Identification of MTFR1 as a Novel Prognostic Biomarker and Putative Oncogene for Breast Cancer: A Multi‐Omics Analysis and in Vitro Experimental Validation

ABSTRACT

Mitochondrial Fission Regulator 1 ( MTFR1 ) plays a critical regulatory role in various malignancies; however, its specific function and clinical significance in breast cancer (BRCA) remain unexplored. This study systematically characterised MTFR1 by integrating multi‐omics data, spatial transcriptomics, and single‐cell sequencing, followed by in vitro experimental validation. MTFR1 was significantly overexpressed in BRCA tissues and predominantly localised to malignant cells. Functionally, MTFR1 was closely associated with cell cycle progression; in vitro knockdown significantly suppressed cell proliferation and induced cell cycle arrest. Clinically, high MTFR1 expression served as an independent predictor of poor prognosis and was linked to chemotherapy resistance. Cross‐cancer immunotherapy analyses revealed that MTFR1 exhibited improved predictive performance for anti‐PD‐1 response during the on‐treatment phase compared with pretreatment settings. This study elucidates the multidimensional role of MTFR1 as a putative oncogene in BRCA, highlighting it as a promising prognostic biomarker and therapeutic target.