Suppression of RAF/MEK or PI3K synergizes cytotoxicity of receptor tyrosine kinase inhibitors in glioma tumor-initiating cells.
Suppression of RAF/MEK or PI3K synergizes cytotoxicity of receptor tyrosine kinase inhibitors in glioma tumor-initiating cells.
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DOI：
10.1186/s12967-016-0803-2
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发表时间：
2016-02-09
影响因子：
7.4
通讯作者：
Bögler O
中科院分区：
文献类型：
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作者：
Shingu T;Holmes L;Henry V;Wang Q;Latha K;Gururaj AE;Gibson LA;Doucette T;Lang FF;Rao G;Yuan L;Sulman EP;Farrell NP;Priebe W;Hess KR;Wang YA;Hu J;Bögler O
大多数胶质母细胞瘤具有异常的受体酪氨酸激酶（RTK）/RAS/磷酸肌醇3激酶（PI 3 K）信号通路，并且恶性胶质瘤细胞被认为依赖于这些信号通路以维持其存活和增殖。然而，最近的研究表明，使用分子靶向药物的单一疗法或不适当的联合疗法的疗效有限，这可能是由于肿瘤的异质性，信号冗余和细胞内信号网络的串扰，这表明有效的个性化联合治疗的理论基础和方法的必要性。在这里，我们评估了来自胶质瘤球体培养物（GSC）的胶质瘤肿瘤起始细胞（GIC）在琼脂糖中获得的集落的生长，并使用影响大多数胶质瘤细胞成瘾的信号传导途径的靶向药物研究了联合治疗对GIC的影响。在琼脂糖中培养人GIC，并用RTK、非受体激酶或转录因子的抑制剂处理。用菌落计数器分析殖民地数和菌落体积，并评价Chou-Talalay组合指数。还分析了自噬和凋亡。通过反相蛋白质阵列和免疫印迹来评估蛋白质的磷酸化。琼脂糖中菌落数量和体积的增加与Gompertz函数相关。GIC表现出不同的药物敏感性，但EGFR抑制剂和MEK抑制剂、索拉非尼和U 0126、厄洛替尼和BKM 120以及EGFR抑制剂和索拉非尼等组合对RTK和RAF/MEK或PI 3 K的抑制在不同亚型的GIC中表现出协同作用。厄洛替尼和索拉非尼联合应用在体外对GSC 11具有协同作用，诱导细胞凋亡和自噬性细胞死亡，并抑制Akt和ERK信号通路，降低核PKM 2和β-catenin，并倾向于改善荷GSC 11脑肿瘤裸鼠的生存率。反相蛋白阵列分析的协同治疗表明参与不仅MEK和PI 3 K信号通路，但也与葡萄糖代谢，脂肪酸代谢，基因转录，组蛋白甲基化，铁转运，应激反应，细胞周期和凋亡。抑制RTK和RAF/MEK或PI 3 K可以诱导协同细胞毒性，但需要个性化。检查由来自每个患者的GIC启动的琼脂糖中的集落可能有助于个性化癌症治疗中的药物敏感性测试。本文的在线版本（doi：10.1186/s12967-016-0803-2）包含补充材料，可供授权用户使用。
The majority of glioblastomas have aberrant receptor tyrosine kinase (RTK)/RAS/phosphoinositide 3 kinase (PI3K) signaling pathways and malignant glioma cells are thought to be addicted to these signaling pathways for their survival and proliferation. However, recent studies suggest that monotherapies or inappropriate combination therapies using the molecular targeted drugs have limited efficacy possibly because of tumor heterogeneities, signaling redundancy and crosstalk in intracellular signaling network, indicating necessity of rationale and methods for efficient personalized combination treatments. Here, we evaluated the growth of colonies obtained from glioma tumor-initiating cells (GICs) derived from glioma sphere culture (GSC) in agarose and examined the effects of combination treatments on GICs using targeted drugs that affect the signaling pathways to which most glioma cells are addicted. Human GICs were cultured in agarose and treated with inhibitors of RTKs, non-receptor kinases or transcription factors. The colony number and volume were analyzed using a colony counter, and Chou-Talalay combination indices were evaluated. Autophagy and apoptosis were also analyzed. Phosphorylation of proteins was evaluated by reverse phase protein array and immunoblotting. Increases of colony number and volume in agarose correlated with the Gompertz function. GICs showed diverse drug sensitivity, but inhibitions of RTK and RAF/MEK or PI3K by combinations such as EGFR inhibitor and MEK inhibitor, sorafenib and U0126, erlotinib and BKM120, and EGFR inhibitor and sorafenib showed synergy in different subtypes of GICs. Combination of erlotinib and sorafenib, synergistic in GSC11, induced apoptosis and autophagic cell death associated with suppressed Akt and ERK signaling pathways and decreased nuclear PKM2 and β-catenin in vitro, and tended to improve survival of nude mice bearing GSC11 brain tumor. Reverse phase protein array analysis of the synergistic treatment indicated involvement of not only MEK and PI3K signaling pathways but also others associated with glucose metabolism, fatty acid metabolism, gene transcription, histone methylation, iron transport, stress response, cell cycle, and apoptosis. Inhibiting RTK and RAF/MEK or PI3K could induce synergistic cytotoxicity but personalization is necessary. Examining colonies in agarose initiated by GICs from each patient may be useful for drug sensitivity testing in personalized cancer therapy. The online version of this article (doi:10.1186/s12967-016-0803-2) contains supplementary material, which is available to authorized users.