Department of Neurosurgery, University Medical Center Freiburg, Freiburg, Germany.
Neurosurgery. 2012 Feb;70(2):497-510; discussion 510. doi: 10.1227/NEU.0b013e31823209cf.
Glutathione S-transferases (GSTs) control multidrug resistance and are upregulated in many cancers, including malignant gliomas. The diazeniumdiolate JS-K generates nitric oxide (NO) on enzymatic activation by glutathione and GST, showing promising NO-based anticancer efficacy.
To evaluate the role of NO-based antitumor therapy with JS-K in U87 gliomas in vitro and in vivo.
U87 glioma cells and primary glioblastoma cell lines were exposed to JS-K and a variety of inhibitors to study cell death by necrosis, apoptosis, and other mechanisms. GST expression was evaluated by immunocytochemistry, polymerase chain reaction, and Western blot, and NO release from JS-K was studied with a NO assay. The growth-inhibitory effect of JS-K was studied in a U87 xenograft model in vivo.
Dose-dependent inhibition of cell proliferation was observed in human U87 glioma cells and primary glioblastoma cells in vitro. Cell death was partially induced by caspase-dependent apoptosis, which could be blocked by Z-VAD-FMK and Q-VD-OPH. Inhibition of GST by sulfasalazine, cGMP inhibition by ODQ, and MEK1/2 inhibition by UO126 attenuated the antiproliferative effect of JS-K, suggesting the involvement of various intracellular death signaling pathways. Response to JS-K correlated with mRNA and protein expression of GST and the amount of NO released by the glioma cells. Growth of U87 xenografts was reduced significantly, with immunohistochemical evidence for increased necrosis and apoptosis and reduced proliferation.
Our data show for the first time the potent antiproliferative effect of JS-K in gliomas in vitro and in vivo. These findings warrant further investigation of this novel NO-releasing prodrug in gliomas.
谷胱甘肽 S-转移酶（GSTs）控制多药耐药性，并在许多癌症中上调，包括恶性神经胶质瘤。重氮氮氧化物 JS-K 通过谷胱甘肽和 GST 的酶促激活生成一氧化氮（NO），显示出有前途的基于 NO 的抗癌疗效。
评估基于 NO 的抗肿瘤治疗 JS-K 在 U87 神经胶质瘤中的体外和体内作用。
将 U87 神经胶质瘤细胞和原代神经胶质瘤细胞系暴露于 JS-K 和各种抑制剂中，以研究坏死、细胞凋亡和其他机制引起的细胞死亡。通过免疫细胞化学、聚合酶链反应和 Western blot 评估 GST 表达，通过 NO 测定研究 JS-K 从 NO 中的释放。在体内 U87 异种移植模型中研究 JS-K 的生长抑制作用。
在体外观察到人类 U87 神经胶质瘤细胞和原代神经胶质瘤细胞的剂量依赖性细胞增殖抑制。细胞死亡部分由 caspase 依赖性细胞凋亡诱导，该凋亡可被 Z-VAD-FMK 和 Q-VD-OPH 阻断。谷胱甘肽抑制剂柳氮磺胺吡啶、cGMP 抑制剂 ODQ 和 MEK1/2 抑制剂 UO126 减弱了 JS-K 的抗增殖作用，表明涉及各种细胞内死亡信号通路。对 JS-K 的反应与 GST 的 mRNA 和蛋白表达以及神经胶质瘤细胞释放的 NO 量相关。U87 异种移植物的生长明显减少，免疫组织化学证据表明坏死和凋亡增加，增殖减少。
我们的数据首次显示了 JS-K 在体外和体内神经胶质瘤中的强大增殖抑制作用。这些发现证明了这种新型 NO 释放前药在神经胶质瘤中的进一步研究是合理的。
