human glioma stem cells (GSC) : undifferentiated versus differentiated in presence or absence of active GSK3beta

Transcriptional profilling of human GSC comparing undifferentiated (ND) and differentiated (Diff 0.5%) GSC treated or not with TWS119 (LW) an inhibitor of GSK3beta Glioblastomas (GBM) are the most common form of primary brain tumors. Highly vascularized, infiltrating, resistant to current therapies, they affect patients at different ages. The median survival is shorter than 18 months. GBM follow the cancer stem cell (CSC) model. This concept proposes that a minority of cells within the tumor mass, with long term self-renewal and differentiation properties, is responsible for the initiation and the growth of tumors. CSCs provide all the subtypes of cells that compose the tumor, including endothelial cells and pericytes. Their functional properties are associated with a molecular signature combining makers of neural and/or embryonic stem cells, and markers of mesenchymal cells. A growing body of evidences supports that tumor’s behavior, including proliferation, progression, invasion and – most importantly - a great part of resistance to therapies are determined by these self-renewing tumor cells. It is becoming therefore evident that failure of current treatments to eliminate glioma-initiating cells (GiCs) contributes to tumor recurrence. Targeting GiCs and their stem-like properties constitutes thus one of the main therapeutic challenges to significantly improve anti-cancer treatments. A relevant solution to target GiCs, is to force them to acquire a non self-renewing state. Under this non stem-like state, the cells lose their tumorigenicity and become vulnerable to therapies. We observed that GiC differentiation is associated to an increase of active GSK3beta expression. Suppression of this activation using a chemical inhibitor (TWS119) altered the differentiation process. To identify transcroptomic changes due to GSK3beta inhibition during differentiation, we have differentiated two GiC cultures (TG1, and TG6) treated or not with TWS119. Total mRNA have been extracted and compared to mRNA extracted from self-renewing TG1 and TG6 cells. For these experiments we used “Agilent human genome whole 44K” chips. two-condition experiment, undifferentiated GSC (ND) vs. Differentiated (diff 0.5%) and undifferentiated GSC (ND) versus differentiated GSC treated with TWS119 (diff 0.5%LW) in monoplicate in TG1 and in TG6 cells (two different primary cultures of GSC).

本数据集为人类胶质母细胞瘤干细胞（GSC）的转录组谱分析，对比未分化（ND）、经0.5%分化诱导的GSC，以及分别经或未经糖原合成激酶3β（GSK3β）抑制剂TWS119（LW）处理的该分化状态GSC。
胶质母细胞瘤（GBM）是最常见的原发性脑肿瘤，具有高血管化、浸润性、对现有治疗耐药的特征，可发生于各年龄段人群，中位生存期不足18个月。
GBM符合癌症干细胞（CSC, Cancer Stem Cell）模型：该理论认为肿瘤组织中少数具备长期自我更新与分化能力的细胞，是肿瘤起始与生长的根源。CSCs可分化为构成肿瘤的所有细胞亚型，包括内皮细胞与周细胞。其功能特性与兼具神经干细胞/胚胎干细胞标志物及间质细胞标志物的分子特征相关。
越来越多的证据表明，肿瘤的增殖、进展、侵袭，以及最为关键的治疗耐药性，在很大程度上由这些自我更新的肿瘤细胞决定。由此可见，现有治疗无法清除胶质瘤起始细胞（GiCs, Glioma-Initiating Cells）是肿瘤复发的重要原因。
靶向GiCs及其干细胞样特性，是显著改善抗肿瘤治疗效果的核心临床挑战之一。针对GiCs的有效策略之一，是诱导其丧失自我更新能力。在这种非干细胞状态下，细胞会失去致瘤性并对治疗变得敏感。
我们的研究发现，GiC的分化与活性GSK3β的表达上调相关。使用化学抑制剂TWS119抑制该激活过程，会干扰分化进程。为明确分化过程中GSK3β抑制所引发的转录组变化，我们对两株GiC原代培养细胞（TG1与TG6）分别进行如下处理：经或未经TWS119处理的0.5%分化诱导条件下的细胞，并与未分化的TG1、TG6细胞进行对比。
本实验采用安捷伦（Agilent）人类全基因组44K表达芯片进行检测，实验为双对照设计：①未分化GSC（ND） vs 0.5%分化诱导GSC（Diff 0.5%）；②未分化GSC（ND） vs 经TWS119处理的0.5%分化诱导GSC（Diff 0.5% LW）。所有实验组均在TG1与TG6两株GSC原代培养细胞中完成单次重复检测。