Exploring the Therapeutic Potential of Stem Cell Biology in Gliomas

我们已经进行了实验，以从分子上了解TSCs中非调控的分化途径：干细胞自我更新和分化之间的微妙平衡受到各种细胞内在和外在因素的控制，这些因素对正常组织的动态平衡至关重要。尽管TSCs与正常干细胞在表型和功能上有广泛的相似性，但TSCs的分化潜能并不完全正常。阐明在正常干细胞和TSCs中均可操作的分化途径对于全面了解肿瘤的发生至关重要，并可能导致新的治疗靶点。我们还鉴定了一组来自人类原发胶质母细胞瘤的TSCs的非调控分化途径。阐明其潜在的分子机制将为预测分化治疗方法的敏感性提供重要线索。TSCs在分化诱导剂方面的特性进一步揭示了传统的胶质瘤细胞系在血清中生长的局限性。例如，维甲酸处理和CNTF暴露可以有效地诱导大多数GBM TIC分化，但不能诱导传统细胞系分化。这促使我们质疑之前在细胞系中研究的许多潜在的肿瘤抑制基因和/或细胞抑制基因是否没有被识别。鉴于生物信息学方法和实验室积累的干细胞培养技术专业知识在胶质母细胞瘤干细胞中鉴定出的潜在TSG和癌基因的数量不断增加，我们建立了筛选系统来研究这些基因在干细胞培养中的功能。此外，我们在Keystone项目之一上取得了重大进展，即了解我们的胶质瘤TSC和正常神经干细胞(NSC)之间的基因组和分子信号的异同。我们对7个不同的GBM来源的TSC和正常胚胎NSC在增殖和分化条件下进行了非常大规模的研究，并获得了高通量的mRNA和microRNAs图谱。我们正在对NSC和TSC之间相似和不同的信号通路进行计算分析，并即将通过对我们发现在TSC生物学中起关键作用的某些转录因子进行芯片序列分析来补充阵列数据。自2014年11月吉尔伯特博士来到NOB以来，我们已经创造并鉴定了更多的胶质瘤来源的TSCs，以探索胶质瘤干细胞生物学的治疗潜力。

We have performed experiments for molecular understanding of deregulated differentiation pathways in TSCs: The delicate balance between stem cell self-renewal and differentiation is controlled by various cell intrinsic and extrinsic factors that are critical for normal tissue homeostasis. Despite extensive phenotypic and functional similarities between TSCs and normal stem cells, the differentiation potentials of TSCs are not entirely normal. Elucidation of the differentiation pathways that are operative in both normal stem cells and TSCs will be critical for fully understanding tumorigenesis and will likely lead to novel therapeutic targets. We have also identified a set of deregulated differentiation pathways in TSCs derived from human primary glioblastoma. Elucidation of underlying molecular mechanism will provide important clues for predicting sensitivity of differentiation therapeutic approach. Characterization of TSCs in aspect of differentiation-inducing agents further revealed the limitations of traditional glioma cell lines grown in serum. For example, retinoic acid treatment and CNTF exposure potently induce differentiation in most GBM TICs but not of traditional cell lines. This prompted us to question whether many of potential tumor suppressors and/or cytostatic genes previously studied in cell lines, were not recognized. Given the ever-increasing number of potential TSGs and oncogenes in glioblastoma TSCs identified from bioinformatics approach and technical expertise of stem cell culture accumulated in the laboratories, we have set up screening systems to study the function of these genes in stem cell cultures. In addition, we have made significant progress on one of keystone projects that is to understand the genomic and molecular signaling similarities and differences between our glioma TSCs and normal neural stem cells (NSC). We have performed a very large scale study of 7 different GBM-derived TSC and normal embryonic NSC lines under both proliferative and differentiating conditions and derived high-throughput mRNA and microRNAs profiling. We are in the midst of performing the computational analyses of the signaling pathways similar and different between NSC and TSC and are about to compliment the array data by performing ChIP-seq analyses of certain transcription factors we have found to be pivotal in TSC biology. Since Dr. Gilbert came to NOB in November 2014, we have created and characterized more glioma-derived TSCs to explore the therapeutic potential of glioma stem cell biology.