Integrated Analysis Identifies an Anoikis-Related Gene Signature for Predicting Prognosis in Patients With Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with limited therapeutic options and poor prognosis. Anoikis resistance contributes to tumour dissemination, metastasis and therapeutic resistance. However, anoikis-related molecular signatures integrating single-cell and bulk transcriptomic data for prognostic prediction in TNBC remain insufficiently characterised. Bulk RNA-seq data from TCGA-TNBC and GSE58812, together with single-cell transcriptomic data, were analysed. Anoikis-related genes were identified by WGCNA and single-cell module scoring. A prognostic signature was constructed using Cox and LASSO regression. Immune features and immunotherapy-related indicators were evaluated, and STC2 was validated by tissue microarray, immunohistochemistry and in vitro anoikis assays. An anoikis-related gene signature (ASS1, COL18A1, STC2, DHX36, S100B and TGFBI) was established. High-risk patients exhibited poor overall survival, increased cancer-associated fibroblast infiltration and reduced T-cell infiltration. Additionally, high anoikis risk scores were associated with increased mutations frequencies of PTEN, PIK3CA and ZEB2, along with lower tumour mutation burden, microsatellite instability and PD-L1 levels. IHC staining confirmed that patients with low STC2 expression had poor prognosis. Furthermore, STC2 knockdown reduced anoikis-related apoptotic rates in an MDA-MB-231-based anoikis-mimic model in vitro. This study established an anoikis-related gene signature that may improve prognostic stratification and reflect immunotherapy-related features in TNBC.