Integrated transcriptomic, protein, and MicroRNA profiling reveals a conserved pyroptosis-related molecular signature across breast cancer subtypes

Background: Pyroptosis, an inflammatory form of programmed cell death, has been implicated in tumor progression, yet its molecular contribution across breast cancer subtypes remains poorly defined. Methods: To characterize pyroptosis-related alterations, we analyzed tumor and matched control tissues from five molecular subtypes of breast cancer using genome-wide messenger RNA and microRNA microarrays, quantitative polymerase chain reaction, enzyme-linked immunosorbent assays, and protein-protein interaction analysis. We identified predicted microRNA-messenger RNA regulatory relationships and constructed a pyroptosis index and inflammasome activation score. To contextualize these findings, temporal expression changes were evaluated in a cryoablation model of benign fibroadenoma. Results: -consistently distinguished cancerous from control tissue across all subtypes at both messenger RNA and protein levels. Aggressive subtypes, particularly human epidermal growth factor receptor 2-enriched and triple-negative tumors, exhibited pronounced activation of inflammasome-related pathways, elevated pyroptosis index and inflammasome activation score values, and coordinated suppression of cell-cycle inhibitors. Predicted microRNA regulators, including microRNA 140-3p, microRNA 124-3p, microRNA 300, microRNA 30a-3p, microRNA 30d-3p, and microRNA 608, showed patterns consistent with loss of post-transcriptional restraint in high-grade tumors. In fibroadenoma, pyroptosis-associated expression changes were rapid and transient, whereas malignant tissue displayed a consistent, subtype-dependent elevation of pyroptosis-related markers at the time of resection. Conclusion: This integrative analysis identifies a conserved pyroptosis-related molecular signature that deepens understanding of inflammatory programmed cell death in breast cancer and highlights interconnected pathways with diagnostic, prognostic, and therapeutic relevance.