Department of Digestive Surgery of Applied Molecular Bioscience, Yamaguchi University Postgraduate School of Medicine, Ube, Yamaguchi 755-8505, Japan.
Int J Oncol. 2010 Jan;36(1):205-12.
We previously identified BASP1 and SRD5A2 as novel hepatocellular carcinoma (HCC) methylation markers from among more than 10,000 screened genes. The present study aimed to improve the diagnostic potential of these genes. We compared the methylation status at distinct regions of the BASP1 and SRD5A2 genes using quantitative methylation-specific PCR, in 46 sets of HCC and corresponding non-tumor liver tissues. We also examined how their epigenetic status affected transcript levels in tissues and several hepatoma cell lines. We found that BASP1 and SRD5A2 loci were methylated in greater than 50% of the HCC tissues. Inverse correlations were identified between the methylation status and transcript levels in the tissues. Assessment of CpG island methylation rate of BASP1 and SRD5A2 resulted in different diagnostic powers for discriminating HCC even in the same CpG island. A combination analysis of BASP1 and SRD5A2 resulted in the optimum diagnostic performance (84.8% sensitivity and 91.3% specificity) with a maximal area under the receiver operating characteristic curve of 0.878. Even in patients with early HCC (well-differentiated, TNM stage I and small in diameter) and those negative for serum alpha-fetoprotein, combination analysis enabled an accurate diagnosis of HCC. In vitro analysis also showed that BASP1 and SRD5A2 transcripts were epigenetically regulated by methylation and acetylation. These results suggest that combined analysis of methylated BASP1 and SRD5A2 may prove useful in the accurate diagnosis of HCC, especially early HCC.
我们之前从超过 10000 个筛选基因中确定了 BASP1 和 SRD5A2 作为新的肝癌（HCC）甲基化标记物。本研究旨在提高这些基因的诊断潜力。我们使用定量甲基化特异性 PCR 比较了 46 对 HCC 和相应非肿瘤肝组织中 BASP1 和 SRD5A2 基因的不同区域的甲基化状态。我们还研究了它们的表观遗传状态如何影响组织和几种肝癌细胞系中的转录水平。我们发现 BASP1 和 SRD5A2 基因座在超过 50%的 HCC 组织中发生甲基化。在组织中，甲基化状态与转录水平之间存在负相关关系。BASP1 和 SRD5A2 的 CpG 岛甲基化率评估导致即使在同一 CpG 岛上区分 HCC 的诊断能力也不同。BASP1 和 SRD5A2 的组合分析导致最佳诊断性能（84.8%的敏感性和 91.3%的特异性），最大受试者工作特征曲线下面积为 0.878。即使在早期 HCC（高分化，TNM 分期 I 和小直径）和甲胎蛋白阴性的患者中，组合分析也能够准确诊断 HCC。体外分析还表明，BASP1 和 SRD5A2 的转录物受甲基化和乙酰化的表观遗传调控。这些结果表明，甲基化 BASP1 和 SRD5A2 的组合分析可能有助于 HCC 的准确诊断，特别是早期 HCC。
