Hua Tian, Kang Shan, Li Xiao-Fei, Tian Yun-Jie, Li Yan
Department of Gynaecology, Affiliated Xing Tai People Hospital of Hebei Medial University, Xingtai, China.
Department of Obstetrics and Gynaecology, Hebei Medical University, Fourth Hospital, Shijiazhuang, China.
J Obstet Gynaecol Res. 2021 Mar;47(3):1031-1039. doi: 10.1111/jog.14634. Epub 2021 Jan 5.
Platinum-based chemotherapy is widely used for epithelial ovarian cancer (EOC). As high as 20-25% of EOC patients will not respond to the initial chemotherapy. Accumulated evidences have implied that DNA methylation may serve as a potential bio-marker for chemotherapy-resistant phenotypic screening; however, the pattern underlying primary platinum resistance remains unclear.
Reduced representation bisulfite sequencing (RRBS) analysis was performed to identify differences in methylation status between primary platinum-resistant patients Progression free survival (PFS) (PFS < 6 months, n = 8) and extreme sensitive patients (PFS ≥ 24 months, n = 8). The Qubit 3.0 Fluorometer was used for the quantification of RRBS library. The RRBS library was sequenced on Illumina HiSeq2500 sequencer as 50 bp paired-end reads.
After screening, 94 valid hyper-/hypo-methylated regions were identified to be located within 94 gene promoter and exon regions (adjusted q ≤ 0.5), which were primarily associated with cell-cell adhesion, B cell activation and lymphocyte activation according to GO analysis. The 19 differentially methylated regions (DMR) located in the promoter region including TRC-GCA11-1, LOC105370912, ANO7P1, DHX4,MSH2, CDCP2, CCNL1, ARHGAP42P2, PRDM13, LOC101928344, USP29, ZIC5,IL1RAPL1, EVX2, ABR, MGRN1, UBALD1, LINC00261, and ISL2 were identified according to the order of P-values from low to high, of which MSH2, LINC00261, MGRN1, ZIC5, EVX2, CCNL1, and DHX40 were presented to play a variety of roles in cancers process based on the previous studies.
DNA methylome profiling based on RRBS assay is an effective method for screening aberrantly methylated genes in primary platinum-resistant patients, which may serve as a potential epigenetic bio-marker for the prediction of primary platinum resistance.
铂类化疗广泛应用于上皮性卵巢癌（EOC）。高达20%-25%的EOC患者对初始化疗无反应。越来越多的证据表明，DNA甲基化可能作为化疗耐药表型筛查的潜在生物标志物；然而，原发性铂耐药的潜在模式仍不清楚。
采用简化代表性亚硫酸氢盐测序（RRBS）分析，以确定原发性铂耐药患者（无进展生存期（PFS）<6个月，n=8）和极度敏感患者（PFS≥24个月，n=8）之间甲基化状态的差异。使用Qubit 3.0荧光计对RRBS文库进行定量。RRBS文库在Illumina HiSeq2500测序仪上进行测序，读取50bp的双端读数。
筛选后，共鉴定出94个有效的高/低甲基化区域，位于94个基因启动子和外显子区域内（校正q≤0.5），根据基因本体（GO）分析，这些区域主要与细胞间粘附、B细胞活化和淋巴细胞活化相关。根据P值从低到高的顺序，鉴定出位于启动子区域的19个差异甲基化区域（DMR），包括TRC-GCA11-1、LOC105370912、ANO7P1-DHX4、MSH2、CDCP2、CCNL1、ARHGAP42P2、PRDM13、LOC101928344、USP29、ZIC5、IL1RAPL1、EVX2、ABR、MGRN1、UBALD1、LINC00261和ISL2，其中根据先前研究，MSH2、LINC00261、MGRN1、ZIC5、EVX2、CCNL1和DHX4在癌症发生过程中发挥多种作用。
基于RRBS分析的DNA甲基化组分析是筛选原发性铂耐药患者异常甲基化基因的有效方法，这些基因可能作为预测原发性铂耐药的潜在表观遗传生物标志物。
