Potential Therapeutic Effect of Glycogen Synthase Kinase 3β Inhibition against Human Glioblastoma
Potential Therapeutic Effect of Glycogen Synthase Kinase 3β Inhibition against Human Glioblastoma
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DOI：
10.1158/1078-0432.ccr-08-0760
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发表时间：
2009-02-01
影响因子：
11.5
通讯作者：
Minamoto, Toshinari
中科院分区：
文献类型：
--
作者：
Miyashita, Katsuyoshi;Kawakami, Kazuyuki;Minamoto, Toshinari
目的：胶质母细胞瘤是最难以治疗的恶性脑肿瘤，迫切需要确定其分子靶点。我们研究了糖原合成酶激酶3 β (GSK3 β)在人类胶质母细胞瘤中的表达、活性和可能的病理作用，GSK3 β是神经退行性疾病的新兴治疗靶点。实验设计：在胶质母细胞瘤细胞系中鉴定了酪氨酸216残基磷酸化的GSK3 β的活性部分（pGSK3 β (Y216)）。通过非放射性同位素体外激酶法检测这些细胞中磷酸化其底物的GSK3 β活性。结果：与非肿瘤脑组织相比，胶质母细胞瘤中GSK3 β和pGSK3 β (Y216)的表达水平较高。通过增加小分子抑制剂（AR-A014418）的剂量或通过RNA干扰抑制GSK3 β的表达，可诱导胶质母细胞瘤细胞的凋亡，并降低胶质母细胞瘤细胞的存活和增殖。抑制GSK3 β与野生型p53的胶质母细胞瘤细胞中p53和p21的表达增加有关，与所有胶质母细胞瘤细胞系中Rb磷酸化和周期蛋白依赖性激酶6的表达减少有关。低剂量AR-A014418使胶质母细胞瘤细胞对替莫唑胺和1-（4-氨基-2-甲基-5-嘧啶基）甲基-3-（2-氯乙基）-3-亚硝基脲、临床使用的化疗药物以及电离辐射显着敏感。结论：这些结果表明，GSK3 β通过p53和/或rb介导的通路失活，促进胶质母细胞瘤细胞的存活和增殖，并保护胶质母细胞瘤细胞免于凋亡，从而发挥病理作用。因此，我们提出GSK3 β为胶质母细胞瘤提供了一个潜在的治疗靶点。
Purpose: Glioblastoma represents the malignant brain tumor that is most refractory to treatment and in which the identification of molecular target(s) is urgently required. We investigated the expression, activity, and putative pathologic role of glycogen synthase kinase 3 beta (GSK3 beta), an emerging therapeutic target for neurodegenerative diseases, in human glioblastoma.Experimental Design: The active fraction of GSK3 beta that is phosphorylated at the tyrosine 216 residue (pGSK3 beta(Y216)) was identified in glioblastoma cell lines. GSK3 beta activity for phosphorylating its substrate was detected in these cells by nonradioisotopic in vitro kinase assay.Results: Higher expression levels of GSK3 beta and pGSK3 beta(Y216) were frequently detected in glioblastomas compared with nonneoplastic brain tissues. Inhibition of GSK3 beta activity by escalating doses of a small-molecule inhibitor (AR-A014418) or inhibition of its expression by RNA interference induced the apoptosis and attenuated the survival and proliferation of glioblastoma cells in vitro. Inhibition of GSK3 beta was associated with increased expression of p53 and p21 in glioblastoma cells with wild-type p53 and with decreased Rb phosphorylation and expression of cyclin-dependent kinase 6 in all glioblastoma cell lines. Administration of AR-A014418 at a low dose significantly sensitized glioblastoma cells to temozolomide and 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea, chemotherapeutic agents used in the clinical setting, as well as to ionizing radiation.Conclusion: These results indicate that GSK3 beta exerts a pathologic role by promoting the survival and proliferation of glioblastoma cells and by protecting them from apoptosis via the inactivation of p53- and/or Rb-mediated pathways. Consequently, we propose that GSK3 beta provides a potential therapeutic target in glioblastoma.