Microenvironment-driven electrical regulation of primary and secondary brain tumor progression

项目摘要/摘要 原发和继发脑肿瘤进展的微环境决定因素不完全 明白了。神经元活动正在成为脑癌行为的关键调节因素。我们最近展示了 激活的谷氨酸能神经元通过激活谷氨酸能神经元对高级别胶质瘤(HGG)发挥有丝分裂作用。 依赖于生长因子的分泌，包括神经连接蛋白-3(NLGN3)-通过激活向胶质瘤发出信号 PI3K/AKT信号转导通路。NLGN3的活性调节释放促进生长，对胶质瘤也是必需的 进展，表明其在胶质瘤病理生理学中的基础作用，并不完全由 单独刺激经典致癌信号通路。我们之前证明了神经连接蛋白-3还 诱导胶质瘤多种突触基因的表达，增加了胶质瘤参与 突触交流。在这里，我们使用电生理学和钙成像技术来说明 神经元-胶质瘤的相互作用包括通过真正的AMPA受体- 依赖性神经元-胶质瘤突触，导致神经胶质瘤兴奋性突触后电流和去极化 细胞。用在体光遗传学评估的胶质瘤膜去极化促进了胶质瘤的进展 类似于在正常神经前体细胞中已经确立的效应。一致地，遗传的或 药物阻断谷氨酸能信号可抑制胶质瘤的生长。现场录音显示 增加了胶质瘤浸润性脑中的兴奋性，强调了通过以下方式的正反馈机制 胶质瘤增加了神经元的兴奋性，从而调节了神经胶质瘤的生长。总而言之，这些发现 提示神经胶质瘤突触与谷氨酸能神经回路的电整合促进肿瘤的发生 肿瘤靶向神经胶质瘤回路动力学的研究进展 心理治疗。这项建议旨在进一步阐明活性介导的脑瘤生长的复杂机制。 利用先进的系统级神经科学技术，拟议的实验将(1)阐明 GABA能信号通过直接神经元-胶质瘤信号机制调节胶质瘤生长 肿瘤微环境对整体神经元兴奋性的影响；(2)定义动态全脑回路 映射不同神经元亚群对胶质瘤进展的影响；(3)扩大我们的理解 神经元活动对非神经胶质来源继发性脑癌的影响，从而提供了新的见解 研究转移性癌症用来播种和定居大脑微环境的机制。这些研究 将开发一个框架，绘制神经元和脑癌之间的串扰图，可能用于阐明 前景看好的新治疗策略。因此，本提案中提出的实验和培训将回答 在癌症神经调节这一新兴领域的基本问题，同时在我的 职业发展和学术向独立的过渡。

Project Summary/Abstract Microenvironmental determinants of primary and secondary brain tumor progression are incompletely understood. Neuronal activity is emerging as a critical regulator of brain cancer behavior. We recently showed that active glutamatergic neurons exert a mitogenic effect on high-grade glioma (HGG) through activity- dependent secretion of growth factors - including neuroligin-3 (NLGN3) - which signals to glioma via activation of the PI3K/AKT pathway. Activity-regulated release of NLGN3 promotes growth and is also required for glioma progression, indicating its fundamental role in glioma pathophysiology and is incompletely explained by stimulation of classical oncogenic signaling pathways alone. We previously demonstrated that neuroligin-3 also induces glioma expression of numerous synaptic genes, raising the possibility that gliomas may engage in synaptic communication. Here, we illustrate using electrophysiology and calcium imaging techniques that neuron-glioma interactions include electrochemical communication through bona fide AMPA receptor- dependent neuron-glioma synapses, resulting in excitatory post-synaptic currents and depolarization of glioma cells. This glioma membrane depolarization assessed with in vivo optogenetics promotes glioma progression similarly to the well-established effect in normal neural precursor cells. Concordantly, genetic or pharmacological blockade of glutamatergic signaling inhibits glioma growth. Field recordings demonstrate increased excitability in the glioma-infiltrated brain, emphasizing the positive feedback mechanisms by which gliomas increase neuronal excitability and thereby activity-regulated glioma growth. Together, these findings indicate that synaptic and electrical integration of glioma into glutamatergic neural circuitry promotes tumor progression and elucidates the previously unexplored potential of targeting glioma circuit dynamics for cancer therapy. This proposal aims to further clarify the complex mechanisms of activity-mediated brain tumor growth. Using advanced systems-level neuroscience techniques, the proposed experiments will (1) clarify the role of GABA-ergic signaling in regulating glioma growth through direct neuron-glioma signaling mechanisms and the effect on overall neuronal excitability in the tumor microenvironment; (2) define the dynamic brain-wide circuit mapping of different neuronal subpopulations contributing to glioma progression; (3) expand our understanding of the influence of neuronal activity on non-glial derived secondary brain cancers, thus providing novel insight into the mechanisms metastatic cancers utilize to seed and colonize the brain microenvironment. These studies will develop a framework which maps crosstalk between neurons and brain cancers that may be used to elucidate promising new therapeutic strategies. The experiments and training presented in this proposal will thus answer fundamental questions in this emerging field of the neural regulation of cancers, while significantly aiding in my career development and academic transition to independence.