Treg and immune proliferative programs characterize anti-PD-1-responsive endometrial cancer: an integrative single-cell, spatial transcriptomic, and TCGA-UCEC reanalysis
Year: 2026
Type: article
Abstract: Background The responses to programmed cell death protein 1 (PD-1)-based therapy in advanced endometrial cancer are heterogeneous. The cellular programs associated with such responses remain incompletely defined, particularly when the immune cell composition, spatial expression patterns, and population-level transcriptomic features are considered together. Methods Publicly available TCGA-UCEC and GSE251923 data were reanalyzed using bulk transcriptomics, single-cell RNA sequencing (scRNA-seq), and the Visium expression space platform. The GSE251923 dataset included one anti-PD-1 responder and one non-responder; hence, all comparisons between these two cases are descriptive. Prespecified immune- and proliferation-related signatures were evaluated across the datasets, and the Visium clusters were assigned broad marker-based expression compartments. Exploratory quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays were used to examine selected transcripts in the Ishikawa and HEC-1A endometrial cancer cell lines under 1% O 2 hypoxia and in primary neutrophils exposed to endometrial-cancer ascites-conditioned medium. These assays were used as ancillary models of condition-associated transcription; neither hypoxia nor ascites exposure was treated as a direct model of clinical immune checkpoint inhibitor response. Results After quality control, we obtained 16,725 single cells that were assigned to 14 populations. Compared with the non-responder sample, the responder sample contained higher proportions of CD8 T cells [+3.1 percentage points (pp)], regulatory T cells (Tregs; +3.3 pp), B cells (+6.7 pp), plasma cells (+5.4 pp), CD4 T cells (+5.9 pp), and proliferating cells (+7.7 pp); the non-responder sample dominantly contained epithelial/tumor and endothelial cells. In TCGA-UCEC (553 tumors and 35 normal tissues), a high Treg signature was associated with longer overall survival [log-rank p = 0.047; hazard ratio (HR) = 0.58; 95% confidence interval (CI): 0.34–1.00], whereas a high proliferation signature was associated with shorter overall survival (HR = 1.72; 95% CI: 1.01–2.94; p = 0.046). The responder Visium section showed descriptively higher Treg and proliferation scores with lower epithelial and extracellular matrix scores. Under hypoxia, the two endometrial cancer cell lines showed higher MKI67 , FOXP3 , CXCL13 , PDCD1 , and CTLA4 transcript levels; the ascites-conditioned medium increased PAD4 and ELANE expressions in primary neutrophils. Conclusion The integrated analyses helped identify Treg- and proliferation-related patterns that differed between two anti-PD-1-treated endometrial cancers and were directionally contextualized in TCGA-UCEC. The qRT-PCR assays provide ancillary evidence of condition-associated transcriptional changes but do not validate immune cell states, clinical response mechanisms, or functional neutrophil extracellular trap formation. These findings are hypothesis-generating and require confirmation in independent treatment-annotated cohorts.
Source: Frontiers in Genetics
Authors: Yuan Zheng, Jingsheng Chen, Qing Wang, Qianqian Li
Institution: Ezhou Central Hospital
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7223146837