1036 - Unveiling Cell Subsets and Molecular Characteristics Associated with Clinical Outcomes of Radiochemotherapy in Cervical Cancer at the Single-Cell Scale
Presenter(s)
T. Lei1, F. Wang2, S. Yue1, Q. Hu1, and C. Liu2; 1Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, China, 2Department of Radiation Oncology, Peking University First Hospital, Beijing, China
Purpose/Objective(s): Currently, clinical practice lacks robust biomarkers to predict radiochemotherapy (RCT) efficacy and patient prognosis in cervical squamous cell carcinoma (CESC), hindering the development of personalized treatment regimens. This study aiming to investigating cell subsets and molecular characteristics at single-cell resolution, holds critical clinical relevance.
Materials/Methods: We conducted single-cell RNA sequencing analysis on tissue samples from three RCT-resistant and five RCT-sensitive CESC samples. Meanwhile, an independent external validation cohort comprising single-cell RNA sequencing data from 63 CESC patients was integrated to cross-validate the clinical relevance of key cellular subsets across platforms. Dimensionality reduction and clustering analyses were employed to identify key cell subsets and molecular characteristics that associated with RCT efficacy and survival outcomes. A total of 187 CESC patients with clinical data including RCT from The Cancer Genome Atlas Program (TCGA) were selected for validation. Additionally, immunofluorescence staining was conducted on thirty-five pairs of RCT-resistant and responsive CESC tissues for further validation.
Results: The study identified that RCT-resistant tissues exhibited a higher prevalence of immune escape-associated cell subpopulations, including neutrophils, myofibroblasts, and exhausted CD8+ T cells. In contrast, RCT-responsive tissues were mainly enriched with anti-tumor CD16_NK cells and CD1C_DC cells. This observation was corroborated through the analysis of bulk RNA sequencing data from 187 patients with CESC who underwent RCT. Patients were categorized into RCT-resistant and RCT-responsive groups based on their 2-year progression-free survival, which confirmed the presence of immune escape-related cell subpopulations, such as neutrophils and myofibroblasts (all P < 0.05), in RCT-resistant group. Furthermore, immunofluorescence assays from 35 paired CESC samples demonstrated an enrichment of exhausted CD8+ T cells within the RCT-resistant group, compared to RCT-responsive group (P < 0.05). In addition, the signatures of neutrophils and myofibroblasts were associated with worse survival in the CESC patients receiving RCT from TCGA, whereas the signatures of CD16_NK cells and CD1C_DC were associated with improved survival. Moreover, RCT-resistant group had the high expression of CXCL1 and CXCL8 related to neutrophil migration, which predicted worse survival in patients receiving RCT in TCGA cohort.
Conclusion: Single-cell analysis highlights the potential of these cellular subsets and molecular characteristics as novel immune microenvironment biomarkers for clinically predicting RCT response and prognosis, while providing a rationale for developing combination therapies targeting immune escape pathways.