Prognostic and therapeutic value of disruptor of telomeric silencing-1-like (DOT1L) expression in patients with ovarian cancer.
Prognostic and therapeutic value of disruptor of telomeric silencing-1-like (DOT1L) expression in patients with ovarian cancer.
复制标题
端粒沉默-1样干扰物（DOT1L）表达对卵巢癌患者的预后和治疗价值
DOI：
10.1186/s13045-017-0400-8
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发表时间：
2017-01-23
影响因子：
28.5
通讯作者：
Gao Q
中科院分区：
文献类型：
--
作者：
Zhang X;Liu D;Li M;Cao C;Wan D;Xi B;Li W;Tan J;Wang J;Wu Z;Ma D;Gao Q
表观遗传学已被认为在调节恶性表型方面起着关键作用。本研究检测正常卵巢组织和卵巢肿瘤组织中组蛋白3赖氨酸79甲基转移酶(DOT1L)和H3K79甲基化的表达，探讨DOT1L在卵巢癌中的作用及其机制。方法采用免疫组织化学方法检测250例卵巢肿瘤和24例正常卵巢组织中DOT1L和H3K79甲基化的表达。用CCK8、集落形成和流式细胞仪检测DOT1L对体外培养细胞增殖的影响。用染色质免疫沉淀结合高通量测序(CHIP-SEQ)和CHIP-PCR确定DOT1L靶向基因。实时定量聚合酶链式反应和免疫印迹法检测基因表达水平。结果卵巢恶性肿瘤组织中DOT1L基因表达和H3K79甲基化水平显著升高。DOT1L的高表达与国际妇产科联合会(FIGO)的分期、组织学分级和淋巴转移有关。DOT1L是影响卵巢癌总生存期(OS)和无进展生存期(PFS)的独立预后因素，DOT1L高表达与OS和PFS差相关。此外，DOT1L通过H3K79二甲基化调控G1期基因CDK6和CCND3的转录，因此阻断DOT1L可导致G1期细胞停滞，从而阻碍体外细胞增殖和体内肿瘤生长。结论DOT1L过表达在卵巢癌中具有重要的临床意义，并阐明了DOT1L通过H3K79甲基化对CDK6和CCND3的转录调控推动细胞周期进展，提示DOT1L可能成为卵巢癌预后评估和治疗干预的潜在靶点。
BackgroundEpigenetics has been known to play a critical role in regulating the malignant phenotype. This study was designed to examine the expression of DOT1L (histone 3 lysine 79 methyltransferase) and H3K79 methylation in normal ovarian tissues and ovarian tumors and to explore the function of DOT1L and its underline mechanisms in ovarian cancer.MethodsThe expression of DOT1L and H3K79 methylation in 250 ovarian tumor samples and 24 normal ovarian samples was assessed by immunohistochemistry. The effects of DOT1L on cell proliferation in vitro were evaluated using CCK8, colony formation and flow cytometry. The DOT1L-targeted genes were determined using chromatin immune-precipitation coupled with high-throughput sequencing (ChIP-seq) and ChIP-PCR. Gene expression levels were measured by real-time PCR and immunoblotting. The effects of DOT1L on tumor growth in vivo were evaluated using an orthotopic ovarian tumor model.ResultsDOT1L expression and H3K79 methylation was significantly increased in malignant ovarian tumors. High DOT1L expression was associated with International Federation of Gynecology and Obstetrics (FIGO) stage, histologic grade, and lymphatic metastasis. DOT1L was an independent prognostic factor for the overall survival (OS) and progression-free survival (PFS) of ovarian cancer, and higher DOT1L expression was associated with poorer OS and PFS. Furthermore, DOT1L regulates the transcription of G1 phase genes CDK6 and CCND3 through H3K79 dimethylation; therefore, blocking DOT1L could result in G1 arrest and thereby impede the cell proliferation in vitro and tumor growth in vivo.ConclusionsOur findings first demonstrate that DOT1L over-expression has important clinical significance in ovarian cancer and also clarify that it drives cell cycle progression through transcriptional regulation of CDK6 and CCND3 through H3K79 methylation, suggesting that DOT1L might be potential target for prognostic assessment and therapeutic intervention in ovarian cancer.