Multiple markers for melanoma progression regulated by DNA methylation: insights from transcriptomic studies
Multiple markers for melanoma progression regulated by DNA methylation: insights from transcriptomic studies
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DOI：
10.1093/carcin/bgi152
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发表时间：
2005-11-01
期刊：
影响因子：
4.7
通讯作者：
Easty, DJ
中科院分区：
文献类型：
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作者：
Gallagher, WM;Bergin, OE;Easty, DJ
黑色素瘤的发病率正在迅速增加，晚期病变通常对常规化疗无效。在这里，我们利用基于DNA微阵列的基因表达谱技术，在一组独特的等基因人类黑色素瘤细胞系中鉴定黑色素瘤进展的分子决定因素。当一种来自早期黑色素瘤的低致瘤性细胞系与两种越来越具有侵袭性的衍生细胞系进行比较时，66个基因的表达发生了显著变化。在独立衍生的转移细胞系中发现了类似的差异基因表达模式。我们通过使用定制的TaqMan低密度阵列（LDA）进一步检查了这些黑色素瘤进展相关基因，代表了我们感兴趣的队列中的大多数基因。通过DNA微阵列和TaqMan LDA方法确定的转录组谱之间存在相当大的一致性。一系列新的标记被确定与黑色素瘤的进展相关。最值得注意的是TSPY，一个Y染色体特异性基因，在亲本和衍生细胞系之间表现出广泛的表达下调。对TSPY基因内假定的CpG岛的检查表明，该区域在衍生细胞系以及男性患者的转移性黑色素瘤中被超甲基化。此外，用DNA甲基转移酶抑制剂2'-脱氧-5-氮杂胞苷（DAC）处理衍生细胞系，将TSPY基因的表达恢复到与亲本细胞相当的水平。另外的DNA微阵列研究发现，上述66个基因队列中的13个基因在DAC处理后表现出重新激活的表达，包括TSPY、CYBA和MT2A。DAC在体外抑制肿瘤细胞生长。此外，用DAC对小鼠进行全身治疗可以减弱黑色素瘤异种移植物的生长，从而导致TSPY mRNA的重新表达。总的来说，我们的数据支持这样的假设，即在黑色素瘤进展过程中，DNA超甲基化直接或间接地靶向多个基因。
The incidence of melanoma is increasing rapidly, with advanced lesions generally failing to respond to conventional chemotherapy. Here, we utilized DNA microarray-based gene expression profiling techniques to identify molecular determinants of melanoma progression within a unique panel of isogenic human melanoma cell lines. When a poorly tumorigenic cell line, derived from an early melanoma, was compared with two increasingly aggressive derivative cell lines, the expression of 66 genes was significantly changed. A similar pattern of differential gene expression was found with an independently derived metastatic cell line. We further examined these melanoma progression-associated genes via use of a tailored TaqMan Low Density Array (LDA), representing the majority of genes within our cohort of interest. Considerable concordance was seen between the transcriptomic profiles determined by DNA microarray and TaqMan LDA approaches. A range of novel markers were identified that correlated here with melanoma progression. Most notable was TSPY, a Y chromosome-specific gene that displayed extensive down-regulation in expression between the parental and derivative cell lines. Examination of a putative CpG island within the TSPY gene demonstrated that this region was hypermethylated in the derivative cell lines, as well as metastatic melanomas from male patients. Moreover, treatment of the derivative cell lines with the DNA methyltransferase inhibitor, 2'-deoxy-5-azacytidine (DAC), restored expression of the TSPY gene to levels comparable with that found in the parental cells. Additional DNA microarray studies uncovered a subset of 13 genes from the above-mentioned 66 gene cohort that displayed re-activation of expression following DAC treatment, including TSPY, CYBA and MT2A. DAC suppressed tumor cell growth in vitro. Moreover, systemic treatment of mice with DAC attenuated growth of melanoma xenografts, with consequent re-expression of TSPY mRNA. Overall, our data support the hypothesis that multiple genes are targeted, either directly or indirectly, by DNA hypermethylation during melanoma progression.