Guo Yi, Shen Dongsheng, Xiao Yuhang, Wu Chenghao, Chen Meiyi, Yang Lina, Li Huaifang, Tong Xiaowen, Chen Rujun, Li Fang
Department of Obstetrics and Gynecology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China.
Department of Laboratory Medicine, Shanghai Tongji Hospital, School of Medicine, Tongji University, Shanghai, China.
Front Immunol. 2025 Aug 29;16:1653096. doi: 10.3389/fimmu.2025.1653096. eCollection 2025.
Uterine leiomyosarcoma (ULSA) is a highly aggressive gynecologic malignancy characterized by early metastasis, profound immunosuppression, and resistance to conventional therapies, including immune checkpoint blockade (ICB). The intricate tumor microenvironment (TME) and cellular heterogeneity driving its progression and therapy resistance remain poorly defined.
We performed single-cell RNA sequencing (scRNA-seq) on metastatic lesions (pelvic cavity, rectum, peritoneum, bladder) from a treatment-naïve ULSA patient and compared them to normal uterine myometrium, MMM (n=5). Integrated analyses included cellular composition mapping, copy number variation (CNV) assessment, pseudotemporal trajectory reconstruction, cell-cell communication inference, functional enrichment, and validation via multiplex immunofluorescence (mpIF). Survival correlations were assessed using the TCGA-SARC cohort.
In this study, the main finding is that the tumor microenvironment (TME) has a strong immunosuppressive effect. Firstly, its characteristic is exhausted CD8T cells. This study found that as time progresses, the initial cell markers (CCR7, MAL) gradually disappear, while the exhaustion markers (LAG3, HAVCR2, TIGIT) are enriched. This is associated with poor prognosis. Secondly, the M2-polarized macrophages are mainly composed of M2-like tumor-associated macrophages (TAMs) with tumor-promoting characteristics (CD163, FTH1, FTL, TIMP1), and there is a polarization from M1 to M2. Finally, the immature, tumor-promoting N2 neutrophils (CD15EDARADD) enriched in the metastatic foci are associated with poor prognosis. The cell communication involves the interaction of MIF-(CD74+CD44) between T/B cells, as well as the role of the CXCL8 signaling axis in promoting angiogenesis, TAM polarization, and immunosuppression.
For the first time, a comprehensive single-cell map of ULSA was constructed, depicting a metastasis-susceptible cell subset (U11-EDARADD) and an extremely immunosuppressed tumor microenvironment dominated by depleted CD8T cells, M2 macrophages and N2 neutrophils. These features shed light on the underlying mechanisms of chemotherapy resistance and immunotherapy failure. The biomarkers identified here (EDARADD, CLDN10, TMIGD2) as well as the dysregulated pathways (TGF-β, angiogenesis, MIF signaling) provide possible targets for future development of combined immunotherapy strategies against this deadly disease.
子宫平滑肌肉瘤（ULSA）是一种侵袭性很强的妇科恶性肿瘤，其特点是早期转移、严重免疫抑制以及对包括免疫检查点阻断（ICB）在内的传统疗法耐药。驱动其进展和治疗耐药的复杂肿瘤微环境（TME）和细胞异质性仍未明确界定。
我们对一名未经治疗的ULSA患者的转移病灶（盆腔、直肠、腹膜、膀胱）进行了单细胞RNA测序（scRNA-seq），并将其与正常子宫肌层、MMM（n = 5）进行比较。综合分析包括细胞组成图谱绘制、拷贝数变异（CNV）评估、伪时间轨迹重建、细胞间通讯推断、功能富集以及通过多重免疫荧光（mpIF）进行验证。使用TCGA-SARC队列评估生存相关性。
在本研究中，主要发现是肿瘤微环境（TME）具有强大的免疫抑制作用。首先，其特征是耗竭的CD8T细胞。本研究发现，随着时间的推移，初始细胞标志物（CCR7、MAL）逐渐消失，而耗竭标志物（LAG3、HAVCR2、TIGIT）富集。这与预后不良相关。其次，M2极化巨噬细胞主要由具有促肿瘤特征（CD163、FTH1、FTL、TIMP1）的M2样肿瘤相关巨噬细胞（TAM）组成，并且存在从M1到M2的极化。最后，转移灶中富集的未成熟、促肿瘤的N2中性粒细胞（CD15EDARADD）与预后不良相关。细胞通讯涉及T/B细胞之间MIF-（CD74+CD44）的相互作用，以及CXCL8信号轴在促进血管生成、TAM极化和免疫抑制中的作用。
首次构建了ULSA的全面单细胞图谱，描绘了一个易发生转移的细胞亚群（U11-EDARADD）以及一个由耗竭的CD8T细胞、M2巨噬细胞和N2中性粒细胞主导的极度免疫抑制的肿瘤微环境。这些特征揭示了化疗耐药和免疫治疗失败的潜在机制。此处鉴定出的生物标志物（EDARADD、CLDN10、TMIGD2）以及失调的通路（TGF-β、血管生成、MIF信号）为未来开发针对这种致命疾病的联合免疫治疗策略提供了可能的靶点。
