Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warsaw, Poland.
Department of Biochemistry and Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230 Odense M, Denmark.
Cells. 2020 Sep 30;9(10):2217. doi: 10.3390/cells9102217.
Glioblastomas are the most frequent and aggressive form of primary brain tumors with no efficient cure. However, they often exhibit specific metabolic shifts that include deficiency in the biosynthesis of and dependence on certain exogenous amino acids. Here, we evaluated, in vitro, a novel combinatory antiglioblastoma approach based on arginine deprivation and canavanine, an arginine analogue of plant origin, using two human glioblastoma cell models, U251MG and U87MG. The combinatory treatment profoundly affected cell viability, morphology, motility and adhesion, destabilizing the cytoskeleton and mitochondrial network, and induced apoptotic cell death. Importantly, the effects were selective toward glioblastoma cells, as they were not pronounced for primary rat glial cells. At the molecular level, canavanine inhibited prosurvival kinases such as FAK, Akt and AMPK. Its effects on protein synthesis and stress response pathways were more complex and dependent on exposure time. We directly observed canavanine incorporation into nascent proteins by using quantitative proteomics. Although canavanine in the absence of arginine readily incorporated into polypeptides, no motif preference for such incorporation was observed. Our findings provide a strong rationale for further developing the proposed modality based on canavanine and arginine deprivation as a potential antiglioblastoma metabolic therapy independent of the blood-brain barrier.
胶质母细胞瘤是最常见和侵袭性最强的原发性脑肿瘤，目前尚无有效的治疗方法。然而，它们通常表现出特定的代谢转变，包括生物合成不足和对某些外源性氨基酸的依赖。在这里，我们使用两种人胶质母细胞瘤细胞模型 U251MG 和 U87MG，在体外评估了一种基于精氨酸剥夺和瓜氨酸（一种植物来源的精氨酸类似物）的新型联合抗胶质母细胞瘤方法。联合治疗显著影响细胞活力、形态、运动和黏附性，破坏细胞骨架和线粒体网络，并诱导细胞凋亡。重要的是，这些影响是针对胶质母细胞瘤细胞的，因为它们对原代大鼠神经胶质细胞没有明显影响。在分子水平上，瓜氨酸抑制了存活相关激酶，如 FAK、Akt 和 AMPK。其对蛋白质合成和应激反应途径的影响更为复杂，且依赖于暴露时间。我们通过使用定量蛋白质组学直接观察到瓜氨酸掺入到新生蛋白质中。尽管在没有精氨酸的情况下瓜氨酸很容易掺入多肽中，但没有观察到这种掺入的偏好模式。我们的研究结果为进一步开发基于瓜氨酸和精氨酸剥夺的拟议方法提供了强有力的依据，该方法作为一种独立于血脑屏障的潜在抗胶质母细胞瘤代谢疗法具有潜力。
