Detection of methylated apoptosis-associated genes in urine sediments of bladder cancer patients
Detection of methylated apoptosis-associated genes in urine sediments of bladder cancer patients
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DOI：
10.1158/1078-0432.ccr-04-0930
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发表时间：
2004-11-15
影响因子：
11.5
通讯作者：
Liang, GN
中科院分区：
文献类型：
--
作者：
Friedrich, MG;Weisenberger, DJ;Liang, GN
目的：越来越多的证据表明，表观遗传沉默在癌症细胞凋亡途径中起着重要作用。DNA甲基化的变化可以以高度的灵敏度检测到，因此我们使用MethyLight检测来确定膀胱癌发生过程中膀胱癌相关基因的甲基化模式如何变化，以及是否可以在尿沉淀物中检测到DNA甲基化。我们分析了12个乳腺癌相关基因5'端的甲基化状态使用定量MethyLight测定法，在18个膀胱癌细胞系、127个膀胱癌样品和37个相邻正常膀胱粘膜样品中测定了细胞因子（ARF、FADD、TNFRSF 21、BAX、LITAF、DAPK、TMS-1、BCL 2、RASSF 1A、TERT、TNFRSF 25和EDNRB）。结果：与癌旁正常组织相比，DAPK、BCL 2、TERT、RASSFIA和TNFRSF 25 5'区的甲基化水平显著升高（P <0.01）。BCL 2甲基化水平与肿瘤分期和分级显著相关（P均小于或等于0.01），RASSFIA和ARF甲基化水平仅与肿瘤分期相关（P均小于或等于0.04），而TERT甲基化和EDNRB甲基化是肿瘤分级的预测因子（P均小于或等于0.02）。为了研究非侵入性膀胱癌检测的临床有用性，我们进一步分析了膀胱癌患者尿液样本中标志物的甲基化状态。在大多数样本（78%）中检测到膀胱癌患者尿沉渣DNA中DAPK，BCL 2和TERT的甲基化，而在年龄匹配的无癌个体的尿沉渣DNA中未甲基化。结论：我们的研究结果表明，膀胱癌相关基因5'区域的甲基化是膀胱癌患者常见的发现。不仅在膀胱组织中，而且在尿沉淀物中检测甲基化的能力表明甲基化标记物是用于膀胱癌的非侵入性检测的有希望的工具。我们的研究结果还表明，一些甲基化标记物，如RASSF 1A和TNFRSF 25区域中的标记物，可能用于检测是有限的，因为它们在正常膀胱组织中也是甲基化的。
Purpose: There is increasing evidence for a fundamental role for epigenetic silencing of apoptotic pathways in cancer. Changes in DNA methylation can be detected with a high degree of sensitivity, so we used the MethyLight assay to determine how methylation patterns of apoptosis-associated genes change during bladder carcinogenesis and whether DNA methylation could be detected in urine sediments.Experimental Design: We analyzed the methylation status of the 5' regions of 12 apoptosis-associated genes (ARF, FADD, TNFRSF21, BAX, LITAF, DAPK, TMS-1, BCL2, RASSF1A, TERT, TNFRSF25, and EDNRB) in 18 bladder cancer cell lines, 127 bladder cancer samples, and 37 samples of adjacent normal bladder mucosa using the quantitative MethyLight assay. We also analyzed the methylation status in urine sediments of 20 cancer-free volunteers and 37 bladder cancer patients.Results: The 5' regions of DAPK, BCL2, TERT, RASSFIA, and TNFRSF25 showed significant increases in methylation levels when compared with nonmalignant adjacent tissue (P less than or equal to 0.01). Methylation levels of BCL2 were significantly associated with tumor staging and grading (P less than or equal to 0.01), whereas methylation levels of RASSFIA and ARF were only associated with tumor stage (P less than or equal to 0.04), and TERT methylation and EDNRB methylation were predictors of tumor grade (P less than or equal to 0.02). To investigate clinical usefulness for noninvasive bladder cancer detection, we further analyzed the methylation status of the markers in urine samples of patients with bladder cancer. Methylation of DAPK, BCL2, and TERT in urine sediment DNA from bladder cancer patients was detected in the majority of samples (78%), whereas they were unmethylated in the urine sediment DNA from age-matched cancer-free individuals.Conclusions: Our results indicate that methylation of the 5' region of apoptosis-associated genes is a common finding in patients with bladder carcinoma. The ability to detect methylation not only in bladder tissue, but also in urine sediments, suggests that methylation markers are promising tools for noninvasive detection of bladder cancers. Our results also indicate that some methyllation markers, such as those in regions of RASSF1A and TNFRSF25, might be of limited use for detection because they are also methylated in normal bladder tissues.