Department of Neuro-Oncology, Brain Tumor Center, The University of Texas M D Anderson Cancer Center, Houston, Texas 77030, USA.
Clin Cancer Res. 2012 Jan 1;18(1):184-95. doi: 10.1158/1078-0432.CCR-11-1558. Epub 2011 Nov 7.
The aim of this study was to show preclinical efficacy and clinical development potential of NVP-BKM120, a selective pan class I phosphatidylinositol-3 kinase (PI3K) inhibitor in human glioblastoma (GBM) cells in vitro and in vivo.
The effect of NVP-BKM120 on cellular growth was assessed by CellTiter-Blue assay. Flow cytometric analyses were carried out to measure the cell-cycle, apoptosis, and mitotic index. Mitotic catastrophe was detected by immunofluorescence. The efficacy of NVP-BKM120 was tested using intracranial U87 glioma model.
We tested the biologic effects of a selective PI3K inhibitor NVP-BKM120 in a set of glioma cell lines. NVP-BKM120 treatment for 72 hours resulted in a dose-dependent growth inhibition and effectively blocked the PI3K/Akt signaling cascade. Although we found no obvious relationship between the cell line's sensitivity to NVP-BKM120 and the phosphatase and tensin homolog (PTEN) and epidermal growth factor receptor (EGFR) statuses, we did observe a differential sensitivity pattern with respect to p53 status, with glioma cells containing wild-type p53 more sensitive than cells with mutated or deleted p53. NVP-BKM120 showed differential forms of cell death on the basis of p53 status of the cells with p53 wild-type cells undergoing apoptotic cell death and p53 mutant/deleted cells having a mitotic catastrophe cell death. NVP-BKM120 mediates mitotic catastrophe mainly through Aurora B kinase. Knockdown of p53 in p53 wild-type U87 glioma cells displayed microtubule misalignment, multiple centrosomes, and mitotic catastrophe cell death. Parallel to the assessment of the compound in in vitro settings, in vivo efficacy studies using an intracranial U87 tumor model showed an increased median survival from 26 days (control cohort) to 38 and 48 days (treated cohorts).
Our present findings establish that NVP-BKM120 inhibits the PI3K signaling pathways, leading to different forms of cell death on the basis of p53 statuses. Further studies are warranted to determine if NVP-BKM120 has potential as a glioma treatment.
本研究旨在展示 NVP-BKM120（一种选择性的 I 类磷脂酰肌醇-3 激酶（PI3K）抑制剂）在体外和体内对人胶质母细胞瘤（GBM）细胞的临床前疗效和临床开发潜力。
通过 CellTiter-Blue 测定法评估 NVP-BKM120 对细胞生长的影响。通过流式细胞术分析测量细胞周期、凋亡和有丝分裂指数。通过免疫荧光检测有丝分裂灾难。使用颅内 U87 神经胶质瘤模型测试 NVP-BKM120 的疗效。
我们在一组神经胶质瘤细胞系中测试了一种选择性 PI3K 抑制剂 NVP-BKM120 的生物学效应。NVP-BKM120 处理 72 小时导致剂量依赖性生长抑制，并有效阻断了 PI3K/Akt 信号级联。虽然我们没有发现细胞系对 NVP-BKM120 的敏感性与磷酸酶和张力蛋白同源物（PTEN）和表皮生长因子受体（EGFR）状态之间存在明显关系，但我们确实观察到了 p53 状态的差异敏感性模式，p53 野生型神经胶质瘤细胞比 p53 突变/缺失细胞更敏感。NVP-BKM120 基于细胞的 p53 状态显示出不同形式的细胞死亡，p53 野生型细胞发生凋亡性细胞死亡，而 p53 突变/缺失细胞发生有丝分裂灾难细胞死亡。NVP-BKM120 通过 Aurora B 激酶介导有丝分裂灾难。p53 野生型 U87 神经胶质瘤细胞中的 p53 敲低显示微管排列紊乱、多个中心体和有丝分裂灾难细胞死亡。与在体外评估化合物平行，使用颅内 U87 肿瘤模型的体内疗效研究显示，中位生存期从 26 天（对照组）增加到 38 天和 48 天（治疗组）。
我们目前的研究结果表明，NVP-BKM120 抑制 PI3K 信号通路，导致基于 p53 状态的不同形式的细胞死亡。需要进一步研究以确定 NVP-BKM120 是否有作为胶质母细胞瘤治疗的潜力。
