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

项目总结/摘要 原发性和继发性脑肿瘤进展的微环境决定因素不完全 明白神经元活动正在成为脑癌行为的关键调节因子。我们最近展示了 活跃的神经胶质细胞能神经元通过活性- 生长因子的依赖性分泌-包括神经连接素-3（NLGN 3）-其通过激活向胶质瘤发出信号 PI 3 K/AKT信号通路NLGN 3的活性调节释放促进生长，也是胶质瘤所需的 进展，表明其在神经胶质瘤病理生理学中的基本作用，并不完全解释 单独刺激经典致癌信号通路。我们之前已经证明神经配素-3也 神经胶质瘤诱导大量突触基因的表达，提高了神经胶质瘤可能参与 突触通讯在这里，我们使用电生理学和钙成像技术来说明， 神经胶质瘤的相互作用包括通过真正的AMPA受体的电化学通讯， 依赖性神经元-胶质瘤突触，导致兴奋性突触后电流和胶质瘤去极化 细胞用体内光遗传学评估的胶质瘤膜去极化促进胶质瘤进展 类似于在正常神经前体细胞中的公认效应。一致地，遗传或 神经胶质瘤能信号传导的药理学阻断抑制神经胶质瘤生长。现场记录显示 神经胶质瘤浸润大脑的兴奋性增加，强调了正反馈机制， 神经胶质瘤增加神经元兴奋性，从而增加活性调节的神经胶质瘤生长。总之，这些发现 这表明胶质瘤突触和电整合到神经元能神经回路中促进肿瘤 进展，并阐明了以前未开发的潜力，针对胶质瘤电路动力学的癌症 疗法该提案旨在进一步阐明活性介导的脑肿瘤生长的复杂机制。 使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-胶质瘤信号机制调控胶质瘤生长及胶质瘤细胞凋亡 对肿瘤微环境中整体神经元兴奋性的影响;（2）定义动态脑回路 绘制不同神经元亚群对胶质瘤进展的贡献;（3）扩大我们的理解 神经元活动对非胶质源性继发性脑癌的影响，从而提供了新的见解 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，映射神经元和脑癌之间的串扰，可用于阐明 有前途的新治疗策略。因此，本提案中提出的实验和培训将回答 基本问题，在这一新兴领域的神经调节癌症，而显着帮助我 职业发展和学术独立过渡。

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.