities in well and poorly differentiated cell lines were compared by in vitro reporter gene transfection.Results. DNMT3B was significantly up-regulated in both Grade I and Grade III cancers as compared to normal controls. Western blot analysis confirmed the increased DNMT3B protein expression in cancer tissues. It was also found that the well-differentiated endometrial cell line, Ishikawa, expressed lower levels of DNMT3B than the poorly differentiated KLE cells, the expression patterns similar to those observed in tumor specimens.Conclusion. The results suggest that DNMT3B overexpression may play a significant role in endometrial cancer development. In addition, the transfection experiments indicated that DNMT3B promoters are more active in the poorly differentiated endometrial cancer cell lines, suggesting that the in vitro assay provides a useful model for studying the DNMT3B transactivation mechanism related to tumor transformation. (C) 2004 Elsevier Inc. All rights reserved.