Carcinogenesis of Intraductal Papillary Mucinous Neoplasm of the Pancreas: Loss of MicroRNA-101 Promotes Overexpression of Histone Methyltransferase EZH2
Carcinogenesis of Intraductal Papillary Mucinous Neoplasm of the Pancreas: Loss of MicroRNA-101 Promotes Overexpression of Histone Methyltransferase EZH2
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DOI：
10.1245/s10434-011-2068-6
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发表时间：
2012-07-01
影响因子：
3.7
通讯作者：
Baba, Hideo
中科院分区：
文献类型：
--
作者：
Nakahara, Osamu;Takamori, Hiroshi;Baba, Hideo
背景。 IPMN 的致癌机制目前尚不清楚。本研究旨在确定EZH2的表达是否促进IPMN和PDCA的肿瘤进展，并阐明miR-101对EZH2表达的调节。方法。通过 PCR 和蛋白质印迹法研究了 8 种人胰腺癌细胞系中的 EZH2 mRNA 和蛋白表达。将前 miR-101 和抗 miR-101 转染至胰腺癌细胞中，以阐明 miR-101 对 EZH2 的调节。为了评估EZH2是否调节IPMN的恶性进展，通过免疫组织化学检查IPMN中EZH2的表达。接下来，我们使用激光捕获显微切割从 IPMN 的 FFPE 样品中收集恶性和良性细胞并提取 RNA。使用实时 PCR 评估 IPMN 中的 miR-101 表达。结果。所有胰腺癌细胞系均表达 EZH2 mRNA 和蛋白质。与对照相比，在MIA PaCa-2中转染pre-miR-101诱导miR-101与EZH2蛋白产量的减少密切相关，而EZH2 mRNA的表达几乎没有差异。抗miR-101转染的胰腺癌细胞显示EZH2蛋白增加，而EZH2 mRNA水平没有升高。免疫组织化学显示EZH2在恶性IPMN中的表达显着高于良性IPMN。恶性IPMN中miR-101的表达显着低于良性IPMN。结论。 MiR-101 在转录后水平靶向 EZH2，miR-101 的缺失可能通过 EZH2 的上调触发 IPMN 的腺癌序列。这项研究表明 miR-101-EZH2 阻断可作为 IPMN 致癌的潜在治疗靶点。
Background. The mechanisms of IPMN carcinogenesis are as yet unclear. This study aimed to determine whether expression of EZH2 promotes neoplastic progression of IPMN and PDCA, and to elucidate regulation of EZH2 expression by miR-101.Methods. EZH2 mRNA and protein expression were investigated in 8 human pancreatic cancer cell lines by PCR and western blotting. Pre-miR-101 and anti-miR-101 were transfected into pancreatic cancer cells to elucidate EZH2 regulation by miR-101. To evaluate whether EZH2 modulates malignant progression of IPMN, EZH2 expression in IPMN was examined by immunohistochemistry. Next, we collected malignant and benign cells from FFPE samples of IPMNs using laser capture microdissection and extracted the RNA. miR-101 expression in IPMN was assessed using real-time PCR.Results. All pancreatic cancer cell lines expressed EZH2 mRNA and protein. The induction of miR-101 by transfection of pre-miR-101 in MIA PaCa-2 was closely related to a reduction in EZH2 protein production compared with control, whereas there was little difference in the expression of EZH2 mRNA. Anti-miR-101 transfected pancreatic cancer cells showed an increase in EZH2 protein, while the level of EZH2 mRNA was not elevated. Immunohistochemistry revealed that the expression of EZH2 was significantly higher in malignant than benign IPMN. Expression of miR-101 was significantly lower in malignant IPMN than benign IPMN.Conclusions. MiR-101 targets EZH2 at the posttranscriptional level, and loss of miR-101 could be a trigger for the adenomacarcinoma sequence of IPMN by upregulation of EZH2. This study suggests miR-101-EZH2 blockade as a potential therapeutic target in IPMN carcinogenesis.