Single-cell transcriptomic analyses reveal heterogeneity and key subsets associated with survival and response to PD-1 blockade in cervical squamous cell carcinoma.

BACKGROUND: Understanding the intricate tumor microenvironment (TME) is crucial for elucidating the mechanisms underlying the progression of cervical squamous cell carcinoma (CSCC) and its response to anti-PD-1 therapy. METHODS: In this study, we characterized 50,649 cells obtained from the CSCC for single-cell RNA sequencing and integrated bulk sequencing data from The Cancer Genome Atlas (TCGA) and clinical samples to explore their cell composition, metabolic processes, signaling pathways, specific transcription factors, lineage tracking and response to immunotherapy. In vivo experiments were performed to validate the function of key cell subsets. RESULTS: We identified ten major cell type and 35 subsets of stromal and immune cells in TME and observed distinct patterns in the metabolic processes and signaling pathways of these cells between tumor and normal tissues. Furthermore, PCNA clamp-associated factor (PCLAF)(+) tumor-associated epithelial cell (TAEpis) was negatively correlated with the number of C-X-C motif chemokine ligand 13 (CXCL13)(+) CD8(+) T cells, overall survival, and response to anti-programmed cell death-1(PD-1) therapy in patients with CSCC. Both in vivo and in vitro experiments demonstrated that PCLAF(+) TAEpis promotes the apoptosis of CD8(+) T and tumor growth, while also inhibiting T cell infiltration and function. CONCLUSION: Our findings illuminate the heterogeneity of the complex TME in CSCC and offer evidence supporting PCLAF(+) TAEpis as a promising therapeutic target.