Updated project metadata. Catechol-O-methyl transferase (COMT) is involved in detoxification of catechol estrogens, playing cancer-protective role in cells producing or utilizing estrogen. Moreover, COMT suppressed migration potential of breast cancer cells. To delineate COMT role in metastasis of estrogen receptor dependent BC, we investigated the effect of COMT overexpression on invasion, transcriptome, proteome and interactome of MCF7 cells, a luminal A breast cancer model, stably transduced with lentiviral vector carrying COMT gene (MCF7-COMT). This PRIDE project includes quantitative analysis results for the total proteome LC-DIA-MS/MS experiment evaluating COMT overexpression in MCF7 breast cancer cell line, and results of pulldown analysis of COMT-interacting proteins in MCF7 cells.