Zhang Jinfeng, Li Yunlong, Chen Jing, Huang Tongtong, Lin Jing, Pi Yilin, Hao Huiting, Wang Dong, Liang Xiao, Fu Songbin, Yu Jingcui
Scientific Research Center, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
Department of General Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
Front Immunol. 2024 Mar 28;15:1369087. doi: 10.3389/fimmu.2024.1369087. eCollection 2024.
The ErbB-2.1(TOB1) signaling transducer protein is a tumor-suppressive protein that actively suppresses the malignant phenotype of gastric cancer cells. Yet, TOB1 negatively regulates the activation and growth of different immune cells. Understanding the expression and role of TOB1 in the gastric cancer immune environment is crucial to maximize its potential in targeted immunotherapy.
This study employed multiplex immunofluorescence analysis to precisely delineate and quantify the expression of TOB1 in immune cells within gastric cancer tissue microarrays. Univariate and multivariate Cox analyses were performed to assess the influence of clinical-pathological parameters, immune cells, , and double-positive cells on the prognosis of gastric cancer patients. Subsequent experiments included co-culture assays of si--transfected neutrophils with AGS or HGC-27 cells, along with EdU, invasion, migration assays, and bioinformatics analyses, aimed at elucidating the mechanisms through which in neutrophils impacts the prognosis of gastric cancer patients.
We remarkably revealed that TOB1 exhibits varying expression levels in both the nucleus (nTOB1) and cytoplasm (cTOB1) of diverse immune cell populations, including CD8 T cells, CD66b neutrophils, FOXP3 Tregs, CD20 B cells, CD4 T cells, and CD68 macrophages within gastric cancer and paracancerous tissues. Significantly, TOB1 was notably concentrated in CD66b+ neutrophils. Survival analysis showed that a higher density of cTOB1/nTOB1CD66b neutrophils was linked to a better prognosis. Subsequent experiments revealed that, following stimulation with the supernatant of tumor tissue culture, the levels of TOB1 protein and mRNA in neutrophils decreased, accompanied by enhanced apoptosis. HL-60 cells were successfully induced to neutrophil-like cells by DMSO. Neutrophils-like cells with attenuated TOB1 gene expression by si-TOB1 demonstrated heightened apoptosis, consequently fostering a malignant phenotype in AGS and HCG-27 cells upon co-cultivation. The subsequent analysis of the datasets from TCGA and TIMER2 revealed that patients with high levels of TOB1 combined neutrophils showed better immunotherapy response.
This study significantly advances our comprehension of TOB1's role within the immune microenvironment of gastric cancer, offering promising therapeutic targets for immunotherapy in this context.
ErbB-2.1（TOB1）信号转导蛋白是一种肿瘤抑制蛋白，可有效抑制胃癌细胞的恶性表型。然而，TOB1对不同免疫细胞的激活和生长具有负调控作用。了解TOB1在胃癌免疫环境中的表达和作用对于最大限度发挥其在靶向免疫治疗中的潜力至关重要。
本研究采用多重免疫荧光分析，精确描绘和量化胃癌组织微阵列中免疫细胞内TOB1的表达。进行单因素和多因素Cox分析，以评估临床病理参数、免疫细胞和双阳性细胞对胃癌患者预后的影响。后续实验包括用si-转染的中性粒细胞与AGS或HGC-27细胞进行共培养实验，以及EdU、侵袭、迁移实验和生物信息学分析，旨在阐明中性粒细胞中TOB1影响胃癌患者预后的机制。
我们显著发现，TOB1在胃癌及癌旁组织中多种免疫细胞群体的细胞核（nTOB1）和细胞质（cTOB1）中表达水平各异，这些免疫细胞群体包括CD8 T细胞、CD66b中性粒细胞、FOXP3调节性T细胞、CD20 B细胞、CD4 T细胞和CD68巨噬细胞。值得注意的是，TOB1明显集中在CD66b+中性粒细胞中。生存分析表明，cTOB1/nTOB1 CD66b中性粒细胞密度较高与较好的预后相关。后续实验表明，在用肿瘤组织培养上清液刺激后，中性粒细胞中TOB1蛋白和mRNA水平下降，同时凋亡增加。通过二甲基亚砜成功将HL-60细胞诱导为中性粒细胞样细胞。经si-TOB1降低TOB1基因表达的中性粒细胞样细胞显示出更高的凋亡率，因此在共培养时促进了AGS和HCG-27细胞的恶性表型。对来自TCGA和TIMER2数据集的后续分析表明，TOB1联合中性粒细胞水平高的患者显示出更好的免疫治疗反应。
本研究显著推进了我们对TOB1在胃癌免疫微环境中作用的理解，为这种情况下的免疫治疗提供了有前景的治疗靶点。
