Abdalla Mai, Khairy Eman, Louka Manal L, Ali-Labib Randa, Ibrahim Eman Abdel-Salam
Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Ain Shams University, Abbassia, Cairo, P.O. box 11381, Egypt.
Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Ain Shams University, Abbassia, Cairo, P.O. box 11381, Egypt.
Gene. 2018 May 5;653:65-71. doi: 10.1016/j.gene.2018.02.024. Epub 2018 Feb 9.
Worldwide, hepatocellular carcinoma (HCC) is the major subtype of primary liver cancers. HCC is typically diagnosed late in its course. With respect to cancer, the genomic actions of vitamin D are mediated through binding to the Vitamin D Receptor (VDR), which allows it to modulate the expression of genes in a cell-and tissue-specific manner. Epigenetics is a rapidly evolving field of genetic study applicable to HCC. Changes in DNA methylation patterns are thought to be early events in hepatocarcinogenesis. Curcumin has great potential as an epigenetic agent. Accordingly, the current study has been designed to study the methylation status of VDR gene promoter for the first time in HCC aiming to find its clinical significance and potential screening role in chronic Liver Disease (CLD). Additionally, we aimed to investigate, the effect of Curcumin on HCC cell line, aiming to discover new therapeutic targets through epigenetics. This study was conducted on 45 formalin-fixed, paraffin-embedded liver tissue blocks including 15 HCC samples (group A), 15 CLD samples (group B) and 15 apparently normal tissue taken from around benign lesions (group C). Methylation Specific Restriction Digestion and qPCR were done on all samples after DNA extraction. The percentage of VDR gene promoter methylation was significantly higher in the HCC group compared to both CLD and control groups (p < 0.01). VDR promoter methylation by (MS-qPCR) was decreased and the relative expression of VDR by (qRT-PCR) was markedly increased in a dose-dependent fashion in cells grown in Curcumin-adequate medium. In conclusion, this study may open a new gate for the use of VDR promoter methylation as a potential biomarker in HCC.
在全球范围内，肝细胞癌（HCC）是原发性肝癌的主要亚型。HCC通常在病程晚期才被诊断出来。关于癌症，维生素D的基因组作用是通过与维生素D受体（VDR）结合来介导的，这使得它能够以细胞和组织特异性的方式调节基因表达。表观遗传学是一个迅速发展的适用于HCC的遗传学研究领域。DNA甲基化模式的变化被认为是肝癌发生的早期事件。姜黄素作为一种表观遗传药物具有很大的潜力。因此，本研究首次设计用于研究HCC中VDR基因启动子的甲基化状态，旨在发现其在慢性肝病（CLD）中的临床意义和潜在的筛查作用。此外，我们旨在研究姜黄素对HCC细胞系的影响，旨在通过表观遗传学发现新的治疗靶点。本研究对45个福尔马林固定、石蜡包埋的肝组织块进行，包括15个HCC样本（A组）、15个CLD样本（B组）和15个取自良性病变周围的明显正常组织（C组）。DNA提取后，对所有样本进行甲基化特异性限制性消化和qPCR。与CLD组和对照组相比，HCC组VDR基因启动子甲基化百分比显著更高（p < 0.01）。在添加姜黄素的培养基中生长的细胞中，通过（MS-qPCR）检测的VDR启动子甲基化降低，通过（qRT-PCR）检测的VDR相对表达以剂量依赖性方式显著增加。总之，本研究可能为将VDR启动子甲基化作为HCC潜在生物标志物的应用打开一扇新的大门。
