ZNF326 promotes a malignant phenotype of breast cancer by interacting with DBC1

The biological role and underlying mechanism of action of zinc-finger protein 326 (ZNF326) in malignant tumors, including breast cancer, are still not clear. In this study, we detected high expression of ZNF326 in breast cancer specimens (60/111, 54.1%) and breast cancer cell lines (7/7); the expression level of ZNF326 was inversely associated with advanced pTNM stage (P = 0.002), positive lymph node metastasis (P = 0.004), poor prognosis in patients with breast cancer (P = 0.0097), and ER/PR/Her2 status (P = 0.013). Meanwhile, the ectopic expression of ZNF326 significantly upregulated MMP7, EMT-related proteins (Snail and Slug), and cell cycle-related proteins (cyclinA2 and cyclinB1); downregulated E-cadherin expression; and promoted the proliferation and invasiveness of breast cancer cells both in vivo and in vitro. Mechanistically, co-immunoprecipitation and immunofluorescence assays both demonstrated that ZNF326 interacted with deleted in breast cancer-1 (DBC1) in breast cancer cells. Additionally, DBC1 knockdown eliminated the up-regulation of MMP7, EMT-related proteins, and cell cycle-related proteins as well as the enhanced proliferation and invasiveness induced by ZNF326. Therefore, we concluded that ZNF326 is highly expressed in breast cancer, is associated with poor prognosis, and plays a vital role in promoting the malignant phenotype of breast cancer cells by interacting with DBC1.