Department of Neurologic Surgery, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (E.P.J., D.R.P., K.A.F., I.F.P.); University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania (E.P.J., D.R.P., A.M., K.A.F., I.F.P.); and University of Pittsburgh Brain Tumor Center, Pittsburgh, Pennsylvania (K.A.F., I.F.P.).
Department of Neurologic Surgery, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (E.P.J., D.R.P., K.A.F., I.F.P.); University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania (E.P.J., D.R.P., A.M., K.A.F., I.F.P.); and University of Pittsburgh Brain Tumor Center, Pittsburgh, Pennsylvania (K.A.F., I.F.P.)
J Pharmacol Exp Ther. 2014 Jul;350(1):22-35. doi: 10.1124/jpet.114.212910. Epub 2014 Apr 16.
Identification of therapeutic strategies that might enhance the efficacy of B-cell lymphoma-2 (Bcl-2) inhibitor ABT-737 [N-{4-[4-(4-chloro-biphenyl-2-ylmethyl)-piperazin-1-yl]-benzoyl}-4-(3-dimethylamino-1-phenylsulfanylmethyl-propylamino)-3-nitro-benzenesulfonamide] is of great interest in many cancers, including glioma. Our recent study suggested that Akt is a crucial mediator of apoptosis sensitivity in response to ABT-737 in glioma cell lines. Inhibitors of phosphatidylinositol 3-kinase (PI3K)/Akt are currently being assessed clinically in patients with glioma. Because PI3K/Akt inhibition would be expected to have many proapoptotic effects, we hypothesized that there may be unique synergy between PI3K inhibitors and Bcl-2 homology 3 mimetics. Toward this end, we assessed the combination of the PI3K/Akt inhibitor NVP-BKM120 [5-(2,6-dimorpholinopyrimidin-4-yl)-4-(trifluoromethyl)pyridin-2-amine] and the Bcl-2 family inhibitor ABT-737 in established and primary cultured glioma cells. We found that the combined treatment with these agents led to a significant activation of caspase-8 and -3, PARP, and cell death, irrespective of PTEN status. The enhanced lethality observed with this combination also appears dependent on the loss of mitochondrial membrane potential and release of cytochrome c, smac/DIABLO, and apoptosis-inducing factor to the cytosol. Further study revealed that the upregulation of Noxa, truncation of Bid, and activation of Bax and Bak caused by these inhibitors were the key factors for the synergy. In addition, we demonstrated the release of proapoptotic proteins Bim and Bak from Mcl-1. We found defects in chromosome segregation leading to multinuclear cells and loss of colony-forming ability, suggesting the potential use of NVP-BKM120 as a promising agent to improve the anticancer activities of ABT-737.
鉴定能增强 B 细胞淋巴瘤-2（Bcl-2）抑制剂 ABT-737[ N-{4-[4-(4-氯联苯-2-基甲基)哌嗪-1-基]-苯甲酰基}-4-(3-二甲基氨基-1-苯硫基甲基-丙基氨基)-3-硝基苯磺酰胺]治疗效果的治疗策略在包括神经胶质瘤在内的许多癌症中都非常重要。我们最近的研究表明，Akt 是神经胶质瘤细胞系中对 ABT-737 诱导的细胞凋亡敏感性的关键介质。目前正在对神经胶质瘤患者进行磷酸肌醇 3-激酶（PI3K）/Akt 抑制剂的临床评估。由于 PI3K/Akt 抑制作用预计会产生许多促凋亡作用，因此我们假设 PI3K 抑制剂和 Bcl-2 同源结构域 3 模拟物之间可能存在独特的协同作用。为此，我们评估了 PI3K/Akt 抑制剂 NVP-BKM120[5-(2,6-二吗啉基嘧啶-4-基)-4-(三氟甲基)吡啶-2-胺]和 Bcl-2 家族抑制剂 ABT-737 在已建立和原代培养的神经胶质瘤细胞中的联合应用。我们发现，这些药物联合治疗可显著激活 caspase-8 和 -3、PARP 和细胞死亡，而与 PTEN 状态无关。这种联合治疗的增强致死性似乎也依赖于线粒体膜电位的丧失和细胞色素 c、smac/DIABLO 和凋亡诱导因子向细胞质的释放。进一步的研究表明，这些抑制剂引起的 Noxa 上调、Bid 截断、Bax 和 Bak 的激活是协同作用的关键因素。此外，我们还证明了 Mcl-1 从 Bim 和 Bak 中释放出促凋亡蛋白。我们发现染色体分离缺陷导致多核细胞和集落形成能力丧失，这表明 NVP-BKM120 有潜力作为一种有前途的药物，以提高 ABT-737 的抗癌活性。
