m5C related-regulator-mediated methylation modification patterns and prognostic significance in breast cancer

5-Methylcytosine (m⁵C) is closely associated with cancer. However, the role of m⁵C in breast cancer(BC)remains unclear. This study combined single-cell RNA sequencing (scRNA-Seq) and transcriptomics datasets to screen m⁵C regulators associated with BC progression and analyze their clinical values. Firstly, This study elucidates the mechanisms of the m⁵C landscape and the specific roles of m⁵C regulators in BC patients. we found that the dysregulation of m⁵C regulators with m⁵Cscore play the essential role of the carcinogenesis and progression in epithelial cells and myeloid cells of BC at single cell level. External validation was conducted using an independent scRNA-Seq datasets. Then, three distinct m⁵C modification patterns were identified by transcriptomics datasets. Based on the m⁵C differentially expressed regulators, the m⁵Cscore was constructed, and used to divide patients with BC into high and low m⁵Cscore groups. Patients with a high m⁵Cscore had more abundant immune cell infiltration, stronger antitumor immunity, and better prognoses. Finally, Quantitative real-time (PCR) and immunohistochemistry were used for the in vitro experimental validation, which had extensive prognostic value. In this study, we aimed to assess the expression of m⁵C regulators involved in BC and investigate their correlation with the tumor microenvironment, clinicopathological characteristics, and prognosis of BC. The m⁵C regulators could be used to effectively assess the cell specific regulation prognosis of patients with BC and develop more effective immunotherapy strategies.