Suo Daqin, Liang Lily, Xia Zengfei, Zhang Ying, Zeng Tingting, Li Shuangjiang, Guan Xin-Yuan, Li Yan
State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-Sen University Cancer Center, Guangzhou, 510060, China.
Department of Thoracic Oncology, Guangdong Esophageal Cancer Institute, Sun Yat-Sen University Cancer Center, Guangzhou, China.
Cell Oncol (Dordr). 2025 Jul 22. doi: 10.1007/s13402-025-01090-5.
Esophageal squamous cell carcinoma (ESCC) is aggressive with a poor prognosis. The tumor microenvironment (TME) significantly affects tumor progression and therapy resistance. Previous work has shown that fibroblasts in metastatic lymph nodes can confer cisplatin resistance to ESCC cells via PI16 (peptidase inhibitor 16). This study investigates the role of fibroblast-derived PI16 in the ESCC TME.
Public single-cell RNA sequencing (scRNA-seq) data for ESCC were analyzed. A cell co-culture assay was performed to evaluate regulatory T cells (Tregs) differentiation from naïve CD4 T cells. Immunoprecipitation and mass spectrometry examined PI16's mechanism in Treg differentiation. In vitro and in vivo assays were conducted to explore fibroblast-derived PI16's function. Additionally, multiplex fluorescent immunohistochemistry (mfIHC) was performed.
Analyses of the scRNA-seq dataset (GSE203115) reveal that fibroblasts can be classified into PI16 and PI16 subclusters based on PI16 expression levels. PI16 induces Treg differentiation from naïve CD4 T cells through a DOCK2-dependent mechanism. Treatment with a DOCK2 inhibitor significantly inhibits PI16-induced Treg differentiation and increases Teff cell infiltration in vivo. Moreover, upregulation of PI16 in the tumor stroma is associated with poorer long-term survival outcomes in patients with ESCC.
PI16 fibroblasts promote the differentiation of Tregs from naïve CD4 T cells through interaction with DOCK2. Upregulation of PI16 in the tumor stroma is associated with poorer long-term survival outcomes in patients with ESCC. Given the accumulating evidence on the therapeutic impact of targeting the TME, PI16 fibroblasts emerge as a promising novel therapeutic target to overcome tumor immune suppression.
食管鳞状细胞癌（ESCC）具有侵袭性，预后较差。肿瘤微环境（TME）显著影响肿瘤进展和治疗耐药性。先前的研究表明，转移性淋巴结中的成纤维细胞可通过PI16（肽酶抑制剂16）赋予ESCC细胞顺铂耐药性。本研究探讨成纤维细胞衍生的PI16在ESCC TME中的作用。
分析ESCC的公共单细胞RNA测序（scRNA-seq）数据。进行细胞共培养试验以评估初始CD4 T细胞向调节性T细胞（Tregs）的分化。免疫沉淀和质谱分析检测PI16在Treg分化中的机制。进行体外和体内试验以探索成纤维细胞衍生的PI16的功能。此外，还进行了多重荧光免疫组织化学（mfIHC）。
对scRNA-seq数据集（GSE203115）的分析表明，成纤维细胞可根据PI16表达水平分为PI16高表达和PI16低表达亚群。PI16通过依赖DOCK2的机制诱导初始CD4 T细胞分化为Tregs。用DOCK2抑制剂处理可显著抑制PI16诱导的Treg分化，并增加体内效应T细胞浸润。此外，肿瘤基质中PI16的上调与ESCC患者较差的长期生存结果相关。
PI16高表达的成纤维细胞通过与DOCK2相互作用促进初始CD4 T细胞分化为Tregs。肿瘤基质中PI16的上调与ESCC患者较差的长期生存结果相关。鉴于越来越多的证据表明靶向TME具有治疗作用，PI16高表达的成纤维细胞有望成为克服肿瘤免疫抑制的新型治疗靶点。
