Bulk and single-cell RNA sequencing data identified HMGB3 of chromatin regulators as a breast cancer biomarker associated with the cell cycle

Background Chromatin regulators (CRs) have been reported to modulate tumorigenesis and progression in multiple pathophysiological processes, but little is known about theirs role and association with the immune microenvironment in breast cancer (BRCA). Methods This study identified differential CRs gene expression in BRCA using transcriptome sequencing data and single-cell RNA sequencing data. We investigated the biological function of HMGB3 gene using western blot, transwell assay and immunohistochemistry (IHC). Results In this research, eleven CRs were discovered and utilized to create a prognostic model. Using median risk scores, patients were sorted into high- and low-risk groups. The nomogram created from this model precisely predicted overall survival (OS). Low-risk patients had notably higher immune cells infiltrating. IHC provided additional evidence that the expression levels of HMGB3 are closely linked to BRCA. In vitro functional assays demonstrated that HMGB3 enhances the invasion of BRCA cells and facilitates malignant progression by controlling cell cycle. Conclusion Based on bioinformatics analysis of the prognostic value of CRs in BRCA, we identified that HMGB3 as a novel target molecule to promote the occurrence and development of BRCA.