Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China.
School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China.
Gene. 2019 Jan 30;683:35-40. doi: 10.1016/j.gene.2018.10.009. Epub 2018 Oct 5.
Aberrant DNA methylation of cyclin-dependent kinase-like 2 (CDKL2) had been observed in several types of tumors. Herein, the present study was aimed to explore the epigenetic and expression status of CDKL2 and evaluate the diagnostic potential of CDKL2 methylation in hepatocellular carcinoma (HCC).
The methylation status of CDKL2 was detected by methylation-sensitive restriction enzyme based quantitative PCR (MSRE-qPCR) and bisulfite genomic sequencing (BGS). The mRNA expression of CDKL2 was measured using real-time quantitative PCR (qPCR). The correlations between the methylation of CDKL2 and mRNA expression, clinicopathological features were evaluated.
Compared with normal liver tissues, the methylation levels of CDKL2 were significantly increased in the HCC tissues and cell lines (All p < 0.05). And the receiver operating characteristic (ROC) analysis showed that the hypermethylation of CDKL2 had a high specificity and sensitivity to distinguish adjacent non-tumor tissues from HCC tissues. Additionally, the mRNA expression levels of CDKL2 were decreased both in HCC tissues and cell lines than those in normal liver tissues (All p < 0.05), and the expression could be upregulated by 5-aza-2'-deoxycytidine treatment in HCC cell lines. Furthermore, the methylation of CDKL2 was negatively correlated with its mRNA expression (p < 0.001, r = -0.513), and was associated with gender (p = 0.023), age (p = 0.001) and tumor size (p = 0.016).
Our results showed that CDKL2 promoter hypermethylation played an important role in hepatocarcinogenesis and might be a valuable biomarker for HCC diagnosis.
细胞周期依赖性激酶样 2（CDKL2）的异常 DNA 甲基化已在多种类型的肿瘤中观察到。在此，本研究旨在探讨 CDKL2 的表观遗传学和表达状态，并评估 CDKL2 甲基化在肝细胞癌（HCC）中的诊断潜力。
采用甲基敏感限制性内切酶定量 PCR（MSRE-qPCR）和亚硫酸氢盐基因组测序（BGS）检测 CDKL2 的甲基化状态。采用实时定量 PCR（qPCR）检测 CDKL2 的 mRNA 表达。评估 CDKL2 甲基化与 mRNA 表达、临床病理特征的相关性。
与正常肝组织相比，HCC 组织和细胞系中 CDKL2 的甲基化水平显著升高（均 p<0.05）。并且，受试者工作特征（ROC）分析显示，CDKL2 的高甲基化对区分癌旁非肿瘤组织与 HCC 组织具有高特异性和敏感性。此外，CDKL2 的 mRNA 表达水平在 HCC 组织和细胞系中均低于正常肝组织（均 p<0.05），并且在 HCC 细胞系中，5-氮杂-2'-脱氧胞苷处理可上调其表达。此外，CDKL2 的甲基化与 mRNA 表达呈负相关（p<0.001，r=-0.513），并且与性别（p=0.023）、年龄（p=0.001）和肿瘤大小（p=0.016）有关。
我们的结果表明，CDKL2 启动子的异常高甲基化在肝癌发生中起重要作用，可能是 HCC 诊断的有价值的生物标志物。
