Subtype-Consistent Upregulation of Ferroptosis-Associated Pathways in Breast Cancer with Heterogeneous Prognostic...

Ferroptosis is an iron-dependent form of regulated cell death driven by lipid peroxidation and oxidative stress, increasingly implicated in cancer biology. However, its molecular regulation across breast cancer subtypes and its potential systemic manifestations remain incompletely understood. The aim of this study was to identify ferroptosis-associated molecular alterations that are largely shared across subtypes and to evaluate their systemic reflection following localized tissue injury. Tumor and matched normal breast tissues representing major molecular subtypes were analyzed. Global mRNA and miRNA expression profiling was performed using microarrays, followed by validation of selected genes using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). Functional enrichment and protein-protein interaction analyses were conducted to characterize associated pathways. In addition, systemic responses were assessed in patients undergoing fibroadenoma cryoablation through longitudinal blood sampling. Six ferroptosis-related genes (SLC7A11, GPX4, FTH1, NQO1, NFE2L2, SQSTM1) demonstrated consistent upregulation across all breast cancer subtypes, with higher expression observed in more aggressive tumors. These genes are functionally linked to antioxidant defense, iron metabolism, and oxidative stress regulation, and their coordinated expression pattern is consistent with activation of NRF2-dependent cytoprotective pathways. Downregulation of selected miRNAs may contribute to this expression profile but likely represents a secondary regulatory mechanism. Survival analysis revealed heterogeneous and subtype-dependent associations, with limited and gene-specific prognostic relevance. Cryoablation induced transient increases in circulating levels of the analyzed proteins, reflecting systemic responses to localized tissue injury. In conclusion, breast cancer is characterized by a largely shared ferroptosis-associated molecular signature across subtypes; however, its clinical impact appears to be variable and context-dependent. Systemic detection of related molecular signals suggests potential utility as indicators of tissue stress responses, although their role as specific biomarkers of ferroptosis requires further validation.