Integrated Single-Cell and Bulk Transcriptomic Analyses Identify a B Cell- and Plasma Cell-Associated Prognostic...

Ovarian cancer (OC) exhibits substantial tumor heterogeneity and an immunosuppressive tumor microenvironment (TME), both contributing to its unfavorable clinical outcomes. Recent studies have increasingly demonstrated that dysregulated glycosylation significantly impacts tumor progression and immune modulation. However, the specific functions and implications of glycosylation-associated regulators in OC remain poorly understood. This study integrates single-cell and bulk transcriptomic data to uncover crucial genes within the TME and investigates the potential role of Fucosyltransferase 8 (FUT8) in OC development.

Single-cell RNA sequencing (scRNA-seq) data from OC and normal ovarian tissues (GSE184880, n = 12) were analyzed using Seurat and Harmony for clustering and annotation. Ro/e analysis identified B cells and plasma cells as enriched immune populations. Their marker genes were integrated with The Cancer Genome Atlas (TCGA) cohort as the training set, while internal testing and an independent external validation cohort (GSE63885) were used to construct and validate the prognostic model. FUT8 function was evaluated in OC cell lines using quantitative real-time PCR (qRT-PCR), cell counting kit-8 (CCK-8) assays, flow cytometry, and transcriptomic sequencing. Gene Set Variation Analysis (GSVA), Gene Set Enrichment Analysis (GSEA), and virtual knockout analyses were performed to explore FUT8-associated pathways.

We constructed a single-cell atlas consisting of 46,235 cells classified into seven principal cell populations, highlighting significant enrichment of B and plasma cells in OC tissues. The prognostic signature could stratify patients into high- and low-risk groups across training, internal validation, and external validation cohorts, showing consistent prognostic stratification capacity. FUT8 expression was elevated in OC samples and was associated with favorable overall survival (OS). Experimental overexpression of FUT8 in OC cell lines resulted in reduced cell proliferation and increased apoptosis. Both transcriptomic analyses and virtual knockout studies consistently associated FUT8 with pathways related to N-glycosylation. High-risk patients exhibited predicted activation of Wnt/β-catenin, Hedgehog, and Kras pathways, coupled with diminished immune cell infiltration.

We developed a prognostic signature informed by single-cell data for OC and identified FUT8 as a potential regulator associated with N-glycosylation processes in OC. These results offer insights into OC molecular characteristics and highlight FUT8 as a candidate biomarker with potential prognostic relevance. Further experimental studies are necessary to validate and elucidate the precise molecular mechanisms involved.