Abstract
Breast cancer progression is increasingly linked to disturbances in circadian rhythm genes, although the underlying molecular mechanisms remain poorly understood. Circadian rhythm genes help maintain normal biological processes and their disruption contributes to breast cancer development. Transcriptomic data from breast cancer (MCF-7) and normal breast (MCF-10A) cell lines from the GSE76370 dataset were analyzed using the limma R package to identify differentially expressed genes. Functional enrichment and network analyses using GO, KEGG, STRING and Cytoscape revealed 1,788 DEGs, including 1,008 upregulated genes involved in DNA replication, chromatin remodeling and PI3K-Akt signaling and 780 downregulated genes associated with cell adhesion and apoptosis. Disrupted expression of core circadian genes (BMAL1, CLOCK and PER3) and hub genes such as ACTB, GAPDH and CDK1 suggests that circadian gene dysregulation promotes breast cancer progression and represents a potential therapeutic target.