TPPP3过表达通过HSPA8关联抑制鼻咽癌进展并促进免疫微环境重塑

文献信息

中文摘要

目的： 鼻咽癌（NPC）发生于免疫抑制性微环境中，该微环境常削弱治疗效果。TPPP3已被认为可能是NPC侵袭性的负调控因子，但其与免疫调节或伴侣蛋白网络的相关性仍不明确。因此，我们旨在确定TPPP3如何塑造NPC免疫景观，并鉴定其相互作用的蛋白伙伴。方法：使用R分析来自头颈部鳞状细胞癌和鼻咽癌的公共单细胞RNA测序数据集。建立稳定过表达TPPP3的HK-1和C666-1细胞。使用这些细胞构建人源化异种移植肿瘤模型，并通过免疫组织化学评估瘤内免疫细胞浸润。在体外，将相同细胞及其对照与外周血单个核细胞间接共培养。对TPPP3过表达细胞的细胞裂解物进行免疫沉淀-质谱分析和免疫荧光染色，鉴定出HSPA8为TPPP3相互作用蛋白。随后在伤口愈合、集落形成、细胞周期和异种移植实验中比较三组——对照组、TPPP3过表达组以及TPPP3过表达加HSPA8抑制剂VER155008组，并对肿瘤切片进行Ki67、TPPP3和CD3的免疫组织化学染色。结果：TPPP3转录本在大多数肿瘤细胞亚群中几乎检测不到，但在NPC上皮细胞簇中优先富集。强制TPPP3表达可抑制异种移植瘤生长，同时增加瘤内CD3+ T细胞、CD8+ T细胞和CD11c+树突状细胞的丰度。用VER155008对HSPA8进行药理学阻断，进一步增强了TPPP3驱动的对迁移、克隆形成和肿瘤扩增的抑制，并改变细胞周期进程，同时促进移植物内CD3+ T细胞积聚。结论：这些发现提示TPPP3与HSPA8之间存在功能性关联，可能有助于NPC中的肿瘤生长抑制和免疫微环境重塑。药理学破坏HSPA8依赖性蛋白稳态增强了体外和体内模型中TPPP3相关的抗肿瘤活性，表明该伴侣蛋白通路是值得进一步机制研究和治疗探索的候选机制。

英文摘要

Objectives: Nasopharyngeal carcinoma (NPC) arises in an immune-suppressive milieu that frequently undermines treatment efficacy. TPPP3 has been implicated as a negative regulator of NPC aggressiveness, yet its relevance to immune modulation or chaperone networks remains poorly defined. We therefore sought to determine how TPPP3 shapes the NPC immune landscape and to identify its interacting protein partners. Methods: Public single-cell RNA-sequencing datasets from head and neck squamous cell carcinoma and nasopharyngeal carcinoma were analyzed using R. HK-1 and C666-1 cells stably overexpressing TPPP3 were established. These cells were used to construct humanized xenograft tumor models, with intratumoral immune cell infiltration evaluated by immunohistochemistry. In vitro, the same cells and their controls were indirectly co-cultured with peripheral blood mononuclear cells. Cellular lysates from TPPP3-overexpressing cells were subjected to immunoprecipitation-mass spectrometry and immunofluorescence staining, which identified HSPA8 as a TPPP3-interacting protein. Three groups-control, TPPP3-overexpressing, and TPPP3-overexpressing plus the HSPA8 inhibitor VER155008-were then compared in wound healing, colony formation, cell-cycle, and xenograft assays, with immunohistochemical staining for Ki67, TPPP3, and CD3 performed on tumor sections. Results: TPPP3 transcripts were barely detectable across most tumor cell subsets but showed preferential enrichment in NPC epithelial clusters. Enforced TPPP3 expression curtailed xenograft outgrowth while increasing intratumoral abundance of CD3+ T cells, CD8+ T cells, and CD11c+ dendritic cells. Pharmacological blockade of HSPA8 with VER155008 further enhanced TPPP3-driven suppression of migration, clonogenicity, and tumor expansion, and also altered cell-cycle progression while boosting CD3+ T-cell accumulation within grafts. Conclusions: These findings suggest a functional association between TPPP3 and HSPA8 that may contribute to tumor growth suppression and immune microenvironment remodeling in NPC. Pharmacological disruption of HSPA8-dependent proteostasis enhanced TPPP3-associated antitumor activity in both in vitro and in vivo models, indicating that this chaperone pathway represents a candidate mechanism worthy of further mechanistic investigation and therapeutic exploration.