Kullar Peter John, Bekale Laurent Adonis, Chen Jing, Duggaraju Rohit, Tun Zin Mie Mie, Parr Florence, Hedrick Mia Lu, Schiel Viktoria, Vasilijic Sasa, Stankovic Konstantina M, Santa Maria Peter Luke
Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California.
Otol Neurotol. 2025 Aug 1;46(7):e269-e277. doi: 10.1097/MAO.0000000000004403.
We hypothesize that gold nanoclusters functionalized with adenosine triphosphate (AuNC@ATP) can inhibit schwannoma growth.
There is an unmet need for an effective pharmacotherapy to treat vestibular schwannoma (VS) that does not carry the risk profile of current therapeutic modalities. Our previous research demonstrated that AuNC@ATP displays antimicrobial properties through its ability to induce a stress response, resulting in unfolded protein accumulation in the periplasm. The accumulation of unfolded proteins in the endoplasmic reticulum (ER) can trigger ER stress, activating the unfolded protein response (UPR). ER stress has been shown to inhibit tumor growth and activate apoptotic pathways. We therefore sought to determine whether AuNC@ATP could enhance ER stress and inhibit schwannoma growth in vitro.
Rat schwannoma (S16) cells were utilized as a cellular model. The growth ability of schwannoma cells in the absence and presence of a sublethal dose of AuNC@ATP was compared to establish the inhibitory activity of this ER stress inducer. The ability of AuNC@ATP to induce ER stress was measured using thioflavin T (Th-T) fluorescence. Unfolded protein imaging was performed using TPE-MI, and apoptosis was interrogated using the Caspase-Glo 3/7 Assay. Human VS cells were isolated from tumor samples of three different VS patients. Cytoxicity of gold nanocluster treated cells was assessed using CellTox Green Dye and metabolic activity by MTT assay.
The addition of AuNC@ATP to S16 cells for 24 hours resulted in a concentration-dependent decrease in cell viability, with a substantial loss observed at a concentration of 27.93 μM, reaching 95%. Subsequently, S16 cells were cultured in a medium containing a sublethal concentration of AuNC@ATP (6.98 μM). After 96 hours, the cell count reached 107 without AuNC@ATP compared with 105 with it. Additionally, the antitumor activity of AuNC@ATP appears to be mediated through amplified ER stress as evidenced by Th-T fluorescence and accumulation of unfolded proteins in the ER as evidenced by TPE-MI fluorescence. In addition, AuNC@ATP caused cell death of human VS cells in a concentration-dependent manner and almost totally abolished metabolic activity of treated cells.
Our study suggests that using a nano-drug capable of inducing ER stress responses could be a promising strategy for reducing schwannoma growth.
我们推测用三磷酸腺苷功能化的金纳米团簇（AuNC@ATP）能够抑制神经鞘瘤生长。
对于治疗前庭神经鞘瘤（VS）而言，目前尚无有效且无现有治疗方式风险的药物疗法。我们之前的研究表明，AuNC@ATP通过诱导应激反应展现出抗菌特性，导致周质中未折叠蛋白积累。内质网（ER）中未折叠蛋白的积累可触发内质网应激，激活未折叠蛋白反应（UPR）。内质网应激已被证明可抑制肿瘤生长并激活凋亡途径。因此，我们试图确定AuNC@ATP是否能增强内质网应激并在体外抑制神经鞘瘤生长。
将大鼠神经鞘瘤（S16）细胞用作细胞模型。比较在无和有亚致死剂量AuNC@ATP情况下神经鞘瘤细胞的生长能力，以确定这种内质网应激诱导剂的抑制活性。使用硫黄素T（Th-T）荧光测量AuNC@ATP诱导内质网应激的能力。使用TPE-MI进行未折叠蛋白成像，并使用Caspase-Glo 3/7检测法检测细胞凋亡。从三名不同VS患者的肿瘤样本中分离出人VS细胞。使用CellTox Green染料评估金纳米团簇处理细胞的细胞毒性，并通过MTT检测法评估代谢活性。
向S16细胞中添加AuNC@ATP 24小时导致细胞活力呈浓度依赖性下降，在浓度为27.93μM时观察到大量细胞死亡，死亡率达到95%。随后，将S16细胞培养在含有亚致死浓度AuNC@ATP（6.98μM）的培养基中。96小时后，无AuNC@ATP时细胞计数达到107，有AuNC@ATP时为105。此外，Th-T荧光证明AuNC@ATP的抗肿瘤活性似乎是通过放大内质网应激介导的，TPE-MI荧光证明内质网中未折叠蛋白的积累也证实了这一点。此外，AuNC@ATP以浓度依赖性方式导致人VS细胞死亡，并几乎完全消除了处理细胞的代谢活性。
我们的研究表明，使用能够诱导内质网应激反应的纳米药物可能是减少神经鞘瘤生长的一种有前景的策略。
