The associations between Deltex1 and clinical characteristics of breast cancer.

Deltex 1 (DTX1) is a single transmembrane protein with ubiquitin E3 ligase activity which has been found to play a role in the development of several cancers. We aimed to investigate the associations between DTX1 and breast cancer (BC). We explored the roles and mechanisms of DTX1 in BC by using BC cell lines in vitro. Levels of DTX1 in serum and tissues were determined in 316 patients with BC, 102 patients with fibroadenoma, and 113 healthy controls by immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR). The associations between DTX1 and clinical characteristics of BC were analyzed using multivariate analysis and Cox regression survival analysis. Lower levels of DTX1 promoted BC cell proliferation, migration, and invasion. The cell growth and survival of BC might be regulated by DTX1 via the Notch signaling pathway. Levels of DTX1 in BC tissues were lower compared to fibroadenoma tissues and peri-neoplastic breast tissues (P<0.01). A lower level of DTX1 was shown to be associated with advanced tumor grade (P=0.017), advanced clinical stage (P=0.031), positive lymph node metastasis (LNM) (P=0.009), and high Ki-67 index (P=0.023). Lower DTX1 expression was recognized as an impact factor for metastasis-free survival (MFS) in BC. Lower levels of DTX1 could promote BC cell proliferation and migration, and are associated with advanced BC. There is potential for DTX1 as a marker to assist the selection of new BC treatment.