Molecular profiling and classification of sporadic renal cell carcinoma by quantitative methylation analysis
Molecular profiling and classification of sporadic renal cell carcinoma by quantitative methylation analysis
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DOI：
10.1158/1078-0432.ccr-03-0692
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发表时间：
2004-11-01
影响因子：
11.5
通讯作者：
Pavlovich, CP
中科院分区：
文献类型：
--
作者：
Gonzalgo, ML;Yegnasubramanian, S;Pavlovich, CP
目的：目前的技术对肾实质性肿块的术前组织学分类仍有局限性。我们确定的定量甲基化分析的基础上表征散发性renal cell carcinoma.Experimental Design的分子谱的效用：原发性肾细胞癌代表三种不同的组织学亚型，共38例进行根治性肾切除术的可疑恶性疾病。从肿瘤中分离基因组DNA并进行亚硫酸氢钠修饰。通过定量实时甲基化特异性PCR在17个不同的基因启动子处确定每个样品的归一化甲基化指数（NIM）。结果：在本研究中分析的大多数基因启动子表现出非常低的甲基化水平（NIM < 1.0）。RASSF 1A基因启动子甲基化率为79%（30/38）。RASSF 1A甲基化在乳头状、透明细胞和嗜酸细胞瘤亚型中的频率分别为100%、90%和25%。在乳头状（平均NIM = 78.9）和透明细胞（平均NIM = 13.4）亚型中观察到最高水平的RASSF 1A甲基化。绝大多数嗜酸细胞瘤是完全未甲基化的，并且没有显示> 1%甲基化（平均NIM = 0.11）。层次聚类分析的基础上定量甲基化水平分层的散发性肾细胞癌到其离散的组织学subtype.Conclusions：分类的散发性肾细胞癌到组织学亚型可以通过多基因定量甲基化分析来完成。这种方法的验证和选择适当的甲基化标记物可能最终导致使用这种技术在术前评估可疑的肾脏肿块。
Purpose: Preoperative histologic classification of solid renal masses remains limited with current technology. We determine the utility of molecular profiling based on quantitative methylation analysis for characterization of sporadic renal cell carcinoma.Experimental Design: Primary renal cell carcinomas representing three different histologic subtypes were obtained from a total of 38 patients who underwent radical nephrectomy for suspected malignant disease. Genomic DNA was isolated from tumors and was subjected to sodium bisulfite modification. The normalized index of methylation (NIM) for each sample was determined by quantitative realtime methylation-specific PCR at 17 different gene promoters. Hierarchical cluster analysis was performed by using an unsupervised neural network with binary tree topology.Results: The majority of gene promoters that were analyzed in this study demonstrated very low levels of methylation (NIM < 1.0). The RASSF1A gene promoter, however, was methylated in 30 of 38 (79%) cases. The frequency of RASSF1A methylation in papillary, clear-cell, and oncocytoma subtypes was 100, 90, and 25%, respectively. The highest levels of RASSF1A methylation were observed in the papillary (mean NIM = 78.9) and clear-cell (mean NIM = 13.4) subtypes. The vast majority of oncocytomas were completely unmethylated, and none demonstrated > 1 % methylation (mean NIM = 0.11). Hierarchical cluster analysis based on quantitative methylation levels resulted in stratification of sporadic renal cell carcinomas into their discrete histologic subtypes.Conclusions: Classification of sporadic renal cell carcinomas into histologic subtypes can lie accomplished via multigene quantitative methylation profiling. Validation of this approach and selection of appropriate methylation markers may ultimately lead to use of this technology in the preoperative assessment of suspicious renal masses.