ADAM 17 and glioma-tumor progression and treatment

描述(申请人提供)：目前还没有治疗多形性胶质瘤的方法可以显著延长患者的生命。无法有效治疗胶质瘤的原因仍不清楚。在这项建议中，基于可靠的初步数据，我们提出了一个新的假设，即该酶，去整合素和金属蛋白酶-17，也被称为肿瘤坏死因子转换酶(ADAM17，TACE)，促进胶质瘤的侵袭，增殖和生存。因此，抑制ADAM17将有效地抑制肿瘤的生长。我们提出了三个特定的目标和相应的假设，旨在充分研究ADAM17作为促肿瘤药物的潜力和抑制ADAM17作为抗肿瘤治疗的可能性。目的1：研究ADAM17在胶质瘤体外侵袭、增殖、存活及体内肿瘤进展中的作用。假设1a：ADAM17活性增加在体外诱导胶质瘤细胞侵袭，促进细胞增殖和存活，促进体内肿瘤进展。假设1b：ADAM17激活表皮生长因子(EGF)信号通路，通过刺激PI3K/Akt通路，促进胶质瘤的侵袭、细胞增殖和存活。目的：探讨ADAM17在低氧应激条件下脑胶质瘤发生发展中的作用。假设2：ADAM17转录和蛋白分解活性在低氧诱导的细胞应激下上调，这种上调导致胶质瘤的增殖、侵袭性和存活率增加。目的：探讨ADAM17靶向RNAi基因治疗裸鼠移植瘤U87和HF66的疗效。假设3：靶向ADAM17的RNAi基因治疗降低了胶质瘤细胞内ADAM17的表达和蛋白分解活性，从而减缓了肿瘤的进展，延长了荷瘤裸鼠的生存时间。在拟议的研究中，采用了胶质瘤的体外和体内模型。方法从siRNA到激光捕获共聚焦显微镜和磁共振成像，努力剖析ADAM17在肿瘤进展中的作用，阐明肿瘤进展和有效治疗的分子基础。我们的长期目标是为这种毁灭性的脑瘤开发一种有效的治疗方法，并将我们的发现从实验系统转化到人类身上。公共卫生相关性：该项目旨在研究去整合素和金属蛋白酶-17(ADAM17/TACE)蛋白分解在多形性胶质母细胞瘤肿瘤进展中的作用。ADAM17在肿瘤细胞增殖和侵袭中的作用将被阐明，特别是由于低葡萄糖和低氧可获得性而诱导ADAM17的作用。我们将确定ADAM17活性的中断或增强是否会导致肿瘤进展的变化，以及ADAM17沉默基因治疗是否在人脑胶质瘤的小鼠模型中提供治疗效果。

DESCRIPTION (provided by applicant): There are no treatments of glioma multiforme that substantially extend life. The reasons behind the inability to effectively treat glioma remain obscure. In this proposal, based on robust preliminary data, we develop a novel hypothesis, that the enzyme, a disintegrin and metalloproteinase-17, also known as, tumor necrosis factor converting enzyme (ADAM17, TACE) fosters glioma invasion, proliferation and survival. Thereby inhibition of ADAM17 will be effective in reducing tumor growth. We propose three specific aims and corresponding hypotheses, directed at fully investigating the potential of ADAM17 as a pro tumorgenic agent and inhibition of ADAM17 as an anti-tumor treatment. Aim 1: Characterize the function of ADAM17 in glioma invasion, proliferation and survival in vitro, and in tumor progression in vivo. Hypothesis 1a: Increased ADAM17 activity induces invasion and promotes cell proliferation and survival of glioma cells in vitro and promotes tumor progression in vivo. Hypothesis 1b: ADAM17 activation of the epidermal growth factor (EGF) signaling pathway promotes glioma invasion, cell proliferation and survival, by stimulating the PI3K/Akt pathway. Aim 2: Investigate the role of ADAM17 in glioma progression in the context of hypoxic stress. Hypothesis 2: ADAM17 transcription and proteolytic activity are up-regulated by hypoxia-induced cellular stress, and this increase leads to enhanced glioma proliferation, invasiveness and survival. Aim 3: Investigate the therapeutic effectiveness of ADAM17-targeting RNAi gene therapy to treat U87 and HF66 human glioma xenographs in nude mouse models. Hypothesis 3: ADAM17-targeting RNAi gene therapy decreases ADAM17 expression and proteolytic activity within glioma cells, and thus reduces tumor progression and prolongs survival of nude mice bearing intracranial glioma xenographs. Both in vitro and in vivo models of glioma are employed in the proposed studies. Methods used range from siRNA to laser capture confocal microscopy and magnetic resonance imaging in an effort to dissect the contribution of ADAM17 to tumor progression and to elucidate the molecular bases for tumor progression and effective treatment. Our long term goal is to develop an effective treatment for this devastating brain tumor and to translate our findings from the experimental system to the human. PUBLIC HEALTH RELEVANCE: This project is designed to investigate the function of a disintegrin and metalloprotease-17 (ADAM17/TACE) proteolysis in glioblastoma multiforme tumor progression. The contribution of ADAM17 to tumor cell proliferation and invasion will be elucidated, with a special focus upon ADAM17 induction due to low glucose and oxygen availability. We will determine whether disruption or augmentation of ADAM17 activity lead to changes in tumor progression, and whether ADAM17-silencing gene therapy provides a therapeutic effect in a mouse model of human glioma.