Role of NKCC1 on Brain Tumor Stem Cell Migration After EGF and Slit-2 Stimulation

描述（申请人提供）：多形性胶质母细胞瘤（GBM）是最常见、最具破坏性的颅内恶性肿瘤，占所有原发性脑肿瘤的20%，中位生存期仅为14个月。肿瘤细胞经常扩散到远离原发肿瘤的地方，单个胶质瘤细胞从肿瘤的总体转移到周围的实质，使得完全的手术切除几乎是不可能的。尽管手术、化疗和放疗取得了进展，但恶性胶质瘤的这种迁移能力对任何潜在的治疗方法都是最大的挑战，剩余侵袭性细胞的生长导致99%的复发率。究竟是什么调控了脑肿瘤细胞的迁移能力尚不完全清楚，需要进一步研究。本研究的主要目的是了解已知的促迁移信号，如表皮生长因子（EGF）和狭缝蛋白与细胞体积调节之间的联系。EGF和Slit蛋白可能通过Akt通路调控GBM源性干细胞的侵袭和迁移能力，进而调控离子共转运NKCC1的激活。我们建议使用各种细胞迁移试验和测量细胞内阴离子浓度来研究导致迁移细胞主要过程延长的侵袭模式和细胞体积变化。这项工作的结果将有助于我们了解脑肿瘤细胞迁移级联机制激活所涉及的下游信号通路。此外，这些知识无疑将导致更好的治疗方案，以取代目前对这种毁灭性疾病的次优治疗方法。

DESCRIPTION (provided by applicant): Glioblastoma multiforme (GBM), the most common and devastating intracranial malignant tumor accounts for 20% of all primary brain tumors and has a median survival rate of only 14 months. Cancer cells often disseminate far from primary tumors and individual glioma cells migrate from the gross tumor into the surrounding parenchyma, making complete surgical resection nearly impossible. This migratory capacity of malignant gliomas represents the greatest challenge to any potential therapy in spite of advances in surgery, chemotherapy and radiotherapy and growth of the remaining invasive cells leads to a recurrence incidence of 99%. What exactly regulates the migratory capacity of brain tumor cells is not fully understood and need to be studied. The main goal of this proposal is to understand the link between known pro- migratory signals such as epidermal growth factor (EGF) and Slit proteins with cell volume regulation. EGF and Slit proteins may play an important role in the modulation of invasive and migratory ability of GBM derived stem cells through Akt pathway that in turn regulates the activation of ion cotransport NKCC1. We propose to study invasive patterns and cell volume changes resulting in the extension of a leading process of a migrating cell, using various cell migration assays and measuring intracellular anion concentration. The results obtained from this work will help us understand the downstream signaling pathways involved in the activation of cascade mechanism responsible for brain tumor cell migration. Further, such knowledge will undoubtedly result in better therapeutic alternatives to current sub-optimal treatments for this devastating disease. PUBLIC HEALTH RELEVANCE: Glioblastoma multiforme (GBM) is the most common and devastating primary malignant tumor. Our project aims to study the migration of GBM-derived Brain Tumor Stem Cells (BTSCs). BTSCs are thought to be responsible for maintaining the bulk of the tumor and to induce recurrence after surgical resection, nevertheless the molecular mechanisms that regulate their migration are not known. In this study, we propose to understand the role of pro-migratory signals in brain tumor invasion in order to increase the available targets to prevent brain tumor dispersal.