小分子高效诱导人恶性胶质瘤定向分化为神经元及机制研究

Due to the exponential and invasive growth of malignant gliomas, and the special occurrence site, conventional surgery, radiotherapy and chemotherapy are not effective for it. Induction differentiation therapy is an effective and promising new strategy. When malignant gliomas differentiate into terminally differentiated neurons, the cells detach from the proliferative state, the invasion ability is reduced, and the disease is effectively controlled. The key to curbing recurrence is the efficient induction rate. In the early stage of this project, a small molecule cocktail was screened that efficiently induced (more than 90%) U87-MG to differentiate into neurons by using the neuron specific promoter reporting system. With the progress of differentiation, cell proliferation was significantly weakened, the expression of genes NES, Olig2 and Prox-1, which were positively correlated with the malignant degree of glioma, gradually decreased, while the expression of tumor suppressor gene Pax6 increased, neural-related transcription factors NeuroD1 and REST were involved in regulating differentiation, and tumor tissue volume decreased in the brain. Next, the molecular mechanisms that induce differentiation were further analyzed by transcriptome sequencing. The changes of tumor malignancy induced by differentiation were explored by comparing the proliferation, apoptosis, migration, invasion and spheroidizing ability of tumor cells before and after differentiation. Finally, the treatment of tumors in vivo was validated by an intracranial brain tumor model. Through in vivo and in vitro validation and elucidation of molecular mechanisms, this study will provide efficient and promising small molecule induction strategies for differentiation therapy of malignant gliomas.

恶性胶质瘤呈指数型及浸润性生长，发生部位特殊，常规的疗法对其效果不佳。分化诱导疗法是一个具有前景的新策略。当恶性胶质瘤分化为终末状态的神经元，细胞脱离增殖状态，侵袭能力降低，病情得到控制，而遏制复发的关键是高效地诱导分化。本课题前期通过神经元特异启动子报告系统筛选获得高效诱导（大于90%）U87-MG向神经元分化的小分子方案。分化导致细胞增殖显著减弱，基因水平与胶质瘤恶性程度呈正相关的基因NES、Olig2和Prox-1表达逐渐减少，而抑癌基因Pax6表达增加，神经相关的转录因子NeuroD1和REST等表达改变，脑内肿瘤组织体积减少。接下来，我们通过转录组测序进一步分析小分子诱导分化的分子机制，检测细胞增殖、凋亡、迁移、侵袭及成球能力探讨分化对恶性程度的改变，在裸鼠脑瘤模型中进行体内肿瘤的治疗，体内外向神经元分化的研究及分子机制的阐明，为恶性胶质瘤的治疗提供高效且具有应用前景的新策略。

恶性胶质瘤呈指数型及浸润性生长，发生部位特殊，常规的疗法对其效果不佳。分化诱导疗法是一个具有前景的新策略。当恶性胶质瘤（GBM）分化为终末状态的神经元，细胞脱离增殖状态，侵袭能力降低，病情得到控制，而遏制复发的关键是高效地诱导分化。本课题通过神经元特异启动子报告系统筛选获得高效诱导(大于90%)GBM向神经元分化的小分子方案。分化导致无论是GBM细胞系还是患者来源的GBM细胞增殖显著减弱，退出细胞周期，成球、迁移和侵袭能力降低，表明恶性程度降低。转录组测序进一步分析小分子诱导转分化的分子机制并发现CEND1参与其中。小分子的肿瘤原位缓释显著抑制PDX脑瘤模型中肿瘤的生长，延长小鼠寿命。体内外向神经元分化的研究及分子机制的阐明，为恶性胶质瘤的治疗提供高效且具有应用前景的新策略。