Clarification on roles of p16 and Survivin in multinuclearity and mitotic cell death of malignant glioma

阐明p16和Survivin在恶性胶质瘤多核和有丝分裂细胞死亡中的作用

基本信息

批准号：
18591591
负责人：
SUGIYAMA Kazuhiko
金额：
$ 2.45万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

Suboellularly localized (nuclear and/or cytoplasmic) survivin has various functions, and correlates with prognosis of malignant tumors. However there have been no reports about the significance of subcellularly localized survivin in high-grade astrocytomas. The aim of the our first paper was to examine the relationship between prognosis and subcellular localization of survivin in high-grade astrocytoma. Methods We immunohistochemically examined the pattern of subcellular localization of survivin expression (nuclear, cytoplasmic, or both)in 51 patients with highgrade astrocytoma (19 anaplastic astrocytomas; 32 glioblastomas). We statistically examined the relationship between survivin localization and prognosis, using multivariate analysis including other clinicopathological factors (age, sex, WHOgrade, extent of resection, MEB-1 labeling hide, and expression of p53 and epidermal growth factor receptor). Results All specimens stained positive for survivinilocalized in nucleus only (nucl … More ear-positive group), 10cases (20%); localized in cytoplasm only (cytoplasmicpositive group), 23cases (45%); simultaneous expression in nucleus and cytoplasm (nuclear-cytoplasmic group), 19cases (35%). There was no significant difference in prognosis between the nuclear-positive group and cytoplasmic-positive group (P=0.796). However, the nuclear-cytoplasmic group had significantly shorter overall survival than the nuclear-positive group and the cytoplasmic-positive group (P<0.0001). Conclusions We found that simultaneous expression of survivin in both the nucleus and cytoplasm is an important prognostic factor for high-grade astrocytoma. The present findings indicate that subcelluliar localization of survivin expression is a reliable prognostic factor for patients with this tumor.Furthermore, survivin, a regulator of chromosome segregation, is highly expressed and known to induce radioresistance in human gliomas. In second paper, we examined the effect of survivin suppression on radiosensitivity in malignant glioma cells, while focusing on centrosome aberration and chromosome instability (CIN). We suppressed survivin by small interfering RNA transktion, and examined the radiosensitivity using a clonogenic assay and a trypan blue exclusion assay in U251MG (p53mutant) and D54MG (p53 wild type) cells. To assess the CIN status, we determined the number of centrosomes using an immunolluorescence analysis, and the centromeric copy number by fluorescence in situ hybridisation. As a result, the radiosensitisation differed regarding the p53 status as U251MG cells quickly developed extreme centrosome amplification (1/4CIN) and enhanced the radiosensitivity, while centrosome amplification and radiosensitivity increased more gradually in D54MG cells. TUNED assay showed that survivin inhibition did not lead to apoptosis after irradiation. This cell death was accompanied by an increased degree of aneuploidy, suggesting mitotic cell death. Therefore, survivin inhibition may be an attractive therapeutic target to overcome the radioresistance while, in addition, proper attention to CIN (centrosome number) is considered important for improving radiosensitivity in human glioma. Less

亚细胞局部（核和/或细胞质）Survivin具有各种功能，并且与恶性肿瘤的预后相关。然而，没有关于高级星形胶质细胞瘤中细胞局部遗传的重要性的报道。第一篇论文的目的是检查高级星形胶质细胞瘤中Survivin的预后和亚细胞定位之间的关系。方法我们在51例较高的星形胶质细胞瘤患者（19例那间层状星形胶质细胞瘤； 32个胶质母细胞瘤）中进行了免疫组织化学检查生存表达（核，细胞质或两者兼有核，细胞质或两者）的亚细胞定位模式。我们使用多变量分析（包括其他临床病理因素（年龄，性别，性别，whograde，切除程度，MEB-1标记隐藏）以及p53的表达和表皮生长因子受体的表达），使用多元病理因素（年龄，性别，性别，切除范围，MEB-1标记和表皮生长因子受体表达），统计检查了生存定位与预后之间的关系。结果所有标本仅在核中仅在核中染色阳性（nucl…更多的耳阳性组），10例（20％）；仅在细胞质（细胞质阳性组）中定位，23例（45％）；核和细胞质（核总质组）中的简单表达，19例（35％）。核阳性组和细胞质阳性基团之间的预后没有显着差异（p = 0.796）。然而，核总质基的总生存率明显短于核阳性基团和细胞质阳性基团（p <0.0001）。结论我们发现，在核和细胞质中，Survivin的简单表达是高级星形胶质细胞瘤的重要预后因素。目前的发现表明，对于这种肿瘤的患者而言，Survivin表达的亚细胞定位是可靠的预后因素。Furthermore，Survivin，Survivin是染色体隔离的调节剂，高度表达并已知可以在人gliomas中诱导放射线。在第二篇论文中，我们研究了抑制survivin对恶性神经胶质瘤细胞放射敏性的影响，同时着重于中心体畸变和染色体不稳定性（CIN）。我们通过小型干扰RNA transktion抑制了Survivin，并使用Clogenic测定法检查了放射敏性，并在U251MG（p53mutant）和D54MG（p53野生型）中进行了锥虫蓝色排除测定法。为了评估CIN状态，我们使用免疫荧光分析确定了中心体的数量，以及通过荧光原位杂交确定了丝粒拷贝数。结果，随着U251MG细胞迅速发展出极端的中心体扩增（1/4cin），并增强了放射敏感性，而在D54MG细胞中逐渐增长了放射线敏感性。调谐测定表明，辐照后，生存抑制不会导致凋亡。该细胞死亡是通过增加的非整倍性来进行的，表明有丝分裂细胞死亡。因此，Survivin抑制作用可能是克服放射线的有吸引力的治疗靶标，而此外，对CIN（中心体数）的适当关注对于改善人神经胶质瘤的放射性敏感性很重要。较少的