脱氧核酶靶向EBV-LMP1的分子机制及其生物学效应的研究

项目名称： 脱氧核酶靶向EBV-LMP1的分子机制及其生物学效应的研究

项目编号： No.30873010

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 生物科学

项目作者： 杨力芳

作者单位： 中南大学

项目金额： 30万元

中文摘要： 根据研究计划，本项目深入、系统地研究了靶向EBV-LMP1的脱氧核酶在鼻咽癌中参与调控细胞周期，细胞凋亡和肿瘤侵袭与转移中的分子机制及其生物学意义。主要研究成果包括：（1）阐明了脱氧核酶所致细胞S期阻滞的分子机制,发现其主要通过调节G1/S及G2/M两个细胞周期监测点中的多个蛋白分子及激酶活性，且不依赖于p53。（2）证明了脱氧核通过抑制LMP1介导的EGFR磷酸化对CyclinD1的反式激活从而影响细胞周期。（3）研究发现在鼻咽癌细胞中LMPl能够上调细胞中p53和其下游靶分子Survivin的表达，同时使p53 20位丝氨酸磷酸化以及Survivin的34位苏氨酸磷酸化增加。（4）首次发现脱氧核酶抑制LMP1介导的STAT3 的活化及其705位酪氨酸、727 位丝氨酸磷酸化，同时发现脱氧核酶抑制细胞中VEGF 的表达及分泌活性，并降低鼻咽癌细胞的侵袭能力。（5）PI3K/AKT是LMP1介导的重要信号通路，利用脱氧核酶这种高效的靶向基因沉默技术，构建了靶向AKT1的脱氧核酶，发现其能够抑制鼻咽癌细胞的增殖、促进细胞凋亡。

中文关键词： LMP1; 脱氧核酶;鼻咽癌; 分子机制

英文摘要： According to the research program, the molecular mechanisms and biological significance of the DNAzyme targeting EBV-LMP1 in NPC involved in the regulation of cell cycle, apoptosis and tumor invasion and metastasis was systematically explored in this project. The main advances include: (1) To clarify the molecular mechanism of DNAzyme induced cell arrest in S phase, found that the DNAzyme regulated a number of protein molecules and their kinase activity in the G1/S and G2/M two main monitoring points of cell cycle, and independent on p53. (2)Found that the DNAzyme inhibited the trans-activation of CyclinD1 through LMP1-mediated EGFR phosphorylation and affected the cell cycle. (3) Study found that LMPl could increase p53 and its downstream target molecule Survivin expression in nasopharyngeal carcinoma cells, while maked 20 of p53 serine phosphorylation, and Survivin in 34 threonine phosphorylation increased. (4) Discovered DNAzyme inhibited LMP1-mediated STAT3 activation and its 705 tyrosine, 727 serine phosphorylation, also found that the DNAzyme inhibited VEGF expression and secretion, and reduced the invasion ability of cancer cells. (5) PI3K/AKT is the important LMP1-mediated signaling pathways, used the efficient targeted gene silencing technology,DNAzyme, we designed a DNAzyme targeting AKT1, found that suppressed proliferation and promoted apoptosis in NPC .

英文关键词： LMP1; DNAzyme; NPC; Molecular mechanism