Abstract
SET domain bifurcated 1 (SETDB1) is a histone H3 lysine 9 methyltransferase that is highly expressed in various tumor types, including breast cancer. However, how SETDB1 functions in breast cancer is unclear. In the present study, proliferation, migration and invasion assays were performed to explore the role of SETDB1 in breast cancer cells. SETDB1 downregulation in BT549 and MDA‑MB‑231 cells reduced cell proliferation, whereas upregulation in MCF7 and T47D cells enhanced proliferation. Depletion of SETDB1 suppressed cell migration and invasion in vitro and reduced lung metastasis in vivo. By contrast, SETDB1 overexpression enhanced cell migration and invasiveness. Notably, SETDB1 overexpression appeared to induce epithelial‑mesenchymal transition (EMT) in MCF7 cells. Mechanistic investigations indicated that SETDB1 acts as an EMT inducer by binding directly to the promoter of the transcription factor Snail. Thus, SETDB1 is involved in breast cancer metastasis and may be a therapeutic target for treating patients with breast cancer.