Department of Neurosurgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
Zhejiang-US Joint Laboratory for Aging and Neurological Disease Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
CNS Neurosci Ther. 2024 Oct;30(10):e70075. doi: 10.1111/cns.70075.
Glioblastoma represents the most frequently diagnosed malignant neoplasm within the central nervous system. Human glioblastoma cells can be phenotypically reprogrammed into neuron-like cells through the forced expression of NEUROG2 and SOXC factors. NEUROG2 serves as a pioneer factor, establishing an initial framework for this transformation. However, the specific role of SOXC factors has not been fully elucidated.
In this study, we used ChIP-seq to determine the potential target gene of NGN2. RNA-seq has been used to evaluate the transcriptional change during NGN2-SOX11-mediated neuron reprogramming. Immunofluorescence was used to determine the neuron reprogramming efficacy and cell proliferation ability. ChIP-qPCR, Co-IP, and Western Blot were performed to investigate the mechanism.
Our findings reveal that SOXC factors, in contrast to their previously identified function as transcriptional activators, act as transcriptional repressors. They achieve this by recruiting TRIM28 to suppress the expression of ECT2, a RhoGEF. This suppression results in the differential regulation of RhoA, RAC1, and CDC42 activities throughout the reprogramming process. We further establish that small molecules targeting RhoA and its effectors can substitute for SOXC factors in facilitating the neuronal reprogramming of glioblastoma cells.
These results underscore the pivotal role of SOXC factors' transcriptional repression and illuminate one of their specific downstream targets.
胶质母细胞瘤是中枢神经系统中最常见的恶性肿瘤。通过强制表达 NEUROG2 和 SOXC 因子，人类胶质母细胞瘤细胞可以表型重编程为神经元样细胞。NEUROG2 作为先驱因子，为这种转化建立了初始框架。然而，SOXC 因子的具体作用尚未完全阐明。
在这项研究中，我们使用 ChIP-seq 来确定 NGN2 的潜在靶基因。RNA-seq 用于评估 NGN2-SOX11 介导的神经元重编程过程中的转录变化。免疫荧光用于确定神经元重编程效率和细胞增殖能力。ChIP-qPCR、Co-IP 和 Western Blot 用于研究机制。
我们的研究结果表明，SOXC 因子与先前被确定的转录激活因子功能相反，它们作为转录抑制因子发挥作用。它们通过招募 TRIM28 来抑制 ECT2（一种 RhoGEF）的表达来实现这一点。这种抑制导致 RhoA、RAC1 和 CDC42 活性在整个重编程过程中的差异调节。我们进一步确定，针对 RhoA 及其效应物的小分子可以替代 SOXC 因子，促进胶质母细胞瘤细胞的神经元重编程。
这些结果强调了 SOXC 因子转录抑制的关键作用，并阐明了它们的一个特定下游靶标。
