Implications of Circadian Clock Control on Glioblastoma

项目摘要/摘要 尽管多形性胶质母细胞瘤(GBM)具有完整的特征，但它仍然是最常见的肿瘤之一 恶性原发脑瘤。目前，患者的预后仍然很差，因为对基底膜的治疗已经 即使使用积极的多式联运也只能适度提高存活率和生活质量 治疗。GBM独特的异质性遗传、表观遗传和微环境特征以及 大脑使肿瘤对治疗其他癌症非常有效的治疗方法产生抗药性 纸巾。特别是，GBM含有癌症干细胞，称为胶质母细胞瘤干细胞(GSCs)，它们是自我- 更新和致瘤，从而支持原发肿瘤的进展和生长，即使在 手术切除。GSCs有能力主动重塑肿瘤微环境并接收 从它们周围的环境中寻找维护线索。在我们实验室最近发表的研究中，GSC已经被 发现表现出独特的昼夜节律，并依赖于核心昼夜节律时钟转录因子，大脑 和肌肉Arnt样蛋白1(BMAL1)，也称为芳烃受体核转运蛋白样蛋白 (ARNTL)，和昼夜机车输出周期Kaput(时钟)。这种依赖并没有观察到 正常神经细胞和分化的胶质母细胞瘤细胞(DGC)之间的联系是一致的 昼夜节律和肿瘤发展的可能性增加。GSCs中BMAL1或时钟的丢失 细胞周期停滞，细胞凋亡，线粒体代谢功能减弱，以及 三羧酸(TCA)循环酶和茎秆基因，如SOX2、OLIG2和MYC。此外，新奇 两种独立负核时钟调节剂隐色素1/2的小分子激动剂和稳定剂 (Cry1/2)和Rev-Erba/b(Rev-ERB)，被发现能够下调干细胞调节因子并减少 GSC增长。在这项研究中，我打算阐明表观遗传机制，特别是 蛋白精氨酸甲基转移酶(PRMTs)，调节生物钟振荡器的转录，促进 干细胞的干性和增殖能力。我还打算确定小分子哭声的疗效。 稳定剂和REV-ERB激动剂单独或相互联合靶向GSC 作为新的GBM疗法。我的发现将阐明生物钟成分的表观遗传调节。 GSC的维持和进展通过药理学治疗GBM的临床前模型 以生物钟为目标。

PROJECT SUMMARY/ABSTRACT Despite being thoroughly characterized, glioblastoma multiforme (GBM) remains one of the most common malignant primary brain tumors. Currently, patient prognosis has remained poor in that treatment for GBM has only moderately improved survival rates and quality of life even with the employment of aggressive multimodal therapies. The unique heterogeneous genetic, epigenetic, and microenvironmental features of GBM and the brain make tumors resistant to treatments that have otherwise been highly effective in treating cancers of other tissues. In particular, GBM contains cancer stem cells, termed glioblastoma stem cells (GSCs), that are self- renewing and tumorigenic, thereby supporting the progression and growth of the primary tumor even after surgical resection. GSCs have the ability to actively remodel the tumor microenvironment and receive maintenance cues from their surroundings. In recent published studies from our laboratory, GSCs have been found to display unique circadian rhythms and dependence on core circadian clock transcription factors, Brain and Muscle ARNT-Like 1 (BMAL1), otherwise known as Aryl Hydrocarbon Receptor Nuclear Translocator Like (ARNTL), and Circadian Locomotor Output Cycles Kaput (CLOCK). This dependence was not observed in normal neural cells nor differentiated glioblastoma cells (DGCs) and is consistent with associations between the circadian rhythm and increased likelihood of tumor development. Loss of BMAL1 or CLOCK in GSCs induced cell cycle arrest, apoptosis, attenuation of mitochondrial metabolic function, and reduced expression of the tricarboxylic acid (TCA) cycle enzymes and stemness genes, such SOX2, OLIG2, and MYC. Additionally, novel small molecule agonists and stabilizers of two independent negative core clock regulators, Cryptochrome 1/2 (CRY1/2) and REV-ERBa/b (REV-ERBs), were found to be able to downregulate stem cell regulators and reduce GSC growth. In this study, I intend to elucidate the mechanisms in which epigenetic machineries, in particular protein arginine methyl transferases (PRMTs), regulate transcription of circadian clock oscillators to promote stemness and proliferation abilities of GSCs. I also aim to determine the efficacy of small molecule CRY stabilizers and REV-ERB agonists, both independently and in combination with each other, in targeting GSCs as novel GBM therapies. My findings will illuminate the epigenetic regulation of circadian clock components in the context of GSC maintenance and progress a preclinical model for GBM treatment via pharmacological targeting of the circadian clock.