The role of pseudogenes in breast cancer: from non-coding relics to functional regulators

Pseudogenes were historically considered non-functional genomic relics. However, they are now acknowledged as possible regulators in various biological processes, including cancer. In breast cancer, emerging evidence implies the critical roles of pseudogenes in tumorigenesis, progression, and metastasis. These roles are mediated through mechanisms such as competitive endogenous RNA (ceRNA) activity, modulation of gene expression, and interaction with signaling pathways. Some pseudogenes, such as DUXAP8, CYP4Z2P, RPSAP52, POU5F1P1, POU5F1P3, POU5F1P4 and OCT4-PG1 exhibit dysregulated expression in breast cancer tissues, influencing oncogenic or tumor-suppressive pathways. Dysregulation of several pseudogenes has been associated with reduced survival of patients. Additionally, their ability to mimic parental genes or sequester microRNAs highlights their functional significance in disease pathogenesis. Despite challenges in differentiating pseudogenes from their parental genes, advancements in genomic technologies have enabled deeper exploration of their biological roles. This review summarizes current knowledge on pseudogene involvement in breast cancer, emphasizing their potential as biomarkers and therapeutic targets. Further research is needed to fully elucidate their mechanisms and clinical relevance in breast cancer biology.