Berrada N, Amzazi S, Ameziane El Hassani R, Benbacer L, El Mzibri M, Khyatti M, Chafiki J, Abbar M, Al Bouzidi A, Ameur A, Attaleb M
Unité de Biologie et recherché Médicale, Centre National de l’Energie, des Sciences et Techniques Nucléaires, Rabat, Maroc.
Cell Mol Biol (Noisy-le-grand). 2012 Sep 10;Suppl.58:OL1744-51.
The CpG promoter methylation has been reported to occur frequently in bladder cancer. Moreover, analysis of gene methylation has been shown to be feasible from voided urine and can be detected with a high degree of sensitivity. The aim of this present study is to determine how methylation patterns of APC, RARβ and Survivin genes change during bladder carcinogenesis and to evaluate whether DNA methylation could be detected in urine sediment. Using the sensitive assay of MSP, we explored the promoter methylation status for the three genes in tumor specimens and urine sediment DNA from 32 bladder cancer patients. Methylation frequencies of the tested genes in tumor specimens were 100%, 75% and 84.4% for APC, RARβ and Survivin, respectively. Hypermethylation of APC was found in all pathological grades and stages of bladder cancer. More frequent promoter hypermethylation of RARβ and Survivin was observed in high grade tumors and the hypermethylation increased from low to high stages, but there was no significant correlation between stages/grades and hypermethylation of these two gene promoters. In order to investigate clinical usefulness for noninvasive bladder cancer detection, we further analyzed the methylation status in urine samples of bladder cancer patients. Methylation of the tested genes in urine sediment DNA was detected in the majority of cases that were hypermethylated in tumor samples (93.7%) and the frequencies were 79.3% 70.8% and 96.3% for APC, RARβ and Survivin, respectively. Our results indicate that methylation of APC, RARβ and Survivin gene promoters 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 cancer.
据报道，CpG启动子甲基化在膀胱癌中频繁发生。此外，已证明从排出的尿液中分析基因甲基化是可行的，并且可以高度灵敏地检测到。本研究的目的是确定APC、RARβ和Survivin基因的甲基化模式在膀胱癌发生过程中如何变化，并评估是否可以在尿沉渣中检测到DNA甲基化。使用灵敏的甲基化特异性PCR（MSP）检测方法，我们探究了32例膀胱癌患者肿瘤标本和尿沉渣DNA中这三个基因的启动子甲基化状态。肿瘤标本中检测基因的甲基化频率分别为：APC为100%，RARβ为75%，Survivin为84.4%。在膀胱癌的所有病理分级和分期中均发现APC高甲基化。在高级别肿瘤中观察到RARβ和Survivin启动子高甲基化更为频繁，且高甲基化从低分期到高分期增加，但这两个基因启动子的分期/分级与高甲基化之间无显著相关性。为了研究非侵入性膀胱癌检测的临床实用性，我们进一步分析了膀胱癌患者尿液样本中的甲基化状态。在大多数肿瘤样本中高甲基化的病例中检测到尿沉渣DNA中检测基因的甲基化（93.7%），APC、RARβ和Survivin的频率分别为79.3%、70.8%和96.3%。我们的结果表明，APC、RARβ和Survivin基因启动子的甲基化在膀胱癌患者中是常见现象。不仅能在膀胱组织中，还能在尿沉渣中检测到甲基化表明甲基化标志物是无创检测膀胱癌的有前景的工具。
