Liu Junyuan, Han Zhigang, Chen Lijuan, Sun Gang
Department of Thoracic Oncology, The Affiliated Cancer Hospital of Xinjiang Medical University, No. 789 Suzhou East Street, Xinshi District, Ürümqi City, 830000, Xinjiang, China.
Department of Breast and Thyroid Surgery, People's Hospital of Xinjiang Uygur Autonomous Region, No. 91 Tianchi Road, Ürümqi City, 830001, Xinjiang, China.
Sci Rep. 2025 Oct 13;15(1):35669. doi: 10.1038/s41598-025-19564-9.
The tumor microenvironment plays a critical role in the progression and metastasis of lung adenocarcinoma (LUAD), characterized by its immunosuppressive nature. Identifying the mechanisms that contribute to the remodeling of this environment is essential for developing therapeutic strategies. Heat shock factor 2-binding protein (HSF2BP) is implicated in tumor proliferation and immune evasion, but the mechanisms by which HSF2BP exerts these effects remain poorly understood. This study investigates the role of HSF2BP in modulating Basonuclin 1 (BNC1) expression and subsequent immune responses in LUAD. Matched tumor and adjacent normal tissue samples from 30 LUAD patients were collected between January 2023 and June 2024. Using lentiviral transduction, HSF2BP and BNC1 were overexpressed or knocked down in LUAD cell lines. Gene and protein expression were quantified by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting. We analyzed the immunological profile of LUAD tumors and assessed the interaction between HSF2BP and the BNC1/Transforming Growth Factor Beta (TGF-β)/SMAD3 signaling pathway through in vitro and in vivo experiments. Immune profiling included flow cytometry for Natural Killer (NK) cells and ELISA for cytokine analysis (IL-2, IL-4, IL-10, INF-γ, and TNF-α). In vivo studies involved subcutaneous tumorigenesis in BALB/c nude mice. Immunohistochemistry and co-immunoprecipitation were used to validate protein interactions and to assess remodeling of the tumor immune microenvironment. HSF2BP expression was markedly higher in LUAD tissues in matched adjacent normal tissues, whereas BNC1 expression was significantly reduced. Overexpression of HSF2BP in LUAD cells (H1299) enhanced proliferation, reduced the proportion of NK cells, decreased levels of IFN-γ, IL-2, and TNF-α, and increased levels of IL-4 and IL-10. Conversely, knockdown of HSF2BP in A549 cells reduced proliferation and restored the proportion of NK cells and levels of pro-inflammatory cytokines. In vivo studies using HSF2BP-overexpressing mice confirmed these findings, demonstrating increased tumor volumes and altered cytokine profiles. Molecular assays revealed that HSF2BP binds directly to BNC1, with the C-terminal hydrophobic domain being essential for this interaction, thereby modulations in TGF-β and SMAD3 signaling pathways. HSF2BP significantly promotes LUAD progression by modulating the BNC1/TGF-β/SMAD3 signaling axis and reshaping the tumor immune microenvironment. Targeting the HSF2BP-BNC1 interaction can provide novel therapeutic strategies for enhancing immune responses against LUAD.
肿瘤微环境在肺腺癌（LUAD）的进展和转移中起着关键作用，其特征在于具有免疫抑制性质。确定促成这种环境重塑的机制对于制定治疗策略至关重要。热休克因子2结合蛋白（HSF2BP）与肿瘤增殖和免疫逃逸有关，但其发挥这些作用的机制仍知之甚少。本研究调查了HSF2BP在调节LUAD中Basonuclin 1（BNC1）表达及随后的免疫反应中的作用。在2023年1月至2024年6月期间收集了30例LUAD患者的配对肿瘤和相邻正常组织样本。利用慢病毒转导在LUAD细胞系中过表达或敲低HSF2BP和BNC1。通过实时定量聚合酶链反应（RT-qPCR）和蛋白质印迹法定量基因和蛋白质表达。我们通过体外和体内实验分析了LUAD肿瘤的免疫图谱，并评估了HSF2BP与BNC1/转化生长因子β（TGF-β）/SMAD3信号通路之间的相互作用。免疫图谱分析包括对自然杀伤（NK）细胞的流式细胞术检测和对细胞因子分析的酶联免疫吸附测定（IL-2、IL-4、IL-10、INF-γ和TNF-α）。体内研究涉及在BALB/c裸鼠中进行皮下肿瘤形成实验。免疫组织化学和免疫共沉淀用于验证蛋白质相互作用并评估肿瘤免疫微环境的重塑。HSF2BP在LUAD组织中的表达明显高于配对的相邻正常组织，而BNC1的表达则显著降低。在LUAD细胞（H1299）中过表达HSF2BP可增强增殖，降低NK细胞比例，降低IFN-γ、IL-2和TNF-α水平，并增加IL-4和IL-10水平。相反，在A549细胞中敲低HSF2BP可降低增殖并恢复NK细胞比例和促炎细胞因子水平。使用过表达HSF2BP的小鼠进行的体内研究证实了这些发现，表明肿瘤体积增加且细胞因子谱改变。分子分析显示HSF2BP直接与BNC1结合，其C末端疏水域对于这种相互作用至关重要，从而调节TGF-β和SMAD3信号通路。HSF2BP通过调节BNC1/TGF-β/SMAD3信号轴和重塑肿瘤免疫微环境显著促进LUAD进展。靶向HSF2BP-BNC1相互作用可为增强针对LUAD的免疫反应提供新的治疗策略。
