Glioblastoma multiforme (GBM) is among the most common adult brain tumors with invariably fatal character. Following the limited conventional therapies, almost all patients, however, presented with symptoms at the time of recurrence. It is dire to develop novel therapeutic strategies to improve the current treatment of GBM. Gallic acid is a well-established antioxidant, presenting a promising new selective anti-cancer drug, while gold nanoparticles (GNPs) can be developed as versatile nontoxic carriers for anti-cancer drug delivery. Here, we prepared gallic acid-GNPs (GA-GNPs) by loading gallic acid onto GNPs, reduction products of tetrachloroauric acid by sodium citrate, through physical and agitation adsorption. GA-GNPs, rather than GNPs alone, significantly inhibited the survival of U251 GBM cells, as well as enhanced radiation-induced cell death. Moreover, GA-GNPs plus radiation arrested the cell cycle of U251 at the S and G2/M phases and triggered apoptotic cell death, which is supported by increased BAX protein levels and decreased expression of BCL-2. Thus, GA-GNPs have great potential in the combination with radiation therapy in future studies for GBM treatment.

中文翻译：

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没食子酸-金纳米粒子增强辐射诱导的人胶质瘤 U251 细胞死亡

多形性胶质母细胞瘤 (GBM) 是最常见的成人脑肿瘤之一，具有致命性。然而，在有限的常规疗法之后，几乎所有患者在复发时都出现了症状。迫切需要开发新的治疗策略来改善目前对 GBM 的治疗。没食子酸是一种成熟的抗氧化剂，是一种很有前途的新型选择性抗癌药物，而金纳米粒子 (GNP) 可以开发为用于抗癌药物递送的多功能无毒载体。在这里，我们通过将没食子酸负载到 GNP 上制备没食子酸-GNP（GA-GNPs），柠檬酸钠还原四氯金酸的产物，通过物理和搅拌吸附。GA-GNPs，而不是单独的 GNPs，显着抑制 U251 GBM 细胞的存活，以及增强的辐射诱导的细胞死亡。此外，GA-GNPs 加辐射使 U251 的细胞周期在 S 期和 G2/M 期停滞并引发细胞凋亡，这得到了 BAX 蛋白水平增加和 BCL-2 表达降低的支持。因此，在未来的 GBM 治疗研究中，GA-GNP 在与放射治疗相结合方面具有巨大潜力。