Neuroimmunology and Neuro-Oncology Unit, Instituto Nacional de Neurología y Neurocirugía (INNN), Insurgentes Sur 3877, 14269, Mexico City, Mexico.
J Cancer Res Clin Oncol. 2014 Feb;140(2):291-301. doi: 10.1007/s00432-013-1565-3. Epub 2013 Dec 14.
Glioblastoma multiforme is the most frequent primary brain tumor, it has poor prognosis, and it remains refractory to current treatment. The success of temozolomide (TMZ) appears to be limited by the occurrence of chemoresistance. Recently, we report the use of pertussis toxin as adjuvant immunotherapy in a C6 glioma model; showing a decrease in tumoral size, it induced selective cell death in Treg cells, and it elicited less infiltration of tumoral macrophages. Here, we evaluated the cytotoxic effect of pertussis toxin in combination with TMZ for glioma treatment, both in vitro and in vivo RG2 glioma model.
We determined cell viability, cell cycle, apoptosis, and autophagy on treated RG2 cells through flow cytometry, immunofluorescence, and Western blot assays. Twenty-eight rats were divided in four groups (n = 7) for each treatment. After intracranial implantation of RG2 cells, animals were treated with TMZ (10 mg/Kg/200 μl of apple juice), PTx (2 μg/200 μl of saline solution), and TMZ + PTx. Animals without treatment were considered as control.
We found an induction of apoptosis in around 20 % of RG2 cells, in both single treatments and in their combination. Also, we determined the presence of autophagy vesicles, without any modifications in the cell cycle in the TMZ - PTx-treated groups. The survival analyses showed an increase due to individual treatments; while in the group treated with the combination TMZ - PTx, this effect was enhanced.
We show that the concomitant use of pertussis toxin plus TMZ could represent an advantage to improve the glioma treatment.
多形性胶质母细胞瘤是最常见的原发性脑肿瘤，预后差，且对当前治疗仍具有抗性。替莫唑胺（TMZ）的成功似乎受到化疗耐药性的限制。最近，我们报告了使用百日咳毒素作为辅助免疫疗法在 C6 神经胶质瘤模型中的应用；该方法显示肿瘤体积减小，诱导 Treg 细胞发生选择性细胞死亡，并减少肿瘤巨噬细胞的浸润。在这里，我们评估了百日咳毒素联合 TMZ 治疗神经胶质瘤的细胞毒性作用，包括体外和体内 RG2 神经胶质瘤模型。
我们通过流式细胞术、免疫荧光和 Western blot 分析来确定经处理的 RG2 细胞的细胞活力、细胞周期、细胞凋亡和自噬情况。28 只大鼠分为四组（每组 n = 7）进行每种治疗。在颅内植入 RG2 细胞后，动物接受 TMZ（10 mg/Kg/200 μl 苹果汁）、PTx（2 μg/200 μl 生理盐水）和 TMZ + PTx 治疗。未接受治疗的动物被视为对照组。
我们发现单独治疗和联合治疗均可诱导约 20%的 RG2 细胞发生细胞凋亡。此外，我们还确定了 TMZ-PTx 治疗组中存在自噬小泡，但细胞周期无任何改变。生存分析显示，单独治疗组的存活率有所提高，而 TMZ-PTx 联合治疗组的效果则有所增强。
我们表明，百日咳毒素联合 TMZ 的使用可能是改善神经胶质瘤治疗的一个优势。
