Down-regulation of tripartite motif protein 59 inhibits proliferation, migration and invasion in breast cancer cells.

Tripartite motif protein 59 (TRIM59), also known as mouse ring finger protein 1 (MRF1), is a surface molecule and belongs to the TRIM family. Recently, TRIM59 has been described in multiple cancers such as gastric, prostatic and lung cancer. However, there have been no reports on its functions in breast cancer. In this study, we elucidated the biological roles of TRIM59 in breast cancer. We found that TRIM59 was up-regulated in breast cancer cells. Down-regulation of TRIM59 inhibited breast cancer cell proliferation, migration and invasion in vitro as well as tumor growth in vivo. In addition, TRIM59 down-regulation reduced the protein expression level of p-Smad2 and thus inhibited the activity of transforming growth factor-β (TGF-β) signaling. Taken together, our study results provided new evidence showing that TRIM59 may be considered as a promising therapeutic target for breast cancer.