Exploring the Therapeutic Potential of Stem Cell Biology in Gliomas

我们已经进行了实验，以从分子上理解TSC中失调的分化途径：干细胞自我更新和分化之间的微妙平衡由各种细胞内在和外在因素控制，这些因素对正常组织的稳态至关重要。尽管TSC和正常干细胞之间存在广泛的表型和功能相似性，但TSC的分化潜力并不完全正常。阐明在正常干细胞和TSCs中起作用的分化途径对于充分理解肿瘤发生至关重要，并可能导致新的治疗靶点。我们还确定了一组失调的分化途径，从人原发性胶质母细胞瘤衍生的TSCs。阐明其分子机制将为预测分化治疗方案的敏感性提供重要线索。肿瘤干细胞在分化诱导剂方面的特性进一步揭示了传统血清培养胶质瘤细胞系的局限性。例如，视黄酸处理和CNTF暴露有效地诱导大多数GBM TIC的分化，但不诱导传统细胞系的分化。这促使我们质疑是否许多潜在的肿瘤抑制基因和/或细胞生长抑制基因先前在细胞系中研究，没有被识别。鉴于从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中鉴定出的胶质母细胞瘤TSC中潜在的TSG和癌基因数量不断增加，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，我们在关键项目之一，即了解我们的胶质瘤TSCs和正常神经干细胞（NSC）之间的基因组和分子信号传导相似性和差异方面取得了重大进展。我们已经在增殖和分化条件下对7种不同的GBM衍生的TSC和正常胚胎NSC系进行了非常大规模的研究，并获得了高通量mRNA和microRNA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，并将通过对我们发现在TSC生物学中至关重要的某些转录因子进行ChIP-seq分析来补充阵列数据。自从吉尔伯特博士于2014年11月来到NOB以来，我们已经创建并表征了更多的胶质瘤源性TSC，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.