Promoter methylation profiling of 30 genes in human malignant melanoma
Promoter methylation profiling of 30 genes in human malignant melanoma
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DOI：
10.1111/j.1349-7006.2004.tb03184.x
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发表时间：
2004-12-01
期刊：
影响因子：
5.7
通讯作者：
Ushijima, T
中科院分区：
文献类型：
--
作者：
Furuta, J;Umebayashi, Y;Ushijima, T
启动子CpG岛的异常甲基化和去甲基化分别导致肿瘤抑制基因的沉默和正常甲基化基因的异常表达。在这里，我们分析了人类黑色素瘤的甲基化和去甲基化特征。对20个(候选)抑癌基因、4个不被认为是肿瘤抑制基因但在人类癌症中经常沉默的基因和6个正常甲基化的黑色素瘤抗原基因(MAGE)的启动子区CpG岛的甲基化状态进行了检测。对13个黑色素瘤细胞系和2个培养的正常人表皮黑素细胞(HEM)的分析表明，在至少1个细胞系中，9个抑癌基因和4个非抑癌基因均发生甲基化，而在HEM中未见甲基化；在3~13个细胞系中，6个MAGE基因全部去甲基化。有趣的是，我们没有检测到MGMT、PTEN、MTAP和p27的甲基化，此前报道这些基因在黑色素瘤中是沉默的。此外，对25例外科黑色素瘤标本中3个细胞系中频繁甲基化的基因和6个MAGE基因进行了分析。RARB、RASSF1A和3-OST-2甲基化分别为5例(20%)、9例(36%)和14例(56%)。MAGE-A1、A2、A3、B2、C1和C2去甲基化分别为9例(36%)、22例(88%)、20例(80%)、7例(28%)、21例(84%)和16例(%)。有18例(72%)至少有1个基因甲基化，24例(96%)至少有1个基因去甲基化。未观察到频繁甲基化和频繁去甲基化之间的相关性。这些图谱表明，异常甲基化和去甲基化在人类黑色素瘤中广泛存在。
Aberrant methylation and demethylation of promoter CpG islands lead to silencing of tumor-suppressor genes and abnormal expression of normally methylated genes, respectively. Here, we analyzed human melanomas for their methylation and demethylation profiles. Methylation status of core regions in promoter CpG islands was examined for 20 (candidate) tumor-suppressor genes, 4 genes that are not considered as tumor-suppressors, but are frequently silenced in human cancers, and 6 normally methylated melanoma antigen genes (MAGEs). Analysis of 13 melanoma cell lines and 2 cultured normal human epidermal melanocytes (HEMs) showed that 9 tumor-suppressor genes and all 4 non-tumor-suppressor genes were methylated in at least 1 cell line, but never in HEMs, and that all 6 MAGE genes were demethylated in 3 to 13 cell lines. Interestingly, we detected no methylation of MGMT, PTEN, MTAP and p27, which were previously reported as silenced in melanomas. Furthermore, 3 genes that were frequently methylated in the cell lines and 6 MAGE genes were analyzed in 25 surgical melanoma samples. RARB, RASSF1A and 3-OST-2 were methylated in 5 (20%), 9 (36%) and 14 (56%) samples, respectively. MAGE-A1, A2, A3, B2, C1 and C2 were demethylated in 9 (36%), 22 (88%), 20 (80%), 7 (28%), 21 (84%) and 16 (64%) samples, respectively. At least 1 gene was methylated in 18 (72%) samples and at least 1 was demethylated in 24 (96%) samples. No correlation between frequent methylation and frequent demethylation was observed. These profiles showed that both aberrant methylation and demethylation occur widely in human melanomas.