PDF(Pubmed)
Abstract：
Ovarian cancer, among all gynecologic malignancies, exhibits the highest incidence and mortality rate, primarily because it is often presents with non-specific or no symptoms during its early stages. For the advancement of Ovarian Cancer Diagnosis, it is crucial to identify the potential molecular signatures that could significantly differentiate between healthy and ovarian cancerous tissues and can be used further as a diagnostic biomarker for detecting ovarian cancer. In this study, we investigated the genome-wide methylation patterns in ovarian cancer patients using Methylated DNA Immunoprecipitation (MeDIP-Seq) followed by NGS. Identified differentially methylated regions (DMRs) were further validated by targeted bisulfite sequencing for CpG site-specific methylation profiles. Furthermore, expression validation of six genes by Quantitative Reverse Transcriptase-PCR was also performed. Out of total 120 differentially methylated genes (DMGs), 68 genes were hypermethylated, and 52 were hypomethylated in their promoter region. After analysis, we identified the top 6 hub genes, namely POLR3B, PLXND1, GIGYF2, STK4, BMP2 and CRKL. Interestingly we observed Non-CpG site methylation in the case of POLR3B and CRKL which was statistically significant in discriminating ovarian cancer samples from normal controls. The most significant pathways identified were focal adhesion, the MAPK signaling pathway, and the Ras signaling pathway. Expression analysis of hypermethylated genes was correlated with the downregulation of the genes. POLR3B and GIGYF2 turned out to be the novel genes associated with the carcinogenesis of EOC. Our study demonstrated that methylation profiling through MeDIP-sequencing has effectively identified six potential hub genes and pathways that might exacerbate our understanding of underlying molecular mechanisms of ovarian carcinogenesis.
摘要：
卵巢癌,在所有妇科恶性肿瘤中，发病率和死亡率最高，主要是因为它通常在早期阶段表现为非特异性或无症状。对于卵巢癌诊断的进展，鉴定能够显著区分健康组织和卵巢癌组织的潜在分子特征是至关重要的,并且可以进一步用作检测卵巢癌的诊断生物标志物.在这项研究中,我们使用甲基化DNA免疫沉淀(MeDIP-Seq)和NGS研究了卵巢癌患者的全基因组甲基化模式.通过针对CpG位点特异性甲基化谱的靶向亚硫酸氢盐测序进一步验证鉴定的差异甲基化区(DMRs)。此外，还通过定量逆转录酶-PCR对六个基因进行了表达验证。在总共120个差异甲基化基因（DMG）中，68个基因高度甲基化，和52在其启动子区域低甲基化。经过分析,我们确定了前6个中心基因，即POLR3B，PLXND1、GIGYF2、STK4、BMP2和CRKL。有趣的是，我们在POLR3B和CRKL的情况下观察到非CpG位点甲基化，这在区分卵巢癌样品与正常对照中具有统计学意义。确定的最重要的途径是粘着斑，MAPK信号通路，和Ras信号通路。高甲基化基因的表达分析与基因的下调相关。POLR3B和GIGYF2被证明是与EOC致癌相关的新基因。我们的研究表明，通过MeDIP测序的甲基化分析已经有效地确定了六个潜在的枢纽基因和通路，这可能会加剧我们对卵巢癌发生的潜在分子机制的理解。
