Effect of genetic variation in Notch regulator DTX1 on SCLC prognosis compared with the effect on NSCLC prongosis

The associations between Deltex1 and clinical characteristics of breast cancer

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Functions and Molecular Mechanisms of Deltex Family Ubiquitin E3 Ligases in Development and Disease

Ubiquitination is a posttranslational modification of proteins that significantly affects protein stability and function. The specificity of substrate recognition is determined by ubiquitin E3 ligase during ubiquitination. Human Deltex (DTX) protein family, which functions as ubiquitin E3 ligases, comprises five members, namely, DTX1, DTX2, DTX3, DTX3L, and DTX4. The characteristics and functional diversity of the DTX family proteins have attracted significant attention over the last decade. DTX proteins have several physiological and pathological roles and are closely associated with cell signal transduction, growth, differentiation, and apoptosis, as well as the occurrence and development of various tumors. Although they have been extensively studied in various species, data on structural features, biological functions, and potential mechanisms of action of the DTX family proteins remain limited. In this review, recent research progress on each member of the DTX family is summarized, providing insights into future research directions and potential strategies in disease diagnosis and therapy.