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Role of developmental regulated genes in biological properties of medulloblastoma

发育调控基因在髓母细胞瘤生物学特性中的作用

基本信息

批准号：
17591509
负责人：
YOKOTA Naoki
金额：
$ 2.24万
依托单位：
Hamamatsu University School of Medicine
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

Recently, it has been clarified that Wnt and sonic hedgehog signals are involved in medulloblastoma oncogenesis. Beside some other signals, such as Notch, which is known to also have roles in this phenomenon, these signals have cross talk with each other, the molecular mechanisms underlying the oncogenesis have not been fully understood. The other hand, with achievement of the Human Genome Project, human genomic database has been established and several methods, DNA microarray and SAGE, with which most of transcripts can be analyzed at once, have been developed. Moreover the concept of cancer stem cell has been suggested. The evidences of cancer stem cell theory and roles in proliferation, recurrence and/or metastasis were recently reported by some investigators.We have analyzed and identified many developmentally regulated genes in medulloblastoma oncogenesis in human and rodents model animals. To clarify the molecular mechanisms underlying this phenomenon and the effect against the b … More iological properties of medulloblastoma cancer stem cell, we performed further analyses. FACS analyses using anti-CD133 mAb, as a cancer stem cell marker, in medulloblastoma cell lines, Daoy and D286MED. A few cells revealed positive immunoreactivity against the antibody. Furthermore, the expression profile was analyzed in CD133 positive cells enriched medulloblastoma cell line.In silicon analyses using SAGE web site, medulloblastoma predominant developmentally regulated gene, zic1, showed reciprocal expression pattern against cmyc, which highly expressed in medulloblastoma tumor tissue of poor prognosis cases. Therefore we are analyzing role of myc in medulloblastoma oncogenesis using conditional deplete system of siRNA against myc. The stable transformant still have not acquired, this experiment is now on going.We have been establishing stem cell therapy for malignant brain tumor, glioblastoma and medulloblastoma. In that precess, the immortalized cells were found in usual mesenchymal stem cell (MSC) culture. Some clones of immortalized MSC were isolated and developed, and the biological properties were analyzed. It was found that the ability of proliferation, mobility were increased, however, apoptosis and totipotency were decreased. The expression profile was also analyzed in this immortalized MSC. It was revealed that constituents of Wnt, Shh, Notch were up-regulated in immortalized MSC and the expression of stem cell marker, CD133 was dramatically decreased. These results were confirmed using quantitative RT-PCR, western analyses and immunohistochemistry. Allograft analyses, inoculation of the immortalized MSC into the rat brain, revealed that these cells could be engrafted whereas primary MSC could not survived. Less

最近，它已被澄清，Wnt和音刺猬信号参与髓母细胞瘤的肿瘤发生。除了一些其他信号，如Notch，已知也在这种现象中起作用，这些信号彼此之间存在串扰，肿瘤发生的分子机制尚未完全了解。另一方面，随着人类基因组计划的完成，人类基因组数据库的建立，DNA微阵列和SAGE等多种方法的发展，使得大多数转录本的分析可以同时进行。此外，还提出了癌症干细胞的概念。近年来，肿瘤干细胞理论的证据以及干细胞在肿瘤增殖、复发和/或转移中的作用被一些研究者报道，我们在人和啮齿类动物模型中分析和鉴定了许多与髓母细胞瘤发生有关的发育调控基因。为了阐明这种现象的分子机制和对B的影响， ...更多信息对髓母细胞瘤肿瘤干细胞的生物学特性进行了进一步分析。在髓母细胞瘤细胞系Daoy和D286 MED中使用抗CD 133 mAb作为癌症干细胞标志物的FACS分析。少数细胞对抗体呈阳性免疫反应。进一步分析CD 133阳性细胞富集的髓母细胞瘤细胞系中的表达谱，在SAGE网站上的芯片分析中，髓母细胞瘤主要发育调控基因zic 1与c myc呈交互表达模式，c myc在预后不良的髓母细胞瘤组织中高表达。因此，我们正在使用针对myc的siRNA的条件耗尽系统来分析myc在髓母细胞瘤肿瘤发生中的作用。目前还没有获得稳定的干细胞，这项实验正在进行中，我们已经建立了恶性脑肿瘤、胶质母细胞瘤和髓母细胞瘤的干细胞治疗。在此过程中，在通常的间充质干细胞（MSC）培养中发现了永生化细胞。分离培养了部分永生化MSC克隆，并对其生物学特性进行了分析。结果表明，细胞增殖能力、迁移能力增强，细胞凋亡能力和全能性降低。还分析了该永生化MSC中的表达谱。结果显示，永生化MSC中Wnt、Shh、Notch表达上调，干细胞标志物CD 133表达明显降低。这些结果证实了使用定量RT-PCR，Western分析和免疫组织化学。同种异体移植物分析，永生化MSC接种到大鼠脑中，显示这些细胞可以移植，而原代MSC不能存活。少