Basic research for the combination with anti-angiogenic therapy and heavy charged particle therapy against malignant gliomas

用VEGF 164转染C6大鼠胶质瘤细胞。将球状体细胞原位植入60只大鼠脑内。免疫组化法检测VEGF和胎肝激酶-1（VEGF受体2）的表达。患有神经胶质瘤的动物接受经口给予的VEGF抑制剂PTK 787/ZK 222584。通过磁共振成像和免疫组织化学评价生长和血管形成。通过磁共振成像体积测定法测量，在荷胶质瘤动物中早期和延迟应用PTK 787/ZK 222584导致肿瘤大小减小（71%和36%）。血管密度显著降低（42.3%和25.7%），肿瘤内坏死面积扩大（早期治疗后增加1.7倍），增殖减少89%和72%。未观察到PTK 787/ZK 222584对细胞的生长抑制作用。PTK 787/ZK 222584通过抑制新血管形成和增殖显著阻止VEGF介导的胶质瘤生长，提供了一种有希望的新的 ...更多信息 雷帕霉素是雷帕霉素哺乳动物靶标（mTOR）的高度特异性抑制剂，并且已经报道在广泛的人肿瘤细胞系中诱导细胞周期停滞并抑制VEGF信号传导。在这里，我们研究了雷帕霉素对细胞和肿瘤生长的影响，并与亚硝基脲（ACNU，盐酸尼莫司汀）在人脑胶质瘤细胞中的组合。在已建立的人恶性胶质瘤细胞中，我们证实雷帕霉素增强了ACNU的凋亡诱导作用，尽管单独用雷帕霉素处理不能诱导凋亡。本实验结果表明，雷帕霉素可抑制ACNU作用后U251 MG细胞p21蛋白和mRNA的表达。此外，雷帕霉素和ACNU的组合处理显示出Bax/Bcl-xL比率比单独ACNU处理更多的增加。接下来，与对照大鼠相比，用雷帕霉素在体内治疗建立的脑内U251 MG异种移植物导致统计学上延长的中位存活率（p<0.05）。最后，在体内用雷帕霉素和ACNU的组合治疗建立的脑内U251 MG异种移植物导致统计学上延长的中位存活（p<0.05）。这些结果表明，mTOR抑制剂和ACNU的联合治疗可能是人类恶性胶质瘤的有用策略。少

C6 rat glioma cells were transfected with VEGF164. Spheroids cells were implanted orthotopically into 60 rat brains. Expression of VEGF and fetal liver kinase-1 (VEGF receptor 2) was assessed immunohistochemically. Animals with gliomas received orally administered VEGF inhibitor PTK787/ZK222584. Growth and vascularization were evaluated by magnetic resonance imaging and immunohistochemistry. Early and delayed application of PTK787/ZK222584 in glioma-bearing animals resulted in a reduction of tumor size (71% and 36%) as measured by magnetic resonance imaging volumetry. Vessel density was significantly reduced (42.3% and 25.7%), and areas of intratumoral necrosis were enlarged (by 1.7-fold after early treatment).Additionally, proliferation was decreased by 89% and 72%. There was no growth-inhibiting effect of PTK787/ZK222584 on cells observed. PTK787/ZK222584 significantly halted VEGF-mediated glioma growth by inhibition of neovascularization and proliferation, providing a promising new … More tool in malignant glioma therapy.Rapamycin is a highly specific inhibitor of the mammalian target of rapamycin (mTOR) and has been reported to induce cell cycle arrest and to inhibit VEGF signaling in a broad range of human tumor cell lines. Here, we investigated the effect of rapamycin on cell and tumor growth and in combination with nitrosourea (ACNU, nimustine hydrochloride) in human glioma cells. In established human malignant glioma cells, we confirmed that rapamycin enhanced the apoptosis-inducing effects of ACNU, although treatment with rapamycin alone could not induce apoptosis. Our studies showed that rapamycin inhibited the expressions of p21 protein and mRNA after ACNU treatment in U251MG cells. Moreover, combined treatment of rapamycin and ACNU demonstrated more increase in the Bax/Bcl-xL ratio than ACNU treatment alone. Next, treatment of established intracerebral U251MG xenografts with the rapamycin in vivo resulted in statistically prolonged median survival (p<0.05) compared with control rats. Finally, treatment of established intracerebral U251MG xenografts with the combination of rapamycin and ACNU in vivo resulted in statistically prolonged median survival (p<0.05). These results suggested that combination therapy with mTOR inhibitors and ACNU might be a useful strategy for human malignant gliomas. Less