Myopodin in Invasive Prostate Cancers

Myopodin 在侵袭性前列腺癌中的作用

• 批准号: 6678665
• 负责人: JIANHUA LUO
• 金额: $ 26.43万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6678665
• 关键词: SCID mouse; actin binding protein; cell line; cell motility; clinical research; gene deletion mutation; gene expression; human tissue; in situ hybridization; matrigel; microfilaments; molecular oncology; neoplasm /cancer invasiveness; oligonucleotides; polymerization; prostate neoplasms; protein protein interaction; protein structure function; site directed mutagenesis

DESCRIPTION (provided by applicant): Prostate cancer is a disease with considerable biological heterogeneity and clinical aggressiveness. Although prostate cancer is prevalent among elderly population, only a small proportion of prostate cancer become invasive, metastatic and life-threatening. Thus, identifying genes and the underlying mechanisms that convert prostate cancer from a relatively indolent disease to an aggressive one hold the key for reducing the mortality of the disease. Recently, by using "differential subtraction chain", we identified a novel gene named "myopodin" that is frequently deleted in aggressive type of prostate cancer. Regardless of Gleason grade, deletions of myopodin, either partial or complete, correlate with high rate of invasion, metastasis or clinical relapse of prostate cancer. Sequence analysis indicates that myopodin shares significant homology with synaptopodin, a protein expressed in neurons and kidney podocytes and responsible for forming physiological cell-cell contact for these cells. Interestingly, over 90% of the partial deletions of myopodin are located in the region sharing homology with synaptopodin. Overexpression of myopodin in PC-3 or LNCaP cells reduced the invasiveness of these cell lines by 3 fold or more in matrigel traverse analysis, and by 10 fold in tumor growth in vivo. Overexpression of myopodin induces actin bundling and retards migration in PC-3. Yeast two-hybrid and co-immunoprecipitation analyses indicate that myopodin binds zyxin, a critical regulatory protein in actin cytoskeleton reorganization, cell motility and mitosis. In our proposal, we hypothesize that myopodin plays an important role in regulating cell motility, maintaining the integrity of normal cell-cell contacts of prostate epithelium, and inhibits the invasiveness of prostate cancer cells, and propose the following specific aims: 1) to overexpress myopodin in PC-3, Du145 and LNCaP cells and subsequently to test the changes of invasiveness of these cells through anchorage independent growth assay, matrigel traverse analysis, diaphragm invasion analysis, metastasis assay and metalloproteinase assays; 2) to define the motifs and minimal domain of myopodin essential for regulation of invasion by constructing arrays of deletion mutants and test their ability to regulate invasiveness; 3) to identify the functional significance of myopodin/zyxin interaction by focusing on cell motility and cytoskeleton re-organization related analysis on myopodin transformed cells; and 4) To identify potential effector genes that might mediate the biological function of myopodin through a comprehensive analysis of gene expression of myopodin expressing cells.

描述（由申请人提供）：前列腺癌是一种具有相当大的生物异质性和临床侵略性的疾病。尽管前列腺癌在老年人群中普遍存在，但只有一小部分前列腺癌变得侵入性，转移性和威胁生命。因此，鉴定基因和将前列腺癌从相对懒惰疾病转化为侵略性疾病的基因机制是降低疾病死亡率的关键。最近，通过使用“差异减法链”，我们确定了一种名为“肌杜以植物”的新基因，该基因经常以侵略性的前列腺癌类型被删除。不管格里森级如何，部分或完整的肌无法缺失，都与前列腺癌的浸润，转移或临床复发率高有关。序列分析表明，肌无法与突触蛋白具有显着同源性，突触蛋白是一种在神经元和肾足细胞中表达的蛋白质，并负责形成这些细胞的生理细胞 - 细胞接触。有趣的是，超过90％的肌无法分解的肌无能的部分位于该区域与突触蛋白共享同源性的区域。 PC-3或LNCAP细胞中肌无毒素的过表达可通过3倍或更多的Matrigel遍历分析中的3倍或更多，而体内肿瘤生长的10倍。肌无素的过表达诱导肌动蛋白捆绑并在PC-3中迁移。酵母两杂交和共免疫沉淀分析表明，肌量蛋白结合Zyxin，Zyxin是肌动蛋白细胞骨架重组，细胞运动和有丝分裂的关键调节蛋白。在我们的提案中，我们假设肌无法蛋白在调节细胞运动，保持前列腺上皮细胞正常细胞接触的完整性中起着重要作用，并抑制前列腺癌细胞的侵入性，并提出以下特定目的：1） PC-3，DU145和LNCAP细胞中的肌无法通过锚定独立生长测定，基质纤维穿越分析，隔膜侵袭分析，转移测定和金属蛋白酶测定法测试这些细胞侵入性的变化； 2）通过构造缺失突变体的阵列并测试其调节侵入性的能力，定义了肌无能的基序和最小界面的肌无能素； 3）通过重点关注细胞运动性和对肌动物转化细胞的细胞骨架重新组织分析，以确定肌无毒素/Zyxin相互作用的功能意义； 4）鉴定可能通过对肌霉素表达细胞的基因表达的全面分析来介导肌无法介导的潜在效应基因。