Identification of biomarkers for radiation-induced coronary heart disease in breast cancer patients

Background: This study aims to identify biomarkers associated with radiation-induced coronary heart disease (RICHD) in breast cancer patients by integrating bioinformatics approaches with single-cell sequencing data, providing potential therapeutic targets for RICHD treatment.Materials and Methods: Gene expression profiles associated with coronary heart disease were sourced from the Gene Expression Omnibus (GEO) database, and GEO2R was utilized to identify differentially expressed genes.Whole-genome sequencing and clinical data of breast cancer patients were obtained from The Cancer Genome Atlas (TCGA) database.Gene expression levels were analyzed using the 'Limma' package to compare radiation-exposed and non-exposed groups.Biological functional enrichment analysis was conducted using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG).The intersection of TCGA and GEO identified key genes.Further analyses of these key genes in breast cancer patients were conducted using the GEPIA, Kaplan-Meier Plotter websites, and single-cell sequencing results.Results: The intersection of datasets from breast cancer and coronary heart disease revealed Hemoglobin A2(HBA2) as a key gene associated with RICHD.HBA2 exhibited statistically significant differences in mRNA expression levels between breast cancer and normal tissues (P<0.05).Kaplan-Meier Plotter analysis revealed a significant prognostic difference between breast cancer patients with varying HBA2 expression levels (P=0.005).HBA2 exhibited significant expression levels in CD8+ T cells.Conclusion: HBA2 could be a biomarker and therapeutic target for RICHD, offering new perspectives for clinical management of RICHD patients.