Zhang Jie Ting, Weng Zhi Hui, Tsang Kam Sze, Tsang Lai Ling, Chan Hsiao Chang, Jiang Xiao Hua
Key Laboratory for Regenerative Medicine, Ministry of Education, Epithelial Cell Biology Research Center, School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong SAR, PR China.
Department of Anatomical and Cellular Pathology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, PR China.
PLoS One. 2016 Jan 27;11(1):e0148062. doi: 10.1371/journal.pone.0148062. eCollection 2016.
The biologic studies of human neural crest stem cells (hNCSCs) are extremely challenging due to the limited source of hNCSCs as well as ethical and technical issues surrounding isolation of early human embryonic tissues. On the other hand, vast majority of studies on MycN have been conducted in human tumor cells, thus, the role of MycN in normal human neural crest development is completely unknown. In the present study, we determined the role of MycN in hNCSCs isolated from in vitro-differentiating human embryonic stem cells (hESCs). For the first time, we show that suppression of MycN in hNCSCs inhibits cell growth and cell cycle progression. Knockdown of MycN in hNCSCs increases the expression of Cdkn1a, Cdkn2a and Cdkn2b, which encodes the cyclin-dependent kinases p21CIP1, p16 INK4a and p15INK4b. In addition, MycN is involved in the regulation of human sympathetic neurogenesis, as knockdown of MycN enhances the expression of key transcription factors involved in sympathetic neuron differentiation, including Phox2a, Phox2b, Mash1, Hand2 and Gata3. We propose that unlimited source of hNCSCs provides an invaluable platform for the studies of human neural crest development and diseases.
由于人类神经嵴干细胞（hNCSCs）来源有限以及围绕早期人类胚胎组织分离的伦理和技术问题，对其进行生物学研究极具挑战性。另一方面，绝大多数关于MycN的研究是在人类肿瘤细胞中进行的，因此，MycN在正常人类神经嵴发育中的作用完全未知。在本研究中，我们确定了MycN在从体外分化的人类胚胎干细胞（hESCs）中分离出的hNCSCs中的作用。我们首次表明，hNCSCs中MycN的抑制会抑制细胞生长和细胞周期进程。hNCSCs中MycN的敲低会增加Cdkn1a、Cdkn2a和Cdkn2b的表达，它们分别编码细胞周期蛋白依赖性激酶p21CIP1、p16INK4a和p15INK4b。此外，MycN参与人类交感神经发生的调节，因为MycN的敲低会增强参与交感神经元分化的关键转录因子的表达，包括Phox2a、Phox2b、Mash1、Hand2和Gata3。我们认为，hNCSCs的无限来源为人类神经嵴发育和疾病的研究提供了一个宝贵的平台。
