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

5-Methylcytosine (mC) is closely associated with cancer. However, the role of mC in breast cancer(BC)remains unclear. This study combined single-cell RNA sequencing (scRNA-Seq) and transcriptomics datasets to screen mC regulators associated with BC progression and analyze their clinical values. Firstly, This study elucidates the mechanisms of the mC landscape and the specific roles of mC regulators in BC patients. we found that the dysregulation of mC regulators with mCscore 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 mC modification patterns were identified by transcriptomics datasets. Based on the mC differentially expressed regulators, the mCscore was constructed, and used to divide patients with BC into high and low mCscore groups. Patients with a high mCscore 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 mC regulators involved in BC and investigate their correlation with the tumor microenvironment, clinicopathological characteristics, and prognosis of BC. The mC regulators could be used to effectively assess the cell specific regulation prognosis of patients with BC and develop more effective immunotherapy strategies.